Microstructure Evolution of Cold-Sprayed Al-Si Alloy Coatings on gamma-TiAl During Heat Treatment

摘要

This paper investigated the influence of heat treatment on the microstructure of Al-Si alloy coatings on gamma-TiAl alloy. The coatings were prepared by cold spraying with Al-12Si and Al-20Si alloy powders as the feedstock, and then the as-sprayed coatings were subjected to heat treatment. The microstructure, chemical composition, and phase transformation of the coatings were studied by SEM, XRD, and EPMA. The diffusing behavior of Al and Si during heat treatment was investigated. The results showed that a silicon-aluminizing coating was formed through the inward diffusion of Al/Si elements into the substrate. The obtained kinetics curve of the formation of silicon-aluminizing coating at 580 A degrees C similarly followed parabolic law.