Performance of H13 and HCHCR Tool Materials on Friction Stir Welded 6070Aluminium Alloy Plates Subjected to Different Temper Conditions

Abstract

In this study, friction stir welding(FSW) process is carried out on heat-treated 6070aluminium alloy plates of 10mm thickness in two stages using two different tool materials. Firstly, annealed 6070aluminium alloy(O-temper condition) is joined with naturally aged 6070aluminium alloy(T4-temper condition) using H13(Tool steel) material and HCHCR-D2(Die steel) material. Similarly, annealed 6070aluminium alloy(O-temper condition) is joined with artificially aged 6070aluminium alloy(T6-temper condition) using the same tool materials. Both the stages are welded for two rotational speeds and two welding speeds using cylindrically threaded H13 and HCHCR tools. The effect of these welding parameters are further investigated on tensile behaviour(ultimate tensile strength, yield strength and percentage-elongation) and hardness for each welded stage to identify better weld-joint strength. Finally micro-structural examinations are carried out on better tensile responses using scanning electron microscope(SEM) and energy dispersive X-ray(EDX) analyzer.