Bar and Rod
Plate and Sheet
Strip
Pipe and Tube
Wire
Welding
Powder Material
Cast Products
Forged Products
Fittings
Fastening
Round Bar:
φ2–500 mm, 1–6 m length
Flat/Square Bar:
4–100 mm thickness/width
Hex Bar:
A/F 3–100 mm
Hollow Bar:
OD 20–300 mm
Sheet:
0.3–6 mm thickness
Medium Plate:
6–25 mm thickness
Heavy Plate:
25–100 mm thickness
Standard Strip:
0.05–3 mm thick,
10–600 mm wide
Precision strip:
0.01–0.5 mm thick,
tight tolerance ±0.005 mm
Foil:
0.005–0.1 mm thick
Seamless Tube:
OD 6–450 mm,
WT 1–50 mm,
1–12 m length
Welded Tube:
OD 10–600 mm,
WT 1–20 mm
Capillary Tube:
OD 1–10 mm,
WT 0.1–2 mm
Wire Form:
Cold Drawn Wire,
Bright Wire,
Spring Wire,
Fine Wire,
Ultra-fine Wire
General Diameter:
φ0.1–10 mm
Coil Weight:
50–500 kg,
customizable tolerance
Solid Wire:
φ0.8–4.0 mm
Flux-cored Wire:
φ1.2–4.0 mm
Welding Rod:
φ2.0–5.0 mm
Powder Form:
AM 3D Printing Powder,
Spherical Powder,
Gas-atomized Powder,
Water-atomized Powder
Particle Size:
10–150 μm
Sphericity:
≥90% for AM grade
Cast Ingot:
φ200–800 mm
Precision Casting:
min wall 0.5 mm
Cast Pipe:
OD 100–600 mm,
WT 10–50 mm
Forged Bar:
Φ35–500 mm
Forged Ring:
OD 200–2000 mm
Forging Weight:
1–5000 kg
Fittings Form:
Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint
Size range:
1/2''–24'' (DN15–DN600)
Wall thickness:
Sch10–Sch160, STD, XS, XXS
Pressure Class:
150–2500 LB
Fastening Form:
Bolt, Nut, Screw, Stud, Washer, Pin, Rivet
Metric: M3–M64
Imperial: #4–2.5''
Length: 6–500 mm
R05240 is a tantalum alloy containing about 40% niobium. This datasheet presents the material within the American (ASTM / ASME / UNS) standard system.
Tantalum is a refractory metal with a very high melting point, high density and outstanding corrosion resistance — comparable to glass in many acids. R05240 is a tantalum alloy ta-40nb; the 40% niobium addition raises strength and high-temperature performance while retaining the broad corrosion resistance of tantalum. It is supplied in the annealed condition. It is essentially inert to most acids (including hot concentrated nitric, hydrochloric and sulfuric) below about 150 °C, is highly biocompatible, and is readily cold-worked and welded under proper shielding. Like other refractory metals it oxidises in air at elevated temperature and is attacked by hydrofluoric acid, fuming sulfuric acid and hot alkalis.
Typical applications include chemical-process equipment (heat exchangers, liners, rupture discs), corrosion-resistant linings, electronics and capacitors, and surgical implants.
| Property | Value | Unit |
|---|---|---|
| Density | 12.0 | g/cm³ |
| Melting point | 2996 | °C |
| Elastic modulus | 186 | GPa |
| Coefficient of thermal expansion (20–100 °C) | 6.5 | µm/m·°C |
| Thermal conductivity (20 °C) | 57.5 | W/m·K |
| Specific heat (20 °C) | 140 | J/kg·K |
| Structure | Body-centred cubic (BCC) | — |
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Tantalum | Ta | Balance | — | Base element (~60%) |
| Niobium | Nb | 38.0 | 42.0 | Alloying; lowers density and cost |
| Tungsten | W | — | 0.05 | Residual impurity |
| Iron | Fe | — | 0.010 | Residual impurity |
| Oxygen | O | — | 0.015 | Interstitial impurity |
| Carbon | C | — | 0.010 | Interstitial impurity |
| Nitrogen | N | — | 0.010 | Interstitial impurity |
| Hydrogen | H | — | 0.0015 | Interstitial impurity |
Annealed condition, typical values for ASTM B708 R05240.
