KasperCalc: MIL-HDBK-5 3.7 7000 Series Wrought Alloys

Aluminum Alloy Index

•Aluminum Alloy Index 3.1General 3.22000 Series Wrought Alloys 3.2.12014 Alloy 3.2.22017 Alloy 3.2.32024 Alloy 3.2.42025 Alloy 3.2.52026 Alloy 3.2.62090 Alloy 3.2.72124 Alloy 3.2.82219 Alloy 3.2.92297 Alloy 3.2.102424 Alloy 3.2.112519 Alloy 3.2.122524 Alloy 3.2.132618 Alloy 3.55000 Series Wrought Alloys 3.5.15052 Alloy 3.5.25083 Alloy 3.5.35086 Alloy 3.5.45454 Alloy 3.5.55456 Alloy 3.66000 Series Wrought Alloys 3.6.16013 Alloy 3.6.26061 Alloy 3.6.36151 Alloy 3.77000 Series Wrought Alloys 3.7.17010 Alloy 3.7.27040 Alloy 3.7.37049/7149 Alloy 3.7.47050 Alloy 3.7.57055 Alloy 3.7.67075 Alloy 3.7.77150 Alloy 3.7.87175 Alloy 3.7.97249 Alloy 3.7.107475 Alloy 3.8200.0 Series Cast Alloys 3.8.1A201.0 Alloy 3.9300.0 Series Cast Alloys 3.9.1354.0 Alloy 3.9.2355.0 Alloy 3.9.3C355.0 Alloy 3.9.4356.0 Alloy 3.9.5A356.0 Alloy 3.9.6A357.0 Alloy 3.9.7D357.0 Alloy 3.9.8359.0 Alloy 3.10Element Properties

Chapter 3.7 Contents

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Chapter 1 — General Chapter 2 — Steel Chapter 3 — Aluminum 3.1 — General 3.2 — 2000 Series Wrought Alloys 3.5 — 5000 Series Wrought Alloys 3.6 — 6000 Series Wrought Alloys 3.7 — 7000 Series Wrought Alloys 3.8 — 200.0 Series Cast Alloys 3.9 — 300.0 Series Cast Alloys 3.10 — Element Properties Chapter 4 — Magnesium

Disclaimer

For reference use only. The formulas, graphs, and values herein are provided in good faith for general engineering guidance. Please verify all data against MIL-HDBK-5J or the applicable superseding document (MMPDS).

Table of Tables

Table of Figures

Table of Figures (cont.)

3.77000 Series Wrought Alloys

The 7000 series of wrought alloys contain zinc as the principal alloying element and magnesium and copper as other major elements. They are available in a wide variety of product forms. They are strengthened principally by solution heat treatment and precipitation hardening and are among the highest-strength aluminum alloys.

The T6-type tempers of these alloys are susceptible to stress-corrosion cracking under certain conditions while the T7-type tempers are more resistant; these alloys should be considered in light of the corrosion resistance discussed in Sections 3.1.2.3 and 3.1.3.

3.7.17010 Alloy

3.7.1.0Comments and Properties

7010 is an Al-Zn-Mg-Cu-Zr alloy developed to have a combination of high strength, high resistance to stress-corrosion cracking, and good fracture toughness, particularly in thick sections. The use of zirconium in lieu of chromium provides a low sensitivity to quench, which results in high strength in thick sections. The alloy is available only in plate. Plate, greater than 2 inches in thickness in the T7451 temper, has static strength equal to or greater than 7075-T651 plate with greater toughness.

Plate in the T7451 temper has a stress-corrosion resistance higher than 7075-T7651. The T73-type temper provides the highest resistance to stress-corrosion for this alloy. The T76-type temper provides for good exfoliation resistance and higher stress-corrosion resistance than T6-type tempers of 7075 and 7178. The T74-type temper provides stress-corrosion and strength characteristics intermediate to those of T76 and T73. Refer to Section 3.1.2.3 for information regarding the resistance of the alloy to stress-corrosion cracking.

Refer to Section 3.1.3.4 for comments regarding the weldability of the alloy.

Material specifications for 7010 are shown in Table 3.7.1.0(a). Room-temperature mechanical properties are shown in Tables 3.7.1.0(b1) and (b2).

Table 3.7.1.0(a). Material Specifications for 7010 Aluminum Alloy
Specification	Form
AMS 4205	Plate
AMS 4204	Plate

Temper Index for 7010 Alloy
Section	Temper
3.7.1.1	T7451
3.7.1.2	T7651

Table 3.7.1.0(b₁). Design Mechanical and Physical Properties of 7010 Aluminum Alloy Plate
Specification	AMS 4205
Form	Plate
Temper	T7451
Thickness, in.	0.250-1.000	1.001-2.000	2.001-3.000		3.001-4.000		4.001-5.000		5.001-6.000
Basis	S	S	A	B	A	B	A	B	A	B
Mechanical Properties:
F_tu, ksi:
L	71	71	70	72	70	71	68^a	71	68	70
LT	72	72	71	72	70	72	69^a	71	67^a	71
ST	···	···	66	68	66	68	65^a	67	63^a	67
F_ty, ksi:
L	62	62	60	62	60	62	59	61	57^a	61
LT	62	62	60	62	59	61	58	60	57^a	60
ST	···	···	55	57	54	56	53	55	52	54
F_cy, ksi:
L	61	61	59	61	58	60	57	59	56	59
LT	63	63	62	64	61	63	60	62	59	63
ST	···	···	61	63	60	62	59	61	58	61
F_su, ksi	41	41	42	42	42	43	42	43	41	43
F_bru^b, ksi:
(e/D = 1.5)	100	101	101	102	100	103	100	103	97	103
(e/D = 2.0)	127	129	130	132	130	134	129	133	126	133
F_bry^b, ksi:
(e/D = 1.5)	81	82	81	84	81	84	81	84	80	84
(e/D = 2.0)	94	97	97	100	98	101	98	101	97	102
e, percent (S-basis):
L	9	9	9	···	9	···	9	···	8	···
LT	6	6	6	···	6	···	5	···	5	···
ST	···	···	2.5	···	2	···	2	···	2	···
E, 10³ ksi	10.2
E_c, 10³ ksi	10.6
G, 10³ ksi	3.9
μ	0.33
Physical Properties:
ω, lb/in.³	0.102
C, Btu/(lb)(°F)	0.21 (at 214°F)
K, Btu/[(hr)(ft²)(°F)/ft]	95 (at 99°F)
α, 10^-6 in./in./°F	13.0 (68-212°F)
^a S-basis values. The rounded T₉₉ values are as follows: for 4.001-5.000-inch thickness, F_tu(L) = 69, F_tu(LT) = 70, and F_tu(ST) = 66; for 5.001-6.000-inch thickness, F_tu(LT) = 69, F_tu(ST) = 65, F_ty(L) = 59, and F_ty(LT) = 58.
^b See Table 3.1.2.1.1. Bearing values are “dry pin” values per Section 1.4.7.1.

Table 3.7.1.0(b₂). Design Mechanical Properties of 7010 Aluminum Alloy Plate—Continued
Specification	AMS 4204
Form	Plate
Temper	T7651
Thickness, in.	0.250-1.000	1.001-2.000	2.001-2.500	2.501-3.000	3.001-4.000	4.001-5.000	5.001-5.500
Basis	S	S	S	S	S	S	S
Mechanical Properties:
F_tu, ksi:
L	76	76	75	73	72	72	71
LT	76	76	75	74	73	72	72
ST	···	···	71	70	69	68	66
F_ty, ksi:
L	66	66	65	64	64	63	62
LT	66	66	65	64	63	62	61
ST	···	···	59	58	56	55	53
F_cy, ksi:
L	65	65	64	63	62	61	60
LT	67	68	67	67	66	65	64
ST	···	···	68	67	65	64	62
F_su, ksi	42	44	44	44	44	45	46
F_bru^a, ksi:
(e/D = 1.5)	105	106	106	105	105	105	105
(e/D = 2.0)	135	137	137	136	135	134	134
F_bry^a, ksi:
(e/D = 1.5)	85	86	87	87	86	86	86
(e/D = 2.0)	103	104	103	102	101	100	99
e, percent:
L	8	8	8	7	7	7	6
LT	6	6	6	5	5	5	4
ST	···	···	2.5	2.5	2	2	2
E, 10³ ksi	10.2
E_c, 10³ ksi	10.6
G, 10³ ksi	3.9
μ	0.33
Physical Properties:
ω, lb/in.³	0.102
C, Btu/(lb)(°F)	0.21 (at 214°F)
K, Btu/[(hr)(ft²)(°F)/ft]	95 (at 104°F)
α, 10^-6 in./in./°F	12.9 (68 to 212°F)
^a See Table 3.1.2.1.1. Bearing values are “dry pin” values per Section 1.4.7.1.

3.7.1.1T7451 Temper

Elevated-temperature curves for plate are presented in Figure 3.7.1.1.1. Figures 3.7.1.1.6(a) through (d) present stress-strain and tangent-modulus curves for plate.

Figure 3.7.1.1.1 Pending digitization via WebPlotDigitizer.

Figure 3.7.1.1.1. Effect of temperature on the tensile ultimate strength (F_tu) and the tensile yield strength (F_ty) of 7010-T7451 aluminum alloy plate.

Figure 3.7.1.1.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.1.6(a). Typical tensile stress-strain curves for 7010-T7451 plate at room temperature (thickness 2.001–5.500 in.).

Figure 3.7.1.1.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.1.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7010-T7451 plate at room temperature (thickness 2.001–5.500 in.).

Figure 3.7.1.1.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.1.6(c). Typical tensile stress-strain curves for 7010-T7451 aluminum alloy plate at room temperature (thickness 0.500–1.500 in.).

Figure 3.7.1.1.6(d) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.1.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7010-T7451 aluminum alloy plate at room temperature (thickness 0.500–1.500 in.).

3.7.1.2T7651 Temper

Figures 3.7.1.2.6(a) through (d) present stress-strain and tangent-modulus curves for plate.

Figure 3.7.1.2.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.2.6(a). Typical tensile stress-strain curves for 7010-T7651 plate at room temperature (thickness 2.001–5.500 in.).

Figure 3.7.1.2.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.2.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7010-T7651 plate at room temperature (thickness 2.001–5.500 in.).

Figure 3.7.1.2.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.2.6(c). Typical tensile stress-strain curves for 7010-T7651 aluminum alloy plate at room temperature (thickness 0.500–1.500 in.).

Figure 3.7.1.2.6(d) Pending digitization via WebPlotDigitizer.

Figure 3.7.1.2.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7010-T7651 aluminum alloy plate at room temperature (thickness 0.500–1.500 in.).

3.7.27040 Alloy

3.7.2.0Comments and Properties

7040 alloy is an Al-Mg-Zn-Cu-Zr alloy developed to provide a higher strength and toughness compromise than the currently available 7010 and 7050 alloys, particularly in heavy gauge plates up to 8.5 inch thickness. The use of a desaturated chemical composition in Mg and Cu together with a very close control of the Zr content and impurities provides 7040 with a much lower quench sensitivity than that of 7050, resulting in high strength and toughness properties in very thick sections.

7040-T7451 plates are particularly suited for structures in which high strength, high toughness, and good corrosion resistance are the major requirements. Parts such as integrally machined spars, ribs, and main fuselage frames can benefit from this outstanding property combination.

7040 is available in the form of plates, ranging in thickness from 3.0 to 8.5 inches.

Manufacturing Considerations — Due to tight control of residual stress level, the 7040 plates exhibit a superior dimensional stability, thus offering a cost-efficient alternative to rolled or forged parts, which require distortion corrections after machining. Refer to Section 3.1.3.4 for comments regarding the weldability of this alloy.

Specifications and Properties — Material specifications are shown in Table 3.7.2.0(a). Room-temperature properties are shown in Table 3.7.2.0(b1). Figure 3.7.2.0 shows the effect of temperature on tensile properties.

