Analysis of the impact factors from the friction stir welding process for dissimilar butt joints between semi-solid cast aluminum 356 and AISI 1018 carbon steel

Abstract

This research aimed to study the impacts of three different rotation speeds of 710, 1000, and 1400 rpm and three welding speeds of 40, 56, and 80 mm·min-1, on dissimilar butt joints between semi-solid aluminum 356 and AISI 1018 carbon steel. Welding tools were made from tungsten carbide material, and the offset was 0 mm. It was found that an increase in the rotation speed and welding speed caused accumulated heat, which led to the appropriate changes in the metallurgical structure. The rotation speed and welding speed factors had the impact on the greater blending of the two metals at the SZ zone. A larger amount of semi-solid aluminum 356 infiltrated into the AISI 1018 carbon steel when the rotation speed and welding speed increased. The findings showed that the most influencing factors on the average tensile strength at the weld lines were the rotation speed of 1000 rpm and the welding speed of 56 mm·min-1. The experiment in this study showed the maximum average tensile strength of 139.9 MPa and the average hardness value of 264.5 HV as the highest hardness value at the welding rotation speed of 1400 rpm and the welding speed of 80 mm·min-1.