Study on surface texture patterns for improving tribological performance of bioimplants

Abstract

A new surface texturing design was proposed for improving the tribological performance of bioimplants. Theoretical analysis was conducted to reveal the positive impact of round corner patterns. Experimental results indicated that round corner would significantly reduce the chance of interlocking phenomenon. Orthogonal experiments suggest that triangle pattern with 200 μm side length, 8–10 μm depth, 10% area density and square-distribution mode turns to be most effective in improving tribological performance of textured bioimplants, showing a 50% reduction in friction coefficient and 44.9% reduction in wear rate than that of polished samples. Working mechanisms of surface texturing in bioimplants were also comprehensively studied. It was confirmed that the extra lifting pressure provided by hydrodynamic effect was less than 1% of the ambient pressure. Further investigations proved that the negligible role of hydrodynamic pressure in the textured bioimplants was due to the low viscosity and slow sliding speed. On the other hand, the capacity to trap particles and second lubrication effect were found to be the main working mechanisms. • Interlocking effect could be the failure mechanism for some patten designs in bioimplants. • Only the patterns with round-corner should be adopted in the bioimplants. • Area density is the most influential pattern parameter while the distribution mode is the least one. • Capacity to trap particles and second lubrication effect are the main working mechanisms for textured bioimplants.