Optimization and modeling of laser forming of stainless steel circular sectors

Mold-less forming produces precise metal parts by thermal variation generated used high power beam irradiation. Some technologies like the laser and the plasma arc have proved to fit the requirements of this new forming technique [M. Geiger and F. Vollersten, Ann. CIRP 42, 301–304 (1993); P. J. Li et al., J. Eng. Manuf. Proc. Part B 214, 0954–4054 (2000)], which can be applied both for rapid prototyping and rapid manufacturing. In particular, a complex shape can be generated using curved path for the irradiating strategy of a circular plate. The forming mechanism induced by this strategy is similar to that of linear irradiation, which is called bending, but its effects are on average lower [T. Hennie, J. Mater. Process. Technol. 102–108 (2000)]. In this article, the forming process of austenitic stainless steels AISI 304 carbon spray precoated sheets has been investigated by numerical and experimental analysis. The experiments were designed and the results optimized using design of experiments analysis techniques [D. C. Montgomery, Design and Analysis of Experiments (Wiley, New York, 1997)]. A CO2 laser, operating in continuous wave regime, was used for the experiments. Numerical analysis was performed in order to predict the final shape and residual stress of the formed or bent sheet. In view of the use of lasers for mold-less forming in the mechanical engineering field this investigation has provided useful knowledge of the process.