MIL-HDBK-5: Chapter 5.3 — Titanium
Chapter 5.3 Contents
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Chapter 1 — General Chapter 2 — Steel Chapter 3 — Aluminum Chapter 4 — Magnesium Chapter 5 — Titanium 5.1 — General 5.2 — Unalloyed Titanium 5.3 — Alpha and Near-Alpha Titanium Alloys 5.4 — Alpha-Beta Titanium Alloys 5.5 — Beta, Near-Beta, and Metastable-Beta Titanium Alloys 5.6 — Element Properties Chapter 6 — Heat-Resistant Alloys
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).

Figures and Tables
Table of Tables
Table 5.3.1.0(a)Material Specifications for Ti-5Al-2.5Sn Table 5.3.1.0(b)Design Mechanical and Physical Properties of Ti-5Al-2.5Sn Sheet, Strip, and Plate Table 5.3.1.0(c)Design Mechanical and Physical Properties of Ti-5Al-2.5Sn Bar and Forging Table 5.3.1.0(d)Design Mechanical and Physical Properties of Ti-5Al-2.5Sn Extrusion Table 5.3.2.0(a)Material Specifications for Ti-8Al-1Mo-1V Table 5.3.2.0(b1)Design Mechanical and Physical Properties of Ti-8Al-1Mo-1V Sheet and Plate Table 5.3.2.0(b2)Design Mechanical and Physical Properties of Ti-8Al-1Mo-1V Sheet and Plate Table 5.3.2.0(c)Design Mechanical and Physical Properties of Ti-8Al-1Mo-1V Bar and Forging Table 5.3.3.0(a)Material Specifications for Ti-6Al-2Sn-4Zr-2Mo Table 5.3.3.0(b)Design Mechanical and Physical Properties of Ti-6Al-2Sn-4Zr-2Mo Sheet Table 5.3.3.0(c)Design Mechanical and Physical Properties of Ti-6Al-2Sn-4Zr-2Mo Bar and Forging
Table of Figures
Fig 5.3.1.0Effect of temperature on the physical properties of Ti-5Al-2.5Sn alloy. Fig 5.3.1.1.1Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of annealed Ti-5Al-2.5Sn alloy sheet. Fig 5.3.1.1.2Effect of temperature on the compressive yield strength (Fcy) and the shear ultimate strength (Fsu) of annealed Ti-5Al-2.5Sn alloy sheet. Fig 5.3.1.1.3Effect of temperature on the bearing ultimate strength (Fbru) and the bearing yield strength (Fbry) of annealed Ti-5Al-2.5Sn alloy sheet. Fig 5.3.1.1.4Effect of temperature on the tensile and compressive moduli (E and Ec) of annealed Ti-5Al-2.5Sn alloy sheet. Fig 5.3.1.1.5Effect of temperature on the elongation (e) of annealed Ti-5Al-2.5Sn alloy sheet. Fig 5.3.1.1.9(a)Fatigue-crack-propagation data for 0.084-inch-thick Ti-5Al-2.5Sn titanium alloy mill-annealed sheet. Environment: Lab air. [Reference 5.3.1.1.9] Fig 5.3.1.1.9(b)Fatigue-crack-propagation data for 0.084-inch-thick Ti-5Al-2.5Sn titanium alloy mill-annealed sheet. Environment: Distilled water. [Reference 5.3.1.1.9] Fig 5.3.1.1.9(c)Fatigue-crack-propagation data for 0.084-inch-thick Ti-5Al-2.5Sn titanium alloy mill-annealed sheet. Environment: 3.5% NaCl. [Reference 5.3.1.1.9] Fig 5.3.2.0Effect of temperature on the physical properties of Ti-8Al-1Mo-1V alloy. Fig 5.3.2.1.1Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of single-annealed Ti-8Al-1Mo-1V alloy sheet. Fig 5.3.2.1.4Effect of temperature on the tensile and compressive moduli (E and Ec) of Ti-8Al-1Mo-1V alloy sheet. Fig 5.3.2.1.6(a)Typical tensile stress-strain curves for single-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures. Fig 5.3.2.1.6(b)Typical compressive stress-strain and compressive tangent-modulus curves for single-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures.
Table of Figures (cont.)
Fig 5.3.2.2.1Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of duplex-annealed Ti-8Al-1Mo-1V alloy sheet. Fig 5.3.2.2.6(a)Typical tensile stress-strain curves for duplex-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures. Fig 5.3.2.2.6(b)Typical compressive stress-strain and compressive tangent-modulus curves for duplex-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures. Fig 5.3.2.2.8(a)Best-fit S/N curves for unnotched, duplex annealed Ti-8Al-1Mo-1V sheet at room temperature, long transverse direction. Fig 5.3.2.2.8(b)Best-fit S/N curves for notched, Kt = 2.6, duplex annealed Ti-8Al-1Mo-1V sheet at room temperature, long transverse direction. Fig 5.3.2.2.8(c)Best-fit S/N curves for unnotched duplex annealed Ti-8Al-1Mo-1V sheet at 400°F, long transverse direction. Fig 5.3.2.2.8(d)Best-fit S/N curves for notched, Kt = 2.6, duplex annealed Ti-8Al-1Mo-1V sheet at 400°F, long transverse direction. Fig 5.3.2.2.8(e)Best-fit S/N curves for unnotched duplex annealed Ti-8Al-1Mo-1V sheet at 650°F, long transverse direction. Fig 5.3.2.2.8(f)Best-fit S/N curves for notched, Kt = 2.6, duplex annealed Ti-8Al-1Mo-1V sheet at 650°F, long transverse direction. Fig 5.3.3.0Effect of temperature on the physical properties of Ti-6Al-2Sn-4Zr-2Mo alloy. Fig 5.3.3.1.1Effect of temperature in the tensile ultimate strength (Ftu) and tensile yield strength (Fty) of duplex- and triplex-annealed Ti-6Al-2Sn-4Zr-2Mo (all products). Fig 5.3.3.1.2Effect of temperature on the compressive yield strength (Fcy) of duplex annealed Ti-6Al-2Sn-4Zr-2Mo alloy sheet. Fig 5.3.3.1.4Effect of temperature on the tensile and compressive moduli (E and Ec) of duplex- and triplex-annealed Ti-6Al-2Sn-4Zr-2Mo alloy. Fig 5.3.3.1.6(a)Typical tensile stress-strain curves for duplex annealed Ti-6Al-2Sn-4Zr-2Mo alloy bar at various temperatures. Fig 5.3.3.1.6(b)Typical tensile stress-strain curves for duplex- and triplex-annealed Ti-6Al-2Sn-4Zr-2Mo alloy sheet at various temperatures. Fig 5.3.3.1.6(c)Typical tensile stress-strain curves (full range) for duplex-annealed Ti-6Al-2Sn-4Zr-2Mo alloy sheet at room and elevated temperatures.
5.3Alpha and Near-Alpha Titanium Alloys

