Sliding wear behavior of plasma sprayed nanoceramic coatings for biomedical applications

This paper reports on the sliding wear performance of the nanostructured Al2O3–13TiO2, ZrO2 and the bilayered (ZrO2/Al2O3–13TiO2) coated biomedical Ti–13Nb–13Zr alloy in simulated body fluid condition. The nanopowders were sprayed using an atmospheric plasma spray technique and the reciprocatory sliding wear behavior of all the above coatings was evaluated using wear testing machine. The bilayered (ZrO2/Al2O3–13TiO2) coating which has not been reported hitherto exhibited two hundred and five hundred fold increase in the wear resistances when compared with that of the nanostructured Al2O3–13TiO2 (AT) and ZrO2 (YSZ) coatings. This substantial improvement in the wear resistance of the bilayered coating is attributed to its lower porosity and higher adhesion strength when compared to the AT and YSZ coatings. This study suggests that this new type of bilayered coating may be a preferred approach to be tried for obtaining much higher wear resistant coatings.