钛合金微弧氧化过程中电学参量的特性研究

Characteristics of electrical parameters during microarc oxidation of titanium alloys

利用自制的数据采集系统研究了恒定电压下TC4钛合金微弧氧化(MAO)过程中有关电学参量随处理时间的变化规律.结果表明,通电回路中的阴极和阳极峰值电流随处理时间的变化明显分为4个阶段;膜厚度随处理时间的变化明显分为3个阶段;氧化膜的动态正、反向电阻和动态正、反向电阻率也随处理时间分阶段变化.MAO过程中,各时刻的动态正、反向电阻值不同,一般情况下,动态正向电阻大于反向电阻.对不同处理时间样品的扫描电子显微镜分析表明,MAO膜呈多孔结构并随处理时间变化.

The variation of electrical parameters during microarc oxidation（MAO）of titanium alloys at constant voltage has been studied by means of a laboratory-made data acquisition system.Experimental results show that the variation of the cathodic and anodic current amplitudes and effective working current in an electrical loop with the duration of treatment show obviously four stages,and the variation of the coating thickness with the treating time has obviously three stages,and the variations of dynamic forward and backward resistance as well as resistance rate of coatings also show different stages.During MAO process,the dynamic forward resistance is always different from the backward resistance,and the former is generally greater than the latter.Scanning electron microscopy shows that the surface morphology of MAO coatings is porous and varies with treatment time in steps.