Table 3.7.2.0(a). Material Specifications for 7040-T7451 Alloy Plate
Specification	Form
AMS 4211	Plate

Table 3.7.2.0(b₁). Design Mechanical and Physical Properties of 7040-T7451 Aluminum Alloy Plate
Specification	AMS 4211
Form	Plate
Temper	T7451
Thickness, in.	3.001-4.000		4.001-5.000		5.001-6.000		6.001-7.000		7.001-8.000		8.001-8.500
Basis	A	B	A	B	A	B	A	B	A	B	A	B
Mechanical Properties:
F_tu, ksi:
L	72	72	71	72	70^a	71	69	70	68^b	70	68^c	70
LT	72^d	74	71^e	73	70^a	72	69	70	68^b	69	68	69
ST	69	70	68^e	70	68	69	66	67	66	67	66	67
F_ty, ksi:
L	62^d	65	62^e	64	62^a	64	62	62	61	62	61	63
LT	62^d	65	62^e	65	61^a	63	60	62	60	61	59	61
ST	59^d	61	58^e	61	58^a	61	57	58	57	58	56	58
F_cy, ksi:
L	60	63	60	62	59	61	58	60	59	60	59	61
LT	64	67	64	67	63	66	62	64	62	64	61	63
ST	63	66	63	66	62	65	61	63	61	63	60	63
F_su, ksi	45	47	44	46	44	45	43	44	43	44	43	44
F_bru^f, ksi:
(e/D = 1.5)	114	117	112	115	110	114	108	110	105	108	105	106
(e/D = 2.0)	145	150	143	147	140	145	137	140	134	136	133	134
F_bry^f, ksi:
(e/D = 1.5)	93	97	93	97	92	96	90	93	90	92	88	91
(e/D = 2.0)	114	119	114	119	112	117	110	113	110	113	108	112
e, percent (S-basis):
L	9	···	9	···	8	···	7	···	6	···	6	···
LT	6	···	5	···	4	···	4	···	4	···	4	···
ST	3	···	3	···	3	···	3	···	3	···	3	···
E, 10³ ksi	10.4
E_c, 10³ ksi	10.6
G, 10³ ksi	3.9
μ	0.33
Physical Properties:
ω, lb/in.³	0.102
C, Btu/(lb)(°F)	0.23
K, Btu/[(hr)(ft²)(°F)/ft]	91
α, 10^-6 in./in./°F	12.8
^a S-basis values. Rounded T₉₉ values are as follows: F_tu(L) = 71 ksi; F_tu(LT) = 71 ksi; F_ty(L) = 63 ksi; F_ty(LT) = 62 ksi; and F_ty(ST) = 59 ksi.
^b S-basis values. Rounded T₉₉ values are as follows: F_tu(L) = 69 ksi; F_tu(LT) = 69 ksi.
^c S-basis values. Rounded T₉₉ values are as follows: F_tu(L) = 69 ksi.
^d S-basis values. Rounded T₉₉ values are as follows: F_tu(LT) = 73 ksi; F_ty(L) = 64 ksi; F_ty(LT) = 64 ksi; and F_ty(ST) = 60 ksi.
^e S-basis values. Rounded T₉₉ values are as follows: F_tu(LT) = 72 ksi; F_tu(ST) = 69 ksi; F_ty(L) = 63 ksi; and F_ty(LT) = 63 ksi, F_ty(ST) = 59 ksi.
^f See Table 3.1.2.1.1. Bearing values are “dry pin” values per Section 1.4.7.1.

Figure 3.7.2.0 Pending digitization via WebPlotDigitizer.

Figure 3.7.2.0. Effect of temperature on the tensile ultimate strength (F_tu) and the tensile yield strength (F_ty) of 7040-T7451 aluminum alloy plate, T/4 location.

3.7.37049/7149 Alloy

3.7.3.0Comments and Properties

7049/7149 alloy is available in the form of die forging, hand forging, plate, and extrusion. Alloy 7149 contains lower residual iron and silicon content than 7049. The T73XX temper provides good static strength with high resistance to stress-corrosion cracking. The fatigue strength of the T73XX temper is about equal to that of 7075-T6, while the toughness is somewhat higher. Refer to Section 3.1.2.3 for comments regarding the resistance of the alloys to stress-corrosion cracking and to Section 3.1.3.4 for comments regarding the weldability of the alloys.

The properties of extrusions should be based upon the thickness at the time of quenching prior to machining. Selection of the mechanical properties based upon its final machined thickness may be unconservative; therefore, the thickness at the time of quenching to achieve properties is an important factor in the selection of the proper thickness column. For extrusions having sections with various thicknesses, consideration should be given to the properties as a function of thickness.

Material specifications for 7049/7149 aluminum alloy are presented in Table 3.7.3.0(a). Room-temperature mechanical and physical properties are shown in Tables 3.7.3.0(b) through (e).

Table 3.7.3.0(a). Material Specifications for 7049/7149 Aluminum Alloy
Specification	Form
AMS-QQ-A-367 (7049)	Forging
AMS 4111 (7049)	Forging
AMS 4320 (7149)	Forging
AMS 4157 (7049)	Extrusion
AMS-A-22771	Forging
AMS 4200 (7049)	Plate
AMS 4343 (7149)	Extrusion

The temper index for 7049/7149 is: Section 3.7.3.1 covers the T73 and T73511 tempers, applicable to plate, die forging, hand forging, and extrusion products.

Table 3.7.3.0(b). Design Mechanical and Physical Properties of 7049 Aluminum Alloy Plate
Specification	AMS 4200
Form	Plate
Temper	T7351
Thickness, in.	0.750-1.000	1.001-1.500	1.501-2.000	2.001-2.500	2.501-3.000	3.001-4.000	4.001-4.500	4.501-5.000
Basis	S	S	S	S	S	S	S	S
Mechanical Properties:
F_tu, ksi:
L	···	···	72	72	71	70	68	68
LT	74	73	73	73	72	70	68	68
ST	···	···	69	69	68	65	63	63
F_ty, ksi:
L	···	···	64	63	62	60	58	58
LT	65	64	64	63	62	60	58	58
ST	···	···	59	58	57	56	54	54
F_cy, ksi:
L	···	···	64	63	62	60	58	···
LT	···	···	69	68	67	64	62	···
ST	···	···	69	68	67	64	62	···
F_su, ksi	···	···	41	41	41	39	38	···
F_bru^a, ksi:
(e/D = 1.5)	···	···	···	114	112	109	106	···
(e/D = 2.0)	···	···	···	146	144	140	136	···
F_bry^a, ksi:
(e/D = 1.5)	···	···	···	91	89	86	83	···
(e/D = 2.0)	···	···	···	106	104	101	97	···
e, percent:
L	···	···	···	···	···	6	6	5
LT	8	8	7	6	6	5	5	5
ST	···	···	···	···	···	2	2	2
E, 10³ ksi	10.1
E_c, 10³ ksi	10.4
G, 10³ ksi	3.9
μ	0.33
Physical Properties:
ω, lb/in.³	0.103
C, Btu/(lb)(°F)	0.23 (at 212°F)
K, Btu/[(hr)(ft²)(°F)/ft]	89 (at 77°F)
α, 10^-6 in./in./°F	13.0 (RT to 212°F)
^a Bearing values are “dry pin” values per Section 1.4.7.1. See Table 3.1.2.1.1.

Table 3.7.3.0(c). Design Mechanical and Physical Properties of 7049/7149 Aluminum Alloy Die Forging
Specification	AMS-QQ-A-367, AMS 4111, AMS 4320, and AMS-A-22771
Form	Die forging
Temper	T73^a
Thickness^b, in.	≤1.000		1.001-2.000		2.001-3.000		3.001-4.000		4.001-5.000
Basis	A	B	A	B	A	B	A	B	A	B
Mechanical Properties:
F_tu, ksi:
L	71	74	70	73	69	72	68	71	67	70
T^c (S-basis)	71^d	···	70^d	···	70^d	···	70^d	···	68^d	···
F_ty, ksi:
L	60	64	59	63	58	61	57	60	55	59
T^c (S-basis)	61^d	···	60^d	···	60^d	···	60^d	···	58^d	···
F_cy, ksi:
L	62	66	61	65	60	63	59	62	57	61
ST	56	60	55	59	54	57	53	56	51	55
F_su, ksi	40	41	39	41	39	40	38	40	37	39
F_bru^e, ksi:
(e/D = 1.5)	100	105	99	103	98	102	96	100	95	99
(e/D = 2.0)	132	138	130	136	128	134	126	132	125	130
F_bry^e, ksi:
(e/D = 1.5)	76	82	75	80	74	78	73	76	70	75
(e/D = 2.0)	93	99	91	97	90	94	88	93	85	91
e, percent (S-basis):
L	7	···	7	···	7	···	7	···	7	···
T^c	3	···	3	···	3	···	2	···	2	···
E, 10³ ksi	10.2
E_c, 10³ ksi	10.7
G, 10³ ksi	3.9
μ	0.33
Physical Properties:
ω, lb/in.³	0.103
C, Btu/(lb)(°F)	0.25 (at 212°F)
K, Btu/[(hr)(ft²)(°F)/ft]	89 (at 77°F)
α, 10^-6 in./in./°F	13.0 (RT to 212°F)
^a Design values were based upon data obtained from testing T73 die forgings, heat treated by suppliers and supplied in T73 temper.
^b Thickness at the time of heat treatment. When die forgings are machined before heat treatment, the mechanical properties are applicable provided the as-forged thickness is not greater than twice the thickness at the time of heat treatment.
^c T indicates any grain direction not within ±15° of being parallel to the forging flow lines. F_cy(T) values are based upon short transverse (ST) test data.
^d Specification value. T tensile properties are presented on an S-basis only.
^e Bearing values are “dry pin” values per Section 1.4.7.1.

Table 3.7.3.0(d). Design Mechanical and Physical Properties of 7049/7149 Aluminum Alloy Hand Forging
Specification	AMS-QQ-A-367, AMS 4111, AMS 4320, and AMS-A-22771
Form	Hand forging
Temper	T73
Thickness^a, in.	2.001-3.000	3.001-4.000	4.001-5.000
Basis	S	S	S
Mechanical Properties:
F_tu, ksi:
L	71	69	67
LT	71	69	67
ST	69	67	66
F_ty, ksi:
L	61	59	56
LT	59	57	56
ST	58	56	55
F_cy, ksi:
L	60	58	57
LT	61	59	57
ST	61	59	58
F_su, ksi:
L	42	41	39
LT	41	39	38
ST	41	40	39
F_bru^b, ksi:
(e/D = 1.5)	102	100	97
(e/D = 2.0)	134	130	126
F_bry^b, ksi:
(e/D = 1.5)	81	79	77
(e/D = 2.0)	96	92	91
e, percent:
L	9	8	7
LT	4	3	3
ST	3	2	2
E, 10³ ksi	10.2
E_c, 10³ ksi	10.6
G, 10³ ksi	3.9
μ	0.33
Physical Properties:
ω, lb./in.³	0.103
C, Btu/(lb)(°F)	0.23 (at 212°F)
K, Btu/[(hr)(ft²)(°F)/ft]	89 (at 77°F)
α, 10^-6 in./in./°F	13.0 (RT to 212°F)
^a When hand forgings are machined before heat treatment, section thickness at time of heat treatment will determine minimum mechanical properties as long as original (as-forged) thickness does not exceed maximum thickness for the alloy as shown in the table. The maximum cross-section area of hand forgings is 256 sq. in.
^b Bearing values are “dry pin” values per Section 1.4.7.1.

Table 3.7.3.0(e). Design Mechanical and Physical Properties of 7049/7149 Aluminum Alloy Extrusion
Specification	AMS 4157 and AMS 4343
Form	Extrusion
Temper	T73511
Thickness,^a in.	≤2.499	2.500-2.999	3.000-5.000
Basis	S	S	S
Mechanical Properties:
F_tu, ksi:
L	74	74	72
LT	70	70	68
ST	···	70	68
F_ty, ksi:
L	64	64	62
LT	60	60	58
ST	···	60	58
F_cy, ksi:
L	65	65	63
LT	···	···	···
ST	···	···	···
F_su, ksi	40	40	39
F_bru^b, ksi:
(e/D = 1.5)	110	110	107
(e/D = 2.0)	144	144	140
F_bry^b, ksi:
(e/D = 1.5)	85	85	83
(e/D = 2.0)	105	105	101
e, percent:
L	7	7	7
LT	5	5	5
ST	···	5	5
E, 10³ ksi	10.5
E_c, 10³ ksi	11.0
G, 10³ ksi	4.0
μ	0.33
Physical Properties:
ω, lb/in.³	0.103
C, Btu/(lb)(°F)	0.23 (at 212°F)
K, Btu/[(hr)(ft²)(°F)/ft]	89 (at 77°F)
α, 10^-6 in./in./°F	13.0 (RT to 212°F)
^a The mechanical properties are to be based upon the thickness at the time of quench.
^b Bearing values are “dry pin” values per Section 1.4.7.1.

