Laser cutting of variable thickness materials - Understanding the problem Available to Purchase

Laser cutting has been widely applied to materials with uniform thickness profiles. The aim of this study is to explore the problems and effects of cutting non-uniform metallic sheets. Mild steel sheets between 2-3 mm thickness with steps of 0.25 mm were cut using both CO₂ and Nd:YAG lasers with equivalent cutting parameters and in 4 different cutting arrangements: a) thin-to-thick from the flat side; b) thick-to-thin from the flat side; c) thin-to-thick from the stepped side; and d) thick-to-thin from the stepped side. Quality of cut was examined in terms of dross attachment, surface roughness, perpendicularity, kerf width, and striation height. The work shows that variation in workpiece thickness affects the cut surface quality due to several factors related to irradiance and assist gas flow. In some situations these effects can be minimized within certain tolerances.