Abrasive wear testing of DLC coatings deposited on plane and cylindrical parts

Testing of mechanical and/or tribological properties of DLC coatings is essential for quality control. A fairly reliable method is testing the wear resistance by high precision ball cratering. This method is presented in detail. The results show that the tribological system chosen here provides stable conditions for a reliable wear measurement. The wear coefficient strongly depends on the geometry of the substrate due to different contact pressures. Also, the wear measurement depends on the humidity of the surrounding atmosphere. A method to compensate this effect is to normalize the actual wear coefficient with a reference sample.