Comparison of joints by pulse electric current bonding and diffusion bonding

Diffusion bonding process is one of solid state bonding processes that produces the joints by the application of pressure at elevated temperature without macroscopic deformation of the workpieces. For a conventional diffusion bonding technique, the joints are heated by the electrical resistance heaters, the induction high frequency heating and so on. Recently the pulse electric current bonding (PECB) process has received much attention as the advanced heating process at the bonding interface of joints. To clarify the difference in the bonding quality by the heating processes, the joints of the SUS304 stainless steel were made using pulse electric current bonding and induction high frequency heat bonding (IHB). The results of fracture surface and tensile strength of the joints showed that the bonding temperature to form the metallic bond by PECB was lower about 100degreesC than that of IHB. The decrease in bonding temperature was attributed to the heating at bonding interface locally, depending on the Joule heating by the contact resistance.