Abstract:

The joining of AA5083/T2 dissimilar materials is carried out by linear friction welding under different welding pressures. Results show that the compression deformation is mainly at the aluminum alloy side, while that of T2 is relatively small. There is a clear narrow weldline at the welding interface with some obvious micropores. The streamline disappears at the aluminum alloy side closing to the weldline, and the grains near the weldline are significantly refined. The tensile strength of joints reaches to 50% of pure copper with low ductility, and the tensile fracture has occurred at the weld zone in a brittle mode. Elements analysis show that: a diffusion layer between Al and Cu is about 2 μm; Cu particles and a large amount of mechanically mixed intermetallics exist at the Al side near the weldline and the thickness is 100 to 500 μm. Pore defects and intermetallics are the main reason of low strength.

Key words: AA5083 alloy, intermetallic, T2 pure copper, linear friction welding