The alpha titanium alloys contain essentially a single phase at room temperature, similar to that of unalloyed titanium. Alloys identified as near-alpha titanium have principally an all-alpha structure but contain small quantities of a beta phase because the composition contains some beta stabilizing elements. In both alloy types, alpha phase is stabilized by aluminum, tin, and zirconium. These elements, especially aluminum, contribute greatly to strength. The beta stabilizing additions (e.g., molybdenum and vanadium) improve fabricability and metallurgical stability of highly alpha-alloyed materials.

All alpha alloys have excellent weldability, toughness at low temperatures, and long-term elevated-temperature strength. They are well suited to cryogenic applications and to uses requiring good elevated-temperature creep strength. The characteristics of near-alpha alloys are predictably between those of all alpha and alpha-beta alloys in regard to fabricability, weldability, and elevated-temperature strength. The hot workability of both alpha and near-alpha alloys is inferior to that of the alpha-beta or beta alloys and the cold workability is very limited at the high-strength level of these grades. However, considerable forming is possible if correct forming temperatures and procedures are used.

5.3.1Ti-5Al-2.5Sn
5.3.1.0Comments and Properties

Ti-5Al-2.5Sn is an all-alpha alloy available in many product forms and at two purity levels. The high purity grade of this composition is used principally for cryogenic applications and may be characterized as having lower strength but higher ductility and toughness than the standard grade. The normal purity grade also may be used at low temperatures but it is primarily suitable for room to elevated temperature applications (up to 900°F or to 1100°F for short times) where weldability is an important consideration.

Manufacturing Considerations — Ti-5Al-2.5Sn is not so readily formed into complex shapes as other alloys with similar room-temperature properties, but far surpasses them in weldability. Except for some forging operations, fabrication of Ti-5Al-2.5Sn is conducted at temperatures where the structure remains all alpha. Severe forming operations may be accomplished at temperatures up to 1200°F. Moderately severe forming can be done at 300 to 600°F and simple forming may be done at room temperature. Most forming and welding operations are followed by an annealing treatment to relieve residual stresses imposed by the prior operation.

Ti-5Al-2.5Sn can be welded readily by inert-gas or vacuum-shielded arc methods or by spot or seam welding without atmospheric shielding. Brazing requires protection from the atmosphere; however, this is accomplished by fluxing as well as by inert gas or vacuum shielding.

Environmental Considerations — Ti-5Al-2.5Sn is metallurgically stable at moderate elevated temperatures. The material is susceptible to hot-salt stress corrosion as well as aqueous chloride solution stress corrosion. Care should be exercised in applications involving such environments. The alloy has good oxidation resistance up to 1050°F. Standard grade material has been used at moderately low cryogenic temperatures; however, the ELI grade has higher toughness and has been used in cryogenic applications down to −423°F. Under certain conditions, titanium, when in contact with cadmium, silver, mercury, or certain of their compounds, may become embrittled. Refer to MIL-HDBK-1568 for restrictions concerning applications with titanium in contact with these metals or their compounds.

Heat Treatment — This alloy is annealed by heating 1400°F for 60 minutes and 1600°F for 10 minutes and cooling in air. Stress relieving requires 1 or 2 hours at 1000 to 1200°F. Ti-5Al-2.5Sn cannot be hardened by heat treatment.

Specifications and Properties — Some material specifications for Ti-5Al-2.5Sn are shown in Table 5.3.1.0(a). Room-temperature mechanical properties for Ti-5Al-2.5Sn are shown in Tables 5.3.1.0(b) through (d). The effect of temperature on physical properties is shown in Figure 5.3.1.0.

