The Influence of Plastic Deformation Performed before and after Electron Beam Irradiation on Mechanical Properties and Wear of UHMWPE

Abstract

The paper compares the modification methods of polymers GUR 1050 and GUR 1020 by means of plastic deformation before (ON) and after (NO) irradiation with an electron beam (N). Evaluation of the effectiveness of the modification methods applied was carried out by means of micromechanical examinations and tribological tests on T-01 and T-05 testers (polymer/Vitalium alloy). The results of micromechanical, sclerometric and tribological tests indicate unequivocally the effectiveness of the modifications applied, as compared to the polymer modification through irradiation with an electron beam only. A decrease in hardness and elasticity modulus was found for materials subjected to the ON and NO technology as compared to N, while maintaining the growing trend of these values along with the applied radiation dose. There was also noted a large increase of the wear resistance coefficient, Wβ, and an increase of the microploughing component’s share in the wear mechanism β, which had a direct influence on the reduction of the linear wear by 2.5–3 times and a nearly twofold decrease of the mass wear. The surface subjected to friction processes became smoother and free of lamella fragments which were visible for the base material not subjected to any modifications. This was documented with the observations performed on a scanning microscope and in the stereometric examination of the surface.