Fretting Wear Properties of Micro-arc Oxidation Treated Magnesium Alloy Under Condition of Simulated Bone Plate-screw Service

Abstract

The fretting wear behavior of micro-arc oxidation (MAO) treated ZK60 magnesium alloy under simulated bone plate-screw service condition was investigated. The MAO treatments on the surface of ZK60 magnesium alloy were conducted with different duty cycles of 20%, 30%, and 40%, respectively. Results show that the surface hardness and corrosion resistance of MAO-treated magnesium alloy specimens with different duty cycles are similar and are improved significantly in comparison with the bare magnesium alloy. Under the simulated bone plate-screw fretting condition, the worn surface of the bare magnesium alloy is characterized by ploughs and corrosion pits, accompanied with a high wear volume of 13.1×106μm3, while the wear is obviously decreased and mainly dominated by ploughs on the surface of the MAO-treated magnesium alloy. With the increase of duty cycle, the wear volume is 6.6×106,6.1×106μm3 and 6.5×106μm3, respectively. There is no obvious difference in the fretting wear behavior and the worn surface morphology among the MAO-treated ZK60 magnesium alloy specimens with different duty cycles. In sum, the anti-fretting wear performance of ZK60 magnesium alloy can be improved obviously after micro-arc oxidation treatment, and the duty cycle has little influence on the microstructure and fretting wear properties of the MAO layer on ZK60 magnesium alloy under the given experimental conditions.

Keywords

• bone plate
• magnesium alloy
• micro-arc oxidation
• duty cycle
• fretting wear