MICROSTRUCTURAL AND MICROCHEMICAL ANALYSIS OF ALUMINIZED SUPERALLOY

In this work, the high temperature stability of aluminized superalloy samples has been examined after oxidation for different intervals at 800-1100 °C. The results showed that dense and adherent aluminized coating can be deposited by pack cementation. The microstructural and microchemical changes that occurred in the aluminized samples under different exposure conditions were studied. It was found that Pt modified samples exhibited better oxidation resistance as compared with the aluminized samples. The microanalysis showed changes in the aluminide coating from a two-layer to a well-defined multilayered structure in the samples oxidized at 1000 °C and above. The consequences of theses changes on the formation of Cr, W, Ti and Mo- rich phases are considered for the integrity of the aluminide superalloy samples.