Product Code: ICAL06_408

Laser Cutting of Variable Thickness Materials - Understanding the Problem
Authors:
Mohamed Sobih, The University of Manchester; Manchester Great Britain
Lin Li, The University of Manchester; Manchester Great Britain
Philip Crouse, The University of Manchester; Manchester Great Britain
Presented at ICALEO 2006

Laser cutting has been widely applied to profiling materials with uniform thickness. 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, 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, surface roughness, perpendicularity, kerf width and striation. The work shows that variation in workpiece thickness affect 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.