Dimensional accuracy optimization of the laser milling process

Laser micromachining provides a new method of producing parts in a wide range of materials directly from CAD data. Particularly, in laser milling technology the material is removed by a laser beam through the layer by layer ablation mechanism. The aim of this paper was to determine the capability of the laser micro-milling process, optimizing the surface finish and at the same time keeping an high material removal rate, using a machine equipped with a pulsed Nd:YVO4 laser having a wavelength of 1064nm, a spot diameter of 40 µm and an average power of 30 W. The material investigated was an aluminum-magnesium alloy. Experimental tests were conducted to evaluate the influence of the parameters involved in the process (laser power, frequency, overlapping, pulse width, scanning speed of the laser source, scanning modality used to fill the single manufactured layers, absorption of laser radiation) on the quality of the ablation process in terms of depth of removed material and surface roughness. A particular benchmark was designed and developed with optimized parameters in order to test the dimensional accuracy of the process.