Effect of full melt temperature sintering and semi-melt heat preservation sintering on microstructure and mechanical properties of Ti₃SiC₂/Cu composites

The influence of sintering parameters on the microstructure, phase composition and mechanical property of the Ti3SiC2/Cu composites sintered by spark plasma sintering technique was investigated and the related sintering mechanism was clarified in detail. Results indicated that during the heating process, one part of the high energy adsorbed by the composites let Cu melt and fill the gaps inside the composites. Meanwhile, there's different molten condition about Cu duel to different heating temperature that cause Cu fill in the most space between Ti3SiC2 particles. The other part of the energy caused to the local high temperature, contributing for the chemical reaction and the formation of TiCx and Cu3Si. Therefore, at the same heating rate, the composites showed better mechanical property and higher density with a longer heating time. The heating stage played an important role in the change of the mechanical property, microstructure and volume of the composites. During the holding stage, because the amount of the reactants significantly decreased, the related chemical reaction got slow and the energy needed during this stage was lower than that during the heating stage. And the particle of Ti3SiC2 need more time for moving to the space of Cu. Therefore, the higher the holding temperature, the more significant was the diffusion of the phases. The more uniform the phases, the higher was the density. When heating temperature (higher than holding temperature) cause Cu complete melt and holding temperature keep the Cu in semi-melt, there will be a more effective sintering method.