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Table 5.3.1.0(a). Material Specifications for Ti-5Al-2.5Sn
SpecificationForm
AMS-T-9046Sheet, strip, and plate
AMS 4926Bar
MIL-T-9047aBar
AMS-T-81556Extruded bar and shapes
AMS 4910Sheet, strip, and plate
AMS 4966Forging
a Inactive for new design
5.3.1.1Annealed Condition

Elevated temperature curves for annealed Ti-5Al-2.5Sn are shown in Figures 5.3.1.1.1 through 5.3.1.1.5. Tensile properties cover the range −423°F to 1000°F; whereas other properties are for the range room temperature to 1000°F. Fatigue-crack-propagation data for sheet are shown in Figures 5.3.1.1.9(a) through (c).

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Table 5.3.1.0(b). Design Mechanical and Physical Properties of Ti-5Al-2.5Sn Sheet, Strip, and Plate
SpecificationAMS 4910 and AMS-T-9046, Comp. A-1
FormStripSheetPlate
ConditionAnnealed
Thickness, in.<0.1870.015-
0.079		0.080-
0.187		0.188-
0.250		0.251-
1.500		1.501-
4.000
BasisSABABABSS
Mechanical Properties:
Ftu, ksi:
L120120a128120a131120a135120115
LT120120a129120a132120a137120115
Fty, ksi:
L113110115113118113a123113110
LT113113118113a121113a125113110
Fcy, ksi:
L115115120118123118128118···
LT118118123118126118130118···
Fsu, ksi7575807582758575···
Fbru, ksi:
(e/D = 1.5)167167179167183167190167···
(e/D = 2.0)250250268250275250285250···
Fbry, ksi:
(e/D = 1.5)133133139133142133147133···
(e/D = 2.0)190190198190203190210190···
e, percent (S-basis):
L1010b···10···10···1010
LT1010b···10···10···1010
E, 103 ksi15.5
Ec, 103 ksi15.5
G, 103 ksi···
μ···
Physical Properties:
ω, lb/in.30.162
C, K, and αSee Figure 5.3.1.0
a S-basis. The rounded T99 values are higher than specification values as follows:
0.015-0.0790.080-0.1870.188-0.250
Ftu  L123126130
LT123126131
Fty  L······118
LT···115120
b Thickness 0.025 inch and above.
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Table 5.3.1.0(c). Design Mechanical and Physical Properties of Ti-5Al-2.5Sn Bar and Forging
SpecificationAMS 4926a and MIL-T-9047bAMS 4966
FormBarForging
ConditionAnnealedAnnealed
Thickness or diameter, in.≤2.999c3.000-4.000c···
BasisABS
Mechanical Properties:
Ftu, ksi:
L115d126115115
LT115e···115115f
ST······115115f
Fty, ksi:
L110d120110110
LT110e···110110f
ST······110110f
Fcy, ksi:
L············
LT············
Fsu, ksi············
Fbru, ksi:
(e/D = 1.5)············
(e/D = 2.0)············
Fbry, ksi:
(e/D = 1.5)············
(e/D = 2.0)············
e, percent (S-basis):
L10···1010
LT10e···1010f
ST······810f
RA, percent (S-basis):
L25···2525
LT25e···2525f
ST······2025f
E, 103 ksi15.5
Ec, 103 ksi15.5
G, 103 ksi···
μ···
Physical Properties:
ω, lb/in.30.162
C, K, and αSee Figure 5.3.1.0
a For AMS 4926, LT and ST values for e and RA may be different than those shown.
b Inactive for new design.
c Maximum of 16-square-inch cross-sectional area.
d The rounded T99 values are higher than S values as follows: Ftu = 117 ksi, Fty = 113 ksi.
e S-basis. Applicable providing LT dimension is >3.000 inches.
f Applicable, providing LT or ST dimension is ≥2.500 inches.
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Table 5.3.1.0(d). Design Mechanical and Physical Properties of Ti-5Al-2.5Sn Extrusion
SpecificationAMS-T-81556, Comp. A-1
FormExtruded bars and shapes
ConditionAnnealed
Thickness or diameter, in.0.188-
1.000		1.001-
2.000		2.001-
3.000		3.001-
4.000
BasisSSSS
Mechanical Properties:
Ftu, ksi:
L120115115115
LT············
Fty, ksi:
L115110110110
LT············
Fcy, ksi:
L············
LT············
Fsu, ksi············
Fbru, ksi:
(e/D = 1.5)············
(e/D = 2.0)············
Fbry, ksi:
(e/D = 1.5)
(e/D = 2.0)
e, percent:
L101086
LT············
E, 103 ksi15.5
Ec, 103 ksi15.5
G, 103 ksi···
μ···
Physical Properties:
ω, lb/in.30.162
C, K, and αSee Figure 5.3.1.0
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C

α

Figure 5.3.1.0. Effect of temperature on the physical properties of Ti-5Al-2.5Sn alloy.

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Figure 5.3.1.1.1. Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of annealed Ti-5Al-2.5Sn alloy sheet.

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Figure 5.3.1.1.2. Effect of temperature on the compressive yield strength (Fcy) and the shear ultimate strength (Fsu) of annealed Ti-5Al-2.5Sn alloy sheet.

