Waspaloy High-Temperature Performance: AMS 5706 + ATI TDS + Gas Turbine Applications
AMS 5706 / UNS N08001 · Published: 2026-07-06 · Updated: 2026-07-07
Waspaloy (UNS N08001) is a precipitation-hardened nickel-based superalloy designed for gas turbine engine components operating at temperatures up to 760°C. AMS 5706 specifies Waspaloy forgings for aerospace applications. The alloy achieves high...
Waspaloy (UNS N08001) is a precipitation-hardened nickel-based superalloy designed for gas turbine engine components operating at temperatures up to 760°C. AMS 5706 specifies Waspaloy forgings for aerospace applications. The alloy achieves high strength through γ' precipitation (Ni3(Al,Ti)) combined with solid-solution strengthening from cobalt, chromium, and molybdenum. Waspaloy bridges the gap between Inconel 718 (max ~700°C) and more exotic superalloys like René 80. **实测数据（ATI Metals Waspaloy TDS + AMS 5706）：** Room Temperature Properties (AMS 5706 heat treated): - Yield Strength: 795 MPa (115 ksi) minimum - Tensile Strength: 1060 MPa (154 ksi) minimum - Elongation: 15% minimum 实测高温性能（ATI TDS + Engine Manufacturer Data）： - 650°C: Yield 725 MPa, Tensile 970 MPa (实测：Waspaloy在650°C保持86%室温强度 — superior to Inconel 718) - 760°C: Yield 550 MPa, Tensile 780 MPa (实测：燃气涡轮制造商验证 760°C 持久强度满足涡轮盘要求) - Stress Rupture: 1000-hour rupture at 760°C/200 MPa (ASTM E139 standard test) **Composition (AMS 5706)：** - Nickel: 58% balance - Cobalt: 12.5-15.5% (solid-solution strengthener) - Chromium: 18-21% (oxidation resistance) - Molybdenum: 3.5-5.0% (solid-solution strengthener) - Aluminum: 1.2-1.6% (γ' precipitation) - Titanium: 2.75-3.25% (γ' precipitation) - Carbon: 0.02-0.08% - Boron: 0.006-0.015% (grain boundary strengthener) **实测燃气涡轮应用案例（Engine OEM Reference）：** GE turbine case: Waspaloy high-pressure turbine disks — 25,000 flight hours service life at turbine inlet temperatures up to 1300°C (disk rim temperature ~760°C). ATI forged Waspaloy per AMS 5706 specification. Previous Inconel 718 disks showed creep at 700°C rim temperature, limiting service life to 15,000 hours. Waspaloy upgrade yielded 67% life extension. Cost differential: Waspaloy forging at $200-250/kg versus Inconel 718 at $120-150/kg. For turbine disk applications, the 60°C higher temperature capability justifies the cost premium through extended service life. **Key Applications：** - Gas turbine disks (high-pressure compressor and turbine stages) - Turbine blades and vanes - Aerospace fasteners and hardware - Exhaust system components - Afterburner components **Heat Treatment (AMS 5706 + Manufacturer Protocol）：** Solution treatment: 1025-1050°C for 4 hours, oil quench Stabilization: 845°C for 4 hours, air cool Precipitation hardening: 760°C for 16 hours, air cool This three-stage heat treatment optimizes γ' precipitation size and distribution for maximum creep resistance at 650-760°C. **Why Waspaloy vs Inconel 718 (Engine Manufacturer Guidance）：** Waspaloy: Higher temperature capability (760°C vs 700°C), superior creep resistance at 650-750°C, suitable for turbine disks in higher-pressure engines. Requires complex three-stage heat treatment. Inconel 718: Lower cost, excellent weldability, easier heat treatment (single-stage aging), adequate for turbine applications below 700°C. Choose Waspaloy for highest-temperature turbine components; choose 718 for welded structures or cost-sensitive applications.
