# NIMONIC Alloy 263 (UNS N07263) Properties and Applications

Introduction to NIMONIC Alloy 263

NIMONIC Alloy 263, also known by its UNS designation N07263, is a nickel-chromium-cobalt alloy that offers exceptional high-temperature strength and oxidation resistance. Developed as part of the renowned NIMONIC series of superalloys, this material is specifically designed for applications in extreme environments where conventional materials would fail.

Chemical Composition

The alloy’s superior performance stems from its carefully balanced chemical composition:

• Nickel (Ni): 51% (base)
• Chromium (Cr): 20%
• Cobalt (Co): 20%
• Molybdenum (Mo): 5.9%
• Titanium (Ti): 2.1%
• Aluminum (Al): 0.4%
• Carbon (C): 0.04-0.08%
• Boron (B): 0.005%

Key Properties

Mechanical Properties

NIMONIC Alloy 263 exhibits outstanding mechanical properties at elevated temperatures:

• Tensile strength: 950-1200 MPa at room temperature
• Yield strength: 550-750 MPa at room temperature
• Elongation: 30-40% at room temperature
• Maintains significant strength up to 800°C (1472°F)

Physical Properties

• Density: 8.36 g/cm³
• Melting range: 1350-1400°C (2462-2552°F)
• Thermal conductivity: 11.2 W/m·K at 20°C
• Electrical resistivity: 1.18 μΩ·m at 20°C

Corrosion Resistance

The alloy demonstrates excellent resistance to:

• Oxidation at high temperatures
• Carburization and sulfidation
• Chloride-induced stress corrosion cracking

Heat Treatment

NIMONIC Alloy 263 typically undergoes the following heat treatment process:

Keyword: NIMONIC Alloy 263 UNS N07263

1. Solution treatment at 1150°C (2102°F) for 2 hours, followed by rapid cooling
2. Aging at 800°C (1472°F) for 8 hours, followed by air cooling

Fabrication and Machining

While NIMONIC Alloy 263 can be fabricated using standard techniques, it presents some challenges:

• Hot working should be performed between 1050-1200°C (1922-2192°F)
• Cold working requires intermediate annealing
• Machining requires rigid setups, sharp tools, and slow speeds
• Welding is possible using TIG or MIG methods with matching filler metal

Applications

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