The Joint of Alumina Ceramics by Using a Microwave Heating Method

Abstract

Joining of alumina ceramics was studied by the microwave heating method. Samples were the sintered 99% alumina rods, 6mm in diameter. The results are summarized as follows:
(1) The joining was carried out easily by covering the joining part with mullite insulating fire brick during application of microwave at the surface temperature on the joining part of higher than 1400°C and under the pressure at joining plane of 0.13-0.5MPa.
(2) There was a peak in the bending strength-heating time curve. The maximal value increased and the time to give the maximum decreased with increasing joining temperature.
(3) The hardness value of joined part was larger than that of the others. The grain size at the joined part increased during microwave heating.
(4) Joining was so good that the joined interface was hard to distinguish from other part by SEM observation of cross section of the joined part.