Study on High Temperature Tribological Properties of Diamond-Like Coatings Used in Textile Steel Collar

In order to study the high temperature friction property of diamond-like coating (DLC) for textile steel, the low temperature PVD coating technology was used to prepare DLC on high carbon steel surface. The surface morphology of DLC coating was observed by SEM. The structure composition of DLC coating was analyzed by X-ray Photoelectron Spectrometer Test and Energy Spectrometer and Raman spectrometer. The mechanical properties of the coating were tested using a scratch tester. High temperature friction and wear testing machine was used to test the friction properties of the coating at different temperatures. The results show that the average friction coefficient between GCr15 sample and steel ball mating pair increases with the increase of temperature, and the maximum is 0.88. The wear volume of steel ball pairs showed the same variation trend, and the maximum wear volume was 2.88×10⁻³ mm³. After deposition of DLC coating, the average friction coefficient of friction pair increases first and then decreases. The average friction coefficient of coating samples at 25℃ is the lowest 0.033, and the ball wear volume is the lowest (3.87×10⁻⁶ mm³). When the test temperature rises to 100℃, the average friction coefficient value increases to 0.212. When the test temperature increased further, the average friction coefficient decreased to 0.088. Conclusion: The high temperature generated in the friction process of the samples without coating leads to the formation of a large number of oxidation particles at the interface, which intensifies the wear degree. However, when the test temperature of the coating sample is higher than the graphitization degree of the coating, the coating will graphitize and form a transfer layer dominated by carbon elements, which plays the role of solid lubricating medium and ultimately leads to the reduction of the friction coefficient.