Feasibility study on dissimilar materials joint made by friction stir forming

Abstract

The need to join dissimilar materials is common to many industry sectors as the current demand is for the products of enhanced performance, reduced cost, weight reduction, optimized of properties or the tailored of the properties for specific applications. This paper is focused on studying the different joint structures made from different material combinations by Friction Stir Forming process. At present, joining Al to steel are successfully joined by this process, the present paper investigates the possibility of making strong joints from Fe-Al, Mg-Steel, as well as Aluminum to carbon fiber composites (Al-CFRP) material combinations. The manufacturing industries are driven by using new lightweight material alternative to steel to form a thinner and stronger joint, which leads to a greater emphasis on the improvement of joining processes to allow interlocking formed by the material itself instead of using any rivets, bolts, adhesives, or any other mass addition. Friction Stir Forming is a relatively new process, which is an alternative to the mechanical fasteners. It is a process where the tool works heated materials into close contact, causing them to form a solid-state joint. No melting of materials occurs. Instead, the joint is formed by plastic deformation of the pieces. The previous part of the experiment is to define the important factors involved during the process, as well as the microstructure analysis on Al-Steel joint. Therefore, at this stage of the experiment, the joint made by Fe-Al, Mg-Steel, as well as Aluminum to carbon fiber composites (Al-CFRP) are studied. Our study showed that friction stir forming process could be carried out over a wide range of operating parameters. It is a process where the shape of the joint could be changed according to the design of anvil. By changing the joint shape, the strength and the quality could be affected. The friction stir forming joints are strong to satisfy the industry requirement. It is possible to form joints with lightweight materials using friction stir forming techniques. The material used to form the joint could affect the strength of the joint.