无机材料学报

• 研究论文 • 上一篇    下一篇

等离子体电解氧化陶瓷膜生长过程的电化学阻抗谱研究

张雪林1, 姜兆华1, 姚忠平1, 吴振东2   

  1. 1. 哈尔滨工业大学化工学院, 哈尔滨 150001; 2. 白城师范学院化学系,白城 137000
  • 收稿日期:2008-03-21 修回日期:2008-05-08 出版日期:2009-01-20 网络出版日期:2009-01-20

Electrochemical Impedance Spectroscopy during the Process ofPlasma Electrolytic Oxidation

ZHANG Xue-Lin1, JIANG Zhao-Hua1, YAO Zhong-Ping1, WU Zhen-Dong2   

  1. 1. School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China; 2. Department of Chemistry, Baicheng Normal College, Baicheng 137000, China
  • Received:2008-03-21 Revised:2008-05-08 Published:2009-01-20 Online:2009-01-20

摘要: 在铝酸钠溶液中,利用直流等离子体电解氧化电源在钛合金表面制备了陶瓷膜,将所制备的膜层在原铝酸钠溶液里进行电化学阻抗谱测试,并利用扫描电镜(SEM)及其附带的能谱仪以及X射线衍射仪(XRD)对膜层的形貌以及组成进行了分析,从而探讨了膜层生长过程中的结构变化特点.结果表明,膜层主要由钛、铝以及氧元素组成.在火花阶段,膜层内未形成结晶相,电流密度对PEO陶瓷膜的生长过程影响较小;在微弧阶段,膜层内形成了Ti2AlO5结晶相,电流密度对PEO陶瓷膜的生长过程,特别是疏松层的生长过程影响显著,而对致密层生长过程的影响相对较小.微弧阶段长时间的击穿放电会对PEO陶瓷膜造成破坏,随电流密度的增大破坏程度增强.

关键词: 等离子体电解氧化, 电化学阻抗谱, 钛合金

Abstract: The growth process of plasma electrolytic oxidation (PEO) coating conducted for Ti6Al4V was studied by electrochemical impedance spectroscopy (EIS). The sample was treated to different voltage in sodium aluminate solution with DC power at current density of 2A/dm2 and 8A/dm2, and then it was transferred with the solution to the electrolytic cell to perform the EIS test. SEM, EDS and XRD were also adopted to characterize the porous structure, element and phase composition of the PEO coating, respectively. The results show that the PEO coating is composed of titanium, aluminum and oxygen. In the spark region, no crystalline phase is detected, and the growth process of PEO coating, especially the loose outer layer, is strongly affected by the treatment voltage, but nearly independent on the current density. In the micro-arc region, the coating consists of aluminum titanate phase, and the current density has strong effects on the growth process of the loose outer layer, but has little effects on the growth process of the dense inner layer.

Key words: plasma electrolytic oxidation, electrochemical impedance spectroscopy, titanium alloys

中图分类号: