The mechanism of material removal in laser fusion cutting

Abstract

Laser cutting is rapidly emerging as a cost effective alternative to the conventional cutting specially, in sheet metal cutting. Its application have grown much faster than its basic understanding. The present study has been performed to develop a comprehensive understanding of the laser fusion cutting (FC). Mechanisms those are operative during the laser FC have been identified using the cutting data from the extensive parametric study of laser cutting of 304 stainless steel. They have been identified as splashing of molten substrate, vaporisation and fracture in the semisolid state. They predominently operate during successive stages of FC as the cut progress through cross section. As a result of which three distinct zones are generally formed on the cut surface. Schemes for characterization of laser cut surface and evaluation of cutting performance have also been proposed. Effect of various process variables on cutting performance have been discussed in detail. Based on proposed mechanisms an approach to obtain a quality cut with minimum specific energy and material loss has been outlined.