Incoloy 909 합금의 최적 알루미나이징 확산 코팅

Abstract

An Fe-Ni-Co based superalloy Incoloy 909 (Incoloy 909) has been used for gas turbine engine component material. This alloy is susceptible to high temperature oxidation and corrosion because of the absence of corrosion resistant Cr. For the improvement of durability of the component of Incoloy 909 aluminizing-chromate coating by pack cementation process has been investigated at relatively low temperature of about 550oC to protect the surface microstructure and properties of Incoloy 909 substrate. As a previous study to aluminizingchromate coating by pack cementation of Incoloy 909, the optimal aluminizing process has been investigated. The size effects of source Al powder and inert filler Al2O3 powder and activator selection have been studied. And the dependence of coating growth rate on aluminizing temperature and time has also been studied. The optimal aluminizing process for the coating growth rate is that the mixing ratio of source Al powder, activator NH4Cl and filler Al2O3 are 80%, 1% and 19% respectively at aluminizing temperature 552oC and time 20 hours.