Microstructure and wear resistance of in situ TiCp composite coating by laser cladding

A new in situ method was realized by one step laser cladding to produce Ni- base alloy composite coating reinforced by in situ reacted and gradiently d istributed TiCp particles. The submicron TiCp particles were formed and uni formly distributed because of the in situ reaction and trapping effect unde r the rapid solidification condition. And, TiCp particles were of gradient distribution on a macro scale and their volume fraction increased from 1.86 % at the layer/substrate interface to a maximum 38.4% at the surface of the layer. Furthermore, the in situ generated TiCp/gamma-Ni interfaces were fr ee from deleterious surface reactions. Additionally, the clad coating also revealed a high microhardness of gradient variation with the layer depth an d the superior abrasive wear resistance.