Electrical Joining of Silicon Nitride Ceramics

Sintered silicon nitride ceramics were joined, employing the joule heating by electric current through the joining paste containing CaF2. The flexual strength of the joint was dependent on the thickness of the joint layer. The thickness was controlled by the time of joule heating. For instance, heating for 10 minutes gave the thickness about 10 to 30μm. This sample showed the maximum strength around 300MPa up to 800°C. But the strength decreased rapidly above 900°C, perhaps because of the softening of the joint layer.