Joining of dense Si3N4 ceramics with tape cast Lu-Al-Si-O-N interlayer

Lu-Al-Si-O-N tapes with different thickness were used to join gas pressure sintered Si 3 N 4 ceramics. The microstructure of the joints and the influences of the joint thickness and joining temperature on the bonding strength of the as-joined Si 3 N 4 ceramics have been investigated. The highest bonding strength about ~ 300   MPa of the joined specimens was achieved by using 450   µm interlayer at 1450   °C. The existence of Si 3 N 4 nanowires was beneficial for the improvement of the bonding strength by interweaving the oxynitride glass matrix in the joint region.