Key factors influencing the bend per pass in laser forming

Laser forming offers the industrial promise of controlled shaping of metallic and non-metallic components for prototyping, the correction of design shape or distortion and precision adjustment applications. The potential process advantages include precise incremental adjustment, flexibility of application and no mechanical ‘spring-back’ effect. To date 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. A key area, however, where there is a limited understanding, is the variation in bend angle per pass during multi-pass laser forming along a single irradiation track, in particular the decrease in bend angle per pass after many irradiations for a given set of process parameters. Understanding of this is essential if the process is to be fully controlled for a manufacturing environment. The research presented in this paper through empirical data offers a coherent picture of the key influencing factors and at which point in the bend evolution each is active.