Characterization of Frictional Stir Welding for two dissimilar materials and Influence of Ageing on their Mechanical Properties

Abstract

The objective of the present study is to examine the influence of ageing on mechanical properties of two dissimilar materials welded together by friction stir welding (FSW) process. The study was accomplished by altering the rotational and traverse speeds of samples. Dissimilar welding of AA5083 and AA6082 samples, aged at 140ºC and 180ºC respectively, was accomplished at 600 RPM and 900 RPM of rotational speeds and 45 mm/min and 90 mm/min of traverse speeds respectively. The tensile test reveals that the properties of AA 6082 increase with an increase in the temperature of ageing. But, these properties were poorer as compared to the parent material. This might be due to the formation of fine precipitates. The ultimate tensile strength and % elongation of the dissimilar weld samples increase with increasing traverse speed. As the ageing temperature increases, the % elongation decreases drastically. But, the weld strength increases even at a low traverse speed. The hardness of the weld zone decreases for the parent material and increases for the aged samples with an increase in the rotational and traverse speed. For a dissimilar weld of AA5083 and AA6082, aged at 180ºC, the optimum rotational speed and traverse speed are found to be 900 RPM and 45 mm/min respectively.