Fiber laser carving under ice layer without laser energy attenuation

Abstract

A novel method of fiber laser carving machining under ice layer without laser energy attenuation was proposed to reduce workpiece defects such as recast layer, dross, high temperature influence area, surface oxidation and heat effect zone that were typically found in machining in air. The mechanism of laser carving process under ice was analyzed to understand the thermal effect of laser pulse on the ice layer and workpiece. A cooling module based on Peltier cooler was designed to form an ice layer on the surface of workpiece. To investigate the effect of ice layer, the laser carving under ice and in air on titanium, red copper and aluminum workpiece were conducted. The results showed that the ice layer attenuated the laser energy barely resulting that the accuracy of machined channel width would not be affected at the condition of laser carving under ice. The recast layer and dross along the machined channel could be well removed. The high temperature influence area, heat effect and surface oxidation could also be decreased. It is due to that the ice isolated the ejective molten material and oxygen from the surface of workpiece and provided a rapid cooling rate.