抄録
Recently, an explosive flaking-like destruction so-called delamination has been reported in retrieved ultra-high molecular weight polyethylene (UHMWPE) knee components. In order to investigate the effects of microscopic substructure such as grain boundaries, two-dimensional sliding fatigue tests were carried out for three types of UHMWPE samples, non-irradiated, gamma-irradiated, and vitamin E-added and gamma-irradiated samples. Morphology of sliding surface was examined by both SEM and an optical microscope. Surface roughness of the sliding surface was also measured. Our result showed that microscopic crack initiation and propagation was observed to occur at surface/subsurface grain boundaries of gamma-irradiated UHMWPE samples.