Figure 5.3.1.1.3. Effect of temperature on the bearing ultimate strength (Fbru) and the bearing yield strength (Fbry) of annealed Ti-5Al-2.5Sn alloy sheet.

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Figure 5.3.1.1.4. Effect of temperature on the tensile and compressive moduli (E and Ec) of annealed Ti-5Al-2.5Sn alloy sheet.

Figure 5.3.1.1.5. Effect of temperature on the elongation (e) of annealed Ti-5Al-2.5Sn alloy sheet.

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Figure 5.3.1.1.9(a). Fatigue-crack-propagation data for 0.084-inch-thick Ti-5Al-2.5Sn titanium alloy mill-annealed sheet. Specimen Thickness: 0.08 inch; Specimen Width: 2.76 inches; Specimen Type: M(T); Environment: Lab air; Temperature: RT; Orientation: L-T and T-L. [Reference 5.3.1.1.9]

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Figure 5.3.1.1.9(b). Fatigue-crack-propagation data for 0.084-inch-thick Ti-5Al-2.5Sn titanium alloy mill-annealed sheet. Specimen Thickness: 0.08 inch; Specimen Width: 2.76 inches; Specimen Type: M(T); Environment: Distilled water; Temperature: RT; Orientation: L-T and T-L. [Reference 5.3.1.1.9]

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Figure 5.3.1.1.9(c). Fatigue-crack-propagation data for 0.084-inch-thick Ti-5Al-2.5Sn titanium alloy mill-annealed sheet. Specimen Thickness: 0.08 inch; Specimen Width: 2.76 inches; Specimen Type: M(T); Environment: 3.5% NaCl; Temperature: RT; Orientation: L-T and T-L. [Reference 5.3.1.1.9]

5.3.2Ti-8Al-1Mo-1V
5.3.2.0Comments and Properties

Ti-8Al-1Mo-1V alloy is a near-alpha composition developed for improved creep resistance and thermal stability up to about 850°F. The alloy is available as billet, bar, plate, sheet, strip, extrusions, and forgings.

Manufacturing Considerations — Room temperature forming of Ti-8Al-1Mo-1V sheet is somewhat more difficult than in Ti-6Al-4V, and for severe operations hot forming is required. Ti-8Al-1Mo-1V can be fusion welded readily with inert-gas protection or spot welding without atmospheric protection. Weld strengths are comparable to those of the parent metal although ductility is somewhat lower in the weldment.

Environmental Considerations — Ti-8Al-1Mo-1V exhibits good oxidation resistance and thermal stability up to 850°F. A decrease in tensile elongation has been reported for single-annealed sheet following 150 hours stressed exposure at 1000°F. Extended exposure to temperatures exceeding 600°F adversely affects room-temperature spot-weld tension strength. This alloy is not recommended for structural applications at liquid-hydrogen temperatures (−423°F). The Ti-8Al-1Mo-1V alloy also is susceptible to chloride stress-corrosion attack in either elevated-temperature (hot-salt stress-corrosion) or ambient-temperature (aqueous stress-corrosion) chloride environments. Thus, care should be exercised in applying the material in chloride containing environments. Under certain conditions, titanium, when in contact with cadmium, silver, mercury, or certain of their compounds, may become embrittled. Refer to MIL-S-5002 and MIL-STD-1568 for restrictions concerning applications with titanium in contact with these metals or their compounds.

Heat Treatment — Three treatments are used with Ti-8Al-1Mo-1V. These are:

Single Anneal: 1450°F for 8 hours, furnace cool.

Duplex Anneal: 1450°F for 8 hours, furnace cool, followed by 1450°F for 15 to 20 minutes, air cool.

Solution Treated and Stabilized: 1825°F for 1 hour, air cool, 1075°F for 8 hours, air cool.

As a general guide, the single anneal is used to obtain highest room-temperature mechanical properties and the duplex anneal to obtain highest fracture toughness. Both the single anneal and the duplex anneal are compatible with hot-forming operations. The solution treated and stabilized condition is used for forgings.

Specifications and Properties — Material specifications for Ti-8Al-1Mo-1V are presented in Table 5.3.2.0(a). Room-temperature mechanical and physical properties for Ti-8Al-1Mo-1V are shown in Tables 5.3.2.0(b) and (c). The effect of temperature on physical properties is shown in Figure 5.3.2.0.

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Table 5.3.2.0(a). Material Specifications for Ti-8Al-1Mo-1V
SpecificationForm
AMS-T-9046Sheet, strip, and plate
MIL-T-9047Bar
AMS 4973Forging
AMS 4915Sheet, strip, and plate
AMS 4916Sheet, strip, and plate
5.3.2.1Single-Annealed Condition

Cryogenic, room-temperature, and elevated temperature property curves for this condition are shown in Figures 5.3.2.1.1 and 5.3.2.1.4. Typical tensile and compressive stress-strain and tangent-modulus curves are shown in Figures 5.3.2.1.6(a) and (b) for room temperature and several elevated temperatures.

5.3.2.2Duplex-Annealed Condition

Cryogenic, room temperature, and elevated temperature curves for this condition are shown in Figure 5.3.2.2.1. Typical tensile and compressive stress-strain and tangent-modulus curves are shown in Figures 5.3.2.2.6(a) and (b) for room temperature and several elevated temperatures. Fatigue S/N curves for unnotched and notched specimens at room temperature and several elevated temperatures are shown in Figures 5.3.2.2.8(a) through (f).

