Tribology of ha/hdpe composites against stainless steel in the presence of proteins

摘要

Various materials have been used for knee and hip prostheses over the last few decades due to considerations for their mechanical and tribological properties and their biocompatibility. Hydroxyapatite (HA) reinforced high density polyethylene (HDPE) composites have been developed as a new generation biomaterial for skeletal applications. in this investigation, the tribological properties (i.e., wear rate, coefficient of friction, and lubrication in the presence of proteins) of HDPE and HA/HDPE composites were evaluated against duplex stainless steel under dry and lubricated conditions. Lubricants included distilled water and aqueous solutions of proteins (egg albumen or glucose). It was found that HA/HDPE composites had lower coefficients of friction than HDPE under certain conditions. Furthermore, HDPE exhibited more severe fatigue failure marks than the composites. The degradation and fatigue failure due to the presence of proteins were severe for low speed wear testing (100 rpM) as compared to high speed wear testing (200 rpm). Both egg albumen and glucose were found to be corrosive to steel and adversely reactive for HDPE and HA/HDPE composites. This was clearly shown by SEM micrographs of HDPE and HA/HDPE specimen surfaces taken after the tests. The wear modes observed were similar to that of UHMWPE. Specimens tested with egg albumen also displayed higher wear rates, which again were attributed to corrosion accelerated wear of these specimens.