Nickel-based superalloys occupy a special and important position in the entire field of superalloys. Nickel-based superalloys are widely used to manufacture the hottest parts of aviation jet engines and various industrial gas turbines.
If the durable strength of 150MPA-100H is used as the standard, the highest temperature that nickel alloys can withstand is >1100°C, while nickel alloys are about 950°C, and iron-based alloys are less 850°C, that is, nickel-based alloys are correspondingly higher by 150°C to about 250°C. So people call the nickel alloy the heart of the engine.
The structure of nickel is very stable, and there is no allotropic transformation from room temperature to high temperature; this is very important for selection as a matrix material.
Nickel has high chemical stability, hardly oxidizes below 500 degrees, and is not affected by warm air, water and some aqueous salt solutions at school temperatures. Nickel dissolves slowly in sulfuric acid and hydrochloric acid, but quickly in nitric acid.
Nickel has great alloying ability, and even adding more than ten kinds of alloying elements does not appear harmful phases, which provides potential possibilities for improving various properties of nickel.
Although the mechanical properties of pure nickel are not strong, its plasticity is excellent, especially at low temperature, the plasticity does not change much.
