Effect of sp³–sp² Transformation on the Wear Rate of the DLC Coating

Abstract

Based on the methods of non-equilibrium thermodynamics, it was found that the implementation of spontaneous processes with positive entropy production during friction leads to an increase in the wear intensity. Non-spontaneous processes with negative entropy production lead to a decrease in wear intensity. The tribological characteristics of diamond-like carbon (DLC) with different silicon content were studied. The wear intensity practically does not correlate with the friction coefficient. It is shown that DLC with the highest content of diamond-like inclusions (sp3) in the coating has the highest wear rate. In the same DLC, the most intense sp3–sp2 transformation during friction was observed. The sp3–sp2 transformation is a spontaneous process.

Keywords

• DLC
• friction
• wear intensity
• coefficient of friction
• sp³–sp² transformation
• non-equilibrium thermodynamics