Incoloy 907 Alloy
Low Thermal Expansion, High-Strength Nickel-Iron-Cobalt Superalloy
Supplied by Huaxiao-Alloy – Your Trusted Global Alloy Partner
Incoloy® 907 Alloy is a precipitation-hardenable nickel-iron-cobalt alloy engineered for applications that require extremely low thermal expansion, high mechanical strength, and exceptional dimensional stability across a wide temperature range. It is widely used in aerospace, gas turbine engines, precision mechanical assemblies, and high-performance structural components where thermal mismatch must be minimized.
Huaxiao-Alloy supplies Incoloy 907 Alloy in all product forms, meeting ASTM, AMS, ASME, and UNS standards, with full traceability and export-grade quality assurance.
1. Incoloy 907 Alloy Overview
Incoloy 907 belongs to the family of low-expansion nickel alloys, similar in concept to Incoloy 903 but optimized for higher strength and improved stress relaxation resistance. By carefully balancing nickel, iron, and cobalt with niobium, titanium, and aluminum, the alloy achieves:
Very low coefficient of thermal expansion (CTE)
High yield and tensile strength after aging
Excellent resistance to stress relaxation
Outstanding fatigue performance
Stable microstructure during thermal cycling
These properties make Incoloy 907 especially suitable for aerospace and high-precision engineering applications.
2. Chemical Composition of Incoloy 907 Alloy (%)
| Element | Content (%) |
|---|---|
| Nickel (Ni) | 36.0 – 38.0 |
| Iron (Fe) | Balance |
| Cobalt (Co) | 12.0 – 14.0 |
| Chromium (Cr) | ≤ 0.50 |
| Niobium (Nb) | 4.3 – 4.8 |
| Titanium (Ti) | 1.2 – 1.6 |
| Aluminum (Al) | 0.2 – 0.5 |
| Carbon (C) | ≤ 0.03 |
| Manganese (Mn) | ≤ 0.50 |
| Silicon (Si) | ≤ 0.50 |
| Sulfur (S) | ≤ 0.015 |
📌 Metallurgical Advantage:
The Nb-Ti-Al system forms fine gamma-prime (γ′) precipitates, delivering high strength without sacrificing low thermal expansion.
3. Mechanical Properties of Incoloy 907 Alloy
Solution Annealed + Aged (Typical)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 1300 MPa |
| Yield Strength (0.2%) | ≥ 900 MPa |
| Elongation | ≥ 10% |
| Hardness | 38 – 44 HRC |
| Fatigue Strength | Excellent |
| Stress Relaxation Resistance | Outstanding |
Actual values may vary with product form and heat-treatment condition.
4. Physical Properties of Incoloy 907 Alloy
| Property | Value |
|---|---|
| Density | 8.20 g/cm³ |
| Melting Range | 1350 – 1420°C |
| Coefficient of Thermal Expansion (20–300°C) | ~7.0 μm/m·K |
| Elastic Modulus | ~200 GPa |
| Electrical Resistivity | ~1.10 μΩ·m |
Key Benefit:
The CTE of Incoloy 907 is significantly lower than most nickel alloys, making it ideal for thermal mismatch-sensitive assemblies.
5. Key Features & Advantages of Incoloy 907 Alloy
📐 Ultra-Low Thermal Expansion
Maintains dimensional accuracy during rapid or repeated temperature changes.
💪 High Strength After Aging
Excellent combination of strength and stability, even in demanding service.
🔁 Superior Stress Relaxation Resistance
Ideal for bolted joints, fasteners, and preload-critical components.
🛠️ Good Fabricability
Machinable and weldable in solution-annealed condition.
6. Available Product Forms (Huaxiao-Alloy Supply)
Huaxiao-Alloy provides Incoloy 907 Alloy in full commercial and custom forms:
Long Products
Round bars
Square & flat bars
Forged bars
Shafts
Flat Products
Plates
Sheets
Strips
Tubular Products
Seamless mechanical tubes
Precision tubing
Precision & Custom Components
Aerospace fasteners
Structural rings
Engine components
Machined precision parts
7. Standards & Equivalent Grades
| Standard | Designation |
|---|---|
| UNS | N19907 |
| ASTM | B637 |
| AMS | AMS 5706 / AMS 5707 |
| ASME | SB-637 |
| EN / DIN | Available upon request |
📄 Documentation: EN 10204 3.1 / 3.2, PMI, full heat traceability
8. Corrosion & Oxidation Resistance
Incoloy 907 is not designed as a corrosion-resistant alloy for aggressive chemical environments. However, it offers:
Good resistance to atmospheric corrosion
Stable oxidation resistance at moderate temperatures
Excellent environmental stability in controlled service conditions
For corrosive environments, alloy selection consultation is recommended.
9. Typical Applications
Aerospace & Aviation
Jet engine casings
Structural rings
Fasteners & preload-critical parts
Control system components
Gas Turbine & Energy
Turbine structural elements
Generator support components
Precision Engineering
Low-expansion shafts
Dimension-critical assemblies
Thermal cycling components
Defense & Advanced Manufacturing
High-performance mechanical structures
Fatigue-sensitive assemblies
10. Heat Treatment & Fabrication Guide
Heat Treatment
Solution annealing: ~980°C, air cool
Aging: 720–760°C for precipitation strengthening
Machining
Best in solution-annealed condition
Carbide tools recommended
Welding
GTAW / GMAW suitable
Weld in annealed condition
Post-weld aging required to restore strength
11. Quality Control & Inspection
Huaxiao-Alloy ensures:
Chemical composition verification
Mechanical & hardness testing
Ultrasonic & surface inspection
Heat-treatment validation
PMI testing
Dimensional inspection
Full mill test certificates
12. Why Choose Huaxiao-Alloy for Incoloy 907?
✔ Certified mill sources
✔ Aerospace-grade quality assurance
✔ Custom heat treatment & machining
✔ Stable supply & competitive pricing
✔ Export-ready packaging
✔ Technical alloy selection support
📍 Manufacturing & Stock: Wuxi · Foshan · Shanghai Baoshan
🌍 Global Export: North America · Europe · Middle East · Asia-Pacific
Incoloy 907 offers higher strength and better stress relaxation resistance.
Yes, it is widely used in engine and structural aerospace components.
Yes, aging heat treatment is essential to achieve full mechanical properties.
It has moderate corrosion resistance but is not intended for aggressive environments.
Yes, AMS-certified material is available on request.
Recent Blog
If you found this article good, feel free to share it on your other social media platforms.
