THE EFFECT OF DIAMOND SMOOTHING ON THE PROPERTIES OF CERAMIC RESTORATIVE COATINGS

Due to the high hardness and strength, the use of ceramic restorative coatings increases the life and durability of machine parts. However, the finishing of ceramic coatings causes difficulties due to the high hardness and low thermal conductivity of the ceramic layer. (Research purpose) The research purpose is studying the properties of restorative ceramic coatings after diamond smoothing. (Materials and methods) The object of research was a thin reducing coating based on boron carbonitride synthesized by short-pulse laser reflow. We have developed a spring diamond smoothing machine to implement diamond smoothing. The surface condition was assessed using modern laboratory and research equipment: the surface roughness was analyzed using a WYKO NT9300 optical profilometer, tribological studies were performed on a friction machine SMT-2070 under boundary friction conditions. (Results and discussion) The results of the research confirmed the possibility of practical implementation of diamond smoothing of ceramic restorative coatings. It was found that the friction coefficient and surface roughness are determined by the main processing parameters - the radius of the diamond tip, the smoothing force, and the longitudinal feed. The speed of diamond smoothing has no practical effect on the surface characteristics. The minimum roughness is achieved with a force of 300 newtons and a longitudinal feed of 0.05 millimeters per revolution. The minimal friction coefficient of 0.048 is observed when processing with a diamond tip of 2.5 millimeters. (Conclusions). Based on the research, the ranges of diamond smoothing modes have been determined, at which high purity and low friction coefficient are achieved. The presented research results are of high practical importance and their application will improve the reliability and durability of machine parts in the conditions of repair and machine-building production.