Temperature dependence of tensile properties and deformation behaviors of nickel-base superalloy M951G

Tensile behaviors of M951G alloy have been studied from 20°C to 1100°C. It shows that the higher W and Hf additions enhance the tensile strength of M951G alloy greatly compared to M951 alloy from RT to 800°C, which has been analyzed from the points of deformation microstructures, the strong effect of solid solution strengthening and precipitation strengthening in detail. The continuous stacking faults present in the microstructures at low temperatures, which have a significant influence on work hardening and rarely been reported in the traditional casting superalloy previously. The primary deformation mechanisms include shearing of the γ′ precipitates by a/2〈110〉 dislocations below 600°C and by-passing of γ′ precipitates by a/2〈110〉 matrix dislocations above 900°C. At intermediate temperatures, it shows a transition from shearing to by-passing. At last, the relationship between tensile properties and microstructures has been reasonably explained.