Joining ceramics to metals by abnormal glow discharge plasma

Abstract

A novel joining technique of ceramics to metals is presented, in which depositing Ti on ceramics with arc-added glow discharge is used as a prior metallizing technique and then brazing the ceramics to metals by abnormal glow discharge is carried out. The heating temperature of the base metals is easily controlled by varying the operating voltage and barometric pressure. The ions beam from the glow discharge anode is efficiently able to sputterclean the surfaces of the base materials, which thereby improves better Ti-deposited adhesion on the ceramics and the wetting and spreading properties of the filler metal. The thickness of the Ti-deposited layer is readily adjusted in terms of the actual requirement. The vacuum pressure during brazing can be up to 5 Pa. The cost and duration of the glow discharge plasma brazing are reduced as compared with the traditional vacuum brazing process. The joining technique developed holds potential for industrial applications leading to high product quality.