In situ Ti2Ni/Ti2S reinforced Ti-based composites with enhanced mechanical properties fabricated by laser cladding on TC4 alloy

摘要

In this study, a Ti2Ni/Ti2S reinforced Ti-based composite coating was fabricated using laser cladding to improve the mechanical properties of TC4 alloy. The results show that the high temperature (>3000 K) of the molten pool ensures the effectiveness of the deposited coating and the thermodynamic conditions for in situ reactions. The phases consisted of beta-Ti, Ti2Ni, Ti2S, TiC, and WC. Furthermore,-Ti beta nucleated and grew with TiC as hetero-geneous cores due to their orientation relationships of beta-Ti{1 0 0}//TiC{1 1 0} and beta-Ti{1 1 0}//TiC{1 1 1}. As a result, the microhardness of the coating was 2.30 times higher than the substrate, and the wear volume decreased by 20.23 compared to the substrate.