Influence of alloying element Nb on the γ′ phase structure and mechanical properties of Co–8.8Al–9.8W alloy
摘要
Effect of Nb element on the microstructure and mechanical properties of Co–8.8Al–9.8W superalloy was analysed by studying the occupancy of Nb element in the lattice and difference in the microstructure evolution during deformation. The calculation results show that Nb atom occupies the first priority position of Al2 and the second priority position of W6, forming a γ′ phase doped structure, and its strength, hardness and structural stability are improved. In the process of high-temperature deformation, the dislocations of 0Nb alloy have the mechanisms of cutting and bypassing, which makes strengthening phase rafting phenomenon, and dislocation propagation in 2Nb alloy is difficult, and there are a lot of stacking faults. Compared to 0Nb alloy, 2Nb alloy has improved nano-indentation hardness and elasticity modulus.