The Influence of Sheet Metal Anisotropy on Laser Forming Process

Cold-rolled sheet metal that is often used in laser forming exhibits anisotropic properties, which are mostly caused by preferred orientations of grains developed during the severe plastic deformation such as cold rolling. In the present study, the textures of cold-rolled mild steel sheets are characterized and the influence of the plastic anisotropy on laser forming process is investigated. Deformation textures are measured in terms of pole figures and orientation distribution function (ODF) plots obtained through electron backscatter diffraction (EBSD). The anisotropy index (⁠$R$-value) of the material with different rolling reductions is obtained by uniaxial tensile tests. Both are compared and agree with the texture development theory. Effects of the plastic anisotropy on bending deformation during the laser forming process are investigated experimentally and numerically. Various conditions including different laser power, scanning speed, and number of scans for sheets of different rolling reductions are considered and results are discussed. The simulation results are consistent with the experimental observations.