Titanium TC11-DA (Duplex annealed)
Heat-treated state
GB TC11
Choose isothermal forging with duplex annealing for disc forgings: it refines and homogenizes the bimodal structure for better thermal stability and low-cycle fatigue life at 980 MPa yield.
Values for the DA condition
Other TC11 tempers and conditions
TC11 is listed in 4 conditions; see the grade overview at TC11.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot worked / as-forged | Take hot-worked or as-forged stock as intermediate billet for later forging or heat treatment; properties scatter and this state is normally not used for finished parts. | 930 | 1,050 | 12 | 33 HRC | 1.1 % IACS |
MDefault Thermomechanically controlled processed | Most common bar and forging supply state, α+β annealed at 950 °C for 1–2 h AC plus 530 °C for 6 h AC, giving the best balance of 960 MPa yield, 13% elongation and structural stability. | 960 | 1,080 | 13 | 34 HRC | — |
DAThis page Duplex annealed | Choose isothermal forging with duplex annealing for disc forgings: it refines and homogenizes the bimodal structure for better thermal stability and low-cycle fatigue life at 980 MPa yield. | 980 | 1,100 | 14 | 35 HRC | 1.1 % IACS |
Solution treated and aged | Pick solution treatment near 950 °C with oil or water quench and ageing at 500–530 °C for small and medium sections needing 1060 MPa yield; ductility and fracture toughness fall. | 1,060 | 1,180 | 10 | 38 HRC | — |
What is TC11-DA?
TC11-DA is TC11 heat treated to DA — choose isothermal forging with duplex annealing for disc forgings: it refines and homogenizes the bimodal structure for better thermal stability and low-cycle fatigue life at 980 MPa yield. TC11-DA has a yield strength of 980 MPa (142 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 91% of titanium grades. Elongation at break is 14% and the elastic modulus is 118 GPa (17.1 Msi). TC11-DA has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,600°C (2,912 °F). M is the default condition FabDigit quotes; DA is available on request or by drawing note.
Advantages
- Stiff — 118 GPa (17.1 Msi), better than 96% of titanium grades
- High service temperature — 500°C (932 °F), better than 94% of titanium grades
- High strength — 980 MPa (142 ksi), better than 91% of titanium grades
Limitations
- Limited formability — 14/100, worse than 97% of titanium grades
- Difficult to weld — 45/100, worse than 92% of titanium grades
- Low fracture toughness — 58 MPa·√m (52.8 ksi·√in), worse than 87% of titanium grades
TC11-DA properties
Typical room-temperature values for TC11-DA; 22 are specific to this condition. Other listed values are TC11 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
TC11-DA has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,600°C (2,912 °F).
Mechanical16
TC11-DA has a yield strength of 980 MPa (142 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 91% of titanium grades. Elongation at break is 14% and the elastic modulus is 118 GPa (17.1 Msi).
Thermal6
TC11-DA is rated for continuous service to 500°C (932 °F). It conducts heat at 7.9 W/m·K (4.56 BTU/hr·ft·°F), better than 50% of titanium grades. Thermal expansion is 8.6 µm/m·K (4.78 µin/in·°F).
Electrical3
TC11-DA conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), worse than 77% of titanium grades.
Sustainability4
Producing a kilogram of TC11-DA takes about 650 MJ of energy and emits 42 kg of CO₂ — less than 75% of titanium grades. Typical recycled content is 25%.
Manufacturability8
TC11-DA's machinability is poor (15/100, worse than 97% of titanium grades); weldability fair (45/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TC11-DA
Is TC11 easy to machine?
Machinability is poor: use low cutting speed with heavy feed, rigid clamping and sharp carbide or solid tooling with high coolant flow. Avoid tool deflection and the surface damage caused by work hardening and alpha-layer formation.
Can TC11 be welded?
GTAW under vacuum or inert-gas shielding, electron-beam welding and friction welding are all usable, with strict gas protection throughout. Post-weld stress relief at 530–600 °C or a full anneal is needed to restore toughness.
Can TC11 be formed, bent or molded?
Cold formability is very low; almost all parts are isothermally or near-isothermally forged at 900–980 °C, below the beta transus. Control the cooling rate after forging to avoid non-uniform microstructure.
What surface finishes work on TC11?
Pickle in HNO₃/HF to remove scale and alpha case, then shot peen for fatigue strength. Color anodizing or anti-galling treatments can be applied; plating for corrosion protection is generally not needed.
TC11 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.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Alalpha stabilizer / solid-solution strengthening | 5.8 – 7 | 6.5 |
| Mobeta-stabilizing element | 2.8 – 3.8 | 3.5 |
| Zrneutral strengthener | 0.8 – 2 | 1.5 |
| Siincreases creep resistance | 0.2 – 0.35 | 0.28 |
| Feimpurity | ≤ 0.25 | — |
| Cimpurity | ≤ 0.1 | — |
| Nimpurity | ≤ 0.05 | — |
| Oimpurity | ≤ 0.15 | — |
| Himpurity | ≤ 0.01 | — |
| Ti | balance | — |
TC11-DA — frequently asked
What is TC11-DA used for?
TC11-DA is typically used for aeroengine compressor disks, compressor blades and high-temperature fasteners. In short: 500 °C alpha-beta titanium; highest strength in family; forging-route alloy.
What is the yield strength of TC11-DA?
TC11-DA has a typical yield strength of 980 MPa (142 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 91% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is TC11-DA easy to machine?
Not especially — machinability is rated poor (15/100, worse than 97% of titanium grades). Machinability is poor: use low cutting speed with heavy feed, rigid clamping and sharp carbide or solid tooling with high coolant flow. Avoid tool deflection and the surface damage caused by work hardening and alpha-layer formation.
Can TC11-DA be welded?
With care — weldability is rated fair (45/100). GTAW under vacuum or inert-gas shielding, electron-beam welding and friction welding are all usable, with strict gas protection throughout. Post-weld stress relief at 530–600 °C or a full anneal is needed to restore toughness.
What surface finishes work on TC11-DA?
Pickle in HNO₃/HF to remove scale and alpha case, then shot peen for fatigue strength. Color anodizing or anti-galling treatments can be applied; plating for corrosion protection is generally not needed.
Can TC11-DA be formed, bent or molded?
Cold formability is very low; almost all parts are isothermally or near-isothermally forged at 900–980 °C, below the beta transus. Control the cooling rate after forging to avoid non-uniform microstructure.
What is the maximum service temperature of TC11-DA?
TC11-DA is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between TC11-M and TC11-STA?
M is the default condition — most common bar and forging supply state, α+β annealed at 950 °C for 1–2 h AC plus 530 °C for 6 h AC, giving the best balance of 960 MPa yield, 13% elongation and structural stability. STA: pick solution treatment near 950 °C with oil or water quench and ageing at 500–530 °C for small and medium sections needing 1060 MPa yield; ductility and fracture toughness fall. Yield strength is 960 MPa in M versus 1,060 MPa in STA.
Sources
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.