3.7.3.1T73 and T73511 Tempers

Figure 3.7.3.1.1 presents elevated-temperature curves for various products. Figures 3.7.3.1.6(a) through (g) present tensile and compressive stress-strain and tangent-modulus curves. Fatigue data for 7049-T73 die and hand forgings are shown in Figures 3.7.3.1.8(a) through (g).

Figure 3.7.3.1.1. Effect of temperature on the tensile ultimate strength (Ftu), the tensile yield strength (Fty), and the compressive yield strength (Fcy) of 7049-T7351 plate, 7049/7149-T73 hand forging, and 7049/7149-T73511 extrusion.

Figure 3.7.3.1.6(a). Typical tensile stress-strain curves for 7049/7149-T73 aluminum alloy die forging at room temperature.

Figure 3.7.3.1.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7049/7149-T73 aluminum alloy die forging at room temperature.

Figure 3.7.3.1.6(c). Typical tensile stress-strain curves for 7049/7149-T73 aluminum alloy hand forging at room temperature.

Figure 3.7.3.1.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7049/7149-T73 aluminum alloy hand forging at room temperature.

Figure 3.7.3.1.6(e). Typical tensile stress-strain curves for 7049-T7351 aluminum alloy plate at room temperature.

Figure 3.7.3.1.6(f). Typical compressive stress-strain and compressive tangent-modulus curves for 7049-T7351 aluminum alloy plate at room temperature.

Figure 3.7.3.1.6(g). Typical tensile and compressive stress-strain and compressive tangent-modulus curves for 7049/7149-T73511 extrusion at room temperature.

Figure 3.7.3.1.8(a). Best-fit S/N curves for unnotched 7049-T73 die and hand forgings, at room temperature, longitudinal and long-transverse directions.

Stresses are based on net section.

Correlative Information for Figure 3.7.3.1.8(a)

Product Form: Die forging, 3 and 4.5 inches thick; hand forging, 2, 3, 4, and 5 inches thick

Properties: (L) TUS 78 ksi, TYS 70 ksi, RT; (LT) TUS 74 ksi, TYS 65 ksi, RT

Specimen Details: Unnotched
Uniform gage, 0.200 inch net diameter
Hourglass, 0.225 inch net diameter, 3.00 inch test-section radius
Hourglass, 0.300 inch net diameter, 9.875 inch test-section radius

Surface Condition: Longitudinally polished to 4 RMS finish or better; unspecified

Reference: 3.7.3.1.8(a), (b), and 3.2.6.1.9(d)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – RT
Environment – Lab air

No. of Heats/Lots: 6

Stress Life Equation:
Log N_f = 9.95 − 3.62 log (S_eq − 24.2)
S_eq = S_max(1−R)^0.57
Std. Error of Estimate, Log (Life) = 0.346
Standard Deviation, Log (Life) = 0.736
R² = 78%

Sample Size: 50

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.3.1.8(b). Best-fit curves for unnotched 7049-T73 die forging, at room temperature, short-transverse direction.

Correlative Information for Figure 3.7.3.1.8(b)

Product Form: Die forging, 3 inches thick

Properties: TUS 73 ksi, TYS 64 ksi, RT

Specimen Details: Unnotched, 0.200 inch net diameter

Surface Condition: Longitudinally polished to 4 µin. finish with no circumferential marks

Reference: 3.7.3.1.8(a)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 1

Maximum Stress Equation:
Log N_f = 16.55 − 6.92 log (S_max)
Std. Error of Estimate, Log (Life) = 0.371
Standard Deviation, Log (Life) = 0.917
R² = 84%

Sample Size: 23

Figure 3.7.3.1.8(c). Best-fit S/N curves for notched, K_t = 2.4, 7049-T73 die forging, at room temperature, longitudinal, long-transverse, and short-transverse directions.

Correlative Information for Figure 3.7.3.1.8(c)

Product Form: Die forging, 3 and 4.5 inches thick

Properties:
(L) Unnotched: TUS 77 ksi, TYS 68 ksi, RT; Notched: TUS 95 ksi, RT
(LT) Unnotched: TUS 73 ksi, TYS 64 ksi, RT; Notched: TUS 77 ksi, RT
(ST) Unnotched: TUS 75 ksi, TYS 66 ksi, RT; Notched: TUS 87 ksi, RT

Specimen Details: Circumferentially notched, K_t = 2.4
0.150 or 2.00 inch gross diameter
0.350 inch net diameter
0.500 inch gross diameter
0.032 inch notch root radius, r
60° flank angle

Surface Condition: Machined notch

References: 3.7.3.1.8(a) and (c)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – RT
Environment – Lab air

No. of Heats/Lots: 2

Stress Life Equation:
Log N_f = 10.6 − 4.18 log (S_eq)
S_eq = S_max(1−R)^0.80
Std. Error of Estimate, Log (Life) = 0.320
Standard Deviation, Log (Life) = 0.500
R² = 59%

Sample Size: 69

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.3.1.8(d). Best-fit S/N curves for unnotched 7049-T73 hand forging, longitudinal direction.

Correlative Information for Figure 3.7.3.1.8(d)

Product Form: Hand forging, 2.0 to 5.0 inches thick

Properties: TUS 70–80 ksi, TYS 60–73 ksi, RT

Specimen Details: Unnotched, 0.125 and 0.300 inch diameter

Surface Condition: Polished with increasingly finer grits of emery paper to surface roughness of 10 rms with polishing marks longitudinal, or not specified

References: 3.2.6.1.9(d) and 3.7.3.1.8(e)

Test Parameters:
Loading – Axial
Frequency – 800, 1500, or 1725 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 6

Equivalent Stress Equation:
Log N_f = 10.6 − 4.31 log (S_eq − 30)
S_eq = S_max(1−R)^0.31
Std. Error of Estimate, Log (Life) = 0.348
Standard Deviation, Log (Life) = 0.944
R² = 86%

Sample Size: 28

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.3.1.8(e). Best-fit S/N curves for unnotched 7149-T73 hand forging, long-transverse direction.

Correlative Information for Figure 3.7.3.1.8(e)

Product Form: Hand forging, 4.00 to 4.75 inches thick

Properties: TUS 73 ksi, TYS 64 ksi, RT

Specimen Details: Unnotched, 0.250 inch diameter

Surface Condition: Not specified

Reference: 3.7.3.1.8(e)

Test Parameters:
Loading – Axial
Frequency – Not specified
Temperature – RT
Environment – Air

No. of Heats/Lots: 3

Equivalent Stress Equation:
Log N_f = 9.9 − 3.46 log (S_eq − 25)
S_eq = S_max(1−R)^0.39
Std. Error of Estimate, Log (Life) = 0.689
Standard Deviation, Log (Life) = 0.845
R² = 34%

Sample Size: 20

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.3.1.8(f). Best-fit S/N curves for notched, K_t = 3.0, 7049-T73 hand forging, longitudinal, long-transverse, and short-transverse directions.

Correlative Information for Figure 3.7.3.1.8(f)

Product Form: Hand forging, 2.0 to 5.0 inches thick

Properties: TUS 71–80 ksi, TYS 62–73 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.200, 0.300, and 0.306 inch gross diameter
0.175, 0.200, and 0.253 inch net diameter
0.006, 0.010, and 0.013 inch notch root radius, r
60° flank angle

Surface Condition: Polished with oil and alumdum grit applied to a rotating wire, or not specified

References: 3.2.6.1.9(d), 3.7.3.1.8(d), and (e)

Test Parameters:
Loading – Axial
Frequency – 800, 1500, or 1725 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 8

Equivalent Stress Equation:
Log N_f = 9.57 − 3.63 log (S_eq)
S_eq = S_max(1−R)^0.49
Std. Error of Estimate, Log (Life) = 0.344
Standard Deviation, Log (Life) = 0.562
R² = 63%

Sample Size: 151

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.3.1.8(g). Best-fit S/N curves for notched, K_t = 3.0, 7149-T73 hand forging, long-transverse direction.

Correlative Information for Figure 3.7.3.1.8(g)

Product Form: Hand forging, 4.00 to 4.75 inches thick

Properties: TUS 73 ksi, TYS 64 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.375 inch gross diameter
0.253 inch net diameter
0.013 inch notch root radius, r
60° flank angle

Surface Condition: Not specified

Reference: 3.7.3.1.8(e)

Test Parameters:
Loading – Axial
Frequency – Not specified
Temperature – RT
Environment – Air

No. of Heats/Lots: 3

Equivalent Stress Equation:
Log N_f = 10.1 − 4.10 log (S_eq − 5)
S_eq = S_max(1−R)^0.42
Std. Error of Estimate, Log (Life) = 0.450
Standard Deviation, Log (Life) = 0.797
R² = 68%

Sample Size: 25

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

3.7.47050 Alloy

3.7.4.0Comments and Properties

7050 is an Al-Zn-Mg-Cu-Zr alloy developed to have a combination of high strength, high resistance to stress-corrosion cracking, and good fracture toughness, particularly in thick sections. The use of zirconium in lieu of chromium provides a low sensitivity to quench, which results in high strengths in thick sections. Plate, hand, and die forgings in the T74 temper have static strengths about equivalent to those of corresponding products of 7079 in the T6 tempers and toughness levels equal to or higher than other conventional high-strength alloys.

Plate in the T7451 temper has stress-corrosion resistance higher than 7075-T7651, and hand and die forgings in the T7452 and T74 tempers, respectively, have stress-corrosion resistance similar to 7175-T74 forgings. The T73 temper provides the highest resistance to stress corrosion for this alloy. The T76 temper provides for good exfoliation resistance and higher stress-corrosion resistance than T6 tempers of 7075 and 7178. The T74 temper provides stress-corrosion and strength characteristics intermediate to those of T76 and T73. Refer to Section 3.1.2.3 for further comments regarding the resistance of the alloy to stress-corrosion cracking. Refer to Section 3.1.3.4 for comments regarding the weldability of this alloy.

Material specifications for 7050 are shown in Table 3.7.4.0(a). Room-temperature properties are shown in Tables 3.7.4.0(b1) through (e3).

Table 3.7.4.0(a). Material Specifications for 7050 Aluminum Alloy
Specification	Form
AMS 4050	Bare plate
AMS 4108	Hand forging
AMS 4107	Die forging
AMS 4333	Die forging
AMS 4340	Extruded shape
AMS 4341	Extruded shape
AMS 4342	Extruded shape
AMS 4201	Bare plate
AMS-A-22771	Forging

The temper index for 7050 is: Section 3.7.4.1 covers the T73510 and T73511 tempers; Section 3.7.4.2 covers the T74, T7451, and T7452 tempers (formerly designated T736, T73651, and T73652); Section 3.7.4.3 covers the T76510 and T76511 tempers.

Table 3.7.4.0(b1) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Plate (AMS 4050, T7451) — pending digitization (dense multi-column property table; MIL-HDBK-5J pp. 3-323–3-324).

Table 3.7.4.0(b2) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Plate (AMS 4201, T7651) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-325).

Table 3.7.4.0(c1) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Die Forging (T74) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-326).

Table 3.7.4.0(c2) — Design Mechanical and Physical Properties of 7050-T7452 Aluminum Alloy Die Forging — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-327).

Table 3.7.4.0(d) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Hand Forging (T7452) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-328).

Table 3.7.4.0(e1) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Extrusion (AMS 4341, T73511) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-329).

Table 3.7.4.0(e2) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Extrusion (AMS 4342, T74511) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-330).

Table 3.7.4.0(e3) — Design Mechanical and Physical Properties of 7050 Aluminum Alloy Extrusion (AMS 4340, T76511) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-331).

3.7.4.1T73510 and T73511 Tempers

Figures 3.7.4.1.6(a) through (d) present stress-strain and tangent-modulus curves for extrusions. Fatigue data are presented in Figures 3.7.4.1.8(a) and (b).

Figure 3.7.4.1.6(a). Typical tensile stress-strain curves for 7050-T7351X aluminum alloy extrusion at room temperature. Thickness ≤ 1.999 in.

Figure 3.7.4.1.6(b). Typical tensile stress-strain curves for 7050-T7351X aluminum alloy extrusion at room temperature. Thickness = 2.000–5.000 in.

