恒流及恒压模式对TC4钛合金微弧氧化膜层性能的影响

Effects of constant current and voltage on structure and properties of MAO film on TC4 alloy surface

为探讨微弧氧化恒压、恒流模式对微弧氧化膜层物相组成、微观结构、耐腐蚀性及单位能耗的影响,利用自制微弧氧化装置在乙酸钙-磷酸盐电解液体系中对TC4钛合金进行微弧氧化处理。采用X射线衍射仪、电化学工作站和扫描电镜等仪器对膜层进行结构表征。结果表明:两种操作模式得到的膜层主要由金红石、锐钛矿及钙磷化合物组成;膜层的耐腐蚀性、单位能耗随着频率的增加而增加;恒流微弧氧化膜层表面有分布均匀、孔径一致的三维连通孔洞,恒压氧化膜层表面孔洞分布不均,孔径不一致。

Effects of constant voltage or constant current of MAO on phase components,micro-structure,corrosion resistance and unit energy consumption of the oxide films were investigated. Micro-arc oxidation（ MAO） process was used on TC4 alloy in a self-made calcium acetatephosphate dual electrolyte system. X ray diffractometer,electrochemical workstation and SEM were used to research micro-structure of the films. The results indicate that the two kinds of films consist of rutile,antase and HA crystal phases. With the frequency increasing,the corrosion resistance and unit energy consumption also improved. The pore size of film on TC4 surface by constant current of MAO method is uniform and three-dimensional connected,but the micro-pore distribution on the film surface by constant voltage of MAO is non-uniform.