Shape Optimization of Ceramics/Metal Joint Based on Reliability

Abstract

New-Ceramics have a great potential in various engineering applications. However, most ceramics are brittle and poor in machinability. These drawbacks are overcome by introducing composite structures consisting of ceramics and metals. In most cases, the ceramics and the metal are joined at an elevated temperature by brazing or diffusion bonding. Due to the large difference in thermal expansion coefficients of the two materials, significant residual stresses are produced during the cooling process after joining [1]. Such residual stress created at the bonding region may cause cracking or reduce the bonding strength. Thus, it is desirable to minimize the magnitude of the residual stress and various techniques have been developed for this purpose. One such technique is to introduce an interlayer [2]. Another possible technique is to reduce stresses by controlling the shape of the bonding zone [3].