On the laser forming process of copper/aluminum bi-metal sheets with a functional thickness

Abstract

Bi-metal sheets with a functional thickness are the heterogeneous materials in which physical/mechanical properties of the sheet change from upper layer to the bottom layer. The scope of this work is to investigate the forming of copper/aluminum bi-metal sheets with a functional thickness using laser forming process. In fact, the combined properties of a bi-metal sheet make it complicated to predict the forming behavior of these materials. For this reason, laser forming process of bi-metal sheets has been simulated using a DFLUX subroutine to define the continuous scan path of laser beam. A detailed discussion has been presented on how to activate the temperature gradient mechanism during the process. Furthermore, a set of experimental tests was also performed to examine the validity of the numerical tests. Thus, the effect of each input process parameter including laser power, scan velocity, and beam diameter has been examined. A full-factorial design of experiment has been utilized to specify the quantitative influences of the parameters on the final bending angle. A statistical model has been also derived for predicting the bending angle in laser forming of bi-metal sheets. The numerical results show that by increasing the laser power and scan velocity and decreasing the beam diameter a maximum forming magnitude would be achieved.