Refractory Metal Pure Ta · heat-treated state · default condition
Refractory Metal Pure Ta Vacuum Annealed
Properties of the Vacuum Annealed condition, compared with the other Pure Ta tempers.
Default stocked condition for sheet, plate, rod and tube: maximum ductility for deep drawing, spinning, bending and lining work, and lowest gas content.
What is Pure Ta Vacuum Annealed?
Pure Ta Vacuum Annealed is Pure Ta heat treated to Vacuum Annealed — default stocked condition for sheet, plate, rod and tube: maximum ductility for deep drawing, spinning, bending and lining work, and lowest gas content. Pure Ta Vacuum Annealed has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 93% of refractory metal grades. Elongation at break is 38% and the elastic modulus is 186 GPa (27 Msi). Pure Ta Vacuum Annealed has a density of 16.6 g/cm³ (0.6 lb/in³), heavier than 83% of refractory metal grades. It melts at 2,996°C (5,425 °F).
Advantages
- Good corrosion resistance — 97/100, better than 97% of refractory metal grades
- Forms and bends easily — 92/100, better than 95% of refractory metal grades
- Ductile — tolerates forming and impact — 38%, better than 94% of refractory metal grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 95% of refractory metal grades
- Low strength — 170 MPa (24.7 ksi), worse than 93% of refractory metal grades
- High embodied carbon — 260 kg CO₂/kg, worse than 91% of refractory metal grades
- Heavy — 16.6 g/cm³ (0.6 lb/in³), worse than 83% of refractory metal grades
Pure Ta Vacuum Annealed properties
Typical room-temperature values for Pure Ta Vacuum Annealed — 17 properties are specific to this condition; the rest are grade-level values shared by every Pure Ta temper. Each bar shows where the value sits among the refractory metal grades in FabDigit's library — further right is higher.
Physical3
Pure Ta Vacuum Annealed has a density of 16.6 g/cm³ (0.6 lb/in³), heavier than 83% of refractory metal grades. It melts at 2,996°C (5,425 °F).
Mechanical13
Pure Ta Vacuum Annealed has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 93% of refractory metal grades. Elongation at break is 38% and the elastic modulus is 186 GPa (27 Msi).
Thermal6
Pure Ta Vacuum Annealed is rated for continuous service to 300°C (572 °F). It conducts heat at 57.5 W/m·K (33.2 BTU/hr·ft·°F), better than 70% of refractory metal grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).
Electrical3
Pure Ta Vacuum Annealed conducts electricity at 12.8 % IACS, better than 69% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (97/100), better than 97% of refractory metal grades.
Sustainability4
Producing a kilogram of Pure Ta Vacuum Annealed takes about 4,200 MJ of energy and emits 260 kg of CO₂ — more than 91% of refractory metal grades. Typical recycled content is 25%.
Manufacturability8
Pure Ta Vacuum Annealed's machinability is poor (22/100, worse than 72% of refractory metal grades); weldability very good (72/100); formability excellent (92/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Pure Ta tempers and conditions
Pure Ta is also supplied in 5 other conditions. The full side-by-side table is on the Pure Ta overview.
- Vacuum AnnealedDefaultDefault stocked condition for sheet, plate, rod and tube: maximum ductility for deep drawing, spinning, bending and lining work, and lowest gas content.170 MPa yield · 95 HB
- CW HardFine wire, springs and capacitor lead wire where maximum strength and stiffness per section is required.560 MPa yield · 20 HRC
- As RolledUse for stiffer sheet, foil, shielding and target backing plates where higher yield strength matters more than drawability.390 MPa yield · 88 HRB
Working with Pure Ta Vacuum Annealed
Is Pure Ta easy to machine?
Very gummy and prone to galling: use sharp high-positive-rake carbide or HSS, slow speeds (~15–25 m/min), heavy feed, generous chlorinated or emulsion coolant, and never let the tool dwell.
Can Pure Ta be welded?
