Fast bonding α-SiAlON ceramics by spark plasma sintering

Yb- and Y-doped α-SiAlON ceramics were effectively bonded by spark plasma sintering in less than 20 min without using any interlayer materials at 1650–1700 °C. The microstructures and mechanical properties of the joints were investigated by means of SEM, STEM, EDX, and three-point bending tests. The results showed that α-SiAlON joint formation was accompanied by fundamental rare earth diffusion. The intergranular liquids in the α-SiAlON ceramics at the bonding temperatures provided the diffusion paths for the species. α-SiAlON grain growth across the joining interfaces modified the joint microstructures to secure high bonding strength.