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Titanium Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed

Heat-treated state

Cheaper as-supplied condition for sheet and plate where full creep optimisation is not required.

High cost $$$$

Values for the Mill Annealed condition

Other Ti-6Al-2Sn-4Zr-2Mo-0.1Si tempers and conditions

Ti-6Al-2Sn-4Zr-2Mo-0.1Si is listed in 7 conditions; see the grade overview at Ti-6Al-2Sn-4Zr-2Mo-0.1Si.

Compare all 7 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
heated above beta transus (~1010–1040 °C), cooled, then stabilised
Transformed (Widmanstätten/basketweave) structure for maximum fracture toughness, creep and crack-growth resistance in discs and casings.8909701232 HRC0.87 % IACS
beta solution treated, cooled and overaged/stabilised (~595–650 °C)
Used for creep- and dwell-fatigue-critical engine hardware where dimensional stability after long hot exposure matters.9001,0001133 HRC0.87 % IACS
As-welded (GTAW/EBW joint, post-weld stress relief 540–650 °C)
Reference condition for fusion-welded rings and cases; joint strength approaches base metal but ductility drops.900980833 HRC0.87 % IACS
Mill AnnealedThis page
790–815 °C, 1–2 h, air cool
Cheaper as-supplied condition for sheet and plate where full creep optimisation is not required.9101,0001431 HRC0.87 % IACS
As-forged + duplex annealed
Typical supply condition for compressor discs, impellers and rings forged below the beta transus.9251,0001432 HRC0.87 % IACS
900–925 °C air cool + 790 °C/8 h stabilise
Standard stocked condition for bar, billet, forgings and sheet: balanced strength, ductility and creep life.9301,0101532 HRC—
Solution treated and aged
Choose when peak room- and mid-temperature strength is needed in thinner sections, accepting lower toughness.1,0001,1001235 HRC—

What is Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed?

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed is Ti-6Al-2Sn-4Zr-2Mo-0.1Si heat treated to Mill Annealed — cheaper as-supplied condition for sheet and plate where full creep optimisation is not required. Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed has a yield strength of 910 MPa (132 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 84% of titanium grades. Elongation at break is 14% and the elastic modulus is 114 GPa (16.5 Msi). Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed has a density of 4.54 g/cm³ (0.164 lb/in³), heavier than 80% of titanium grades. It melts at 1,650°C (3,002 °F). Duplex Annealed is the default condition FabDigit quotes; Mill Annealed is available on request or by drawing note.

Advantages

  • High service temperature — 480°C (896 °F), better than 90% of titanium grades
  • High strength — 910 MPa (132 ksi), better than 84% of titanium grades

Limitations

  • Low electrical conductivity — 0.87 % IACS, worse than 100% of titanium grades
  • Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 96% of titanium grades
  • Difficult to weld — 65/100, worse than 77% of titanium grades

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed properties

Typical room-temperature values for Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed; 22 are specific to this condition. Other listed values are Ti-6Al-2Sn-4Zr-2Mo-0.1Si reference data and may not represent this condition. Bars are the position among titanium grades.

Physical3

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed has a density of 4.54 g/cm³ (0.164 lb/in³), heavier than 80% of titanium grades. It melts at 1,650°C (3,002 °F).

Density4.54 g/cm³0.16 lb/in³
Melting Point (Solidus)1,650°C3,002 °F
Liquidus Temperature1,705°C3,101 °F

Mechanical16

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed has a yield strength of 910 MPa (132 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 84% of titanium grades. Elongation at break is 14% and the elastic modulus is 114 GPa (16.5 Msi).

Elastic (Young's) Modulus114 GPa16.5 Msi
Shear Modulus44.5 GPa6.5 Msi
Bulk Modulus107 GPa15.5 Msi
Poisson's Ratio0.32
Tensile Strength (Ultimate)1,000 MPa145 ksi
Yield Strength (0.2% offset)910 MPa132 ksi
Elongation at Break14%
Reduction in Area30%
Compressive Strength950 MPa138 ksi
Shear Strength615 MPa89.2 ksi
Fatigue Strength (Endurance Limit)500 MPa72.5 ksi
Fracture Toughness (K_IC)50 MPa·√m45.5 ksi·√in
Charpy V-Notch Impact (RT)22 J16.2 ft·lbf
Hardness, Brinell310 HB
Hardness, Rockwell C31 HRC
Hardness, Vickers320 HV

Thermal6

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed is rated for continuous service to 480°C (896 °F). It conducts heat at 7 W/m·K (4.04 BTU/hr·ft·°F), worse than 76% of titanium grades. Thermal expansion is 7.7 µm/m·K (4.28 µin/in·°F).

Thermal Conductivity7 W/m·K4 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)7.7 µm/m·K4.3 µin/in·°F
Latent Heat of Fusion365 J/g157 BTU/lb
Max Service Temperature (continuous)480°C896 °F
Min Service Temperature-196°C-321 °F

Electrical3

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed conducts electricity at 0.87 % IACS, worse than 100% of titanium grades.

Electrical Conductivity0.87 % IACS
Electrical Resistivity1.98×10⁻⁶ Ω·m78 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (85/100), worse than 93% of titanium grades.

Galvanic Potential (seawater, vs SCE)-0.1 V
Corrosion ResistanceExcellent85/100
Chemical Resistance SummaryExcellent in seawater, chlorides, oxidising acids and most organics thanks to a passive oxide film; attacked by HF, hot concentrated HCl/H2SO4 and dry chlorine, and picks up hydrogen in reducing acids. Above ~600 °C in air it oxidises and forms brittle alpha case.

