Experimental Study of Optimal Process Parameters for Deformation Welding of Dissimilar Metals

Abstract

The market trends of automobile, aerospace and marine are towards greater demand on light, strong, economical, and corrosion-resistant parts and components. However, no single metal or alloy can perfectly satisfy all these requirements. This has led to the rapid growth in interest of joining dissimilar metals. For example, inexpensive materials can be conserved to combine with high-strength, high-toughness, light-weight, or excellent corrosion-resistant materials. Solid-state welding is particularly suitable for producing such dissimilar-metal joints because the melting of base metals is nearly avoided, the metals being joined can retain their original properties with less effect on heat-affected zone, and the metallurgical damage of the joints can be minimized. Diffusion bonding has been developed for many years among the solid-state welding processes. Since its processing time is very long (from minutes to hours) and the specific work environment such as a vacuum, inert gas, or reducing atmosphere is required, this process has not been widely accepted and implemented in the industry. Deformation welding is another solid-state welding process. It is similar to the diffusion bonding in which both processes require the application of heat and pressure. Comparing to the diffusion bonding, the processing time of deformation welding is relatively short (within seconds) and the requirements of working conditions are less stringent. However, most literatures on joining dissimilar metals tend to use of diffusion bonding, the previous publications of deformation welding of dissimilar metals are very rare as most studies are focusing on joining similar metals. Hence, deformation welding of dissimilar metals is immature for the industrial applications and the optimal process parameters such as welding temperature, amount of deformation, and contact time are difficult to be determined precisely.