高面圧条件下における金属表面改質Metal-on-Metal摺動の摩擦摩耗特性

抄録

In total joint arthroplasty, debris from the wear of ultra-high molecular weight polyethylene is widely recognized as a major cause of osteolysis. Clinical interest has been renewed in the use of metal-on-metal bearings. Metal surface coatings, however, are subject to delamination in local contact, i.e., the head-and-insert rim and area of polar contact in total hip arthroplasty. In local contact, contact stress is very high and the articulation surface is easily damaged. Studies have been conducted on reducing metal wear debris and corrosion by introducing surface treatment.
We applied carbon ion implantation (CII) and diamond-like carbon (DLC) films to a cobalt-chrome alloy substrate using plasma source ion implantation. Once films were prepared, we put them through simple geometry wear tests under high contact pressure -an average load of 1030 MPa- to establish tribological properties. CII-coated bearings showed less wear, lower friction coefficients, and higher resistance to catastrophic damage compared to uncoated Co-Cr alloy and DLC couples, even under high contact pressure. The CII-coated surface thus offers potential advantages as a hard coating for articulating joints.