Fatigue Crack Behavior and Fracture Toughness of Gamma Irradiated 1900H and GUR 1050 UHMWPE

Gamma irradiation, oxidation and crosslinking of ultra-high molecular weight polyethylene (UHMWPE) may influence the material’s resistance to delamination in reciprocating sliding experiments and in knee simulators. It may also alter fracture toughness and fatigue crack propagation resistance. While 1900H components displayed less delamination wear as compared to machined GUR 415 [1], strength and ductility were reduced in aged, gamma irradiated, compression molded 1900H as compared to GUR 1050 [2]. The purpose of the present study was to determine the effects of gamma irradiation crosslinking, at different levels of irradiation, on the fatigue crack growth resistance and fracture toughness of 1900H and GUR 1050 UHMWPE. It was hypothesized that, for both resins, fatigue crack resistance and fracture toughness would decrease when gamma irradiation was applied, and that decreases would be dosage dependent. We further conjectured that the GUR 1050 resin would, overall, outperform the 1900H resin.