Refractory Metal Ta-2.5W · heat-treated state · default condition
Refractory Metal Ta-2.5W Vacuum Annealed
Properties of the Vacuum Annealed condition, compared with the other Ta-2.5W tempers.
Standard supply condition for sheet, plate, rod and tube where maximum ductility, deep-drawability and weldability are required.
What is Ta-2.5W Vacuum Annealed?
Ta-2.5W Vacuum Annealed is Ta-2.5W heat treated to Vacuum Annealed — standard supply condition for sheet, plate, rod and tube where maximum ductility, deep-drawability and weldability are required. Ta-2.5W Vacuum Annealed has a yield strength of 310 MPa (45 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 56% of refractory metal grades. Elongation at break is 28% and the elastic modulus is 200 GPa (29 Msi). Ta-2.5W Vacuum Annealed has a density of 16.7 g/cm³ (0.603 lb/in³), heavier than 86% of refractory metal grades. It melts at 3,030°C (5,486 °F).
Advantages
- Good corrosion resistance — 97/100, better than 97% of refractory metal grades
- Polishes to a fine finish — 80/100, better than 97% of refractory metal grades
- Readily welded — 80/100, better than 92% of refractory metal grades
- Forms and bends easily — 85/100, better than 87% of refractory metal grades
- Ductile — tolerates forming and impact — 28%, better than 80% of refractory metal grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 95% of refractory metal grades
- High embodied carbon — 260 kg CO₂/kg, worse than 91% of refractory metal grades
- Heavy — 16.7 g/cm³ (0.603 lb/in³), worse than 86% of refractory metal grades
- Difficult to machine — 18/100, worse than 80% of refractory metal grades
Ta-2.5W Vacuum Annealed properties
Typical room-temperature values for Ta-2.5W Vacuum Annealed — 8 properties are specific to this condition; the rest are grade-level values shared by every Ta-2.5W temper. Each bar shows where the value sits among the refractory metal grades in FabDigit's library — further right is higher.
Physical3
Ta-2.5W Vacuum Annealed has a density of 16.7 g/cm³ (0.603 lb/in³), heavier than 86% of refractory metal grades. It melts at 3,030°C (5,486 °F).
Mechanical11
Ta-2.5W Vacuum Annealed has a yield strength of 310 MPa (45 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 56% of refractory metal grades. Elongation at break is 28% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Ta-2.5W Vacuum Annealed is rated for continuous service to 300°C (572 °F). It conducts heat at 54 W/m·K (31.2 BTU/hr·ft·°F), better than 66% of refractory metal grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).
Electrical3
Ta-2.5W Vacuum Annealed conducts electricity at 9.9 % IACS, better than 64% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (97/100), better than 97% of refractory metal grades.
Sustainability3
Producing a kilogram of Ta-2.5W Vacuum Annealed takes about 4,400 MJ of energy and emits 260 kg of CO₂ — more than 94% of refractory metal grades. Typical recycled content is 20%.
Manufacturability8
Ta-2.5W Vacuum Annealed's machinability is poor (18/100, worse than 80% of refractory metal grades); weldability very good (80/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Ta-2.5W tempers and conditions
Ta-2.5W is also supplied in 4 other conditions. The full side-by-side table is on the Ta-2.5W overview.
- Vacuum AnnealedDefaultStandard supply condition for sheet, plate, rod and tube where maximum ductility, deep-drawability and weldability are required.310 MPa yield · 120 HV
Working with Ta-2.5W Vacuum Annealed
Is Ta-2.5W easy to machine?
Very gummy and galling — use sharp positive-rake carbide, heavy flood of chlorinated or emulsion coolant, slow speeds (15–30 m/min) and generous feeds to avoid rubbing and smearing.
Can Ta-2.5W be welded?
GTAW in a high-purity argon glove box, or electron-beam/laser welding in vacuum; any O/N/H pickup above ~300 °C embrittles the weld, so trailing shields and clean surfaces are mandatory.
Can Ta-2.5W be formed, bent or molded?
Excellent cold formability — deep drawing, spinning and bending to tight radii are routine in the annealed condition; use lubricants and non-steel tooling inserts to avoid galling and iron pickup.
What surface finishes work on Ta-2.5W?
Pickle in HF/HNO3 mixtures to remove oxide and iron smear, then vacuum anneal; electropolishing or anodic Ta2O5 films give clean, stable surfaces for chemical or implant service.
Ta-2.5W 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 |
|---|---|---|
| Wsolid-solution strengthener | 2 – 3.5 | 2.5 |
| Nb | ≤ 0.1 | — |
| Mo | ≤ 0.02 | — |
| Ti | ≤ 0.01 | — |
| Fe | ≤ 0.01 | — |
| Ni | ≤ 0.01 | — |
| Si | ≤ 0.01 | — |
| C | ≤ 0.01 | — |
| O | ≤ 0.02 | — |
| N | ≤ 0.01 | — |
| H | ≤ 0 | — |
| Ta | balance | — |
Ta-2.5W Vacuum Annealed — frequently asked
What is Ta-2.5W Vacuum Annealed used for?
Ta-2.5W Vacuum Annealed is typically used for chemical reactor liners and cladding, shell-and-tube heat exchangers, rupture discs and bursting diaphragms, thermowells and immersion heater sheaths, acid-service valve and pump components and furnace heat shields and support structures. In short: strengthened tantalum alloy.
What is the yield strength of Ta-2.5W Vacuum Annealed?
Ta-2.5W Vacuum Annealed has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 56% of refractory metal grades. Strength varies by condition: see the 5 listed tempers.
Is Ta-2.5W Vacuum Annealed easy to machine?
Not especially — machinability is rated poor (18/100, worse than 80% of refractory metal grades). Very gummy and galling — use sharp positive-rake carbide, heavy flood of chlorinated or emulsion coolant, slow speeds (15–30 m/min) and generous feeds to avoid rubbing and smearing.
Can Ta-2.5W Vacuum Annealed be welded?
Yes — weldability is rated very good (80/100). GTAW in a high-purity argon glove box, or electron-beam/laser welding in vacuum; any O/N/H pickup above ~300 °C embrittles the weld, so trailing shields and clean surfaces are mandatory.
What surface finishes work on Ta-2.5W Vacuum Annealed?
Pickle in HF/HNO3 mixtures to remove oxide and iron smear, then vacuum anneal; electropolishing or anodic Ta2O5 films give clean, stable surfaces for chemical or implant service.
Can Ta-2.5W Vacuum Annealed be formed, bent or molded?
Excellent cold formability — deep drawing, spinning and bending to tight radii are routine in the annealed condition; use lubricants and non-steel tooling inserts to avoid galling and iron pickup.
What is the maximum service temperature of Ta-2.5W Vacuum Annealed?
Ta-2.5W 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 Ta-2.5W Vacuum Annealed?
Yes — Ta-2.5W 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 and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
- Tantalum and tantalum alloys product data — Plansee / H.C. Starck Solutions (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.