Effect of Tool Rotational Speeds on Friction Stir Welded AA6082 T6 Aluminium Alloy Joints

Abstract

In the current work, an attempt has been made to investigate the effect of tool rotational speed on microstructural and mechanical properties of friction stir welded AA6082-T6 aluminium alloy. Four different tool rotational speeds such as 500, 700, 900 and 1100 rpm were used to produce the joints while keeping the other process parameters constant. The tool used to fabricate the welded samples was tungsten carbide with straight cylindrical pin profile. The microstructural properties were examined using an optical and scanning electron microscope and found that the 700 rpm produced joint showed equiaxed grain structure with 14.3 μm average grain size. The mechanical characteristics such as tensile strength, impact strength and microhardness were evaluated and found the highest tensile strength of 265 MPa, impact energy of 10 J and micro hardness of 76 HV in the weld zone for the sample prepared with 700 rpm tool rotational speed. The fractographic studies were also carried out to study the mode of failure.