Investigation of antiwear coatings deposited by the pvd process

Abstract

The tribological properties of various PVD‐deposited coatings (vacuum arc method) have been tested, both single‐layer coatings (TiN, CrN, Ti(C,N), and Cr(C,N)) and multilayer coatings (Cr(C,N)/CrN/Cr and CR(C,N)/(CrN+Cr2N)/CrN/Cr). An unlubricated ball‐on‐disc tribosystem was used in which an Al2O3 ball is pressed against a coated steel disc rotating in the horizontal plane. A novelty of the method is the removal of wear debris from the contact zone using a draught of dry argon. This improves the repeatability of the test results and the stability of the tribological characteristics. It is shown that CrN coatings exhibit the best antiwear properties and Ti(C,N) the worst. Multilayer coatings have better antiwear properties than single‐layer ones. The friction coefficients for CrN and Cr(C,N) coatings are much smaller than for the commonly used TiN. A correlation has also been found between the physical properties of the coatings tested (adhesion of the coating to the substrate assessed in scratch tests, and coating hardness) and their antiwear properties. An improvement in coating‐substrate adhesion results in wear reduction, while greater hardness (causing a coating embrittlement increase and a change in the wear mechanism) brings about greater wear. There is no correlation between the physical properties and the friction coefficients of the coatings tested.

The Effect of WC/C Coating on the Wear of Bevel Gears Used in Coal Mines

“…When one of the mating materials (coating) is much harder than the other one (steel), there is a reduction in the tendency to adhesive bonding, friction, hence scuffing. The same occurrence was observed when testing the coated spur gears [5]. Both phenomena also led to the reduction in the oil temperature in case of the coated wheel during the laboratory stage of the experiment (Fig.…”

Comparative Study on the Friction Property of Bearing Steel Modified Bygraphite/MoS2 Composite Coating and Manganese Phosphate Coating

“…Shot peening is a new technology that is categorized into: laser shock peening [8], ultrasonic shot peening [9], fine particle peening [10], and water cavitation peening [11]. Gear surface coating modification commonly utilizes TiN coating [12], MoS2/Ti membrane [13], and phosphate coating. Lv Y. et al investigated the effect of shot peening modification and radar surface processing parameters on the fatigue property of 20CrMnTi gear; results showed that the fatigue lifetimes of the LSMSSP gears are grain determined by the retained austenite and surface roughness [5].…”