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
R04295 is the niobium-hafnium-titanium alloy C-103, containing nominally 10% hafnium and 1% titanium. This datasheet presents the material within the American (ASTM / ASME / UNS) standard system.
Developed during the 1960s space programme, C-103 (Nb-10Hf-1Ti) is the dominant niobium alloy for aerospace and propulsion. The hafnium and titanium additions give a strong, formable, weldable alloy that retains useful strength to very high temperature (service to about 1480 °C) while keeping the relatively low density and excellent fabricability of niobium. Like all refractory metals it oxidises in air at elevated temperature and requires a protective coating or inert/vacuum service. It is supplied in the annealed condition.
Typical applications include rocket-nozzle extensions, thrust chambers, spacecraft and propulsion components, hypersonic-vehicle structures, and other high-temperature aerospace hardware.
| Property | Value | Unit |
|---|---|---|
| Density | 8.85 | g/cm³ |
| Melting point | ~2350 | °C |
| Elastic modulus | 105 | GPa |
| Coefficient of thermal expansion (20–100 °C) | 7.3 | µm/m·°C |
| Thermal conductivity (20 °C) | 53.7 | W/m·K |
| Specific heat (20 °C) | 265 | J/kg·K |
| Structure | Body-centred cubic (BCC) | — |
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Niobium | Nb | Balance | — | Base element (~89%) |
| Hafnium | Hf | 9.0 | 11.0 | Strength, oxidation resistance |
| Titanium | Ti | 0.7 | 1.3 | Strength, mechanical properties |
| Zirconium | Zr | — | 0.7 | Residual / minor |
| Tantalum | Ta | — | 0.5 | Residual |
| Tungsten | W | — | 0.5 | Residual |
| Oxygen | O | — | 0.015 | Interstitial impurity |
| Carbon | C | — | 0.015 | Interstitial impurity |
Annealed condition, typical values for ASTM B654 / AMS 7852 R04295 (C-103).
| Condition | Property | Value |
|---|---|---|
| Annealed | Tensile strength (UTS) | ≥310 MPa (45 ksi) |
| Annealed | 0.2% yield strength | ≥210 MPa (30 ksi) |
| Annealed | Elongation at break | ≥20 % |
| Cold-worked | Tensile strength (UTS) | higher; less ductile |
| — | Elastic modulus | 105 GPa |
Confirm against the mill test report. C-103 retains useful strength to very high temperature; the alloy is readily formed and welded.
| Environment | Performance | Notes |
|---|---|---|
| Liquid alkali metals | Excellent | Used in nuclear / heat-transfer service |
| Many acids (non-fluoride) | Excellent | Stable passive oxide |
| Atmospheric / general | Good | Stable at room temperature |
| Oxidizing atmospheres (>400 °C) | Poor | Oxidises in air; must be protected |
| High-temperature air service | Coated | Silicide coating (e.g. R512E) used |
C-103 resists many media through a stable surface oxide, but oxidises in air at elevated temperature; for high-temperature service in air it is protected by a silicide or aluminide coating (for example R512E).
A refractory metal; not hardenable by precipitation. Properties are governed by working and annealing.
Anneal Anneal in vacuum or a high-purity inert atmosphere at approximately 1200–1320 °C to recrystallise and restore ductility after cold work. Avoid oxygen, nitrogen and hydrogen pickup, which embrittle the metal.
Excellent weldability by inert-gas and high-vacuum processes; the weld and hot metal must be fully shielded from air, because oxygen, nitrogen and hydrogen pickup cause 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 protection from oxidation |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Aerospace propulsion | Rocket-nozzle extensions, thrust chambers | High-temperature strength + formability |
| Spacecraft | Structures, propulsion components | Strength-to-weight at temperature |
| Hypersonics | Leading edges, hot structures | Thermal shock + strength |
| Defense | High-temperature components | Refractory performance |
| Product Form | ASTM Standard | Notes |
|---|---|---|
| Foil, sheet, strip and plate | ASTM B654 | C-103 (R04295) |
| Bar, rod and wire | ASTM B655 | C-103 (R04295) |
| Aerospace sheet/plate | AMS 7852 | C-103 |
| Material designation | UNS R04295 | Nb-10Hf-1Ti |
C-103 niobium-hafnium-titanium alloy (Nb-10Hf-1Ti). UNS R04295.
| UNS | Composition | Grade | Best Used For |
|---|---|---|---|
| R04200 | Unalloyed Nb | Type 1, reactor grade | Reactor-grade niobium; nuclear service |
| R04210 | Unalloyed Nb | Type 2, commercial grade | Commercial unalloyed niobium |
| R04251 | Nb-1Zr | Type 3, reactor grade | Reactor-grade niobium-zirconium alloy |
| R04261 | Nb-1Zr | Type 4, commercial grade | Commercial niobium-zirconium alloy |
| R04295 | Nb-10Hf-1Ti | C-103 | High-temperature aerospace/propulsion alloy; rocket nozzles |
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