PROSPECTS FOR IMPLEMENTATION OF THIN-FILM COATINGS IN REPAIRING PROCESS
The use of thin films has an undeniable advantage over traditional coatings, which is determined by high fatigue resistance, structure, “flexibility”, low dislocation activity, and high adhesion to the object. Obtaining thin coatings is mainly implemented in tool production, thus increasing the wear-and-tear resistance and redness resistance of the tool cutting edges. To obtain such coatings, PVD and CDV technologies have been implemented in practice since the 80s, which provide superhard coatings with a thickness of not more than 15 microns. The negative side of these technologies is obtaining homogeneous structures with a narrow range of physical and operational properties. In the conditions of mechanical engineering, the synthesized coatings should have a set of properties that equally resist fatigue, thermal, dynamic, etc. loading. Obtaining such coatings is associated with heterogeneity of the structure, with the presence of a multiphase composition that affects the kinetics of the processes of structure formation and thereby complicate the technology of synthesis of the coating. The authors have presented the possibility of obtaining stable thin coatings on the surface of machine parts, in order to increase their wear resistance and durability. To implement the technology, a thin-film coating technology based on the symbiosis of structural and instrumental compositions has been proposed, with the implementation of the Charpy principle. For the synthesis of a thin coating, the technology of short-pulse laser radiation had been used followed by the effect of amorphization of the structure occurring due to high crystallization rates. To obtain the coating, a powder composition based on B83 babbitt alloy doped with boron carbide was used. The percentage of boron carbide was determined based on exploratory research and was limited to 1.5 % by weight. The research results had demonstrated the stability of coatings under conditions of fatigue loading that was not inferior to traditional babbitt coatings, whereas the bearing capacity of the coating, as well as the scoring resistance, had significantly exceeded the performance of traditional coatings by more than 4 times. The micro-hardness of the coating had increased by more than 3 times, and amounted to 1080, while the structure was characterized by a finely dispersed structure with transition to amorphous one.The results obtained are of high practical significance and can be applied to when restoring shafts and axis operating under high dynamic and kinematic conditions.