Influence of non-conventional beam profile on edge effects in laser forming of AISI 304 stainless steel plate

摘要

Laser forming is an innovative technique that uses a defocused laser beam to form sheet metal by thermal stresses rather than external forces. This offers excellent and promising potential applications in rapid prototyping, straightening, aligning, and adjusting of macro/micrometallic components. However, the undesirable edge effects in laser forming reflect that the bending angle is not constant along the scanning line. This paper presents an analytical study of edge effects in laser bending of AISI 304 stainless steel plate. Experimental and numerical investigations aimed at understanding the effects of the triangular beam geometry with different aspect ratios were clearly demonstrated. A validated thermal model was developed, and different sets of FE simulations were carried out by varying heat input values and aspect ratio of laser beam with constant scanning speed. It is evident that triangular beam with highest aspect ratio was preferable to produce a higher bending angle with lesser edge effect at higher power intensity. It is found that triangular beam geometries are more effective in minimizing the bending angle variation compared with the circular beam.