Effect of Fluid Pressure on Weld-Line Movement and Thickness Distribution in Hydro-Mechanical Deep Drawing of Tailor-Welded Blanks (TWBs)

Use of Tailor-Welded Blanks (TWBs) in production has significant advantages such as weight and cost reduction. However, their application requires processes that increase their poor formability in comparison to base materials. One of these procedures is the use of fluid pressure in sheet metal forming. In this paper hydro-mechanical deep drawing process of tailor-welded low carbon steel (St12) blanks with different thicknesses is studied using FEM and verified experimentally, and effect of fluid pressure on weld-line movement and thickness distribution is investigated. Results of FEM are in good agreement with experiments. Results show that there is an optimum value of final pressure in which the least maximum thinning occurs. Furthermore, using fluid pressure we can obtain higher drawing ratios and also reduce the weld-line movement compared to conventional deep drawing.