# Nimonic 901 (UNS N09901) Superalloy: Properties and Applications
Introduction to Nimonic 901
Nimonic 901 (UNS N09901) is a nickel-based superalloy known for its exceptional strength and corrosion resistance at elevated temperatures. Developed by Special Metals Corporation, this alloy is widely used in demanding applications where high mechanical strength and resistance to oxidation are required.
Chemical Composition
The chemical composition of Nimonic 901 plays a crucial role in its performance characteristics:
- Nickel (Ni): 40-45%
- Chromium (Cr): 11-14%
- Iron (Fe): Balance
- Titanium (Ti): 2.8-3.1%
- Aluminum (Al): 0.9-1.5%
- Molybdenum (Mo): 5.0-6.5%
- Carbon (C): ≤0.10%
- Manganese (Mn): ≤1.0%
- Silicon (Si): ≤0.50%
- Sulfur (S): ≤0.015%
Mechanical Properties
Nimonic 901 exhibits impressive mechanical properties that make it suitable for high-stress applications:
| Property | Value |
|---|---|
| Tensile Strength | 1100-1400 MPa |
| Yield Strength | 700-1000 MPa |
| Elongation | 10-20% |
| Hardness (Rockwell C) | 30-40 HRC |
Physical Properties
The physical characteristics of Nimonic 901 include:
- Density: 8.14 g/cm³
- Melting Point: 1320-1365°C
- Thermal Expansion Coefficient: 13.5 μm/m°C (20-100°C)
- Thermal Conductivity: 11.7 W/m·K
- Electrical Resistivity: 1.18 μΩ·m
Key Features and Advantages
Nimonic 901 offers several notable advantages:
- Excellent creep resistance at high temperatures
- Good oxidation resistance up to 800°C
- High strength-to-weight ratio
- Good fatigue resistance
- Resistance to thermal fatigue
- Maintains mechanical properties at elevated temperatures
Heat Treatment
Nimonic 901 typically undergoes the following heat treatment process:
- Solution treatment at 1080-1120°C followed by rapid cooling
- Aging at 700-800°C for 16 hours
- Optional double aging