Influence of tool rotational and transverse speed on friction stir welding of dissimilar aluminum 6061 composites

Abstract

• The study aims to weld the newly developed Al composites. • The FSW is performed based on the design matrix developed using RSM. • The effect of process parameters is studied through the UTS and hardness. • The grain refinement of the composite was significantly analysed by microstructure images. In the present study friction stir welding of dissimilar aluminum 6061 composite is performed. The Al 6061 with B 4 C and Al 6061 with Cr 2 O 3 composite were fabricated using stir casting. B 4 C and Cr 2 O 3 were reinforced in steps of 2, 4, and 6 wt%. The stirring time and stirring speed was maintained common throughout the casting. The preheating temperature of mold and reinforcement is 400 °C and 600 °C respectively. The response surface methodology based design matrix is utilized to perform the welding. The three tool rotational speed and tool transverse speed is used during welding, keeping same weight percentage composite on either side. The W-shaped hardness profile is seen in welding zone having maximum microhardness of 65 HV at nugget zone and minimum microhardness 52 HV at heat affected zones. When the tool transverse speed is increased from 20 to 25 mm/min, an increase in ultimate tensile strength of 59 % is observed.