Effect of variations in tool offset friction stir welding aluminum 5083 on tensile strength and hardness

With the use of aluminum in the transportation sector in Indonesia, reducing the weight of transportation equipment has become one of the most critical issues for manufacturers, who are still trying to reduce the weight of transportation equipment to optimize fuel. 5083 aluminum alloy is a suitable material for making transportation equipment lighter because of its many benefits, such as an excellent strength-to-weight ratio and corrosion resistance. It is ideal for application in the field of marine equipment. This research aims to determine the effect of tool offset variations of 0 mm, 0.2 mm, and 0.4 mm on the tensile strength and hardness of 5083 series aluminum friction stir welding joints. Based on the research that has been carried out, the specimens produce the highest tensile strength values with a tool offset variation of 0.2 mm and a tensile strength value of 218.6 MPa, and the specimens produce the lowest tensile strength values with a tool offset variation of 0.4 mm and a tensile strength value of 127.35 MPa. Meanwhile, the hardness values for each tool offset variation were 92 VHN, 66.75 VHN, and 108.87 VHN, with the fracture of each test specimen being in the weld metal area due to its hardness.