Design and Development of Stirring Tool Pin Profile for Reconfigured Milling Machine to Perform Friction Stir Welding Process

Abstract

Three customized stirring tool pin profiles have been designed which are (1) straight cylinder, (2) triangle shape, and (3) tapered shape to be used by reconfigured milling machine (Cheng Yin-CY-GH 260) to perform friction stir welding process. Shoulder geometry is constant for all tools (20 mm having 8 deg concave and length of the pin from shoulder is 2.7 mm). Then, all the tools were fabricated and tested by joining two similar plates of Al 6061 and Al 7075. The tools are made of H13 steel (chromium-molybdenum). Welding parameter used are 1270 RPM for rotating speed and 218 mm/min for welding speed. The samples produced were evaluated based on physical appearance of weldment, tensile strength value, surface roughness value, and physical tool wear. From the result, all the designed and fabricated tool pin profiles were able to perform FSW successfully using reconfigured milling machine. Tapered tool produced the highest tensile strength with 134.95 MPa. However, straight cylinder tool produced smoothest surface roughness with 1.850 μm which provide better surface finish. Weldability of Al 6061 is better compared to Al 7075.