Study of tool Penetration Behavior in Dissimilar Al5083 /C10100 Friction Stir Spot Welds

Abstract

Friction Stir Spot Welding, is an advanced solid state material joining technique, which is gaining wide popularity in automotive and aerospace industries, as it can be efficiently used to spot join dissimilar materials, with different mechanical and metallurgical characteristics. In this investigation, dissimilar friction stir spot welds of Aluminum 5083 and C10100 Copper joints (1.5 mm thick) were made using a non-consumable tool made up of H13 tool steel material, having a cylindrical straight flat geometry with shoulder diameter of 16 mm, pin diameter 6 mm and pin length 1.5 mm. The effect of piercing and puncturing of the tool on the top (Al) plate and the bottom Cu plate were analyzed by varying the predominant friction stir spot welding process parameters like tool rotational speed, dwell time and plunge depth. The extent of flash formation on the top Al plate, top side of the bottom Cu plate, were analyzed by studying the material flow due to the frictional heat generated in the weld zone. Microstructures at the interfaces were analyzed using SEM, and the dependence of tensile properties on the extent of the deformation (depth of keyhole and protuberance) caused by the rotating tool plunge were analyzed.