Joining of Powder Metallurgy Products to Metals

摘要

Joining technologies of ceramic powder metallurgy products to metals have been advanced in recent years, especially in powder metallurgy industries. There have a lot of difficult problems to be overcome in developing joining techniques. To control the chemistry of interfaces is, of course, one of the major key points. The active metal brazing has been established for solving this problem and gives scientists high quality of joints. To construct an appropriate interlayer for reducing thermal stress originating from thermal expansion mismatch between a ceramic and a metal is another critical problem. The soft metal interlayer and the soft metal/hard and low expansion metal laminate interlayer are proved to be two of the effective interlayers. The other bonding parameters such as surface roughness of bond face and bonding pressure are also important into get new sound as well as strong ceramic/metal joints. Most ceramic-metal bonding is conducted at high temperatures, where chemical reaction is to be expected. In this article the new recent developments in joining ceramics to metals considering the interfacial behavior of their bonds are discussed. Therefore, methods of joining were compromised and the most famous insert layers were introduced. In addition, recent developments of joining of powder metallurgy products to metals in terms of case studies have been conducted in detail.