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Refractory Metal T-111-CW (Cold worked)

Supply condition

UNS R05340 · ASTM B364

Highest room-temperature strength and hardness for springs, fasteners and thin foil; strength is lost on exposure above ~1300 °C.

High cost $$$$

Values for the CW condition

Other T-111 tempers and conditions

T-111 is listed in 5 conditions; see the grade overview at T-111.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Spheroidize annealed
Ingot or cast-shape condition supplied for further working or for non-critical high-temperature hardware; coarse grain lowers strength and ductility.38050018208 HB6.9 % IACS
As-welded deposit
Property basis for weld joints — T-111 welds retain good ductility provided the chamber atmosphere is oxygen/nitrogen free.40054018225 HB6.9 % IACS
AnnealedDefault
Annealed (recrystallized, vacuum 1500–1650 °C)
Standard stocked condition for sheet, plate, rod and tube — maximum ductility and formability, best for forming and welding.4155502521 HRC6.9 % IACS
Stress relieved
Choose when higher room-temperature strength is needed but residual cold-work stresses must be removed before service.6207201528 HRC6.8 % IACS
CWThis page
Cold worked
Highest room-temperature strength and hardness for springs, fasteners and thin foil; strength is lost on exposure above ~1300 °C.830900832 HRC6.7 % IACS

What is T-111-CW?

T-111-CW is T-111 supplied in the CW condition — highest room-temperature strength and hardness for springs, fasteners and thin foil; strength is lost on exposure above ~1300 °C. T-111-CW has a yield strength of 830 MPa (120 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 91% of refractory metal grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi). T-111-CW has a density of 16.8 g/cm³ (0.607 lb/in³), heavier than 89% of refractory metal grades. It melts at 3,030°C (5,486 °F). Annealed is the default condition FabDigit quotes; CW is available on request or by drawing note.

Advantages

  • High strength — 830 MPa (120 ksi), better than 91% of refractory metal grades

Limitations

  • High embodied carbon — 265 kg CO₂/kg, worse than 95% of refractory metal grades
  • Heavy — 16.8 g/cm³ (0.607 lb/in³), worse than 89% of refractory metal grades
  • Limited ductility — 8%, worse than 75% of refractory metal grades

T-111-CW properties

Typical room-temperature values for T-111-CW; 22 are specific to this condition. Other listed values are T-111 reference data and may not represent this condition. Bars are the position among refractory metal grades.

Physical3

T-111-CW has a density of 16.8 g/cm³ (0.607 lb/in³), heavier than 89% of refractory metal grades. It melts at 3,030°C (5,486 °F).

Density16.8 g/cm³0.61 lb/in³
Melting Point (Solidus)3,030°C5,486 °F
Liquidus Temperature3,055°C5,531 °F

Mechanical17

T-111-CW has a yield strength of 830 MPa (120 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 91% of refractory metal grades. Elongation at break is 8% and the elastic modulus is 200 GPa (29 Msi).

Elastic (Young's) Modulus200 GPa29 Msi
Shear Modulus74 GPa10.7 Msi
Bulk Modulus210 GPa30.5 Msi
Poisson's Ratio0.35
Tensile Strength (Ultimate)900 MPa131 ksi
Yield Strength (0.2% offset)830 MPa120 ksi
Elongation at Break8%
Reduction in Area30%
Compressive Strength845 MPa123 ksi
Shear Strength540 MPa78.3 ksi
Fatigue Strength (Endurance Limit)400 MPa58 ksi
Fracture Toughness (K_IC)55 MPa·√m50.1 ksi·√in
Charpy V-Notch Impact (RT)30 J22.1 ft·lbf
Hardness, Brinell300 HB
Hardness, Rockwell B99 HRB
Hardness, Rockwell C32 HRC
Hardness, Vickers320 HV

Thermal6

T-111-CW is rated for continuous service to 1,200°C (2,192 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 55% of refractory metal grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).

Thermal Conductivity40 W/m·K23.1 BTU/hr·ft·°F
Specific Heat Capacity140 J/kg·K0.03 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)6.5 µm/m·K3.6 µin/in·°F
Latent Heat of Fusion195 J/g83.8 BTU/lb
Max Service Temperature (continuous)1,200°C2,192 °F
Min Service Temperature-253°C-423 °F

Electrical3

T-111-CW conducts electricity at 6.7 % IACS, better than 52% of refractory metal grades.

Electrical Conductivity6.7 % IACS
Electrical Resistivity2.58×10⁻⁷ Ω·m10.2 µΩ·in
Magnetic Responsenon-magnetic (paramagnetic)

Chemical & Environmental3

Corrosion resistance is excellent (92/100), better than 86% of refractory metal grades.

Galvanic Potential (seawater, vs SCE)-0.05 V
Corrosion ResistanceExcellent92/100
Chemical Resistance SummaryEssentially inert to most mineral acids (HCl, HNO3, H2SO4 below ~150 °C), chlorides and organics like unalloyed Ta; attacked by HF, fluorides, fuming/oleum SO3, hot strong alkalis, and absorbs hydrogen when cathodically polarised. Oxidises catastrophically in air above roughly 400 °C — inert gas or vacuum only at temperature.

