Ni-AlN纳米复合镀层的制备及耐蚀性能研究

Electrodeposition Preparation and Corrosion Resistant Behavior of Ni-AlN Nanocomposite Coatings

采用电沉积的方法在低碳钢表面成功制备了Ni-AlN纳米复合镀层,通过称量法计算出沉积速率,采用X-射线衍射、扫描电镜和电化学测量技术探究了镀液中不同AlN浓度对镀层的组织结构、微观形貌和耐蚀性能的影响。结果表明,在电沉积过程中,沉积速率随镀液中AlN浓度的增大呈先增大后减小的趋势;镀液中AlN的加入,使镀层表面产生了米粒状的多晶单元,提高了镀层的耐蚀性能,随着镀液中AlN浓度的增加耐蚀性能先提高后降低。当镀液中纳米AlN质量浓度为1 g/L时,复合镀层中的AlN质量分数约为4.5%,表面致密性最好,与纯Ni镀层相比,腐蚀电流密度降低了2个数量级,耐蚀性能最佳。

Ni-AlN nanocomposite coatings were successfully prepared on the surface of mild steel by ultrasonic electrodeposition. Weighing method was used to calculate the deposition rate. The effects of the different AlN nanoparticles content in the plating solution on the microstructure, micro-morphology and anti-corrosion of coatings were investigated by X-ray diffraction （XRD）, scanning electron microscope （SEM） and electrochemical measurement techniques, respectively. The results show that the deposition rate increases first, and then decreases with the increase of AlN concentration. In the electroplating solu- tion, the addition of AlN produces rice-shaped polycrystalline unit which improves the corrosion resistant performance of the coatings. In addition, the corrosion resistance increases first, and then decreased with the increase of AlN concentration. The best coatings are obtained when the concentration of AlN at 1g/L in the electroplating solution and the content of AlN in composite at 4.5wt% ,which decreases the corro- sion current density by two orders compared with pure Ni.