Modification of Tribotechnical Properties of Carbon Composites by the Laser Surface Treatment Method

The study of the structure and tribotechnical characteristics of composite material based on polyacrylonitrile (PAN) carbon fabric and a matrix obtained by the vapor deposition method has been carried out. One of the samples of the investigated material was subjected to laser treatment, with local laser heating of the surface layer to 2800–3000°C. The other composite sample was heat treated at a temperature T > 2000°C. Tribotechnical tests were carried out and values of friction and wear coefficients were obtained in the pair with steel and ceramic counterbodies. In order to determine the peculiarities of friction and wear mechanisms of modified materials, the surface of composites after friction was investigated by scanning electron microscopy with X-ray spectral analysis. It was found that laser treatment significantly improves antifriction properties of carbon composite paired with a steel counterbody (friction coefficient reduction by two times, wear reduction by three times). It is revealed that such treatment significantly changes the nature of the third body film (TB) formed on the friction surface of composites paired with steel. No elements of the counterbody material are detected in the composition of the film, which indicates its minimal wear during the friction process. The TB film itself becomes thicker and denser, completely covering the surface of the composite. This allows it to exhibit solid lubricant and anti-wear properties to a greater extent, improving the tribological characteristics of the composite.