Effect of the combination of aluminum plate thickness 2024 T42 on hardness, tensile strength, and photo micro in the process of resistance spot welding part cover side L aircraft

Abstract

The automotive industry, particularly the aerospace industry, frequently uses resistance spot welding. Connection failure is often caused by several things, namely the plate thickness factor. For this test, a combination of two kinds of plate thickness mixtures was used, namely 0.8 + 0.6 mm and 0.8 + 0.8 mm. Through several tests, the quality of the welding results will be compared using the same welding parameters. Tensile test testing cannot be used to see welding results. However, additional testing, including macrographic and hardness tests, is required. The tensile test of the two combinations gave higher results than the previous industry standards, namely 383.60 lbf and 344.27 lbf respectively. For the macrographic test results, the penetration value for variations with a thickness of 0.8 + 0.6 mm corresponds to the minimum and maximum standard values of (20.00 ÷ 80.00), more specifically 37.2% ÷ 74.6%. As for the thickness variation of 0.8 + 0.8 mm, it is standard but very close to the maximum value of 45% ÷ 79.2%. For the size of a nugget or spot weld the two mixtures are very good and go beyond current principles. Furthermore, for the final results of the hardness test with the Vickers Microhardness technique, the hardness value of the weld piece from the weld point area to the parent metal increases due to the effect of using welding which will cause softening of the 2024 T-42 aluminum material. In the end, the hardness value of each thickness variation will be different due to different parameters.