Multi-Phase Ceramic System

Bearing surfaces are typically either metal-on-metal (MOM), ceramic-on-ceramic (COC), or metal-on-polyethylene (MOP). MOM and MOP couplings have the drawback that metallic or polyethylene particles can sometimes separate from the couplings, which can cause significant problems, particularly in a hip or joint replacement. COC couplings are less likely to lose particles due to wear, which makes them more biocompatible, but they are more susceptible to fracture. COC couplings also have a tendency to squeak as they move. Innovators at NASA’s Glenn Research Center have developed a technique using rare earth elements to fabricate a dual-phase ceramic composite that combines a wear-resistant phase and a solid-state lubricant phase. The result is a coupling material that, compared to currently used materials, exhibits a tenfold reduction in the friction coefficient, a sixfold reduction in wear, and a significant reduction in debris caused by wear. Glenn’s groundbreaking rare-earth aluminate composite has considerable potential, not only in biomedical applications, but also in commercial and industrial sectors.