Generation of 3D shapes using a laser forming technique

Abstract

There has been a considerable amount of work carried out on two-dimensional laser forming, using multi-pass straight line scan strategies to produce a reasonably controlled bend angle in a number of materials, including aerospace alloys. However in order to advance the process further for realistic forming applications and for straightening and aligning operations in a manufacturing industry it is necessary to consider larger scale 3D laser forming. It is possible to form complex 3D surfaces from flat sheet material in a controlled way using a non-contact laser forming approach, thus eliminating the need for expensive dies. The technique can also be used to align or correct pre-formed 3D surfaces. This investigation demonstrates the 3D laser forming of a saddle shape from flat sheet mild steel using a CO2 laser source. The double curvature of the saddle provides a useful case study with which to build up the design rules for such 3D surfaces. However the results of the investigation show that the problem of 3D laser forming is extremely complex. It was found that once a successful scan strategy was discovered symmetry was difficult to achieve due to the asymmetrical nature of the forming process itself, in that it was not possible to form the whole sheet at the same time.There has been a considerable amount of work carried out on two-dimensional laser forming, using multi-pass straight line scan strategies to produce a reasonably controlled bend angle in a number of materials, including aerospace alloys. However in order to advance the process further for realistic forming applications and for straightening and aligning operations in a manufacturing industry it is necessary to consider larger scale 3D laser forming. It is possible to form complex 3D surfaces from flat sheet material in a controlled way using a non-contact laser forming approach, thus eliminating the need for expensive dies. The technique can also be used to align or correct pre-formed 3D surfaces. This investigation demonstrates the 3D laser forming of a saddle shape from flat sheet mild steel using a CO2 laser source. The double curvature of the saddle provides a useful case study with which to build up the design rules for such 3D surfaces. However the results of the investigation show that the problem ...