Reduction of Thermal Deflection in the Cutting of Zinc Sheet by Using Different Laser Machining Techniques

This paper presents the cutting of thin zinc sheet by using seven different laser machining techniques. A nanosecond pulse laser associated with a laser scanning head was employed to cut through the metal sheet in air, argon and water environments. The deflection of workpiece, size of heat-affected zone and kerf width obtained after the cutting process were observed and measured. By comparing all cutting techniques examined in this study, the backside-wetting method incorporated with the air flow on the top surface of workpiece was found to be the most effective one as the zinc sheet was able to be cut through its thickness by the laser with the minimum heat-affected zone and workpiece deflection. This technique could be a better alternative to the laser cutting of metal sheet where the thermal damage of work material is the first priority to be minimized.