Influence of Mo Content on the Microstructure Stability and Stress Rupture Properties of a Single Crystal Superalloy

The single crystal superalloy with 1 and 3% Mo was prepared using the high vacuum induction melting furnace. The effect of Mo content on the structural stability and endurance properties of the alloy was studied. The results showed that the γ′ precipitate size reduced and turned uniform and the cube form became regular with increasing Mo content. The γ′ directional rafting and topologically close-packed phase precipitation appeared in the 1 and 3% Mo alloy after aged for 1000 h at 1100 °C. The volume fraction of topologically close-packed phase significantly enhanced with rise of Mo percentage. The stress rupture properties at 1100 °C/140 MPa of the alloy depredated with rise of Mo percentage.