复配BTA与TTA钝化纯铜工艺研究  

Chromium-free Passivating Technology Based on BTA and TTA for Copper

作　　者：宋久龙 陈文革[1] 郑艳 

机构地区：[1]西安理工大学材料科学与工程学院,西安710048

出　　处：《表面技术》2018年第1期168-175,共8页Surface Technology

基　　金：陕西省教育厅重点实验室科研计划项目(17JS080)~~

摘　　要：目的为了提高纯铜表面的耐腐蚀性。方法通过苯并三氮唑(BTA)与甲基苯并三氮唑(TTA)复配,对纯铜进行钝化,并分析钝化温度、时间及pH值对纯铜钝化效果的影响。分别运用电化学法、硝酸点滴实验、中性盐雾实验、SEM等手段对不同钝化液钝化膜的微观结构与耐蚀性能进行研究,并与铬酸盐钝化结果进行对比。结果将4 g/L BTA、4 g/L TTA复配,辅以氧化剂20 m L/L H_2O_2,对纯铜以pH值为4、钝化时间3 min、钝化温度40℃、自然风干老化1 d的钝化工艺处理后,可以生成明显的钝化膜。其表面致密,耐蚀性较好,在盐雾试验中腐蚀缓慢,其平均腐蚀速率为0.76 mg/d,自腐蚀电流密度仅为1.5660μA/cm2,缓蚀率达到81.9%,接近铬酸盐钝化的抗腐蚀效果。结论在适宜的钝化工艺下,经过BTA与TTA复配钝化后,可以在基体表面生成Cu/Cu_2O/Cu(I)BTA聚合物保护膜,同时TTA的非极性甲基形成的单分子层膜的疏水性更好,两者共同作用,形成较为致密的钝化膜覆盖在铜基体表面,明显提高纯铜表面耐蚀性。The work aims to improve corrosion resistance of pure copper surface. Pure copper was passivated by compounding benzotriazole （BTA） and methyl benzotriazole （TTA）, and effects of passivation temperature, time and pH on passivation of the pure copper were analyzed. Microstructure and corrosion resistance of different passivation solutions and passivation films were studied in electrochemical method, and by performing nitric acid droplet experiment and neutral salt spray test, and using SEM, and the study results were compared with chromate passivation results. A clear and dense passivation film of better corrosion resistance formed after treatment of pure copper provided with following process parameters： 4 g/L BTA, 4 g/L TTA, 20 mL/L H202, pH 4, passivation time 3 min, passivation temperature 40 ℃, natural air-drying aging duration 1 day. In the salt spray test, corrosion rate of the film was low, and average corrosion rate was 0.76 mg/d, corrosion current density was only 115660 μA/cm2, inhibition rate was 81.9%, which was close to corrosion resistance of chromate passivation. Provided with appropriate passivation process, after the passivation by BTA and TTA, Cu/Cu2O/Cu（I）BTA polymer protective film forms on the surface of substrate. TTA non-polar methyl-forming monolayer film is more hydrophobic, both of which act together to form a more dense passivation film covering the surface of the copper substrate, thus significantly improving corrosion resistance of pure copper.

关 键 词：纯铜 钝化 BTA 无铬 TTA 

分 类 号：TG174.4[金属学及工艺—金属表面处理]