电流密度对AZ91D镁合金阳极氧化膜表面形貌及粘接性能的影响

Influences of the Current Density on Surface Morphology and Adhesion of Anodic Films of AZ91D Magnesium Alloy

采用恒电流方式在AZ91D镁合金表面制备多孔阳极氧化膜。通过电压-时间曲线研究了电流密度对氧化行为的影响。采用SEM、单板拉剪试验研究了电流密度对氧化膜表面形貌及拉伸强度的影响。结果表明,电流密度不影响击穿电压及临界电压的大小。随着电流密度增加,电压达到击穿电压及临界电压的时间缩短,氧化膜孔隙率及拉伸强度均先增加后减小,当电流密度为10 mA/cm^2时拉伸强度最大,可达到22.40 MPa。

Porous anodic films on AZ91D magnesium alloy were prepared at constant current densities.Effects of the current density on anodizing process were studied according to voltage-time response.The morphologies and adhesive properties of the anodic films were studied.The results showed that the current density had no effect on the value of breakdown voltage and critical voltage,but the anodizing time to reach breakdown voltage and critical voltage decreased as the current density increased. The porosity and the adhesive bonding strength of the anodic films increased first and then decreased as the current density increased.The films formed at the current density of 10 mA/cm^2 and exhibited the highest adhesive bonding strength,approaching to 22.40 MPa.