抄録
The fracture strength of ceramic-metal bonded material is determined by the characteristics of its interface. In the case of the bonding attained by using insert metal such as Ag brazing, the yielding phenomenon would affect the stress singularity at the interface near the end position and its strength. In this paper, the effects of plastic deformation and layer thickness on the stress singularity and strength of the bonded joint were studied. The results obtained are as follows.
The material dynamic role of soft insert metal was considered to relieve its stress singularity at the bonded interface. This effect became larger with decreasing thickness of insert metal. But when a large plastic deformation concentrated at the bonded interface, the fracture strength came down. This phenomenon seemed to be caused by the high normal stress acting to the interface, which was induced by the movement of slip lines being prevented by the bonded interface. In addition, the stress singularity was found to become smaller as the Young's modulus of the insert metal became higher.
