Weld Quality Improvement with Hybrid FSW Technology assisted by Preheating for Copper T21Aluminium 5A06 Dissimilar Materials

摘要

Copper and aluminium alloy could be welded by friction stir welding (FSW) but it is quite difficult to achieve a defect-free welding joint for welding dissimilar materials because of the enormous difference of their thermo-physical performances.In this paper,another friction stir tool was applied as a heating source to preheat the copper side to 150～200°C in the welding direction.Preheating temperature can make up the lost heat,improve the temperature of copper plate before the FSW process,achieve the refining grains,and then obtain a high quality welding joint.We concentrated on hybrid heat-source equipments design and procedure optimization in our studies.The microstructure,mechanical properties and phase constituents of FSW joints were studied through mechanical test and metallographic analysis.The results indicated that the hybrid FSW technology with preheating for copper T2/aluminium 5A06 dissimilar materials can not only improve the welding efficiency,but also obtain the high quality welding joint.This special welding technology could solve the welding problems of A1-Cu dissimilar materials and had a good potential for application in aerospace manufacturing.