Optimization of Process Parameters in Laser Sheet Metal Bending

Abstract

Laser sheet metal bending is a die less sheet metal forming process and a non-contact method. It is a thermo mechanical process where by a focussed or partially focused laser beam is used to induce localized heating and consequently deflection of the sheet along the incident beam occurs. The bending occurs because of internal thermal stresses developed as a result of irradiation instead of external forces. It can be very helpful in the process of rapid prototyping of various sheet metal parts because of its process flexibility and ability to design intricate shapes which are the major advantage against conventional methods. In the experiment Nd:YAG laser is used and the work-piece is AISI 304 stainless steel. Various process parameters in the experiment are laser power, scanning speed, beam diameter, pulse duration and number of passes. The effect of each process parameters is observed with respect to total deflection at the free end and bending angle by keeping other parameters constant. Design of experiment (DOE) is done with the help of Taguchi method. The results are analysed graphically and also with the help of ‘Analysis of variance’ and S/N ratios, so as to determine the optimum values of the process parameters and their individual effectiveness towards the net bending effect.