Effect of refractory modifiers on the structure of coatings based on chromium carbide

Abstract

Chromium carbide-based coatings with and without TiC and TiB2 modifiers were fabricated by non-vacuum electron-beam cladding. Addition of the modifiers to the initial Cr3C2 powder mixture led to a change in the phase composition, microhardness and wear resistance of the composite coatings and the α → γ transformation of Fe. TiC and TiB2 particles formed the many crystallization centers in composite coatings, which led to a refinement of their microstructure. Larger TiC particles compared to the TiB2 particles were formed in the coatings as a result of melt crystallization. TiC modifier caused a decrease in the size of dendrites, while TiB2 led to a transition from a coarse dendritic structure to an equiaxed one. The coatings with TiC modifier demonstrated the maximum microhardness, and TiB2 coating had increased wear resistance.