Optimizing phase interface of titanium carbide-reinforced copper matrix composites fabricated by electropulsing-assisted flash sintering

Abstract

Full density TiC reinforced Cu matrix composites are fabricated by electropulsing-assisted flash sintering within 40 s. The addition of TiC significantly increases the hardness of the sintered sample. However, liquid Cu does not wet stoichiometric TiC, leading to a poor interface bonding strength between TiC and Cu, thus the tensile strength of the sintered sample is destroyed. By adding a small amount of Ti, the bonding strength of the interface between TiC and Cu can be effectively optimized, thereby the mechanical strength of the samples is improved, showing an increased hardness and tensile strength. Skillfully use the relationship between hardness and tensile strength curve to intuitively show the bonding strength of the micro interface from the macro characteristics. The reaction between dissolved Ti and stoichiometric TiC and the decomposition of stoichiometric TiC cause the formation of near-surface non-stoichiometric TiCx (x < 1) with a marked metal-like electronic structure, which is the fundamental reason for the optimization of the interface bonding between TiC particles and Cu matrix. In the process of powder metallurgy, it is a promising strategy to enhance the composite materials by adjusting the stoichiometry of ceramic to form metal-like electronic structure and alter the bonding strength of ceramic/metal interface.