Multi-parameter Assessment of Wear Resistance of Antifriction Ion-Plasma Coatings Deposited on a Cemented Steel Substrate

The work solves the problem of multi-parameter optimization of vacuum ion-plasma coatings based on the use of a database, which was formed by the authors over several years of experimental and applied work in the field of increasing the antifriction properties of engineering products. Three types of monolayer vacuum ion-plasma coatings (thin films) with a thickness of 0.5–3.5 μm were considered as the object of study: coatings of two nitride systems TiAlN and CrAlSiN, as well as a diamond-like carbon coating (DLC) with a gradient distribution of carbon electronic configurations sp2 and sp3 in depth. The coatings were applied to a substrate made of structural steel 12Cr2Ni4, subjected to carburization with a followed hardening and low tempering. Wear-resistant cemented surface layers of steel products are widely used in mechanical engineering as a contact surface in loaded friction units. Therefore, when conducting a comparative analysis, the mechanical and tribological properties of the cemented surface of the samples (without coatings) were used as a standard and were considered in the optimization process along with coatings. The work used a multi-parameter optimization technique in the form of an integral assessment of each material by constructing radial (ray) diagrams, which were based on a complex of eight characteristics, combining 4 physical-mechanical and 3 tribological properties, as well as the coating thickness parameter. The results of the analysis showed a consistent pattern: in terms of a complex of eight parameters, all coatings are significantly superior to the reference cemented layer. The CrAlSiN coating has the highest integral property indicator.