Microstructure and properties of Inconel 718 matrix composite coatings reinforced with submicron TiC particles prepared by laser cladding

Abstract

Submicron TiC particles reinforced Inconel 718 coatings were prepared by laser cladding. The coatings have a dense microstructure, uniformly distributed TiC particles, and good metallurgical bonding to the substrates. TiC particles serve as the crystal nucleus for alloy solidification, and the alloy solidifies into an equiaxed grain structure, reducing element segregation during the solidification process. The TiC morphology changes from a petal-like structure to nearly spherical particles as the TiC content increases from 10 wt% to 50 wt%. The spherical TiC particles grow based on the unmelted TiC nuclei when TiC content is 50 wt%, and these TiC particles consist of unmelted TiC and newly solidified Ti(Nb, Mo, Cr)C. The coating hardness slightly decreases and then increases with TiC increasing from 0 wt% to 50 wt%, and the wear resistance increases with increasing TiC content.