Influence of nanosecond laser processed surface textures on the tribological characteristics of diamond films sliding against zirconia bioceramic

Abstract

CVD Diamond films have shown much potential in bioimplantable applications. Aiming at enhancing the tribological properties of CVD diamond and bioceramic tribopair, two types of surface texture, namely groove surface and square surface, are fabricated on free-standing diamond films by nanosecond (ns) laser processing technology. Reciprocating friction and wear experiments against zirconia bioceramic (ZBC) balls in simulated body fluid (SBF) lubrication are performed to evaluate the influence of as-processed surface textures on the tribological behavior of diamond films. It is demonstrated that the counterpart balls sliding against surface-textured diamond films present obviously lower wear rate than that sliding against the untreated diamond films. This can be ascribed to the reduction of adhesive wear and abrasive wear by the surface texture. On the other hand, the heat-affected zone (HAZ), which is caused by the ns laser process, can greatly degrade the friction behavior and wear resistance of as-fabricated surface textures. In this work, after the HAZ is worn out, the groove surface exhibits lower friction coefficient than the untreated surface and square surface. And yet owing to more severe in-depth HAZ, the square surface shows higher friction coefficient and much more abrasion loss than the groove surface.