Sustainability4

Producing a kilogram of Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed takes about 680 MJ of energy and emits 40 kg of CO₂ — more than 51% of titanium grades. Typical recycled content is 25%.

Embodied Energy (primary production)680 MJ/kg292,348 BTU/lb
Embodied Carbon (primary production)40 kg CO₂/kg
Embodied Water800 L/kg95.9 gal/lb
Typical Recycled Content25%

Manufacturability8

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed's machinability is poor (19/100, worse than 78% of titanium grades); weldability good (65/100); formability poor (28/100).

MachinabilityPoor19/100
Machinability Rating (AISI 1212 = 100 %)19%
WeldabilityGood65/100
Formability (cold)Poor28/100
CastabilityPoor30/100
Brazeability / SolderabilityFair35/100
PolishabilityVery good70/100
Anodizing Responsefair — decorative/colour (Type II-like) and AMS 2488 Type II conversion anodising work for wear and galling control, but the film is thin and not a hard coating; plasma spray or nitriding preferred for wear duty.

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed

Is Ti-6Al-2Sn-4Zr-2Mo-0.1Si easy to machine?

Machine like a tough near-alpha Ti: rigid setups, sharp uncoated-carbide or PVD-coated tools, low surface speed (~20–40 m/min), heavy positive feed, flood high-pressure coolant, never dwell — work-hardened smearing and chip fires are the main risks.

Can Ti-6Al-2Sn-4Zr-2Mo-0.1Si be welded?

GTAW, plasma, electron-beam and laser welding are practical with full inert-gas or vacuum shielding and clean surfaces; hydrogen/oxygen pickup must be avoided and a 540–650 °C post-weld stress relief is normal.

Can Ti-6Al-2Sn-4Zr-2Mo-0.1Si be formed, bent or molded?

Cold formability is poor; hot form or hot size at 700–870 °C (forge below the ~995–1010 °C beta transus for alpha/beta structure), then chemically mill or grind off alpha case.

What surface finishes work on Ti-6Al-2Sn-4Zr-2Mo-0.1Si?

Grit-blast/pickle to remove alpha case, then conversion anodise (AMS 2488) or shot-peen for fatigue; thermal-spray, nitride or DLC coatings are used for wear and galling since titanium galls against itself.

Ti-6Al-2Sn-4Zr-2Mo-0.1Si chemical composition (wt %)

Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.

ElementSpec limit (wt %)Nominal
Al5.5 – 6.56
Sn1.8 – 2.22
Zr3.6 – 4.44
Mo1.8 – 2.22
Sicreep-strengthening addition that distinguishes the 'S' variant0.06 – 0.10.08
Fe≤ 0.25—
Omax; often 0.10–0.12 for creep grades≤ 0.150.11
C≤ 0.05—
N≤ 0.05—
Hmax (bar/forging)≤ 0.01—
Ymax, aerospace melt cleanliness≤ 0.01—
other, eachresiduals total 0.40 max≤ 0.1—
Tibalance—

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed — frequently asked

What is Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed used for?

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed is typically used for turbine engine compressor discs, compressor blades and blisks, engine casings and spacer rings, forged rings and shafts for engines, high-temperature airframe structure and sheet-metal exhaust and nozzle structures. In short: creep resistant to 510 °C; silicon-modified Ti-6242; hot-section engine alloy.

What is the yield strength of Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed?

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed has a typical yield strength of 910 MPa (132 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 84% of titanium grades. Strength varies by condition: see the 7 listed tempers.

Is Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed easy to machine?

Not especially — machinability is rated poor (19/100, worse than 78% of titanium grades). Machine like a tough near-alpha Ti: rigid setups, sharp uncoated-carbide or PVD-coated tools, low surface speed (~20–40 m/min), heavy positive feed, flood high-pressure coolant, never dwell — work-hardened smearing and chip fires are the main risks.

Can Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed be welded?

Yes — weldability is rated good (65/100). GTAW, plasma, electron-beam and laser welding are practical with full inert-gas or vacuum shielding and clean surfaces; hydrogen/oxygen pickup must be avoided and a 540–650 °C post-weld stress relief is normal.

What surface finishes work on Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed?

Grit-blast/pickle to remove alpha case, then conversion anodise (AMS 2488) or shot-peen for fatigue; thermal-spray, nitride or DLC coatings are used for wear and galling since titanium galls against itself.

Can Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed be formed, bent or molded?

Cold formability is poor; hot form or hot size at 700–870 °C (forge below the ~995–1010 °C beta transus for alpha/beta structure), then chemically mill or grind off alpha case.

What is the maximum service temperature of Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed?

Ti-6Al-2Sn-4Zr-2Mo-0.1Si Mill Annealed is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between Ti-6Al-2Sn-4Zr-2Mo-0.1Si Duplex Annealed and Ti-6Al-2Sn-4Zr-2Mo-0.1Si-STA?

Duplex Annealed is the default condition — standard stocked condition for bar, billet, forgings and sheet: balanced strength, ductility and creep life. STA: choose when peak room- and mid-temperature strength is needed in thinner sections, accepting lower toughness. Yield strength is 930 MPa in Duplex Annealed versus 1,000 MPa in STA.

Sources

  1. AMS 4975 — Ti-6Al-2Sn-4Zr-2Mo bar, forgings and rings — SAE International (2021)
  2. AMS 4919 — Ti-6Al-2Sn-4Zr-2Mo sheet, strip and plate, duplex annealed — SAE International (2017)
  3. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
  4. Materials Properties Handbook: Titanium Alloys — ASM International (1994)
  5. MMPDS — Metallic Materials Properties Development and Standardization — Battelle/FAA (2019)
  6. TIMETAL 6-2-4-2 alloy datasheet — TIMET (2020)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.