Improvement on surface quality of Inconel-718 slits via laser cutting and wire electrochemical machining processes

Abstract

In the paper, we present a combined gas–assisted laser machining and wire electrochemical machining (W-ECM) process to improve the surface quality of slits produced in Inconel-718, a high-strength nickel-based alloy widely used in aircraft engine parts. First, a laser cutting was applied to produce the slit structure in Inconel-718, where the power and feed rate were varied to identify the optimal processing parameters. Subsequently, the slits were processed by a custom-developed W-ECM process. The results were evaluated by characterizing the surface roughness and kerf width of the slits. Through this combined approach, a 90% average improvement on surface finish was achieved with a 10% increase in kerf width. In addition, the typical striation marks and thermal damages from laser machining processes were entirely eliminated in all slits. The new process is precise and low-cost, which may find important applications in high-precision laser machining applications.