Wear Behavior of Micro-arc Oxidized Magnesium Alloy in Flowing Simulated Body Fluid

The micro-arc oxidation was conducted on AZ91D magnesium alloy surface, and then the corrosive degradation resistance of the non-oxidized and micro-arc oxidized alloys was studied during immersion in the simulated body fluid of 2 mL·min^-1 for 5 d. The friction and wear experiment in the flowing simulated body fluid was performed on the micro-arc oxidized magnesium alloy with immersion for 5 d. The effects of load, rotating speed and wear time on the friction and wear properties were investigated and the wear morphology and mechanism were analyzed. The results show that the micro-arc oxide film had a porous structure and local tiny cracks. The corrosive degradation resistance of the micro-arc oxidized magnesium alloy was better than that of the magnesium alloy substrate. During the wear of micro-arc oxidized magnesium alloy with 5 d immersion in the simulated body fluid, the friction coefficient increased with the increasing load and decreased with the increasing rotating speed and wear time, while the wear losses increased with the increase of the load, rotating speed and wear time. The wear mechanism was mainly adhesive wear at the low rotating speed while delamination wear at high rotating speed.