Figure 3.7.4.1.6(c). Typical compressive stress-strain and tangent-modulus curves for 7050-T7351X aluminum alloy extrusion at room temperature. Thickness ≤ 1.999 in.

Figure 3.7.4.1.6(d). Typical compressive stress-strain and tangent-modulus curves for 7050-T7351X aluminum alloy extrusion at room temperature. Thickness = 2.000–5.000 in.

Figure 3.7.4.1.8(a). Best-fit S/N curves for unnotched 7050-T7351X extruded shape, longitudinal and long-transverse directions.

Correlative Information for Figure 3.7.4.1.8(a)

Product Form: Extruded shape, 0.5 to 5.0 inch thick

Properties: TUS 72–79 ksi, TYS 62–69 ksi, RT

Specimen Details: Unnotched, 0.300 inch diameter

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.7.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 10.5 − 3.79 log (S_eq − 16)
S_eq = S_max(1−R)^0.55
Std. Error of Estimate, Log (Life) = 0.516
Standard Deviation, Log (Life) = 1.10
R² = 78%

Sample Size: 128

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.1.8(b). Best-fit S/N curves for notched, K_t = 3.0, 7050-T7351X extruded shape, longitudinal and long-transverse directions.

Correlative Information for Figure 3.7.4.1.8(b)

Product Form: Extruded shape, 0.5 to 5.0 inch thick

Properties: TUS 72–79 ksi, TYS 62–69 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.359 inch gross diameter
0.253 inch net diameter
0.013 inch root radius, r
60° flank angle

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.7.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 7.73 − 2.58 log (S_eq − 5.0)
S_eq = S_max(1−R)^0.56
Std. Error of Estimate, Log (Life) = 0.268
Standard Deviation, Log (Life) = 0.733
R² = 87%

Sample Size: 103

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

3.7.4.2T74, T7451, and T7452 Tempers

Elevated-temperature curves for T7451 plate are presented in Figure 3.7.4.2.1. Figures 3.7.4.2.6(a) through (j) present stress-strain and tangent-modulus curves for various products and tempers. Fatigue data are presented in Figures 3.7.4.2.8(a) through (l). Fatigue-crack-propagation data for T7451 plate are presented in Figures 3.7.4.2.9(a) through (c).

Figure 3.7.4.2.1. Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of 7050-T7451 aluminum alloy plate.

Figure 3.7.4.2.6(a). Typical tensile stress-strain curves for 7050-T7451 aluminum alloy plate at room temperature. Thickness = 0.500–4.000 in.

Figure 3.7.4.2.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7050-T7451 aluminum alloy plate at room temperature. Thickness = 0.500–4.000 in.

Figure 3.7.4.2.6(c). Typical tensile stress-strain curves for 7050-T7452 aluminum alloy hand forging at room temperature. Thickness ≤ 7.000 in.

Figure 3.7.4.2.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7050-T7452 aluminum alloy hand forging at room temperature. Thickness ≤ 7.000 in.

Figure 3.7.4.2.6(e). Typical tensile stress-strain curves for 7050-T74 aluminum alloy die forging at room temperature. Thickness ≤ 3.000 in.

Figure 3.7.4.2.6(f). Typical compressive stress-strain and compressive tangent-modulus curves for 7050-T74 aluminum alloy die forging at room temperature. Thickness ≤ 3.000 in.

Figure 3.7.4.2.6(g). Typical tensile stress-strain curves for 7050-T74511 aluminum alloy extrusion at room temperature. Thickness ≤ 1.750 in.

Figure 3.7.4.2.6(h). Typical compressive stress-strain and tangent-modulus curves for 7050-T74511 aluminum alloy extrusion at room temperature. Thickness ≤ 1.750 in.

Figure 3.7.4.2.6(i). Typical tensile stress-strain curves for 7050-T7452 aluminum alloy die forging at room temperature. Thickness ≤ 6.000 in.

Figure 3.7.4.2.6(j). Typical compressive stress-strain and tangent-modulus curves for 7050-T7452 aluminum alloy die forging at room temperature. Thickness ≤ 6.000 in.

Figure 3.7.4.2.8(a). Best-fit S/N curves for unnotched 7050-T7451 plate, longitudinal direction and T/2 specimen location.

Correlative Information for Figure 3.7.4.2.8(a)

Product Form: Plate, 1.0 inch thick

Properties: TUS 79 ksi, TYS 72 ksi, RT

Specimen Details: Unnotched, 0.30 inch diameter

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.8.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 10

Equivalent Stress Equation:
Log N_f = 9.73 − 3.24 log (S_eq − 15.5)
S_eq = S_max(1−R)^0.63
Std. Error of Estimate, Log (Life) = 0.490
Standard Deviation, Log (Life) = 0.942
R² = 73%

Sample Size: 35

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(b). Best-fit S/N curves for unnotched 7050-T7451 plate, long-transverse direction, t/4 specimen location.

Correlative Information for Figure 3.7.4.2.8(b)

Product Form: Plate, 4.25 to 8.50 inches thick

Properties: TYS 62–67 ksi, RT (TUS not applicable)

Specimen Details: Unnotched, 0.250 inch diameter

Surface Condition: Polished, final surface finish unspecified

References: 3.7.4.2.8(d) and (e)

Test Parameters:
Loading – Axial
Frequency – 20 Hz
Temperature – RT
Environment – Air

Equivalent Stress Equation:
Log (N_f) = 16.410 − 6.624 log (S_eq − 5.0)
S_eq = S_max(1−R)^0.65
Std. Error of Estimate, Log (Life) = 0.183
Standard Deviation, Log (Life) = 0.814
R² = 95.0%

Sample Size: 57

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(c). Best-fit S/N curves for unnotched 7050-T7451 plate, long-transverse direction, t/2 specimen location.

Correlative Information for Figure 3.7.4.2.8(c)

Product Form: Plate, 4.25 to 8.50 inches thick

Properties: TYS 62–67 ksi, RT (TUS not applicable)

Specimen Details: Unnotched, 0.250 inch diameter

Surface Condition: Polished, final surface finish unspecified

References: 3.7.3.2.8(d) and (e)

Test Parameters:
Loading – Axial
Frequency – 20 Hz
Temperature – RT
Environment – Air

Equivalent Stress Equation:
Log (N_f) = 12.484 − 4.878 log (S_eq − 60/t)
S_eq = S_max(1−R)^0.42, t = plate thickness in inches
Std. Error of Estimate, Log (Life) = 0.204
Standard Deviation, Log (Life) = 0.594
R² = 88.2%

Sample Size: 36

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios and plate thicknesses beyond those represented above.]

Figure 3.7.4.2.8(d). Best-fit strain-life curves, cyclic stress-strain curve, and mean-stress-relaxation curve for 7050-T7451 plate, long-transverse direction, t/4 specimen location.

Correlative Information for Figure 3.7.4.2.8(d)

Product Form: Plate, 4.25 to 8.50 inches thick

Properties: TYS 62–67 ksi, RT (TUS not applicable)

Specimen Details: Unnotched, 0.250 inch diameter

Surface Condition: Polished, final surface finish unspecified

References: 3.7.3.2.8(d) and (e)

Test Parameters:
Loading – Axial, triangular waveform
Frequency – 0.50 Hz
Temperature – RT
Environment – Air

Sample Size: 53

[Caution: The equivalent strain model may provide unrealistic life predictions for strain ratios beyond those represented above.]

The cyclic stress-strain and mean-stress-relaxation equations for this figure were not transcribed: the OCR text extracted from MIL-HDBK-5J pp. 3-345–3-346 is corrupted (Greek-letter strain/stress symbols and exponents did not survive extraction) and could not be reconstructed with confidence. Refer to the original PDF for the equation set.

Figure 3.7.4.2.8(e). Best-fit S/N curves for unnotched 7050-T7451 plate, long-transverse direction, t/4 specimen location.

Correlative Information for Figure 3.7.4.2.8(e)

Product Form: Plate, 1.0 to 6.0 inches thick

Properties: TUS 73–81 ksi, TYS 62–72 ksi, RT

Specimen Details: Unnotched, 0.250 and 0.300 inch diameter

Surface Condition: Not specified

References: 3.7.4.2.9(b), 3.7.8.2.8(b), and (e)

Test Parameters:
Loading – Axial
Frequency – 800 cpm and unspecified
Temperature – RT
Environment – Air

No. of Heats/Lots: 15

Equivalent Stress Equation:
Log N_f = 10.7 − 3.81 log (S_eq − 10)
S_eq = S_max(1−R)^0.59
Std. Error of Estimate, Log (Life) = 0.507
Standard Deviation, Log (Life) = 0.794
R² = 59%

Sample Size: 85

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(f). Best-fit S/N curves for notched, K_t = 3.0, 7050-T7451 plate, longitudinal and long-transverse directions, t/4 specimen location.

Correlative Information for Figure 3.7.4.2.8(f)

Product Form: Plate, 1.0 to 6.0 inches thick

Properties: TUS 75–81 ksi, TYS 65–72 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.306 and 0.373 inch gross diameter
0.253 inch net diameter
0.013 inch notch-tip radius, r
60° flank angle

Surface Condition: Not specified

References: 3.7.4.2.9(b), 3.7.8.2.8(b), and (c)

Test Parameters:
Loading – Axial
Frequency – 800 cpm and unspecified
Temperature – RT
Environment – Air

No. of Heats/Lots: 11

Equivalent Stress Equation:
Log N_f = 10.0 − 3.96 log (S_eq)
S_eq = S_max(1−R)^0.64
Std. Error of Estimate, Log (Life) = 0.248
Standard Deviation, Log (Life) = 0.728
R² = 88%

Sample Size: 79

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(g). Best-fit S/N curves for notched, K_t = 2.6, 7050-T7451X extruded shape, longitudinal direction.

Correlative Information for Figure 3.7.4.2.8(g)

Product Form: Extruded shape, 0.5 to 5.0 inch thick

Properties: TUS 76–77 ksi, TYS 67–68 ksi, RT

Specimen Details: Notched, center hole, K_t = 2.6
0.150 inch diameter
0.250 inch thick
1.00 inch wide

Surface Condition: Not specified

Reference: 3.7.4.2.8(a)

Test Parameters:
Loading – Axial
Frequency – Not specified
Temperature – RT
Environment – Air

No. of Heats/Lots: 6

Equivalent Stress Equation:
Log N_f = 8.23 − 2.82 log (S_eq − 10)
S_eq = S_max(1−R)^0.30
Std. Error of Estimate, Log (Life) = 0.243
Standard Deviation, Log (Life) = 0.724
R² = 89%

Sample Size: 34

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(h). Best-fit S/N curves for unnotched 7050-T7452 hand forgings, longitudinal direction.

Correlative Information for Figure 3.7.4.2.8(h)

Product Form: Hand forgings, 2.0 to 8.0 inch thick

Properties: TUS 76–81 ksi, TYS 66–72 ksi, RT

Specimen Details: Unnotched, 0.300 inch diameter

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.7.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 10

Equivalent Stress Equation:
Log N_f = 7.06 − 1.89 log (S_eq − 30)
S_eq = S_max(1−R)^0.60
Std. Error of Estimate, Log (Life) = 0.400
Standard Deviation, Log (Life) = 0.982
R² = 83%

Sample Size: 25

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(i). Best-fit S/N curves for unnotched 7050-T7452 hand forgings, long-transverse and short-transverse directions.

Correlative Information for Figure 3.7.4.2.8(i)

Product Form: Hand forgings, 2.0 to 8.0 inch thick

Properties: TUS 73–80 ksi, TYS 59–70 ksi, RT

Specimen Details: Unnotched, 0.300 inch diameter

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.8.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm and unspecified
Temperature – RT
Environment – Air

No. of Heats/Lots: 10

Equivalent Stress Equation:
Log N_f = 7.58 − 2.14 log (S_eq − 21)
S_eq = S_max(1−R)^0.57
Std. Error of Estimate, Log (Life) = 0.400
Standard Deviation, Log (Life) = 0.803
R² = 75%

Sample Size: 55

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(j). Best-fit S/N curves for notched, K_t = 3.0, 7050-T7452 hand forgings, longitudinal, long-transverse, and short-transverse directions.

