Study on Strengthening Mechanism of Arc Welding Interface Between TiC Steel-Bonded Carbides and Welding Material Based on First Principles

In this study, the effects of W, Cr, and Mo alloying elements on the microstructure and mechanical properties of the arc welding interface between TiC steel-bonded carbide and welding material were investigated using TEM, SEM, microhardness testing, and mechanical property testing. First-principles calculations were employed for verification. The results indicate that, under the experimental conditions, the shear strength of the arc welding interface between the ZDZC60 carbide and the multi-component composite welding material (enhanced with W, Cr, and Mo) was 83% higher than that before optimization. The order of the three metal atoms when substituting Ti atoms in TiC particles was determined as W > Mo > Cr. The “core–rim” structure of TiC particles in the partially melted zone (PMZ) of the arc welding interface was proposed. The coherent structure of TiC particles, characterized by (200)TiC//(200)TiMoC2//(200)TiWC2 and [011]TiC//[011]TiMoC2//[011]TiWC2, was identified. W and Mo atoms exert an inhibitory effect on the dissolution of TiC particles, while Cr atoms disperse in the binder phase in the form of carbides and solid solutions, thereby effectively strengthening the interface.