钛合金电解加工电化学特性研究

Electrochemical Characteristics of Titanium Alloy in Electrochemical Machining

针对钛合金材料的电解加工方式,为了确保加工出的钛合金产品具有优异的性能和质量,并改善电解加工过程中出现的问题,文中对TC4钛合金电化学特性进行研究。通过TC4钛合金在NaCl溶液、NaNO_(3)溶液中的开路电位、极化曲线实验和电化学阻抗谱实验,分析不同温度和不同浓度对极化曲线和阻抗的影响,结合实验研究,分析电解液浓度对加工点蚀情况的影响。研究结果表明:TC4钛合金在NaNO 3溶液比在NaCl溶液中更容易发生腐蚀;NaCl溶液能够提高加工效率,NaNO _(3)溶液能够提高加工成型精度;TC4钛合金表面钝化膜的阻抗性随温度的升高而降低,物质的传输速度加快,促进了电化学反应的进行;电解液浓度越高,点蚀现象越严重。

In order for the titanium alloy products machined electrochemically to have excellent performance and quality and to solve the problems emerging in the process of electrochemical machining,the paper studies the electrochemical characteristics of TC4 titanium alloys.The open circuit potential test,the polarization curve test and the electrochemical impedance spectroscopy test were conducted on TC4 titanium alloy in NaCl solutions and NaNO_(3) solutions,on the basis on which the effects of temperature and concentration on polarization curve and impedance and the influence of electrolyte concentration on machining pitting corrosion were analyzed.The findings are as follows.TC4 titanium alloy is more prone to corrosion in NaNO 3 solutions than in NaCl solutions.NaCl solution can improve the processing efficiency,while NaNO_(3) solution the processing precision.The impedance of the passive film on the surface of TC4 titanium alloy decreases with increasing temperature,and the material transfer is accelerated,promoting electrochemical reactions.Higher concentration of the electrolytes causes more severe pitting corrosion.