Tribocorrosion behaviour of hot pressed CoCrMo−HAP biocomposites

Bioactivity of CoCrMo can be enhanced by incorporation of hydroxyapatite (HAP), but the poor mechanical properties of HAP is the most serious hindrance for its application on load-bearing implants, especially when exposed to corrosion and wear, simultaneously. Thus, the present work aims to investigate the tribocorrosion behaviour of CoCrMo−HAP composites. The tribocorrosion tests were performed under open circuit potential (OCP) in 8 g/l NaCl at 37 ºC by using a ball-on-plate tribometer. Results suggested that HAP particle addition increased the corrosion rate due to localized corrosion taking place on the pore sites near the matrix/reinforcement interface. However, under tribological action, composite samples presented relatively lower tendency to corrosion and lower coefficient of friction values.