Correlative Information for Figure 3.7.4.2.8(j)

Product Form: Hand forgings, 2.0 to 8.0 inch thick

Properties: TUS 73–81 ksi, TYS 59–72 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.306 inch gross diameter
0.253 inch net diameter
0.013 inch root radius, r
60° flank angle

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.8.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 10

Equivalent Stress Equation:
Log N_f = 8.21 − 2.96 log (S_eq − 5)
S_eq = S_max(1−R)^0.68
Std. Error of Estimate, Log (Life) = 0.307
Standard Deviation, Log (Life) = 0.735
R² = 83%

Sample Size: 80

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(k). Best-fit S/N curves for unnotched 7050-T74 die forging, longitudinal direction.

Correlative Information for Figure 3.7.4.2.8(k)

Product Form: Die forging

Properties: TUS 74–81 ksi, TYS 68–71 ksi, RT

Specimen Details: Unnotched, 0.300 inch diameter

Surface Condition: Not specified

References: 3.7.4.2.9(b) and 3.7.8.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 4

Equivalent Stress Equation:
Log N_f = 16.8 − 6.97 log (S_max)
Std. Error of Estimate, Log (Life) = 0.381
Standard Deviation, Log (Life) = 0.820
R² = 78%

Sample Size: 20

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.8(l). Best-fit S/N curves for notched, K_t = 3.0, 7050-T74 die forging, longitudinal direction.

Correlative Information for Figure 3.7.4.2.8(l)

Product Form: Die forging

Properties: TUS 77–81 ksi, TYS 68–71 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.306 and 0.305 inch gross diameter
0.253 or 0.222 inch net diameter
0.013 or 0.012 inch root radius, r
60° flank angle

Surface Condition: Not specified

References: 3.7.4.2.8(b), 3.7.4.2.9(b), and 3.7.8.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800, 1800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 6

Equivalent Stress Equation:
Log N_f = 10.5 − 4.14 log (S_eq)
S_eq = S_max(1−R)^0.629
Std. Error of Estimate, Log (Life) = 0.506
Standard Deviation, Log (Life) = 0.896
R² = 68%

Sample Size: 73

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.2.9(a). Fatigue-crack-propagation data for 3.15-inch-thick 7050-T7451 aluminum plate.

Specimen and Test Details for Figure 3.7.4.2.9(a)

Specimen Thickness: 0.499–0.500 inch

Specimen Width: 2.989–3.000 inches

Specimen Type: C(T)

Stress Ratio, R: 0.1

Environment: Lab air (~50% humidity) and humid air (100% humidity)

Temperature: RT

Frequency, f: 10–20 Hz

Reference: 3.7.4.2.9(a)

Figure 3.7.4.2.9(b). Fatigue-crack-propagation data for 1- and 6-inch-thick 7050-T7451 aluminum plate, dry air.

Specimen and Test Details for Figure 3.7.4.2.9(b)

Specimen Thickness: 0.999–1.000 inch

Specimen Width: 3.805 inches

Specimen Type: C(T)

Stress Ratio, R: 0.33

Environment: Dry air (< 10% humidity)

Temperature: RT

Frequency, f: 18.3 Hz

Reference: 3.7.4.2.9(b)

Figure 3.7.4.2.9(c). Fatigue-crack-propagation data for 1- and 6-inch-thick 7050-T7451 aluminum plate, humid air.

Specimen and Test Details for Figure 3.7.4.2.9(c)

Specimen Thickness: 0.998–1.000 inch

Specimen Width: 3.805 inches

Specimen Type: C(T)

Stress Ratio, R: 0.33

Environment: Humid air (>90% humidity)

Temperature: RT

Frequency, f: 18.3 Hz

Reference: 3.7.4.2.9(b)

3.7.4.3T76510 and T76511 Tempers

Figures 3.7.4.3.6(a) through (f) present stress-strain and tangent-modulus curves for extruded shapes and plate. Fatigue data are presented in Figures 3.7.4.3.8(a) and (b).

Figure 3.7.4.3.6(a). Typical tensile stress-strain curves for 7050-T7651X aluminum alloy extrusion at room temperature. Thickness < 1.999 in.

Figure 3.7.4.3.6(b). Typical tensile stress-strain curves for 7050-T7651X aluminum alloy extrusion at room temperature. Thickness = 2.000–5.000 in.

Figure 3.7.4.3.6(c). Typical compressive stress-strain and compressive tangent-modulus curves for 7050-T7651X aluminum alloy extrusion at room temperature. Thickness < 1.999 in.

Figure 3.7.4.3.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7050-T7651X aluminum alloy extrusion at room temperature. Thickness = 2.000–5.000 in.

Figure 3.7.4.3.6(e). Typical tensile stress-strain curves for 7050-T7651 aluminum alloy plate at room temperature. Thickness ≤ 2.000 in.

Figure 3.7.4.3.6(f). Typical compressive stress-strain and compressive tangent-modulus curves for 7050-T7651 aluminum alloy plate at room temperature. Thickness ≤ 2.000 in.

Figure 3.7.4.3.8(a). Best-fit S/N curves for unnotched 7050-T7651X extruded shape, longitudinal and long-transverse directions.

Correlative Information for Figure 3.7.4.3.8(a)

Product Form: Extruded shape, 0.5 to 5.0 inch thick

Properties: TUS 84–90 ksi, TYS 75–81 ksi, RT

Specimen Details: Unnotched, 0.300 inch diameter

Surface Condition: Not specified

References: 3.7.4.3.8(b), 3.7.4.2.9(b), and 3.7.7.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 10

Equivalent Stress Equation:
Log N_f = 11.8 − 4.38 log (S_eq − 12)
S_eq = S_max(1−R)^0.61
Std. Error of Estimate, Log (Life) = 0.493
Standard Deviation, Log (Life) = 1.01
R² = 76%

Sample Size: 161

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.4.3.8(b). Best-fit S/N curves for notched, K_t = 3.0, 7050-T7651X extruded shape, longitudinal and long-transverse directions.

Correlative Information for Figure 3.7.4.3.8(b)

Product Form: Extruded shape, 0.5 to 5.0 inch thick

Properties: TUS 78–90 ksi, TYS 68–81 ksi, RT

Specimen Details: Circumferentially notched, K_t = 3.0
0.359 inch gross diameter
0.253 inch net diameter
0.013 inch root radius, r
60° flank angle

Surface Condition: Not specified

References: 3.7.4.2.9(b), 3.7.4.3.8(a), and 3.7.7.2.8(b)

Test Parameters:
Loading – Axial
Frequency – 800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: 10

Equivalent Stress Equation:
Log N_f = 10.38 − 4.26 log (S_eq)
S_eq = S_max(1−R)^0.563
Std. Error of Estimate, Log (Life) = 0.398
Standard Deviation, Log (Life) = 0.778
R² = 74%

Sample Size: 179

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

3.7.57055 Alloy

3.7.5.0Comments and Properties

7055 is an Al-Zn-Mg-Cu-Zr alloy and provides higher strength properties than 7150. 7055 is available in the form of plate and extrusions. The T77-type temper provides high tensile and compressive strength with guaranteed toughness (plate only) and exfoliation corrosion resistance. The T77-type temper has exfoliation corrosion resistance comparable to the T76-type temper of other 7XXX series aluminum alloys.

The properties of extrusions should be based upon the thickness at the time of extrusion, solution heat treatment, and quenching prior to machining. Selection of the mechanical properties based upon final machined thickness may be overstated; therefore, the thickness at the time of extrusion, solution heat treatment, and quenching to achieve properties is an important factor in the selection of the proper thickness column. For extrusions having sections with various thicknesses, consideration should be given to the properties as a function of thickness.

Material specifications for 7055 are shown in Table 3.7.5.0(a). Room-temperature mechanical properties are presented in Tables 3.7.5.0(b) through (e).

Table 3.7.5.0(a). Material Specifications for 7055 Aluminum Alloy
Specification	Form
AMS 4206 (T7751)	Plate
AMS 4324 (T74511)	Extrusion
AMS 4336 (T76511)	Extrusion
AMS 4337 (T77511)	Extrusion

Temper Index for 7055 Alloy
Section	Temper
3.7.5.1	T74511
3.7.5.2	T76511
3.7.5.3	T7751 and T77511

Tables 3.7.5.0(b) through (e) — Design Mechanical and Physical Properties of 7055-T74511 extrusions, 7055-T76511 extrusions, 7055-T7751 plate, and 7055-T77511 extrusion — pending digitization (dense multi-column property tables by thickness range; MIL-HDBK-5J pp. 3-364–3-367).

3.7.67075 Alloy

3.7.6.0Comments and Properties

7075 is a high-strength Al-Zn-Mg-Cu alloy and is available in a wide variety of product forms. It is also available in several types of tempers, the T6, T73, and T76 type. The T6 temper has the highest strength but lowest toughness and resistance to stress-corrosion cracking. Since toughness decreases with a decrease in temperature, the T6 temper is not generally recommended for cryogenic applications. As shown in Table 3.1.2.3.1(a), 7075-T6 rolled plate, rod and bar, extruded shapes, and forgings have a “D” SCC rating. This is the lowest rating and means that SCC failures have occurred in service or would be anticipated if there is any sustained stress. In-service failures are caused by stresses produced by any combination of sources including solution heat treatment, straightening, forming, fit-up, clamping, sustained service loads, or high service compression stresses that produce residual tensile stresses. These stresses may be tension or compression as well as the stresses due to the Poisson effect, because the actual failures are caused by the resulting sustained shear stresses. Pin-hole flaws in corrosion protection are sufficient for SCC. The T73 temper provides for much improved stress-corrosion resistance over T6 temper with a decrease in strength. The T76 temper provides for improved exfoliation resistance and limited stress-corrosion resistance over T6 temper with some decrease in strength. Refer to Section 3.1.2.3 for comments regarding the resistance of the alloy to stress-corrosion cracking and to Section 3.1.3.4 for comments regarding the weldability of this alloy.

Material specifications for 7075 aluminum alloy are presented in Table 3.7.6.0(a). Room-temperature mechanical and physical properties are shown in Tables 3.7.6.0(b1) through (g3). The effect of temperature on the physical properties of this alloy is presented in Figure 3.7.6.0.

Table 3.7.6.0(a). Material Specifications for 7075 Aluminum Alloy
Specification	Form
AMS 4044	Bare sheet and plate
AMS 4045	Bare sheet and plate
AMS 4078	Bare plate
AMS-QQ-A-250/12, 24	Bare sheet and plate
AMS-QQ-A-250/13, 25	Clad sheet and plate
AMS 4049	Clad sheet and plate
AMS 4122	Bar and rod, rolled or cold-finished
AMS 4123	Bar and rod, rolled or cold-finished
AMS 4124	Bar and rod, rolled or cold-finished
AMS 4186	Bar and rod, rolled or cold-finished
AMS 4187	Bar and rod, rolled or cold-finished
AMS-QQ-A-225/9	Rolled or drawn bar and rod
AMS-QQ-A-200/11, 15	Extruded bar, rod, and shapes
AMS 4126	Forging
AMS 4141	Die forging
AMS 4147	Forging
AMS-A-22771	Forging
AMS-QQ-A-367	Forging

The temper index for 7075 is: Section 3.7.6.1 covers the T6, T651, T652, T6510, and T6511 tempers; Section 3.7.6.2 covers the T73, T7351, T7352, T73510, and T73511 tempers.

Table 3.7.6.0(b1) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Sheet (T6, T62) and Plate (T651) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-371).

Table 3.7.6.0(b2) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Plate (T62), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-372).

Table 3.7.6.0(b3) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Sheet (T73) and Plate (T7351), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-373).

Table 3.7.6.0(b4) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Sheet and Plate (T76, T7651), concluded — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-374).

Table 3.7.6.0(c1) — Design Mechanical and Physical Properties of Clad 7075 Aluminum Alloy Sheet (T6) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-375).

Table 3.7.6.0(c2) — Design Mechanical and Physical Properties of Clad 7075 Aluminum Alloy Sheet (T6, T62), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-376).

Table 3.7.6.0(c3) — Design Mechanical and Physical Properties of Clad 7075 Aluminum Alloy Plate (T651), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-377).

Table 3.7.6.0(c4) — Design Mechanical and Physical Properties of Clad 7075 Aluminum Alloy Plate (T62), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-378).

Table 3.7.6.0(c5) — Design Mechanical and Physical Properties of Clad 7075 Aluminum Alloy Sheet and Plate (T76, T7651), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-379).

Table 3.7.6.0(d) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Bar, Rod, and Shapes: Rolled, Drawn, or Cold-Finished (T6, T651, T62, T73, T7351) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-380).

