Weld metal ductility in aluminum tailor welded blanks

The objective of the research described in this article was to characterize and numerically describe the ductility of weld material in aluminum tailor welded blanks under uniaxial tension conditions. Aluminum tailor welded blanks consist of multiple thickness and alloy sheet materials welded together into a single, variable thickness blank. To evaluate the mechanical properties of the weld material in these tailor welded blanks, a series of tensile specimens containing varying ratios of weld and monolithic material in the gage area of the specimen were tested. These experimental results show that increasing the amount of weld in the cross-sectional area of the specimen decreases the ductility of the specimen and that the weld characteristics have a pronounced impact on ductility. Using the experimental results and classical tensile instability and necking models, a numerical model was developed to describe the ductility of the weld metal. The model involves basic material properties and an initial imperfection level in both the weld and monolithic materials. The specimens studied were produced from 1- to 2-mm AA5182-O aluminum alloy sheet material welded into blanks using an autogenous gas tungsten are welding process.