The Investigation of Production Parameters and Their Effect on the Tribomechanical Properties of the Compression Molded Polymeric Bearing Materials

Abstract

UHMWPE (Ultra High Molecular Weight Polyethylene) is a widely used polymer due to its superior mechanical properties. The microstructural, mechanical, and tribological properties of this polymer material produced by the compression molding technique significantly depend on the production parameters. The different molding pressures and temperatures dramatically impact the properties of the material. In this study, UHMWPE polymer samples were produced at three different molding pressures (150 Bar, 250 Bar, and 350 Bar) and molding temperatures (120°C, 150°C, and 180°C) using the compression molding technique. The microstructural, mechanical, and tribological properties of the samples were examined. It is observed that low-temperature molding production parameters cause an increase in strength. On the other hand, this situation enables decreased ductility. It has been determined that as the molding temperatures increase, ductility increase in all the same molding pressure groups. Similarly, it was observed that increasing the molding pressure in the same temperature group increased the strength of the material. It has been determined that there is an optimum molding pressure and temperature for wear resistance. It has been observed that the coefficient of friction (COF) behavior is not much affected by the molding parameters. Agglomeration of polymer particles is envisaged as the main reason for forming optimum pressure and temperature conditions in wear resistance. Agglomerated particles in the microstructure reduce bonding strength and deteriorate wear resistance. The study determined the optimum molding pressure (250 Bar) and temperature (150°C) for the production of UHMWPE material by a compression molding technique.