Changing the integrity of the material surface by combining laser surface texturing and PVD magnetron sputtering technologies

Abstract

The presented research combines laser micromachining technology (LST, Laser Surface Texturing) using an ultra-short femtosecond laser beam and PVD deposition of thin layers using magnetron sputtering. This combination has multiple benefits. It provides uniform and highly adhesive coatings with improved tribological properties. By optimising the deposition parameters when applying a thin layer of TiN, an improvement in the tribological properties of the tool steel surface and the laser micromachining (LST) surface can be achieved. On the laser-modified and coated surface with Ellipses-texture, the wear reduction was almost 19 % compared to the reference texture. The TiN coating exhibited very good adhesion to the substrate with critical force values of L_C3 greater than 45 N and a nano hardness value of 26.5 GPa. The adhesion of the TiN coating to the laser-affected substrate, as well as the resistance of the coating to damage, was high. Damage primarily occurred on the original polished surface around the edges of the machined textures, where stresses are likely to concentrate.