Table 3.7.6.0(e1) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Die Forging (T6, T652) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-381).

Table 3.7.6.0(e2) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Die Forging (T73, T7352), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-382).

Table 3.7.6.0(f1) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Hand Forging (T6, T652) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-383).

Table 3.7.6.0(f2) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Hand Forging (T73, T7352), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-384).

Table 3.7.6.0(g1) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Extrusion (T6, T6510, T6511, T62) — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-385).

Table 3.7.6.0(g2) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Extrusion (T73, T73510, T73511), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-386).

Table 3.7.6.0(g3) — Design Mechanical and Physical Properties of 7075 Aluminum Alloy Extrusion (T76, T76510, T76511), continued — pending digitization (dense multi-column property table; MIL-HDBK-5J p. 3-387).

Figure 3.7.6.0. Effect of temperature on the physical properties of 7075 aluminum alloy.

3.7.6.1T6, T651, T652, T6510, T6511 Tempers

Figures 3.7.6.1.1(a) and (b) permit calculation of residual tensile strengths for complex thermal exposure conditions. They are based upon the rate parameter T(C + log t), in which T is exposure temperature in degrees Rankine, t is exposure time in hours, and C is a constant evaluated for each material. These curves have been verified for use only within the ranges of temperatures and exposure times covered in the figures. The following example illustrates their use.

Sample problem: Find Ftu at 250°F following a complex exposure of 300°F, 8 hours plus 350°F, 1 hour.

Reduce given complex exposure by converting the 350°F exposure to an equivalent exposure time at 300°F.
1. On the 350°F single-exposure-temperature line, find 350°F, 1 hour.
2. From this point move vertically to the 300°F exposure-temperature line and then read right, 12 hours exposure.
3. Total equivalent exposure time at 300°F is therefore 8 hours + 12 hours, or 20 hours.
Find Ftu at 250°F following 300°F, 20 hours exposure:
1. On the 300°F exposure-temperature line, find 300°F, 20 hours.
2. From this point move vertically to the 250°F test-temperature curve and then read left, 76 percent Ftu.

Solution: Ftu is 76 percent of the original room-temperature Ftu. Fty is determined in like manner. Fcy can be closely estimated by using the percent reduction factor determined for Fty. For specific data, see Reference 3.7.6.1.

Stressed Thermal Exposure — Stress applied during simple and complex thermal exposure of 7075-T6 can have an additional effect in reducing material strength. However, the effect becomes significant only when exposure strains exceed 0.2 percent. For specific data, see Reference 3.7.6.1.

Figures 3.7.6.1.1(c) through 3.7.6.1.5(b) present elevated-temperature curves for various mechanical properties. Figures 3.7.6.1.6(a) through (m) present tensile and compressive stress-strain and tangent-modulus curves at several temperatures. Figures 3.7.6.1.6(n) through (q) are full-range stress-strain curves for various products. Figures 3.7.6.1.8(a) through (h) provide room-temperature fatigue curves for T6-temper products. Fatigue-crack-propagation data for sheet are presented in Figure 3.7.6.1.9. Graphical displays of the residual-strength behavior of middle-tension panels are presented in Figures 3.7.6.1.10(a) through (h).

Figure 3.7.6.1.1(a). Effect of temperature on the tensile ultimate strength (Ftu) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products). Instructions for use of these curves are presented in Section 3.7.6.1.

Figure 3.7.6.1.1(b). Effect of temperature on the tensile yield strength (Fty) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products). Instructions for use of these curves are presented in Section 3.7.6.1.

Figure 3.7.6.1.1(c). Effect of temperature on the tensile ultimate strength (Ftu) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products).

Figure 3.7.6.1.1(d). Effect of temperature on the tensile yield strength (Fty) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products).

Figure 3.7.6.1.2(a). Effect of temperature on the compressive yield strength (Fcy) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products).

Figure 3.7.6.1.2(b). Effect of temperature on the shear ultimate strength (Fsu) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products).

Figure 3.7.6.1.3(a). Effect of temperature on the bearing ultimate strength (Fbru) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products).

Figure 3.7.6.1.3(b). Effect of temperature on the bearing yield strength (Fbry) of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products).

Figure 3.7.6.1.4. Effect of temperature on the tensile and compressive moduli (E and Ec) of 7075 aluminum alloy.

Figure 3.7.6.1.5(a). Effect of temperature on the elongation of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products except thick extrusions).

Figure 3.7.6.1.5(b). Effect of exposure at elevated temperatures on the elongation of 7075-T6, T651, T6510, and T6511 aluminum alloy (all products except thick extrusions).

Figures 3.7.6.1.6(a) through (q) present typical stress-strain and tangent-modulus curves for T6-family products and are not individually reproduced here; each figure corresponds to a specific product form, temper, test temperature, and (where applicable) thermal-exposure time. The run covers: clad 7075-T6 sheet, tensile and compressive stress-strain and tangent-modulus curves at room temperature through 600°F with exposures of 1/2, 2, 10, 100, and 1000 hours [(a) through (f)]; 7075-T651 and -T62 plate at room temperature [(g) through (i)]; 7075-T6/T651 rolled bar, rod, and shape at room temperature [(j)]; 7075-T651X and -T62 extrusion at room temperature [(k) through (m)]; and full-range (to-fracture) tensile stress-strain curves for clad T6 sheet, T6/T651 rolled bar, and T651X/T62 extrusion at room temperature [(n) through (q)]. See MIL-HDBK-5J pp. 3-395–3-405 for the individual curves.

Figure 3.7.6.1.8(a). Best-fit S/N curves for unnotched 7075-T6 aluminum alloy, various product forms, longitudinal direction.

Correlative Information for Figure 3.7.6.1.8(a)

Product Form: 0.75 inch diam. drawn rod, 1.25 inch diam. rolled rod, 1 x 7.5 inch bar, extruded 1.25 inch bar and 1.25 inch rod

Properties: TUS 82 ksi, TYS 72 ksi, RT

Specimen Details: Unnotched, minimum diameter 0.200 inch

Surface Condition: Unspecified

Reference: 3.7.6.1.8

Test Parameters:
Loading – Axial
Frequency – 30 Hz
Temperature – RT
Environment – Air

No. of Heats/Lots: 8

Equivalent Stress Equation:
Log N_f = 18.22 − 7.77 log (S_eq − 10.15)
S_eq = S_max(1−R)^0.62
Std. Error of Estimate, Log (Life) = 0.626
Standard Deviation, Log (Life) = 1.435
R² = 81%

Sample Size: 130

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(b). Best-fit S/N curve for notched, K_t = 1.6, 7075-T6 aluminum alloy rolled bar, longitudinal direction.

Correlative Information for Figure 3.7.6.1.8(b)

Product Form: 1.125 inch diam. rolled bar

Properties: TUS 99.2 ksi, RT

Specimen Details: Notched, K_t = 1.6
Notch-root radius = 0.100 inch
Net test-section diameter = 0.400 inch
Gross diameter = 0.450 inch
60° groove

Surface Condition: Polished to 10 micro-inches

Reference: 3.2.1.1.8(b)

Test Parameters:
Loading – Axial
Frequency – 60 Hz
Temperature – RT
Atmosphere – Air

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log N_f = 8.26 − 2.62 log (S_eq − 15.3)
S_eq = S_max(1−R)^0.525
Std. Error of Estimate, Log (Life) = 0.418
Standard Deviation, Log (Life) = 0.985
R² = 82%

Sample Size: 34

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(c). Best-fit S/N curves for notched, K_t = 3.4, 7075-T6 aluminum alloy rolled bar, longitudinal direction.

Correlative Information for Figure 3.7.6.1.8(c)

Product Form: 1.125 inch diam. rolled bar

Properties: TUS 96.5 ksi, RT

Specimen Details: Notched, K_t = 3.4
Notch-root radius = 0.010 inch
Net test-section diameter = 0.400 inch
Gross diameter = 0.450 inch
60° groove

Surface Condition: Polished to 10 micro-inches

Reference: 3.2.1.1.8(b)

Test Parameters:
Loading – Axial
Frequency – 60 Hz
Temperature – RT
Atmosphere – Air

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log N_f = 9.19 − 3.646 log (S_eq − 5.36)
S_eq = S_max(1−R)^0.386
Std. Error of Estimate, Log (Life) = 0.282
Standard Deviation, Log (Life) = 0.782
R² = 87%

Sample Size: 48

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(d). Best-fit S/N curves for unnotched 7075-T6 aluminum alloy sheet, longitudinal direction.

Stresses are based on net section.

Correlative Information for Figure 3.7.6.1.8(d)

Product Form: Bare sheet, 0.090 inch

Properties: TUS 82 ksi, TYS 76 ksi, RT

Specimen Details: Unnotched, 0.5 to 1.0 inch width

Surface Condition: Electropolished, 150 grit emery paper

References: 3.2.3.1.8(a) and (f)

Test Parameters:
Loading – Axial
Frequency – 300 to 1800 cpm
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 14.86 − 5.80 log (S_eq)
S_eq = S_max(1−R)^0.49
Std. Error of Estimate, Log (Life) = 0.41
Standard Deviation, Log (Life) = 0.92
R² = 80%

Sample Size: 176

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(e). Best-fit S/N curves for notched, K_t = 1.5, 7075-T6 aluminum alloy sheet, longitudinal direction.

Correlative Information for Figure 3.7.6.1.8(e)

Product Form: Bare sheet, 0.090 inch

Properties: Unnotched TUS 82 ksi, TYS 76 ksi, RT; Notched TUS 87 ksi, RT

Specimen Details: Edge notched
3.000 inch gross width
1.500 inch net width
0.760 inch notch radius
60° flank angle

Surface Condition: Electropolished

Reference: 3.2.3.1.8(d)

Test Parameters:
Loading – Axial
Frequency – 1100 to 1500 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 9.54 − 3.52 log (S_eq − 18.7)
S_eq = S_max(1−R)^0.49
Std. Error of Estimate, Log (Life) = 0.41
Standard Deviation, Log (Life) = 1.00
R² = 83%

Sample Size: 30

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(f). Best-fit S/N curves for notched, K_t = 2.0, 7075-T6 aluminum alloy sheet, longitudinal direction.

Correlative Information for Figure 3.7.6.1.8(f)

Product Form: Bare sheet, 0.090 inch

Properties: Unnotched TUS 82 ksi, TYS 76 ksi, RT; Notched TUS 88 ksi, RT

Specimen Details: Notched – center (4.50 in. gross / 1.50 in. net / 1.50 in. notch radius), edge (2.25 in. gross / 1.50 in. net / 0.3175 in. notch radius), and fillet (2.25 in. gross / 1.50 in. net / 0.1736 in. notch radius)

Surface Condition: Electropolished

References: 3.2.3.1.8(b) and (f)

Test Parameters:
Loading – Axial
Frequency – 1100 to 1500 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 7.50 − 2.46 log (S_eq − 18.6)
S_eq = S_max(1−R)^0.54
Std. Error of Estimate, Log (Life) = 0.31
Standard Deviation, Log (Life) = 0.85
R² = 87%

Sample Size: 112

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(g). Best-fit S/N curves for notched, K_t = 4.0, 7075-T6 aluminum alloy sheet, longitudinal direction.

Correlative Information for Figure 3.7.6.1.8(g)

Product Form: Bare sheet, 0.090 inch

Properties: Unnotched TUS 82 ksi, TYS 76 ksi, RT; Notched TUS 82 ksi, RT

Specimen Details: Notched – edge (2.25 in. gross / 1.500 in. net / 0.057 in. notch radius; 4.10 in. gross / 1.500 in. net / 0.070 in. notch radius) and fillet (2.25 in. gross / 1.500 in. net / 0.0195 in. notch radius)

Surface Condition: Electropolished

References: 3.2.3.1.8(b), (f), (g), and (h)

Test Parameters:
Loading – Axial
Frequency – 1100 to 1800 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 10.2 − 4.63 log (S_eq − 5.3)
S_eq = S_max(1−R)^0.51
Std. Error of Estimate, Log (Life) = 0.51
Standard Deviation, Log (Life) = 1.08
R² = 78%

Sample Size: 126

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.8(h). Best-fit S/N curves for notched, K_t = 5.0, 7075-T6 aluminum alloy sheet, longitudinal direction.

Stresses are based on net section.

