Influence of Pin Offset and Weave Pattern on the Performance of Al-Cu Joints Reinforced with Graphene Particles

Abstract

The friction stir welding technique is currently employed for different alloy combinations like magnesium, titanium, copper, nickel-based composites. Dissimilar materials may be efficiently joined by the process and this has been used in several structural applications such as automotive components, aircraft structure, shipbuilding, and space shuttle external tank and train bodies. Even though improvement in the joint strength was achieved, problems such as voids, tunnels, cracks persisted in the weldments. The objective is to achieve defect-free joints. Tool pin offset for joining of aluminum alloy enables better stirring action and an easy flow of plasticised material in the weld nugget. Hence, to overcome the above-mentioned problem, a technique of combined effect of weaving, tool pin offset, and reinforcement of self-lubricated graphene nanoplatelets was attempted. The tensile strength obtained with the effect of tool rotational speed under weave weld with pin offset condition with reinforcement was 13.82 % higher than the weld obtained under the same condition without reinforcement. IMCs such as AlCu, Al₂Cu, and Al₄Cu₉ large size band layers were observed with the linear welding condition, whereas weave welding conditions resulted in the formation of the thin uniform layer.