“…Due to its excellent optical, tribological, mechanical, and biological qualities, it has drawn much scientific attention. − DLC films are widely used on the surfaces of various engineering parts because of their high hardness and wear resistance, and because they have an extremely low coefficient of friction. − However, due to the test conditions and environmental conditions, the DLC film will have chemical or physical reactions with different components in the atmosphere. Therefore, the frictional properties of DLC films are highly dependent on the experimental environment. , Undoubtedly, the predominant gas in the atmosphere is nitrogen, with a content of up to 78%, about 3.7 times that of oxygen. As a result, it is important to understand the friction mechanism of DLC in nitrogen environment.…”