Microstructure and mechanical properties of friction stir welded 6082-T6 aluminium alloy

Abstract

Aluminium alloy 6082-T6 is vital in the fabrication of light weight structures requiring high strength-to-weight ratio and good corrosion resistance. In this work, investigation is carried out at three different heat energy inputs termed as hot weld (HW), cold weld (CW) and weld at optimum condition (WOC). Heat energy in friction stir welding depends on spindle speed and weld speed. The characteristic study of tensile strength, micro-hardness and metallographic structure at different weld conditions were carried out. Higher heat input, ie. HW, shows fine and harmonised grains, but softening occurred across the weld. Lower heat input, ie. CW, shows better mechanical properties compared with HW, but prone to brittle fracture. The WOC compromises the CW as well as HW and provides better results.