Advance in research of carbon effect on single crystal Ni-base superalloy

The effect of carbon on the solidification microstructure, grain defects, alloying elements segregation, phase stability and tensile, creep, fatigue properties of single crystal superalloys as well as the mechanism were introduced. The results indicate that with increasing of carbon content, the incipient melting temperature of alloys decreased, the volume fraction and the size of γ/γ' eutectic increased, at the same time the creep life greatly decreased and minimum creep rate increased. The solidification segregation also changed with increasing of carbon content, the segregation of W and Al decreased, but the segregation of Ta and Ti increased. Minor addition of carbon improved fatigue life, and the yield stress decreased with increasing of carbon level. The effecting mechanisms of carbon addition on the microstructure and mechanical properties were compared and analyzed, and the research direction in future is pointed out.