Effect of heat treatment on microstructure and stress rupture life of DD32 single crystal Ni-base superalloy

The effect of heat treatment on microstructure and stress rupture life of DD32 single crystal Ni-base superalloy was investigated in this paper. Experimental results show that the more regular the cubic shape of γ′ precipitate, the more homogeneous the size of γ′ precipitate, the longer the creep rupture life after heat treatment. The solution temperature has more significant role on the microstructure than the hold time. The optimum solution heat treatment is 1280 °C/4 h, ac + 1290 °C/4 h, ac and the optimum high temperature ageing treatment is 1150 °C/4 h, ac. MC-type carbide in DD32 alloy is very stable during heat treatment.