Bending of stainless steel thin sheets by a raster scanned low power CO2 laser

Laser forming of thin metal sheet plates using a low output power CO2 laser has been successfully performed using a mirror based scanning system. Graphite coated AISI 302 stainless steel plates, 0.3 mm thick, have been bent using a 60 W CO2 laser with a stepped scanning pattern, varying relevant parameters such as scanning pattern width, scanning step and traverse velocity. Due to the small thickness of the metal plates, the resultant bending mechanism is basically buckling, but with two important differences. Unlike traditional buckling mechanism, it seems possible to predict the direction of the bending, which takes place towards the energy source. Secondly, a thermal gradient mechanism component apparently operates perpendicular to the traversing direction due to the high scanning speed of the laser beam along the scanning direction. Additionally, it has been found that when different scanning pattern widths are used, it is possible to change the turn radius of the bending corners, distributing the bending effect evenly across the scanning width, obtaining very smooth and round corners, more suitable from a mechanical resistance point of view, rather than traditional sharp corners.