| Condition | Property | Value |
|---|---|---|
| Annealed | Tensile strength (UTS) | ≥275 MPa (40 ksi) |
| Annealed | 0.2% yield strength | ≥170 MPa (25 ksi) |
| Annealed | Elongation at break | ≥25 % |
| Cold-worked | Tensile strength (UTS) | higher; less ductile |
| — | Elastic modulus | 186 GPa |
Confirm against the mill test report. The alloying addition raises strength over unalloyed tantalum; cold work raises it further.
| Environment | Performance | Notes |
|---|---|---|
| Mineral acids (HNO₃, HCl, H₂SO₄) | Excellent | Inert below ~150 °C; glass-like resistance |
| Body fluids / physiological | Excellent | Highly biocompatible |
| Most chemicals | Excellent | Very broad resistance |
| Hydrofluoric acid / fuming H₂SO₄ | Poor | Attacked |
| Hot alkalis / oxidizing air (>300 °C) | Poor | Attacked / oxidises |
Tantalum offers corrosion resistance comparable to glass across most acids and is highly biocompatible, but is attacked by hydrofluoric acid, oleum and hot alkalis, and oxidises in air at elevated temperature.
A refractory metal; not hardenable by precipitation. Properties are governed by working and annealing.
Anneal Anneal in high vacuum at approximately 1000–1400 °C to recrystallise and restore ductility after cold work. Avoid oxygen, nitrogen and hydrogen pickup, which embrittle the metal.
Excellent weldability by high-vacuum and inert-gas processes; the weld and hot metal must be fully shielded from air, because interstitial pickup causes embrittlement.
| Welding Process | Applicability | Notes |
|---|---|---|
| GTAW / TIG | Excellent | High-purity inert shielding or chamber |
| EBW (vacuum) | Excellent | Preferred for clean welds |
| Resistance / spot | Good | — |
Weld under high-purity shielding or in vacuum; protect the cooling weld from atmospheric contamination.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Machinability | Soft and gummy; sharp tooling, positive rake |
| Tendency | Galls and smears; avoid built-up edge |
| Coolant | Ample non-chlorinated coolant |
Forming Processes
| Process | Notes |
|---|---|
| Cold forming | Excellent; very ductile when annealed |
| Hot forming | Performed hot under vacuum or protection |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Chemical process | Heat exchangers, liners, rupture discs | Acid corrosion resistance |
| Medical | Surgical implants, markers | Biocompatibility |
| Electronics | Capacitors, sputtering targets | Stability + purity |
| Industrial | Corrosion-resistant equipment | Broad chemical resistance |
| Product Form | ASTM Standard | Notes |
|---|---|---|
| Plate, sheet and strip | ASTM B708 | R05240 |
| Rod and wire | ASTM B365 | R05240 |
| Seamless and welded tube | ASTM B521 | R05240 |
| Process route | Vacuum-arc / electron-beam melted | — |
Tantalum Alloy Ta-40Nb. UNS R05240.
| UNS | Composition | Process | Best Used For |
|---|---|---|---|
| R05200 | Unalloyed Ta | Vacuum melted | Unalloyed tantalum; chemical, medical |
| R05400 | Unalloyed Ta | Powder metallurgy | Powder-metallurgy unalloyed tantalum |
| R05252 | Ta-2.5W | Vacuum melted | Higher-strength tantalum alloy |
| R05255 | Ta-10W | Vacuum melted | High-strength tantalum-tungsten alloy |
| R05240 | Ta-40Nb | EB / vacuum-arc melted | Lower-density, lower-cost tantalum alloy; chemical service |
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