Technology to Drill Micro-Holes without Recast Layer by Laser on Nickel-Based Alloy

Abstract

The technology to produce micro-holes without recast layer on nickel-based alloy is studied in this work. The holes are firstly drilled with Nd: YAG laser, a millisecond pulsed laser of high power and efficiency. For the reason of thermal effect, however, holes drilled by this laser always have the defect of recast layer, which is a serious problem, especially in the application as aviation and aerospace engine. In order to remove the recast layer, laser parameters are optimized to produce micro-holes with the least recast layer, and then a kind of chemical etching is used to clear the residual recast layer completely.