Correlative Information for Figure 3.7.6.1.8(h)

Product Form: Bare sheet, 0.090 inch

Properties: Unnotched TUS 82 ksi, TYS 76 ksi, RT; Notched TUS 77 ksi, RT

Specimen Details: Edge notched
2.25 inch gross width
1.500 inch net width
0.03125 inch notch radius

Surface Condition: Electropolished

Reference: 3.2.3.1.8(c)

Test Parameters:
Loading – Axial
Frequency – 1100 to 1500 cpm
Temperature – RT
Environment – Air

No. of Heats/Lots: Not specified

Equivalent Stress Equation:
Log N_f = 7.51 − 2.92 log (S_eq − 6.7)
S_eq = S_max(1−R)^0.58
Std. Error of Estimate, Log (Life) = 0.23
Standard Deviation, Log (Life) = 1.08
R² = 95%

Sample Size: 37

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]

Figure 3.7.6.1.9. Fatigue-crack-propagation data for 0.090-inch-thick 7075-T6 aluminum alloy sheet with buckling restraint.

Specimen and Test Details for Figure 3.7.6.1.9

Specimen Thickness: 0.090 inch

Specimen Width: 1-1/2 to 12 inches

Specimen Type: M(T)

Environment: Lab air

Temperature: RT

Orientation: L-T

References: 3.7.6.1.9(a) through (e)

Figures 3.7.6.1.10(a) through (h) present the residual-strength behavior of 7075-T6 middle-tension panels for a range of sheet, clad-sheet, and plate thicknesses and crack orientations, summarized below.

Figure 3.7.6.1.10(a). Residual-strength behavior of 0.063-inch-thick 7075-T6 aluminum alloy sheet at room temperature. Crack orientation is T-L.

Figure 3.7.6.1.10(b). Residual-strength behavior of 0.063-inch-thick 7075-T6 aluminum alloy sheet at room temperature. Crack orientation is T-L.

Figure 3.7.6.1.10(c). Residual-strength behavior of 0.090- and 0.100-inch-thick 7075-T6 aluminum alloy sheet at room temperature. Crack orientation is L-T.

Figure 3.7.6.1.10(d). Residual-strength behavior of 0.100-inch-thick 7075-T6 aluminum alloy sheet at room temperature. Crack orientation is L-T.

Figure 3.7.6.1.10(e). Residual-strength behavior of 0.313-inch-thick 7075-T6 aluminum alloy plate at room temperature. Crack orientation is L-T.

Figure 3.7.6.1.10(f). Residual-strength behavior of 0.040-inch-thick 7075-T6 clad aluminum alloy sheet at room temperature. Crack orientation is L-T.

Figure 3.7.6.1.10(g). Residual-strength behavior of 0.080-inch-thick 7075-T6 clad aluminum alloy sheet at room temperature. Crack orientation is L-T.

Figure 3.7.6.1.10(h). Residual-strength behavior of 0.090-inch-thick 7075-T6 clad aluminum alloy sheet at room temperature. Crack orientation is L-T.

3.7.6.2T73, T7351, T7352, T73510, T73511 Tempers

Figures 3.7.6.2.6(a) through (d) present stress-strain and tangent-modulus curves for various products and tempers. Figures 3.7.6.2.6(e) and (f) are full-range stress-strain curves at room temperature for extrusion. Fatigue-crack-propagation data for plate are presented in Figures 3.7.6.2.9(a) through (c). Graphical displays of the residual-strength behavior of middle-tension panels are presented in Figures 3.7.6.2.10(a) and (b).

Figure 3.7.6.2.6(a). Typical tensile and compressive stress-strain and compressive tangent-modulus curves for 7075-T73 aluminum alloy extrusion at room temperature. Thickness = 0.250–1.499 in.

Figure 3.7.6.2.6(b). Typical tensile and compressive stress-strain and compressive tangent-modulus curves for 7075-T7351X aluminum alloy extrusion at room temperature. Thickness = 0.500–0.749 in.

Figure 3.7.6.2.6(c). Typical tensile stress-strain curves for 7075-T7352 aluminum alloy hand forging at room temperature. Thickness = 3.001–5.000 in.

Figure 3.7.6.2.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7075-T7352 aluminum alloy hand forging at room temperature. Thickness = 3.001–5.000 in.

Figure 3.7.6.2.6(e). Typical tensile stress-strain curves (full range) for 7075-T7351X aluminum alloy extrusion at room temperature. Thickness = 0.500–0.749 in.

Figure 3.7.6.2.6(f). Typical tensile stress-strain curves (full range) for 7075-T73 aluminum alloy extrusion at room temperature.

Figure 3.7.6.2.9(a). Fatigue-crack-propagation data for 0.250-inch-thick 7075-T7351 aluminum alloy plate with buckling restraint.

Specimen and Test Details for Figure 3.7.6.2.9(a)

Specimen Thickness: 0.250 inch

Specimen Width: 8, 16, 36 inches

Specimen Type: M(T)

Environment: 50% R.H.

Temperature: RT

Orientation: L-T

References: 3.2.5.1.9(d) and 3.7.6.2.9(a)

Figure 3.7.6.2.9(b). Fatigue-crack-propagation data for 0.500-inch-thick 7075-T7351 aluminum alloy plate with buckling restraint.

Specimen and Test Details for Figure 3.7.6.2.9(b)

Specimen Thickness: 0.475 to 0.500 inch

Specimen Width: 6, 8, 16, 36 inches

Specimen Type: M(T)

Environment: 50–95% R.H.

Temperature: RT

Orientation: L-T

References: 3.1.2.1.6(j) and 3.7.6.2.9(a) through (c)

Figure 3.7.6.2.9(c). Fatigue-crack-propagation data for 1.00-inch-thick 7075-T7351 aluminum alloy plate without buckling restraint.

Specimen and Test Details for Figure 3.7.6.2.9(c)

Specimen Thickness: 1.00 inch

Specimen Width: 6, 8, 16, 36 inches

Specimen Type: M(T), C(T)

Environment: 50% R.H.

Temperature: RT

Orientation: L-T

References: 3.2.5.1.9(d) and 3.7.6.2.9(a) and (b)

Figure 3.7.6.2.10(a). Residual-strength behavior of 0.600-inch-thick 7075-T7351 aluminum alloy plate at room temperature. Crack orientation is L-T.

Figure 3.7.6.2.10(b). Residual-strength behavior of 1.00-inch-thick 7075-T7351 aluminum alloy plate at room temperature. Crack orientation is L-T.

3.7.77150 Alloy

3.7.7.0Comments and Properties

7150, a second-generation version of 7050, is an Al-Zn-Mg-Cu-Zr alloy developed to provide higher strength properties than 7050 in thicknesses through 3 inches. 7150 is available in the form of plate and extrusion. The T61-type temper provides high strength with guaranteed levels of fracture toughness for plate. The T77-type temper provides high strength with guaranteed toughness and corrosion resistance. The T77-type temper has exfoliation and stress-corrosion resistance comparable to the T76-type temper of the other 7000 series aluminum alloys. Refer to Section 3.1.2.3 for further comments regarding resistance of the alloy to stress-corrosion cracking.

Refer to Section 3.1.3.4 for comments regarding the weldability of the alloy.

Material specifications for 7150 are shown in Table 3.7.7.0(a). Room-temperature mechanical properties are presented in Tables 3.7.7.0(b1) through (c2).

Table 3.7.7.0(a). Material Specifications for 7150 Aluminum Alloy
Specification	Form
AMS 4306	Bare plate
AMS 4252	Bare plate
AMS 4307	Extrusion
AMS 4345	Extrusion

Temper Index for 7150 Alloy
Section	Temper
3.7.7.1	T6151 and T61511
3.7.7.2	T7751 and T77511

Tables 3.7.7.0(b1) through (c2) — Design Mechanical and Physical Properties of 7150 plate (T6151, T7751) and extrusion (T61511, T77511) — pending digitization (dense multi-column property tables by thickness range; MIL-HDBK-5J pp. 3-428–3-431).

3.7.7.1T6151 and T61511 Tempers

Figures 3.7.7.1.6(a) and (b) present stress-strain and tangent-modulus curves for bare plate. Figures 3.7.7.1.6(c) and (d) depict stress-strain and tangent-modulus curves for extrusion.

Figure 3.7.7.1.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.1.6(a). Typical tensile stress-strain curves for 7150-T6151 aluminum alloy plate at room temperature (thickness 0.750–1.000 in.).

Figure 3.7.7.1.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.1.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7150-T6151 aluminum alloy plate at room temperature (thickness 0.750–1.000 in.).

Figure 3.7.7.1.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.1.6(c). Typical tensile stress-strain curves for 7150-T61511 aluminum alloy extrusion at room temperature (thickness 0.800–2.750 in.).

Figure 3.7.7.1.6(d) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.1.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7150-T61511 aluminum alloy extrusion at room temperature (thickness 0.800–2.750 in.).

3.7.7.2T7751 and T77511 Tempers

Figures 3.7.7.2.6(a) and (b) present stress-strain and tangent-modulus curves for bare plate. Figures 3.7.7.2.6(c) and (d) depict stress-strain and tangent-modulus curves for extrusion. Figures 3.7.7.2.8(a) through (c) present best-fit S/N fatigue curves for unnotched and notched (K_t = 3.0) 7150-T77511 extrusion.

Figure 3.7.7.2.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.6(a). Typical tensile stress-strain curves for 7150-T7751 aluminum alloy plate at room temperature (thickness 0.340–1.875 in.).

Figure 3.7.7.2.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.6(b). Typical compressive stress-strain and tangent-modulus curves for 7150-T7751 aluminum alloy plate at room temperature (thickness 0.340–1.875 in.).

Figure 3.7.7.2.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.6(c). Typical tensile stress-strain curves for 7150-T77511 aluminum alloy extrusion at room temperature (thickness 0.700–1.145 in.).

Figure 3.7.7.2.6(d) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.6(d). Typical compressive stress-strain and tangent-modulus curves for 7150-T77511 aluminum alloy extrusion (thickness 0.700–1.145 in.).

Figure 3.7.7.2.8(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.8(a). Best-fit S/N curves for unnotched 7150-T77511 aluminum alloy extrusion, longitudinal orientation.

Figure 3.7.7.2.8(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.8(b). Best-fit S/N curves for unnotched 7150-T77511 aluminum alloy extrusion, long transverse orientation.

Figure 3.7.7.2.8(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.7.2.8(c). Best-fit S/N curves for notched, K_t = 3.0, 7150-T77511 aluminum alloy extrusion, longitudinal and long transverse orientations.

3.7.87175 Alloy

3.7.8.0Comments and Properties

7175 is a high-purity, high-strength Al-Zn-Mg-Cu alloy. In the form of die forgings the alloy is available in the T66, T74, and T7452 tempers. Die forgings of 7175-T66 develop higher static strength than 7075-T6 forgings, with fatigue, fracture, and stress-corrosion properties about equivalent to those of 7075-T6 forgings. 7175-T74-type die and hand forgings develop static strengths about equivalent to those of 7075-T6 forgings, with toughness and fatigue properties equal or superior to those of 7075-T73 forgings. The T74-type temper provides stress-corrosion resistance and strength characteristics intermediate to those of T76 and T73 in 7075. Refer to Section 3.1.2.3 for comments regarding the resistance of the alloy to stress-corrosion cracking, and to Section 3.1.3.4 for comments regarding the weldability of the alloy.

The properties of extrusions should be based upon the thickness at the time of quenching prior to machining. Selection of the mechanical properties based upon final machined thickness may be unconservative; the thickness at the time of quenching to achieve properties is an important factor in the selection of the proper thickness column. For extrusions having sections with various thicknesses, consideration should be given to the properties as a function of thickness.

Material specifications for 7175 are presented in Table 3.7.8.0(a). Room-temperature mechanical and physical properties are shown in Tables 3.7.8.0(b) through (d).

Table 3.7.8.0(a). Material Specifications for 7175 Aluminum Alloy
Specification	Form
AMS 4148	Die forging
AMS 4149	Die and hand forging
AMS 4179	Hand forging
AMS-A-22771	Forging
AMS 4344	Extrusion

The temper index for 7175 is: Section 3.7.8.1 covers the T73511 temper (extrusion); Section 3.7.8.2 covers the T74 and T7452 tempers (formerly designated T736 and T73652, die and hand forging).

Tables 3.7.8.0(b) through (d) — design mechanical/physical properties for die forging, hand forging, and extrusion — pending digitization (dense multi-column property tables; MIL-HDBK-5J pp. 3-440–3-443).

