Tribological behavior of plasma-sprayed carbon nanotube-reinforced hydroxyapatite coating in physiological solution

Wear behavior of plasma-sprayed carbon nanotube (CNT)-reinforced hydroxyapatite (HA) coating is evaluated in the simulated body fluid environment. Apart from enhancing the fracture toughness and providing biocompatibility, CNT-reinforced HA coating demonstrated superior wear resistance compared with that of hydroxyapatite coating without CNT. Initiation and propagation of microcracks during abrasive wear of plasma-sprayed hydroxyapatite coatings was suppressed by CNT reinforcement. Surface characterization and wear studies have shown that in addition to acting as underprop lubricant, CNTs provide reinforcement via stretching and splat-bridging for enhanced abrasion resistance in vitro.