Investigations on eccentric weave friction stir welding of aa6061 t6 aluminium alloy with copper

Abstract

Modern engineering applications require joining of dissimilar materials for achieving specific thermal, electrical and physical properties. For example, the components made of Aluminium alloy and Copper find extensive use in different industries due to their great conductivity and corrosion resistant nature. Fusion and solid state welding processes can be employed for the joining of aluminium alloy and copper materials. However, fusion welding of dissimilar materials results in defects such as porosity and formation of brittle inter metallic compounds due to difference in the properties of parent materials. Friction Stir Welding (FSW) is energy efficient, environment friendly and a comparatively new solid-state joining process used for joining dissimilar metals. Hence, in this study, FSW technique was applied for joining of aluminium alloy (AA6061-T6) and pure copper to retain the special properties of both the materials with strong bonding. In this research work, the effect of tool pin offset, eccentric weave tool path and addition of graphene nano-platelets were studied and compared with the conventional FSW. Variations were made in welding parameters like tool rotational speed, welding speed and axial load on tool to find the appropriate process windows for the four different welding conditions, namely Linear Weld Without Pin Offset (LW-WOPO), Linear Weld With Pin Offset (LW-WPO), Weave Weld Without Pin Offset (WW-WOPO), and eccentric weave weld with pin offset (EWW-WPO) with the objective of achieving a reduction in micro and macro structural defects with strong weld nugget. newline