3.7.8.1T73511 Temper

Figures 3.7.8.1.6(a) and (b) show tensile and compressive stress-strain and tangent-modulus curves for 7175-T73511 extrusion at room temperature. Figures 3.7.8.1.8(a) through (d) present best-fit S/N fatigue curves — unnotched and notched (K_t = 3.0, 5.0, and 7.0) — for extrusion in the longitudinal direction.

Figure 3.7.8.1.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.1.6(a). Typical tensile stress-strain curves for aluminum alloy 7175-T73511 extrusion at room temperature.

Figure 3.7.8.1.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.1.6(b). Typical compressive stress-strain and tangent-modulus curves for aluminum alloy 7175-T73511 extrusion at room temperature.

Figure 3.7.8.1.8(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.1.8(a). Best-fit S/N curves for unnotched 7175-T73511 alloy extrusion, longitudinal direction.

Figure 3.7.8.1.8(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.1.8(b). Best-fit S/N curves for notched, K_t = 3.0, 7175-T73511 alloy extrusion, longitudinal direction.

Figure 3.7.8.1.8(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.1.8(c). Best-fit S/N curves for notched, K_t = 5.0, 7175-T73511 alloy extrusion, longitudinal direction.

Figure 3.7.8.1.8(d) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.1.8(d). Best-fit S/N curves for notched, K_t = 7.0, 7175-T73511 alloy extrusion, longitudinal direction.

3.7.8.2T74 and T7452 Tempers

Figures 3.7.8.2.6(a) through (f) present tensile and compressive stress-strain and tangent-modulus curves for 7175-T74 die forging and 7175-T74/T7452 hand forging at room temperature, for thicknesses ranging up to 6 inches. Figures 3.7.8.2.8(a) and (b) present best-fit S/N fatigue curves for die and hand forging.

Figure 3.7.8.2.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.6(a). Typical tensile stress-strain curves for 7175-T74 aluminum alloy die forging at room temperature.

Figure 3.7.8.2.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7175-T74 aluminum alloy die forging at room temperature.

Figure 3.7.8.2.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.6(c). Typical tensile stress-strain curves for 7175-T74 aluminum alloy hand forging at room temperature.

Figure 3.7.8.2.6(d) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.6(d). Typical compressive stress-strain and compressive tangent-modulus curves for 7175-T74 aluminum alloy hand forging at room temperature.

Figure 3.7.8.2.6(e) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.6(e). Typical tensile stress-strain curves for aluminum alloy 7175-T7452 hand forging at room temperature.

Figure 3.7.8.2.6(f) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.6(f). Typical compressive stress-strain and compressive tangent-modulus curves for aluminum alloy 7175-T7452 hand forging at room temperature.

Figure 3.7.8.2.8(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.8(a). Best-fit S/N curves for notched, K_t = 3.0, 7175-T74 alloy die forging, longitudinal direction.

Figure 3.7.8.2.8(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.8.2.8(b). Best-fit S/N curves for unnotched 7175-T74 alloy hand forging, longitudinal and transverse directions.

3.7.97249 Alloy

3.7.9.0Comments and Properties

7249 is an Al-Zn-Mg-Cu-Cr alloy developed as a derivative from alloy 7149. Alloy 7249 has tighter compositional tolerances on its major constituents and lowered maximums on the interstitials such as Si, Fe, Mn, and Ti than alloy 7149.

7249-T7452 was developed as a replacement material for 7075-T6 forgings, which are susceptible to stress-corrosion cracking and exfoliation. 7249 also has higher strength at the higher thickness ranges and higher ductility than 7075-T6.

Material specifications for 7249 are shown in Table 3.7.9.0(a). Room-temperature mechanical properties are shown in Table 3.7.9.0(b).

Table 3.7.9.0(a). Material Specification for 7249 Alloy
Specification	Form
AMS 4334	Hand forging

Temper Index for 7249 Alloy
Section	Temper
3.7.9.1	T7452

Table 3.7.9.0(b) — Design Mechanical and Physical Properties of 7249 Aluminum Alloy Hand Forging — pending digitization (dense multi-column property table by thickness range, 1.500–6.000 in.; MIL-HDBK-5J p. 3-455).

3.7.9.1T7452 Temper

Figures 3.7.9.1.6(a) and (b) present the typical tensile and compressive stress-strain curves and compressive tangent-modulus curves at room temperature. Figure 3.7.9.1.6(c) presents the full-range stress-strain curves for hand-forged material at room temperature.

Figure 3.7.9.1.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.9.1.6(a). Typical tensile stress-strain curves for 7249-T7452 aluminum alloy hand forging at room temperature.

Figure 3.7.9.1.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.9.1.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7249-T7452 aluminum alloy hand forging at room temperature.

Figure 3.7.9.1.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.9.1.6(c). Typical tensile stress-strain curves (full range) for 7249-T7452 aluminum alloy hand forging at room temperature.

3.7.107475 Alloy

3.7.10.0Comments and Properties

7475 is an Al-Zn-Mg-Cu alloy developed for applications requiring the high strength of 7075 but having fracture toughness superior to that of 7075. Sheet is available in the T61 and T761 tempers and plate in the T651 and T7651 tempers. Sheet has strength approximately the same as that of 7075 combined with toughness about the same as 2024-T3 at room temperature. Plate has strengths similar to those of corresponding tempers of 7075; the toughness of 7475-T651 equals or exceeds that of 7075-T7351.

Resistance to stress-corrosion cracking and exfoliation are comparable to that of 7075. The T73-type temper provides for much improved stress-corrosion resistance over T6-type temper with a decrease in strength. The T76-type temper provides for improved exfoliation resistance and stress-corrosion resistance over T6-type temper with some decrease in strength. Refer to Section 3.1.2.3.1 for information regarding resistance to stress-corrosion cracking, and to Section 3.1.3.4 for comments regarding the weldability of the alloy.

Material specifications are shown in Table 3.7.10.0(a). Room-temperature mechanical and physical properties are shown in Tables 3.7.10.0(b) through (d).

Table 3.7.10.0(a). Material Specifications for 7475 Aluminum Alloy
Specification	Form
AMS 4084	Bare sheet
AMS 4085	Bare sheet
AMS 4090	Bare plate
AMS 4089	Bare plate
AMS 4202	Bare plate
AMS 4207	Clad sheet
AMS 4100	Clad sheet

The temper index for 7475 is: Section 3.7.10.1 covers the T61 and T651 tempers; Section 3.7.10.2 covers the T7351 temper; Section 3.7.10.3 covers the T761 and T7651 tempers.

Tables 3.7.10.0(b) through (d) — design mechanical/physical properties for bare sheet and plate, T7351 plate, and clad sheet — pending digitization (dense multi-column property tables; MIL-HDBK-5J pp. 3-459–3-462).

3.7.10.1T61 and T651 Tempers

Figures 3.7.10.1.6(a) through (f) present tensile and compressive stress-strain and tangent-modulus curves for T61 bare sheet, clad T61 sheet, and T651 plate. Figure 3.7.10.1.6(g) contains full-range tensile stress-strain curves for T61 sheet. Fatigue data for sheet are shown in Figures 3.7.10.1.8(a) through (c). Graphical displays of the residual strength behavior of middle-tension panels for bare and clad T61 sheet, in both the L-T and T-L crack orientations, are presented in Figures 3.7.10.1.10(a) through (d).

Figure 3.7.10.1.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.1.6(a). Typical tensile stress-strain curves for 7475-T61 aluminum alloy sheet at room temperature.

Figure 3.7.10.1.6(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.1.6(c). Typical tensile stress-strain curves for clad 7475-T61 aluminum alloy sheet at room temperature.

Figure 3.7.10.1.6(e) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.1.6(e). Typical tensile stress-strain curves for 7475-T651 aluminum alloy plate at room temperature.

Figures 3.7.10.1.6(b), (d), (f) (companion compressive stress-strain/tangent-modulus curves for bare sheet, clad sheet, and plate) and 3.7.10.1.6(g) (full-range tensile curve for T61 sheet) pending digitization via WebPlotDigitizer (MIL-HDBK-5J pp. 3-463–3-466).

Figure 3.7.10.1.8(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.1.8(a). Best-fit S/N curve for unnotched 7475-T61 and T761 sheet, thickness 0.125 inch, longitudinal and long transverse directions.

Figure 3.7.10.1.8(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.1.8(b). Best-fit S/N curve for unnotched 7475-T61 and T761 sheet, thickness > 0.125 inch, longitudinal and long transverse directions.

Figure 3.7.10.1.8(c) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.1.8(c). Best-fit S/N curve for notched, K_t = 3.0, 7475-T61 and T761 sheet, longitudinal and long transverse directions.

Figures 3.7.10.1.10(a) through (d) — residual strength behavior of 0.063-inch-thick bare and clad 7475-T61 sheet, crack orientations L-T and T-L — pending digitization via WebPlotDigitizer (MIL-HDBK-5J pp. 3-470–3-471).

3.7.10.2T7351 Temper

Figures 3.7.10.2.6(a) and (b) present tensile and compressive stress-strain and tangent-modulus curves for T7351 plate. Fatigue data for 7475-T7351 plate are presented in Figures 3.7.10.2.8(a) and (b); Figure 3.7.10.2.8(b) also covers 7475-T7651 plate. Figures 3.7.10.2.9(a) and (b) present fatigue-crack-propagation data for T7351 plate.

Figure 3.7.10.2.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.2.6(a). Typical tensile stress-strain curves for 7475-T7351 aluminum alloy plate at room temperature.

Figure 3.7.10.2.6(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.2.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for 7475-T7351 aluminum alloy plate at room temperature.

Figure 3.7.10.2.8(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.2.8(a). Best-fit S/N curves for unnotched 7475-T7351 plate, longitudinal and long transverse orientation.

Figure 3.7.10.2.8(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.2.8(b). Best-fit S/N curves for notched, K_t = 3.0, 7475-T7351 and T7651 plate, longitudinal and long transverse direction.

Figures 3.7.10.2.9(a) and (b) — fatigue-crack-propagation data for 1.5-inch-thick (lab air) and 0.5-inch-thick (95% R.H.) 7475-T7351 plate — pending digitization via WebPlotDigitizer (MIL-HDBK-5J pp. 3-476–3-477).

3.7.10.3T761 and T7651 Tempers

Figures 3.7.10.3.6(a) through (j) present tensile and compressive stress-strain and tangent-modulus curves for T761 bare and clad sheet (in three thickness ranges: 0.040–0.062, 0.063–0.187, and 0.188–0.249 inch) and T7651 plate. Figures 3.7.10.3.6(k) and (l) contain full-range tensile stress-strain curves for T761 bare and clad sheet, respectively. Fatigue data for 7475-T761 sheet are presented in Figures 3.7.10.1.8(a) through (c) (Section 3.7.10.1); fatigue data for 7475-T7651 plate are shown in Figure 3.7.10.2.8(b) (Section 3.7.10.2). Graphical displays of the residual strength behavior of middle-tension panels are presented in Figures 3.7.10.3.10(a) and (b).

Figure 3.7.10.3.6(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.3.6(a). Typical tensile stress-strain curves for 7475-T761 aluminum alloy sheet at room temperature.

Figure 3.7.10.3.6(i) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.3.6(i). Typical tensile stress-strain curves for 7475-T7651 aluminum alloy plate at room temperature.

Figures 3.7.10.3.6(b), (c)–(h), and (j) (companion compressive curves for bare T761 sheet, tensile/compressive curves for clad T761 sheet at three thickness ranges, and compressive curves for T7651 plate) and 3.7.10.3.6(k)–(l) (full-range tensile curves for bare and clad T761 sheet) pending digitization via WebPlotDigitizer (MIL-HDBK-5J pp. 3-478–3-484).

Figure 3.7.10.3.10(a) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.3.10(a). Residual strength behavior of 0.063-inch-thick 7475-T761 aluminum alloy sheet at room temperature. Crack orientation is L-T.

Figure 3.7.10.3.10(b) Pending digitization via WebPlotDigitizer.

Figure 3.7.10.3.10(b). Residual strength behavior of 0.063-inch-thick 7475-T761 aluminum alloy sheet at room temperature. Crack orientation is T-L.

Other MIL-HDBK-5 Chapters

Chapter 2 (Steel) Chapter 4 (Magnesium)

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