Material flow control in tailor welded blanks by a combination of heat treatment and warm forming

A new process design for manufacturing high strength aluminum structural parts from tailor welded blanks is presented. After an initial friction stir welding the sheet material is post weld heat treated and finally warm formed in a stretch forming operation. Plastic material behavior and the forming limits are studied at elevated temperatures. Numerical and experimental investigations are carried out to determine the material flow with respect to the heat treatment condition as well as the forming parameters. This fundamental knowledge is used in a numerically based process design to improve the formability and the final part properties.