Pure magnesium laser surface modification using Nd:YAG laser

Abstract

Magnesium (Mg) and its alloys are promising materials for a wide range of biomedical applications due to its biodegradability. Nevertheless, their rapid corrosion dictates the need to develop strategies to control these materials' corrosion rate. In fact, several surface modification techniques have been used to retard the corrosion of Mg and its alloys. Laser technology can be used to tailor Mg surfaces aiming to modify exposed area/roughness and thus control the biocorrosion process. This work presents a detailed study on pure Mg surface texturing by an Nd:YAG laser and their morphological characterisation, aiming to create either localised texturing or remelted areas. The characterisation of the textured and remelted surfaces was carried out by scanning electron microscopy and analysed using image analysis software (Image J) for obtaining their depth and width. Results show that higher scan speed (400 mm/s) and lower laser power (1.5 W) were unsuitable for machining pure Mg. The parameters to perform texturing and remelting are discussed herein.