Microstructural characteristics of laser surface melted MoSiBTiC alloy

Abstract The microstructural characteristics of a TiC-added Mo-Si-B (MoSiBTiC) alloy fabricated by laser surface melting were investigated. The microstructure inside a melt pool consisted of many cells, and each cell was composed of an ultrafine ternary eutectic lamellar structure with Mo solid solution (Moss), Mo5SiB2, and (Mo,Ti)2C phases. The lamellar structure completely disappeared in a heat affected zone (HAZ) formed by multi tracks test, and a fine round (Ti,Mo)C phase newly precipitated in the HAZ together with other phases. The chemical composition analyses identified the elemental supersaturation of Si and Ti in the Moss phase and of Ti in the T2 phase in the lamellar structure.