Dissimilar Welding of Cu and Al Alloys by Friction Stir Welding and Impulse Friction Stir Welding

摘要

The 2 mm thickness sheets of Al-5Mg and technical purity Cu (Cu-ETP)were FSWed to receive butt joints. The geometry of the tool and FSWparameters were determined in order to get sound welds with high levelof mechanical properties. Hardness measurements and tensile tests of thewelds were provided. The hardness was measured at the welds crosssections and the measured values in stir zones of the dissimilar joints aremuch higher than of the base materials. Maximum observed averageUTS is 214 MPa and average YTS is 147 MPa after tensile tests,maximum observed average elongation is 12%. Therefore, the optimalcombination of FSW parameters and tool geometry were set for the buttjoint and the influence of the FSW parameters on the properties of theCu–Al dissimilar materials joints was defined. The technology ofImpulse Friction Stir Welding (IFSW) was implemented to receivesound weld of dissimilar materials. The results of hardness profilemeasurement show the same behavior as hardness profile of the weldsreceived by conventional FSW. The observed average UTS is 129 MPaand average YTS is 80 MPa after tensile tests, the observed averageelongation is 8%. It should be proposed that obtained results showed thatthe additional deformation generated by impulse force during IFSWreduces the weldability of dissimilar Cu-Al joints.