Sustainability3

Producing a kilogram of T-111-CW takes about 4,400 MJ of energy and emits 265 kg of CO₂ — more than 94% of refractory metal grades. Typical recycled content is 20%.

Embodied Energy (primary production)4,400 MJ/kg1,891,661 BTU/lb
Embodied Carbon (primary production)265 kg CO₂/kg
Typical Recycled Content20%

Manufacturability8

T-111-CW's machinability is poor (32/100, better than 67% of refractory metal grades); weldability very good (70/100); formability poor (30/100).

MachinabilityPoor32/100
Machinability Rating (AISI 1212 = 100 %)26%
WeldabilityVery good70/100
Formability (cold)Poor30/100
CastabilityPoor30/100
Brazeability / SolderabilityGood55/100
PolishabilityVery good70/100
Anodizing Responsen/a as a decorative finish; Ta does form a stable anodic oxide (used for capacitor dielectrics) but no engineering anodize spec exists for this alloy

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

Working with T-111-CW

Is T-111 easy to machine?

Machines like a soft gummy metal: slow speeds, heavy positive-rake sharp carbide, rigid setups, generous chlorinated or sulfurised coolant to stop galling and built-up edge; degrease and etch after machining to remove embedded contaminants.

Can T-111 be welded?

GTAW or EB weld in high-purity argon glove box or vacuum only — any O2/N2/H2 pickup embrittles the joint; no filler needed, clean with acid pickle and vacuum degas before welding.

Can T-111 be formed, bent or molded?

Excellent cold formability in the annealed state (bending, deep drawing, spinning); anneal at 1450–1650 °C in vacuum between heavy passes and never form or heat in air above ~300 °C.

What surface finishes work on T-111?

Chemical polish or electropolish in HF/HNO3-based baths; no decorative anodize or plating is normally applied, and iridium/silicide coatings are used only when short air exposure at temperature is unavoidable.

T-111 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
Wsolid-solution strengthener7 – 98
Hfoxygen getter / carbide-forming strengthener1.8 – 2.42
Nb≤ 0.5—
Mo≤ 0.02—
Ti≤ 0.02—
Fe≤ 0.01—
Ni≤ 0.01—
Si≤ 0.01—
C≤ 0.01—
Ointerstitials control ductility≤ 0.02—
N≤ 0.01—
H≤ 0—
Tabalance—

T-111-CW — frequently asked

What is T-111-CW used for?

T-111-CW is typically used for nuclear reactor components, rocket thruster liners, high-temperature furnace fixtures and space power system heat exchangers. In short: high-creep-strength tantalum alloy; ductile above 1300 °C; vacuum or inert service only.

What is the yield strength of T-111-CW?

T-111-CW has a typical yield strength of 830 MPa (120 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 91% of refractory metal grades. Strength varies by condition: see the 5 listed tempers.

Is T-111-CW easy to machine?

Not especially — machinability is rated poor (32/100, better than 67% of refractory metal grades). Machines like a soft gummy metal: slow speeds, heavy positive-rake sharp carbide, rigid setups, generous chlorinated or sulfurised coolant to stop galling and built-up edge; degrease and etch after machining to remove embedded contaminants.

Can T-111-CW be welded?

Yes — weldability is rated very good (70/100). GTAW or EB weld in high-purity argon glove box or vacuum only — any O2/N2/H2 pickup embrittles the joint; no filler needed, clean with acid pickle and vacuum degas before welding.

What surface finishes work on T-111-CW?

Chemical polish or electropolish in HF/HNO3-based baths; no decorative anodize or plating is normally applied, and iridium/silicide coatings are used only when short air exposure at temperature is unavoidable.

Can T-111-CW be formed, bent or molded?

Excellent cold formability in the annealed state (bending, deep drawing, spinning); anneal at 1450–1650 °C in vacuum between heavy passes and never form or heat in air above ~300 °C.

What is the maximum service temperature of T-111-CW?

T-111-CW is rated for continuous use to about 1,200°C (2,192 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between T-111 Annealed and T-111-CW?

Annealed is the default condition — standard stocked condition for sheet, plate, rod and tube — maximum ductility and formability, best for forming and welding. CW: highest room-temperature strength and hardness for springs, fasteners and thin foil; strength is lost on exposure above ~1300 °C. Yield strength is 415 MPa in Annealed versus 830 MPa in CW.

Sources

  1. ASTM B708 — Tantalum and Tantalum Alloy Plate, Sheet, and Strip — ASTM International (2021)
  2. ASTM B365 — Tantalum and Tantalum Alloy Rod and Wire — ASTM International (2018)
  3. ASTM B364 — Tantalum and Tantalum Alloy Castings — ASTM International (2018)
  4. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Refractory Metals) — ASM International (1990)
  5. NASA technical reports on Ta-8W-2Hf (T-111) for space power systems — NASA (1970)
  6. Tantalum alloy Ta-8W-2Hf product data — refractory-metal producers (H.C. Starck / Plansee / ) (2023)

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.