Effect of Ce Addition on the Microstructures and Mechanical Properties of a Ni-Co-Based Superalloy

Effects of Ce addition on the microstructures and mechanical properties of the Ni-Co-based superalloy were investigated. The results showed that addition of Ce to the alloys resulted in a Ce-rich phase (Ni,Co)₃Ce formation. The rupture life was improved greatly by Ce addition and the optimal Ce addition was about 0.2 wt.%. Both peak stress and critical stress of dynamic recrystallization were increased with increasing (Ni,Co)₃Ce phases, which was mainly due to pinning effect on grain boundary sliding by precipitation.