Joining of Sintered Silicon Carbide Ceramics Using Sodium Borosilicate Glass as the Solder

Abstract

Sodium borosilicate glass powder with the Si : B : Na molar ration of 53:44:6 has been developed and used as the solder to join sintered SiC ceramics. The coefficient of thermal expansion of the glass matches the silicon carbide substrate well at low temperature, and the wettability of the solder on SiC substrate becomes excellent above 1150°C. The 4‐point bending strength of the joint reaches 218 ± 23 MP a at room temperature and the joint strength at 400°C can be kept at 154 ± 35 MP a. The microstructure, compositions, and interfacial properties were studied. Results showed that a good adhesion between SiC substrate and the solder layer was achieved.