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α

Figure 5.3.2.0. Effect of temperature on the physical properties of Ti-8Al-1Mo-1V alloy.

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Table 5.3.2.0(b1). Design Mechanical and Physical Properties of Ti-8Al-1Mo-1V Sheet and Plate
SpecificationAMS 4915, AMS-T-9046, and Comp A-4
FormSheetPlate
ConditionSingle Annealed
Thickness, in.≤0.18750.1875-
0.500		0.501-
1.000		1.001-
2.500		2.501-
4.000
BasisSSSSS
Mechanical Properties:
Ftu, ksi:
L145145140130120
LT145145140130120
ST············120b
Fty, ksi:
L135135130120110
LT135135130120110
ST············110b
Fcy, ksi:
L144············
LT149············
ST···············
Fsu, ksi93············
Fbru, ksi:
(e/D = 1.5)239············
(e/D = 2.0)294············
Fbry, ksi:
(e/D = 1.5)196············
(e/D = 2.0)214············
e, percent:
La1010108
LTa1010108
ST············8b
E, 103 ksi17.5c
Ec, 103 ksi18.0c
G, 103 ksi6.7
μ0.32
Physical Properties:
ω, lb/in.30.158
C, Btu/(lb)(°F)0.12
K and αSee Figure 5.3.2.0
a 0.008-0.014 in. thickness, 6 percent; 0.015-0.024 in. thickness, 8 percent; > 0.025 in. thickness, 10 percent.
b Applicable, providing ST dimension is > 3.000 inches.
c Average, values may vary with test direction.
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Table 5.3.2.0(b2). Design Mechanical and Physical Properties of Ti-8Al-1Mo-1V Sheet and Plate
SpecificationAMS 4916, AMS-T-9046, and Comp A-4
FormSheetPlate
ConditionDuplex Annealed
Thickness, in.0.015-0.0240.025-0.18750.1875-0.5000.501-1.0001.001-2.0002.001-4.000
BasisSSSSSS
Mechanical Properties:
Ftu, ksi:
L135135130130125120
LT135135130130125120
Fty, ksi:
L120120120120115110
LT120120120120115110
Fcy, ksi:
L126126············
LT126126············
Fsu, ksi8484············
Fbru, ksi:
(e/D = 1.5)223223············
(e/D = 2.0)269269············
Fbry, ksi:
(e/D = 1.5)174174············
(e/D = 2.0)191191············
e, percent:
L8101010108
LT8101010108
E, 103 ksi17.5a
Ec, 103 ksi18.0a
G, 103 ksi6.7
μ0.32
Physical Properties:
ω, lb/in.30.158
C, Btu/(lb)(°F)0.12
K and αSee Figure 5.3.2.0
a Average, L and LT; values may vary with test direction.
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Table 5.3.2.0(c). Design Mechanical and Physical Properties of Ti-8Al-1Mo-1V Bar and Forging
SpecificationMIL-T-9047AMS 4973
FormBarForging
ConditionDuplex annealedSolution treated and stabilized
Thickness or diameter, in.≤2.500a2.501-4.000a≤2.4992.500-4.000
BasisSSSS
Mechanical Properties:
Ftu, ksi:
L130120130120
LT130b120b130c120
ST···120b···120
Fty, ksi:
L120110120110
LT120b110b120c110
ST···110b···110
Fcy, ksi:
L············
LT············
ST············
Fsu, ksi············
Fbru, ksi:
(e/D = 1.5)············
(e/D = 2.0)············
Fbry, ksi:
(e/D = 1.5)············
(e/D = 2.0)············
e, percent:
L10101010
LT10b10b10c10
ST···8b···10
E, 103, ksi17.5d
Ec, 103 ksi18.0d
G, 103 ksi6.7
μ0.32
Physical Properties:
ω, lb/in.30.158
C, Btu/(lb)(°F)0.12
K and αSee Figure 5.3.2.0
a Maximum of 16 square-inch cross-sectional area.
b Applicable, providing LT or ST dimension is > 3.000 inches.
c Applicable, providing LT dimension is ≥ 2.500 inches.
d Average, values may vary with test direction.
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Figure 5.3.2.1.1. Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of single-annealed Ti-8Al-1Mo-1V alloy sheet.

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Figure 5.3.2.1.4. Effect of temperature on the tensile and compressive moduli (E and Ec) of Ti-8Al-1Mo-1V alloy sheet.

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Figure 5.3.2.1.6(a). Typical tensile stress-strain curves for single-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures.

Compressive Stress-Strain

Compressive Tangent Modulus

Figure 5.3.2.1.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for single-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures.

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Figure 5.3.2.2.1. Effect of temperature on the tensile ultimate strength (Ftu) and the tensile yield strength (Fty) of duplex-annealed Ti-8Al-1Mo-1V alloy sheet.

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Figure 5.3.2.2.6(a). Typical tensile stress-strain curves for duplex-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures.

Compressive Stress-Strain

Compressive Tangent Modulus

Figure 5.3.2.2.6(b). Typical compressive stress-strain and compressive tangent-modulus curves for duplex-annealed Ti-8Al-1Mo-1V alloy sheet at room and elevated temperatures.

