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Refractory Metal Ta-2.5W EB Melted

Grade

UNS R05252 · ASTM B365 · also Tantalum-Tungsten

Primary electron-beam melted ingot or sputtering-target blank stock, prior to breakdown forging/rolling; coarse grain and low strength.

Specialty cost $$$$$

Values for the EB Melted condition

Other Ta-2.5W tempers and conditions

Ta-2.5W is listed in 4 conditions; see the grade overview at Ta-2.5W.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
EB MeltedThis page
EB Melted Ingot / As-Cast
Primary electron-beam melted ingot or sputtering-target blank stock, prior to breakdown forging/rolling; coarse grain and low strength.24034030100 HB10 % IACS
fully recrystallized (default mill condition)
Standard supply condition for sheet, plate, rod and tube where maximum ductility, deep-drawability and weldability are required.31041528115 HB9.9 % IACS
partially recovered, not recrystallized
Choose when dimensional stability and higher strength are needed but some residual cold-work ductility must be kept, e.g. formed diaphragms and rupture discs.44052015160 HB9.6 % IACS
as-rolled / as-drawn hard temper
Highest strength and springback; used for hard sheet, foil, fasteners and wire where no further forming or welding is planned.620690520 HRC9.4 % IACS

What is Ta-2.5W EB Melted?

Ta-2.5W EB Melted is Ta-2.5W in the EB Melted grade — primary electron-beam melted ingot or sputtering-target blank stock, prior to breakdown forging/rolling; coarse grain and low strength. Ta-2.5W EB Melted has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 76% of refractory metal grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi). Ta-2.5W EB Melted has a density of 16.7 g/cm³ (0.603 lb/in³), heavier than 87% of refractory metal grades. It melts at 3,030°C (5,486 °F). Vacuum Annealed is the default condition FabDigit quotes; EB Melted is available on request or by drawing note.

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
  • Ductile — tolerates forming and impact — 30%, better than 86% 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 92% of refractory metal grades
  • Heavy — 16.7 g/cm³ (0.603 lb/in³), worse than 87% of refractory metal grades
  • Difficult to machine — 20/100, worse than 77% of refractory metal grades
  • Low strength — 240 MPa (34.8 ksi), worse than 76% of refractory metal grades

Ta-2.5W EB Melted properties

Typical room-temperature values for Ta-2.5W EB Melted; 20 are specific to this condition. Other listed values are Ta-2.5W reference data and may not represent this condition. Bars are the position among refractory metal grades.

Physical3

Ta-2.5W EB Melted has a density of 16.7 g/cm³ (0.603 lb/in³), heavier than 87% of refractory metal grades. It melts at 3,030°C (5,486 °F).

Density16.7 g/cm³0.6 lb/in³
Melting Point (Solidus)3,030°C5,486 °F
Liquidus Temperature3,040°C5,504 °F

Mechanical14

Ta-2.5W EB Melted has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 76% of refractory metal grades. Elongation at break is 30% and the elastic modulus is 200 GPa (29 Msi).

Elastic (Young's) Modulus200 GPa29 Msi
Shear Modulus72 GPa10.4 Msi
Bulk Modulus200 GPa29 Msi
Poisson's Ratio0.35
Tensile Strength (Ultimate)340 MPa49.3 ksi
Yield Strength (0.2% offset)240 MPa34.8 ksi
Elongation at Break30%
Reduction in Area60%
Compressive Strength250 MPa36.3 ksi
Shear Strength210 MPa30.5 ksi
Fatigue Strength (Endurance Limit)150 MPa21.8 ksi
Hardness, Brinell100 HB
Hardness, Rockwell B56 HRB
Hardness, Vickers105 HV

Thermal6

Ta-2.5W EB Melted is rated for continuous service to 300°C (572 °F). It conducts heat at 55 W/m·K (31.8 BTU/hr·ft·°F), better than 67% of refractory metal grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).

Thermal Conductivity55 W/m·K31.8 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 Fusion200 J/g86 BTU/lb
Max Service Temperature (continuous)300°C572 °F
Min Service Temperature-269°C-452 °F

Electrical3

Ta-2.5W EB Melted conducts electricity at 10 % IACS, better than 65% of refractory metal grades.

Electrical Conductivity10 % IACS
Electrical Resistivity1.72×10⁻⁷ Ω·m6.77 µΩ·in
Magnetic Responsenon-magnetic (paramagnetic)

Chemical & Environmental3

Corrosion resistance is excellent (97/100), better than 97% of refractory metal grades.

Galvanic Potential (seawater, vs SCE)-0.05 V
Corrosion ResistanceExcellent97/100
Chemical Resistance SummaryEssentially inert to all concentrations of HCl, HNO3, H2SO4 (to ~175 °C), aqua regia, most organics and salt solutions; attacked by HF and fluoride-bearing acids, oleum/SO3, hot concentrated alkalis and fused salts; absorbs hydrogen above ~250 °C causing embrittlement.

Sustainability3

Producing a kilogram of Ta-2.5W EB Melted 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%.

Embodied Energy (primary production)4,400 MJ/kg1,891,661 BTU/lb
Embodied Carbon (primary production)260 kg CO₂/kg
Typical Recycled Content20%

Manufacturability8

Ta-2.5W EB Melted's machinability is poor (20/100, worse than 77% of refractory metal grades); weldability very good (80/100); formability good (65/100).

MachinabilityPoor20/100
Machinability Rating (AISI 1212 = 100 %)20%
WeldabilityVery good80/100
Formability (cold)Good65/100
CastabilityPoor25/100
Brazeability / SolderabilityGood65/100
PolishabilityVery good80/100
Anodizing Responsen/a for decorative anodizing; forms a stable Ta2O5 anodic film used in capacitors and for colour interference finishes on implants

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

Working with Ta-2.5W EB Melted

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.

ElementSpec limit (wt %)Nominal
Wsolid-solution strengthener2 – 3.52.5
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—
Tabalance—

Ta-2.5W EB Melted — frequently asked

What is Ta-2.5W EB Melted used for?

Ta-2.5W EB Melted 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 EB Melted?

Ta-2.5W EB Melted has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 76% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.

Is Ta-2.5W EB Melted easy to machine?

Not especially — machinability is rated poor (20/100, worse than 77% 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 EB Melted 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 EB Melted?

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 EB Melted 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 EB Melted?

Ta-2.5W EB Melted 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.

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 B521 — Tantalum and Tantalum Alloy Seamless and Welded Tubes — ASTM International (2018)
  4. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
  5. 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.