Nimonic 86 has become a popular choice for components ranging from the turbine to exhaust valves in the aerospace and automotive industries. The material’s high strength, corrosion resistance, and high-temperature capabilities make it a popular choice for harsh environments. In this blog post, we’ll delve into what nimonic 86 is, its composition, properties, and uses.
What is Nimonic 86?
Nimonic 86 is a nickel-based superalloy primarily composed of nickel, chromium and cobalt. It features excellent mechanical strength, corrosion resistance, and oxidation resistance even at elevated temperatures up to 900°C. Its superior high-temperature strength makes it ideal for aircraft turbines, rocket engines and other applications where high-temperature performance is essential.
Composition
Nimonic 86 is an age-hardening nickel-based superalloy developed by special metals corporation. This material is made of nickel, chromium, cobalt, and titanium. Additionally, it has small amounts of iron, aluminium, and manganese, which gives this alloy its unique properties.
| Element | Content (%) |
|---|---|
| Nickel, Ni | 65 |
| Chromium, Cr | 25 |
| Molybdenum, Mo | 10 |
| Carbon, C | 0.050 |
| Cerium, Ce | 0.030 |
Physical Properties
Nimonic 86 has an impressive composition that results in a combination of high strength, ductility, and toughness, making it an excellent fit for harsh environments.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.54 g/cm³ | 0.309 lb/in³ |
| Melting point | 1357°C | 2475°F |
Mechanical properties
Regarding mechanical properties, nimonic 86 has an ultimate tensile strength of 1500 MPa with a yield strength of 1200 MPa. It also elongates 35%, which is noteworthy for a material with such high power. Moreover, its physical properties include its density of 8.37 gm/cc, thermal conductivity of 14 W/m-K, and specific heat capacity of 444 J/kg-K.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength (solution annealed, value at room temperature) | 825 MPa | 120000 psi |
| Yield strength (solution annealed, value at room temperature, @strain 0.200%) | 410 MPa | 59500 psi |
| Elastic modulus | 210 GPa | 30500 ksi |
| Elongation at break (solution annealed) | 42% | 42% |
Uses
Nimonic 86 is a popular choice for applications that require high temperature and corrosion resistance. It has excellent corrosion resistance to marine and alkalis environments, making it a popular choice for oceanic and coastal construction. Nimonic 86 is also popular in turbojet and turbofan applications due to its high-temperature capabilities. Additionally, it is suitable for high-stress environment applications such as exhaust valves, airframe components, and heat exchangers.
Heat-treatment
Heat treatment of nimonic 86 is critical to its mechanical and physical properties. It is typically heat treated to 1070°C and held at temperature for four hours. It is then water-quenched to cool it quickly, which hardens the alloy.
Machining
Machining nimonic 86 is challenging due to its brutal and ductile nature; however, it can be machined with a sharp cutting tool and slow spindle speed. Additionally, the best results come from finishing cuts at high speed and with suitable coolant.
Welding
Welding nimonic 86 requires an experienced welder with appropriate equipment. It can be welded using tungsten inert gas welding and other fusion welding techniques. Nimonic 86 can also be joined using resistance welding or brazing. Proper post-weld heat treatment is necessary to prevent the formation of brittle phases or cracks.
Conclusion
Nimonic 86 is a versatile superalloy designed for high-temperature and corrosive applications where high strength and toughness are needed. Its high temperature, corrosion resistance, and excellent mechanical and physical properties make it an ideal material for harsh environments. Nimonic 86’s composition and properties make it popular in the aerospace, automotive, and marine industries. To get the best results with nimonic 86, proper heat treatment, machining, and welding is necessary.
Abhishek is a seasoned blogger and industry expert, sharing his insights and knowledge on various topics. With his research, Abhishek offers valuable insights and tips for professionals and enthusiasts. Follow him for expert advice on the latest trends and developments in the metal industry.
