Grinding of superalloys using metal-bonded CBN wheel

Superalloys, used for turbine blades and jet engines for airplanes, have low heat conduction and high strength at elevated temperature. These properties make it very difficult to obtain effective grinding processes with high accuracy. Superalloys with fine performance under high temperature circumstances attract great attention to be used as the material for turbine blades. It has been expected to establish reliable efficient grinding of superalloys at the final grinding process. In this study, the influence of wheel wear, grinding ratio, and surface roughness, with the grinding process of superalloys, using metal bonded CBN wheel were carefully observed. Since superalloys have lower heat conduction and they cause a severe wheel wear, which leads to low grinding ratio. However, the high grinding ratio of about 800 and the stable figure of surface roughness of Rz=2μm were obtained when Co-base PWA647 and X45 were ground by using metal-bonded CBN wheel. Consequently, the Co-base superalloys perform rather well producing finer grinding process than the intensive Ni-base or Fe-base superalloys.