“Experimental Study the Effect of Tool Design on the Mechanical Properties of Bobbin Friction Stir Welded 6061-T6 Aluminum Alloy”. Al-Khwarizmi Engineering Journal 14, no. 3 (August 15, 2018): 1–11. Accessed April 27, 2024. https://alkej.uobaghdad.edu.iq/index.php/alkej/article/view/85.