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Figure 5.3.2.2.8(a)Not digitized in this pass.

Figure 5.3.2.2.8(a). Best-fit S/N curves for unnotched, duplex annealed Ti-8Al-1Mo-1V sheet at room temperature, long transverse direction.

Correlative Information for Figure 5.3.2.2.8(a)

Product Form: Sheet, 0.050 inch thick

Properties: TUS 147.2 ksi, TYS 135.6 ksi, RT

Specimen Details: Unnotched
0.750 inch net width

Surface Condition: HNO3/HF pickled

References: 5.3.2.2.8(a) and (b)

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

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log Nf = 10.57 − 3.46 log (Seq − 66.7)
Seq = Smax(1−R)0.61
Std. Error of Estimate, Log (Life) = 0.47
Standard Deviation, Log (Life) = 0.81
R2 = 66.7%

Sample Size: 24

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]
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Figure 5.3.2.2.8(b)Not digitized in this pass.

Figure 5.3.2.2.8(b). Best-fit S/N curves for notched, Kt = 2.6, duplex annealed Ti-8Al-1Mo-1V sheet at room temperature, long transverse direction.

Correlative Information for Figure 5.3.2.2.8(b)

Product Form: Sheet, 0.050 inch thick

Properties: TUS 147.2 ksi, TYS 135.6 ksi, RT
Unnotched

Specimen Details: Notched, hole type, Kt = 2.6
1.500 inch, gross width
1.250 inch, net width
0.250 inch, diameter hole

Surface Condition: HNO3/HF pickled

References: 5.3.2.2.8(a) and (b)

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

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log Nf = 14.49 − 5.90 log (Seq − 12.7)
Seq = Smax(1−R)0.55
Std. Error of Estimate, Log (Life) = 0.33
Standard Deviation, Log (Life) = 1.10
R2 = 90.9%

Sample Size: 26

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]
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Figure 5.3.2.2.8(c)Not digitized in this pass.

Figure 5.3.2.2.8(c). Best-fit S/N curves for unnotched duplex annealed Ti-8Al-1Mo-1V sheet at 400°F, long transverse direction.

Correlative Information for Figure 5.3.2.2.8(c)

Product Form: Sheet, 0.050 inch thick

Properties: TUS 119.5 ksi, TYS 100.8 ksi, 400°F

Specimen Details: Unnotched
0.750 inch net width

Surface Condition: HNO3/HF pickled

References: 5.3.2.2.8(a) and (b)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – 400°F
Environment – Air

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log Nf = 8.30 − 2.53 log (Seq − 73.9)
Seq = Smax(1−R)0.74
Std. Error of Estimate, Log (Life) = 0.38
Standard Deviation, Log (Life) = 0.87
R2 = 80.9%

Sample Size: 23

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]
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Figure 5.3.2.2.8(d)Not digitized in this pass.

Figure 5.3.2.2.8(d). Best-fit S/N curves for notched, Kt = 2.6, duplex annealed Ti-8Al-1Mo-1V sheet at 400°F, long transverse direction.

Correlative Information for Figure 5.3.2.2.8(d)

Product Form: Sheet, 0.050 inch thick

Properties: TUS 119.5 ksi, TYS 100.8 ksi, 400°F
Unnotched

Specimen Details: Notched, hole type, Kt = 2.6
1.500 inch, gross width
1.250 inch, net width
0.250 inch, diameter hole

Surface Condition: HNO3/HF pickled

References: 5.3.2.2.8(a) and (b)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – 400°F
Environment – Air

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log Nf = 13.39 − 5.68 log (Seq − 18.7)
Seq = Smax(1−R)0.46
Std. Error of Estimate, Log (Life) = 0.41
Standard Deviation, Log (Life) = 1.16
R2 = 87.2%

Sample Size: 20

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]
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Figure 5.3.2.2.8(e)Not digitized in this pass.

Figure 5.3.2.2.8(e). Best-fit S/N curves for unnotched duplex annealed Ti-8Al-1Mo-1V sheet at 650°F, long transverse direction.

Correlative Information for Figure 5.3.2.2.8(e)

Product Form: Sheet, 0.050 inch thick

Properties: TUS 110.2 ksi, TYS 86.8 ksi, 650°F

Specimen Details: Unnotched
0.750 inch, net width

Surface Condition: HNO3/HF pickled

References: 5.3.2.2.8(a) and (b)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – 650°F
Environment – Air

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log Nf = 9.83 − 3.66 log (Seq − 73)
Seq = Smax(1−R)0.78
Std. Error of Estimate, Log (Life) = 0.88
Standard Deviation, Log (Life) = 1.18
R2 = 44.3%

Sample Size: 20

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]
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Figure 5.3.2.2.8(f)Not digitized in this pass.

Figure 5.3.2.2.8(f). Best-fit S/N curves for notched, Kt = 2.6, duplex annealed Ti-8Al-1Mo-1V sheet at 650°F, long transverse direction.

