Microstructural characteristics of TiC-reinforced composite coating produced by laser syntheses

An in situ method has been developed to produce a Ni alloy composite coating reinforced by in situ reacted and gradiently distributed TiC particles by one-step laser cladding. The dispersed, ultrafine TiC particles in the coating ate observed. Most of TiC particles, evidently with a gradient distribution, are uniformly distributed within interdendritic regions due to the trapping effect of advanced solid-liquid interface. The TiC/gamma-Ni interface is clean and free from deleterious surface reactions. The microhardness of the coating also has a gradient variation, with the highest value being 1250 Hv 0.2.