GTAW/EBW/laser welds cleanly only in vacuum or high-purity argon/helium chambers with full backside shielding — any O₂, N₂ or H₂ pickup above ~50 ppm causes severe embrittlement; no filler normally needed.
Can Pure Ta be formed, bent or molded?
Excellent cold formability — deep drawing, spinning, hydroforming and tight bends in the annealed state; use non-galling tooling with PTFE/oil interlayers and interstage vacuum anneals at 1000–1300 °C.
What surface finishes work on Pure Ta?
Pickle in HF/HNO₃ to remove oxide, then electropolish for chemical or implant service; anodizing produces stable colored Ta₂O₅ films, and no paint or plating is needed for corrosion protection.
Pure Ta 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 |
|---|---|---|
| Nbprincipal metallic impurity | ≤ 0.1 | 0.03 |
| Ointerstitial; embrittles if high | ≤ 0.02 | 0.01 |
| N | ≤ 0.01 | 0 |
| C | ≤ 0.01 | 0 |
| H | ≤ 0 | 5×10⁻⁴ |
| W | ≤ 0.05 | 0.01 |
| Mo | ≤ 0.02 | 0.01 |
| Fe | ≤ 0.01 | 0 |
| Ti | ≤ 0.01 | 0 |
| Ni | ≤ 0.01 | 0 |
| Si | ≤ 0.01 | 0 |
| Tabalance, metallic basis (Nb excluded from purity count per ASTM) | ≥ 99.9 (balance) | — |
Pure Ta Vacuum Annealed — frequently asked
What is Pure Ta Vacuum Annealed used for?
Pure Ta Vacuum Annealed is typically used for chemical process vessel liners and cladding, heat exchanger tubing and bayonet heaters, capacitor anodes, surgical implants and radiopaque markers, rupture discs and thermowells and furnace heat shields and crucibles. In short: corrosion-proof tantalum plate.
What is the yield strength of Pure Ta Vacuum Annealed?
Pure Ta Vacuum Annealed has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 93% of refractory metal grades. Strength varies by condition: see the 6 listed tempers.
Is Pure Ta Vacuum Annealed easy to machine?
Not especially — machinability is rated poor (22/100, worse than 72% of refractory metal grades). Very gummy and prone to galling: use sharp high-positive-rake carbide or HSS, slow speeds (~15–25 m/min), heavy feed, generous chlorinated or emulsion coolant, and never let the tool dwell.
Can Pure Ta Vacuum Annealed be welded?
Yes — weldability is rated very good (72/100). GTAW/EBW/laser welds cleanly only in vacuum or high-purity argon/helium chambers with full backside shielding — any O₂, N₂ or H₂ pickup above ~50 ppm causes severe embrittlement; no filler normally needed.
What surface finishes work on Pure Ta Vacuum Annealed?
Pickle in HF/HNO₃ to remove oxide, then electropolish for chemical or implant service; anodizing produces stable colored Ta₂O₅ films, and no paint or plating is needed for corrosion protection.
Can Pure Ta Vacuum Annealed be formed, bent or molded?
Excellent cold formability — deep drawing, spinning, hydroforming and tight bends in the annealed state; use non-galling tooling with PTFE/oil interlayers and interstage vacuum anneals at 1000–1300 °C.
What is the maximum service temperature of Pure Ta Vacuum Annealed?
Pure Ta Vacuum Annealed is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in Pure Ta Vacuum Annealed?
Yes — Pure Ta Vacuum Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B708 — Tantalum and Tantalum Alloy Plate, Sheet, and Strip — ASTM International (2021)
- ASTM B365 — Tantalum and Tantalum Alloy Rod and Wire — ASTM International (2018)
- ASTM B521 — Tantalum and Tantalum Alloy Seamless and Welded Tubes — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties of Refractory Metals and Alloys — ASM International (1990)
- CRC Handbook of Chemistry and Physics — CRC Press (2020)
- Tantalum metal product data (sheet, rod, tube) — H.C. Starck / Global Advanced Metals (2022)
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.