Correlative Information for Figure 5.3.2.2.8(f)

Product Form: Sheet, 0.050 inch thick

Properties: TUS 110.2 ksi, TYS 86.8 ksi, 650°F
Unnotched

Specimen Details: Notched, hole type, Kt = 2.6
1.500 inch, gross width
1.250 inch, net width
0.250 inch, diameter hole

Surface Condition: HNO3/HF pickled

References: 5.3.2.2.8(a) and (b)

Test Parameters:
Loading – Axial
Frequency – 1800 cpm
Temperature – 650°F
Environment – Air

No. of Heats/Lots: 1

Equivalent Stress Equation:
Log Nf = 10.16 − 3.88 log (Seq − 23)
Seq = Smax(1−R)0.69
Std. Error of Estimate, Log (Life) = 0.38
Standard Deviation, Log (Life) = 0.65
R2 = 66.0%

Sample Size: 22

[Caution: The equivalent stress model may provide unrealistic life predictions for stress ratios beyond those represented above.]
5.3.3Ti-6Al-2Sn-4Zr-2Mo
5.3.3.0Comments and Properties

Ti-6Al-2Sn-4Zr-2Mo is a near-alpha titanium composition developed for improved elevated-temperature performance. The alloy has a titanium-aluminum base that is solid solution strengthened by additions of tin and zirconium. Molybdenum improves both room and elevated temperature strength, creep and thermal stability. Introduction of this alloy initially met the requirements for certain advanced performance gas turbine engine applications. Some of the more recent applications, however, require better creep strength than the alloy initially provided. Development work showed that a small addition of silicon, approximately 0.08 percent, substantially improved the creep strength of the alloy without significantly affecting the thermal stability. The alloy is creep resistant and relatively stable to about 1050°F. Creep and thermal stability of the alloy are further enhanced by solution treating high in the alpha-beta phase field. The alloy is available in bar, billet, plate, sheet, strip, and extrusions.

Manufacturing Conditions — Forging of Ti-6Al-2Sn-4Zr-2Mo at temperatures below the beta transus temperature is recommended. For optimum creep properties beta forging or a modification of it is recommended with some loss in ductility to be expected. Elevated temperatures may be used for severe sheet forming operations while room-temperature forming may be used for mild contouring. Stress relief annealing may be combined with a final hot-sizing operation. The material can be welded using TIG or MIG fusion processes to achieve 100 percent joint efficiencies but with limited weld zone ductility. As in welding any titanium alloy, shielding from atmospheric contamination is required except for spot or seam welding.

Environmental Considerations — Ti-6Al-2Sn-4Zr-2Mo is somewhat more resistant to hot-salt cracking than either Ti-8Al-1Mo-1V or Ti-6Al-4V alloys. The material is marginally susceptible to aqueous chloride solution stress-corrosion cracking. Surface oxides formed during exposure to service temperature (~950°F) do not adversely affect properties. Under certain conditions, titanium, when in contact with cadmium, silver, mercury, or certain of their compounds, may become embrittled. Refer to MIL-S-5002 and MIL-STD-1568 for restrictions concerning applications with titanium in contact with these metals or their compounds.

Heat Treatment — Several different annealing treatments, which are described below, are available for Ti-6Al-2Sn-4Zr-2Mo.

For sheet and strip: Duplex Anneal: 1650°F for ½ hour, air cool, followed by 1450°F for ¼ hour, and air cool. Triplex Anneal: 1650°F for ½ hour, air cool, followed by 1450°F for ¼ hour, air cool, followed by 1100°F for 2 hours and air cool.

For plate: Duplex Anneal: 1650°F for 1 hour, air cool, followed by 1100°F for 8 hours and air cool. Triplex Anneal: 1650°F for ½ hour, air cool, followed by 1450°F for ¼ hour, air cool, followed by 1100°F for 2 hours and air cool.

For bars and forgings: Duplex Anneal: Solution anneal 25 to 50°F below beta transus temperature for 1 hour, air cool or faster, followed by 1100°F for 8 hours and air cool.

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Table 5.3.3.0(a). Material Specifications for Ti-6Al-2Sn-4Zr-2Mo
SpecificationForm
AMS-T-9046Sheet and strip
AMS 4975Bar
AMS 4976Forging
AMS 4919Sheet, strip, and plate

Specifications and Properties — Material specifications for Ti-6Al-2Sn-4Zr-2Mo are given in Table 5.3.3.0(a). Room-temperature mechanical and physical properties for Ti-6Al-2Sn-4Zr-2Mo are presented in Table 5.3.3.0(b) and (c). The effect of temperature on physical properties is shown in Figure 5.3.3.0.

5.3.3.1Single, Duplex, and Triplex Annealed

Room and elevated temperature property curves are shown in Figures 5.3.3.1.1, 5.3.3.1.2, and 5.3.3.1.4. Typical stress-strain curves at room and elevated temperatures are shown in Figures 5.3.3.1.6(a) and (b). Full range stress-strain curves at room and elevated temperatures are shown in Figure 5.3.3.1.6(c).

