Experimental and numerical studies on mechanical properties of hot-stamped tailor welded AA7075-T6

Abstract

AA7075-T6 sheets with 1, 1.5, and 2 mm thicknesses were tailor-welded using the gas tungsten arc welding process. The welded blanks were solution heat treated, hot stamped, and simultaneously quenched to produce U-shaped components, and finally artificially aged. A finite element model using the ABAQUS software was developed to simulate the forming process. The experimental and numerical results showed no rupture in the components. Tensile and hardness tests revealed that the maximum tensile strength, yield strength, and microhardness of the aged specimen were approximately 96%, 93%, and 107% of the initial material, respectively. Maximum and minimum microhardness of 196 and 145 HV were observed in the heat-affected and fusion zones of the specimens, respectively. Increasing the tailoring ratio increased the strengthening behavior of the components. With a tailoring ratio of 1, the maximum and minimum elongations at break were 70% and 40% of the original aluminum sheet for 2 mm and 1 mm thick sheets, respectively.