The synergistic mechanism of transition layer and transfer layer on dry sliding wear of multi-layered diamond-like carbon (DLC) coating at wide temperature

Abstract

Abstract The friction and wear characteristics of Cr/CrC/DLC coatings deposited on the surface of 17-4PH stainless steel by a combination of linear anode layer ion source (LIS) and direct current magnetron sputtering (DCMS) techniques at a wide temperature were studied. The analysis of the wear mechanism and tribochemical reaction mechanism of multi-layered coatings at wide temperatures (25–200 ℃) revealed that the transfer layer generated during wear and the transition layer (Cr/CrC) of multi-layered coatings had a beneficial effect on wear. The friction test results show that the transformation of graphitization mechanism of the DLC coating surface and the lubricating effect of the transfer layer lead to a reduction of the friction coefficient to 0.03. With the increase of temperature, the wear mechanism of DLC coating changes from abrasive wear to adhesive wear, and finally delamination, which is caused by the intensification of surface graphitization. The complex tribochemical reaction in the wear process leads to the dynamic change of its graphitization transformation, which is mainly because the transition layer Cr/CrC and Si3N4 play a role in inhibiting the graphitization transformation of DLC layer during the wear process, thus affecting the friction properties of DLC.