Study on Dissimilar Butt Joining of Aluminum Alloy, AA5052 and High Strength Low Alloy Steel through a Modified FSW Process

In the preset investigation, aluminum alloy, AA5052 and HSLA steel are successfully butt welded using a modified FSW process wherein the work pieces submerged in a liquid medium are stirred by the FSW tool. The trials are conducted by varying the tool rotational speed from 400 rpm to 900 rpm while keeping the other parameters constant. The welded joints are tested for ultimate tensile strength (UTS) and the joint interface microstructure is analyzed using SEM and EDS. The results show that when compared to the normal FSW process, the peak value of UTS is marginally low but the range of tool rotational speed that could produce defect free joints with good joint strength is almost doubled in the modified FSW process.