Advances in Laser Forming Research

In this review, a number of recent developments of laser forming are presented based on the work in Manufacturing Research Laboratory (MRL) of Columbia University. In order to advance laser forming to realistic forming application, it is necessary to consider non-straightening and larger scale 3D laser forming, so that anisotropy and size effect need to be investigated in detail. In this paper, the textures of cold-rolled mild steel sheets are characterized and the influence of 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). Effects of plastic anisotropy on laser forming process under various conditions, such as different laser power, scanning speed, number of scans for sheets of different rolling reductions are experimentally and numerically investigated. In present paper, the influence of size effect, including variation of sheet width and sheet length, on laser -induced deformation is also investigated. Distinctive trends in bending angle are identified for varying sheet width, length or both. The results are interpreted in terms of heat sink effect and bending non-uniformity. An analytic model is developed to facilitate size effect prediction. The model is based on the solution to a moving strip heat source over a finite size sheet and on the account for pre-bending effect among consecutive segments on the scanning path. Analytical results are compared with an existing analytical model and numerical simulation.