Joining of silicon nitride by microwave local heating

Microwave local heating was used to join silicon nitride. Glass was placed at the joint between two silicon nitride pipes and a silicon carbide susceptor was placed around the joint. The susceptor was locally heated by absorbing the microwave radiation. On heating to 1500°C, the glass melted and filled the space between the pipes, thereby joining the two pipes. Average strength of the specimen cut out from the joined pipe was 446 MPa. This demonstrates the potential of microwave local heating for joining silicon nitride.