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Table 5.3.3.0(b). Design Mechanical and Physical Properties of Ti-6Al-2Sn-4Zr-2Mo
SpecificationAMS 4919AMS-T-9046, Comp. AB-4
FormSheet
ConditionDuplex annealedTriplex annealed
Thickness or diameter, in.≤0.0460.047-0.0930.094-0.1400.141-0.187≤0.187
BasisABABABABSa
Mechanical Properties:
Ftu, ksi:
L135b143135b143135b143135b143145
LT135b143135b143135b143135b143145
Fty, ksi:
L125c136125c136125c136125c136135
LT125c134125c134125c134125c134135
Fcy, ksi:
L132142132142132142132142···
LT132142132142132142132142···
Fsu, ksi···························
Fbrud, ksi:
(e/D = 1.5)195206205217214227219232···
(e/D = 2.0)217230243258266282279295···
Fbryd, ksi:
(e/D = 1.5)171183171183171183171183···
(e/D = 2.0)202217202217202217202217···
e, percent (S-basis):
L8e···e···10···10···e
LT8e···e···10···10···e
E, 103 ksi16.5
Ec, 103 ksi18.0
G, 103 ksi6.2
μ0.32
Physical Properties:
ω, lb/in.30.164
C, K, and αSee Figure 5.3.3.0
a S-basis values are representative of test specimens excised from duplex annealed material and thermally treated to triplex annealed condition in a laboratory furnace.
b S-basis. The rounded T99 values are as follows: Ftu(L&LT) = 139 ksi.
c S-basis. The rounded T99 values are as follows: Fty(L) = 131 ksi and Fty(LT) = 129 ksi.
d Bearing values are “dry pin” values per Section 1.4.7.1.
e 8% for 0.025 through 0.062 inch and 10% for >0.062 inch.
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Table 5.3.3.0(c). Design Mechanical and Physical Properties of Ti-6Al-2Sn-4Zr-2Mo
SpecificationAMS 4975AMS 4976
FormBarForging
ConditionSTA (Duplex annealed)STA (Duplex annealed)
Cross-Sectional area, in.2≤16≤9
Thickness, or diameter, in.≤3.000≤3.000
BasisABS
Mechanical Properties:
Ftu, ksi:
L130a144130
LT130b···130b
ST130b···130b
Fty, ksi:
L120a131120
LT120b···120b
ST120b···120b
Fcy, ksi:
L·········
LT·········
ST·········
Fsu, ksi·········
Fbru, ksi:
(e/D = 1.5)·········
(e/D = 2.0)·········
Fbry, ksi:
(e/D = 1.5)·········
(e/D = 2.0)·········
e, percent (S basis):
L10···10
LT10b···10b
ST10b···10b
RA, percent (S basis):
L25···25
LT25b···25b
ST25b···25b
E, 103 ksi16.5
Ec, 103 ksi18.0
G, 103 ksi6.2
μ0.32
Physical Properties:
ω, lb/in.30.164
C, K, and αSee Figure 5.3.3.0
a S basis. The rounded T99 values are as follows: Ftu(L) = 138 ksi and Fty(L) = 125 ksi.
b S basis. Applicable providing transverse dimension is ≥2.500 in.
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C

α

Figure 5.3.3.0. Effect of temperature on the physical properties of Ti-6Al-2Sn-4Zr-2Mo alloy.

Figure 5.3.3.1.1. Effect of temperature in the tensile ultimate strength (Ftu) and tensile yield strength (Fty) of duplex- and triplex-annealed Ti-6Al-2Sn-4Zr-2Mo (all products).

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Figure 5.3.3.1.2. Effect of temperature on the compressive yield strength (Fcy) of duplex annealed Ti-6Al-2Sn-4Zr-2Mo alloy sheet.

Figure 5.3.3.1.4. Effect of temperature on the tensile and compressive moduli (E and Ec) of duplex- and triplex-annealed Ti-6Al-2Sn-4Zr-2Mo alloy.

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Figure 5.3.3.1.6(a). Typical tensile stress-strain curves for duplex annealed Ti-6Al-2Sn-4Zr-2Mo alloy bar at various temperatures.

Figure 5.3.3.1.6(b). Typical tensile stress-strain curves for duplex- and triplex-annealed Ti-6Al-2Sn-4Zr-2Mo alloy sheet at various temperatures.

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Figure 5.3.3.1.6(c). Typical tensile stress-strain curves (full range) for duplex-annealed Ti-6Al-2Sn-4Zr-2Mo alloy sheet at room and elevated temperatures.

References
  • 5.3.1.1.9Wanhill, R. J. et al, “Fatigue Crack Propagation Data for Titanium Sheet Alloys”, Interim Report NLR-TR-72093U, National Aerospace Laboratory, The Netherlands (July 1972) (MCIC 88911).
  • 5.3.2.2.8(a)McCulloch, A. J., Melcon, M. A., and Young, L., “Fatigue Behavior of Sheet Materials for the Supersonic Transport, Volume 1—Summary and Analysis of Fatigue and Static Test Data”, Lockheed-California Company, AFML-TR-64-399, Volume 1, January 1965 (MCIC 62421).
  • 5.3.2.2.8(b)McCulloch, A. J., Melcon, M. A., and Young, L., “Fatigue Behavior of Sheet Materials for the Supersonic Transport: Volume 11—Static Test Data, S/N Test Data and S/N Diagrams”, Lockheed-California Company, AFML-TR-64-399, Volume II, January 1965 (MCIC 62422).
Other MIL-HDBK-5 Chapters
Chapter 1 (General) Chapter 2 (Steel) Chapter 3 (Aluminum) Chapter 4 (Magnesium) Chapter 6 (Heat-Resistant Alloys)

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