Study on tribological performance of groove-textured bioimplants.

Surface texturing is an effective approach to improve the tribological performance of artificial joints. In this paper, the frictional performance of Ultra-High-Molecular-Weight-Polyethylene and Cobalt-Chromium-Molybdenum material combination with micro grooves fabricated on the metal bearings is studied. The results show that grooves with width of 500 μm, depth of 4.5 μm and pitch distance of 3 mm could provide the optimized tribological performance, the coefficient of friction of which can be down to 0.05 showing a reduction of 51.9% compared to that of polished samples without micro grooves. A two-dimensional simulation of hydrodynamic pressure, based on Reynolds equation, is conducted. It is concluded that hydrodynamic pressure has little effect on the improved tribological performance of textured bioimplants. Otherwise, second lubrication effect induced by the polymer plastic deformation is proved to play a major role in the reduction of coefficient of friction.