Development of a Wear-Sensitive Criterion for the Example of Simulating Surface Damage by the Polytetrafluoroethylene and F4K20 Molecular Models

Abstract

Several energy parameters of molecular models of polytetrafluoroethylene and its composite F4K20 are calculated. As a result of friction and wear modeling, the energies of intermolecular bonds in the volume of the constructed \(U_{{{\text{inter}}}}^{{\text{V}}}\) models, in the surface zone \(U_{{{\text{inter}}}}^{{\text{S}}}\), and at the transfer layer–counterbody interface are determined, and the shear moduli of the material models under study are assessed. It is found that, in F4K20, compared with the original matrix, all of the above parameters increase, which may indicate stabilization of the kinetic state of molecules in the presence of a filler. Based on the results of a comparative analysis of \(U_{{{\text{inter}}}}^{{\text{V}}}\), \(U_{{{\text{inter}}}}^{{\text{S}}}\), and \(U_{{{\text{inter}}}}^{{{\text{ad}}}}\) with the value of the linear wear rate determined for the materials under study as a result of tribological tests, the \(U_{{{\text{inter}}}}^{{\text{V}}}\) value is proposed as a wear-sensitive criterion at the molecular level, and the \(U_{{{\text{inter}}}}^{{{\text{ad}}}}\) value is proposed as an additional parameter characterizing the adhesive strength of the transfer layers.