重铬酸钾对钛合金表面微等离子体氧化陶瓷膜结构和耐蚀性的影响

Effect of potassium dichromate on structure and anticorrosive properties of ceramic film grown on Ti alloy by micro-plasma oxidation

在钛合金表面用微等离子体氧化能产生一层陶瓷膜。将重铬酸钾引入磷酸盐电解液将使钛合金微等离子体氧化过程的槽电压升高 ,经对所得微等离子体氧化陶瓷膜表面和截面进行扫描电镜 (SEM )形貌观察 ,发现重铬酸钾的加入使陶瓷膜的致密性增加。XRD分析表明 ,不同电解液中所得膜层都是以锐钛矿型TiO2 为主晶相 ,同时还含有少量的金红石型TiO2 ,重铬酸钾的加入使锐钛矿型TiO2 的含量增加。对膜层进行电偶电流和循环伏安测试表明 ,重铬酸钾的加入使所得的膜层对金属的接触腐蚀降低 。

A layer of ceramic film can be grown on Ti alloy by the micro plasma oxidation. In order to improve the properties of ceramic film, potassium dichromate is added into the solution of phosphate. SEM, XRD and circling volt ampere were employed to characterize the ceramic film. It is found that ceramic film with 20?μm becomes more compact; it consists of anatase and rutile TiO 2, and anatase TiO 2 is dominant; its anti point corrosive property is greatly improved and its contact corrosion to Cu decreases because of the addition of potassium dichromate.