一种新型锌镍合金电镀工艺及镀层的耐蚀性  

Study on the Zn-Ni Alloy Electroplating and Corrosion Resistance of Coating

作　　者：李景轩 LI Jing - xuan(College of Chemistry and Biological Engineering, Guilin University of Engineering and Technology, Guilin 541006, China)

机构地区：[1]桂林理工大学化学与生物工程学院,广西桂林541006

出　　处：《材料保护》2018年第9期74-79,共6页Materials Protection

摘　　要：针对目前锌镍合金电镀工艺不稳定、镀层中镍含量难精确控制等问题,开发了新型HK-35锌镍合金电镀工艺,并在A3冷轧钢表面电镀锌镍合金,通过Tafel曲线、循环伏安曲线、交流阻抗等研究了镀层的耐蚀性,采用X射线衍射仪(XRD)分析了镀层的结构、含量,利用扫描电镜(SEM)对其微观形貌进行分析,研究了工艺参数pH值、温度、电流密度等对镀层耐蚀性的影响。结果表明:工艺参数为电流密度1.5～4.0 A/dm2、pH值4.0～5.5、温度30～40℃时,锌镍镀层厚度为18. 8μm、维氏硬度320 HV,镀层镍含量可精确控制在13%左右,晶型结构为Ni3Zn22,镀层耐蚀性较好,是纯锌镀层的5～6倍,经钝化处理后,耐蚀性是纯锌镀层的7倍以上。In order to solve the problems such as present unstable zinc-nickel alloy electroplating process and the nickel content in the coating being not easily controlled, the new HK-35 zinc-nickel alloy electroplating process was developed and used to synthesize Zn-Ni alloy coating on A3 cold-rolled steel surface. Tafel curves, cyclic vohammetry curves and electrochemical impedance spectroscopy were employed to analyze the corrosion resistance of coating. X- ray diffraction （XRD） was utilized to study the structure and composition of coating, and the micromorphology was observed by scanning electron microscope （SEM）. Moreover, the effects of process parameters containing pH value, temperature and current density on the coating were studied. Results showed that when the process parameters were current density 1.5-4.0 A/dm^2, pH value 4.0-5.5 and temperature 30-40 ℃, the thickness of as- prepared zincnickel coating was 18.8 μm and the vickers hardness was 320 HV. In addition, the content of Ni could be controlled accurately in the 13% and crystal structure was Ni3Zn22. The corrosion resistance of alloy coating was excellent, 5-6 times of that of pure Zn coating. After passivation, the corrosion resistance was above 7 times as great as that of Zn coating.

关 键 词：锌镍合金电镀 pH值 温度 电流密度 耐蚀性 镍含量 

分 类 号：TQ153.2[化学工程—电化学工业]