Explanation

The grain boundary free high temperature alloy was prepared by directional solidification process. Its composition is characterized by no addition of grain boundary strengthening elements, simple composition of phase, and higher melting temperature and high temperature strength than equiaxed and directionally solidified high-temperature alloy. Nickel base singlecrystal superalloy added with metallic element Re to improve creep strength and temperature holding capacity is a prominent feature in the chemical composition. 3% Re and 6% Re almost become the symbols of the second and third generation singlecrystal superalloy. Another outstanding feature of the fourth and fifth generation singlecrystal superalloy is the addition of Ru elements that further improve creep strength and inhibit the precipitation of TCP phase. Among them, the fourth generation singlecrystal superalloy add 2%? 5% Ru, adding about 6% Ru to the fifth generation singlecrystal superalloy. The third feature of chemical composition of singlecrystal superalloy is that the content of Ci ■ to improve oxidation resistance and corrosion resistance is greatly reduced. The Cr content of the first generation singlecrystal superalloy is mostly 8%? 10%, while the second generation striding alloy is reduced to 5%? 8%, reduced to less than 5% for the third to fifth generations. singlecrystal superalloy has high creep fracture strength, good plasticity and excellent cold and hot fatigue properties, but it has anisotropy. From the first generation to the fifth generation, the thermal capacity can be increased by 25? At 30 ° C, singlecrystal superalloy is mainly used to make solid and hollow turbine blades or guide vanes for advanced aeroengines and gas turbines. High performance singlecrystal superalloy, combined with advanced air-cooled blade design, exquisite precision casting technology and excellent protective coating process, has increased the turbine inlet temperature of aeroengines by about 300 ° C.

Classification