A novel nano Cu/Ti–Si3N4 ceramic substrates fabricated by spark plasma sintering and its bonding mechanism

Abstract

The nanocrystalline materials have prominent advantages, but the fabrication of nanocrystalline bulk materials, especially nanocrystalline structure parts, is still difficult. In the practical application of nanocrystalline materials, it is very necessary to join them to other structural materials. In this study, a novel nano-Cu/Ti–Si3N4 ceramic substrates is first fabricated using SPS with the addition of Ti transition layers. Microstructural evolution in the bonding zone of nano Cu/Ti–Si3N4 ceramic substrates is investigated to determine the interfacial bonding mechanism, which is based on the microstructures obtained at different holding times. The analysis of microstructural evolution reveals that the diffusion of O, Ti and Cu atoms under the action of pulse current promotes three important interfacial reactions, which in turn promotes the microstructural evolution of the bonding zone. The joint with a two-layer structure, which consist of a Ti2O layer and a Cu layer with dispersed Ti4Cu2O (Ti3Cu3O), exhibits has the best bonding properties.