Combined effect of thickness ratio and selective heating on weld line movement in stamped tailor-welded blanks

Tailor-welded blanks (TWBs) are welded sheets consisting of different materials, thicknesses, shapes, and sizes. They are subjected to forming at a particular temperature to achieve the desired shape. One of the problems encountered in TWBs is the undesirable weld line movement which may lead to the formation of wrinkles, tearing, and distortion of components. In order to restrict the weld line movement in TWBs, an experimental setup with a specialized punch is used. The specialized punch is split into two parts separated by insulating material. One part is used for heating the stronger/thicker material and the other part for cooling the weaker/thinner material. With the selective method of heating, the weld line movement reduced drastically as compared to the movement in a single punch. In this work, the influence of thickness ratios on the weld line movement at different temperatures is also studied. Experiments were conducted at room temperature as well as elevated temperature for the same thickness of sheets. Results of experimental work are correlated with numerical analysis. The combined effect of thickness ratio with the selective method of heating has shown a greater effect in controlling the weld line movement.