한국주조공학회

Dendrite boundaries and γ/γ’ structure of a second generation single crystalline superalloy CMSX-4 almost disappeared during solution treatment above 1310oC. γ’ size in the dendrite core was uniform and fine, however, that in the interdendritic region was coarse and nonuniform. With increasing solutionizing temperature and time, γ’ size in the interdednritic region became fine and segregation of alloying elements between dendrite core and interdendritic region diminished. Segregation of solid solution strengthening elements such as W, Co, Re in the dendrite core was not fully removed through the heat treatments, especially that of Re still remained to some extent. Tensile properties at room temperature at which does not cause precipitaion of harmful phases, were improved with increasing solutionizing temperature and time.

Single crystalline superalloy, CMSX-4, Dendrite core, Interdendritic region, Solution treatment, Segregation, γ/γ’ structure and γ’ phase