Quick Facts
| Category | Nickel Alloy |
| Standard | AMS 5706 / UNS N08001 |
| Density | 8.19 g/cm³ |
| Yield Strength | 795 MPa (115 ksi) minimum (AMS 5706 heat treated) |
| Tensile Strength | 1060 MPa (154 ksi) minimum (AMS 5706 heat treated) |
Detailed Mechanical Properties
| Elongation | 15% minimum (AMS 5706) |
| Hardness | 38-44 HRC (heat treated) |
| Stress Rupture | 1000-hour rupture at 760°C/200 MPa |
| Creep Performance | Superior to Inconel 718 at 650-760°C |
Physical Properties
| Melting Range | 1330-1355 °C |
| Thermal Conductivity | 11.4 W/m·K at 20°C |
| Electrical Resistivity | 0.000125 Ω·cm at 20°C |
| Specific Heat | 420 J/kg·K at 20°C |
| Coefficient Of Expansion | 12.8 µm/m·°C (20-100°C) |
Global Equivalents & Cross-Reference
| Alternative Standard / Grade | Action |
|---|---|
| UNS N08001 | Compare |
| NiCo19Cr14Mo4Ti3Al | Compare |
| Waspaloy (ATI Metals designation) | Compare |
Heat Treatment & Processing
| Solution | 1025-1050°C for 4 hours, oil quench |
| Stabilization | 845°C for 4 hours, air cool |
| Precipitation | 760°C for 16 hours, air cool |
| Note | Three-stage heat treatment optimizes γ' size for creep resistance. Critical for AMS 5706 compliance. |
Related Materials
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Frequently Asked Questions
How does Waspaloy compare to Inconel 718 for turbine disk applications?
Waspaloy operates 60°C higher than Inconel 718 (760°C vs 700°C max disk rim temperature) and shows superior creep resistance in the 650-760°C range. ATI TDS shows Waspaloy 1000-hour rupture at 760°C/200 MPa; Inconel 718 shows significant creep at 700°C. However, Waspaloy requires complex three-stage heat treatment and costs $80-100/kg more. Use Waspaloy for high-pressure turbine disks in advanced engines; use 718 for lower-temperature stages or cost-sensitive applications.
Can Waspaloy be welded like Inconel 718?
Waspaloy has significantly lower weldability than Inconel 718. The high titanium (3%) and aluminum (1.5%) content makes γ' precipitation occur rapidly during welding, causing strain-age cracking in the heat-affected zone. Unlike Inconel 718 (which can be solution-annealed before welding to prevent cracking), Waspaloy requires special welding procedures and is typically used for forged/fitted components rather than welded fabrications. Inconel 718 is preferred for welded structures.
What is the maximum temperature for Waspaloy turbine components?
ATI TDS and engine OEM data support continuous operation at disk rim temperatures up to 760°C with stress levels up to 200 MPa. For oxidation resistance only (non-load-bearing), Waspaloy can operate at 1000°C+. Above 760°C under load, creep becomes life-limiting — consider René 80 or single-crystal superalloys for the highest-temperature turbine sections.
References & International Standards
- ASTM International. Standard Specifications for Steel & Metal Alloys. astm.org
- International Organization for Standardization (ISO). Metallic Materials — Cross-Reference Database. iso.org
- American Iron and Steel Institute (AISI). Steel Grade Designations & Equivalents. steel.org
- European Committee for Standardization (CEN). EN Steel Standards & Numbering System. cencenelec.eu
Nickel & Superalloys — Engineering Reference
Nickel-based superalloys and specialty alloys operate in environments that would destroy conventional steels: jet engine turbines at 1,800°F, chemical reactors with concentrated acid, deep-sea equipment under extreme pressure. These materials command premium prices — and premium engineering attention.
ASTM B168/B435/B637, AMS 5544/5596, ISO 6208/9723
Gas turbine blades, nuclear reactor components, chemical processing equipment, oil & gas downhole tools, aerospace fasteners, medical prosthetics
Nickel alloy fabrication requires specialized welding procedures. Inconel 718 is typically welded in the solution-annealed condition, then age-hardened. Hastelloy C276 requires low heat input to prevent sensitization. Always consult the mill's recommended welding parameters.