镀液循环流量对封闭循环电沉积Ni-SiC复合镀层的影响

Effect of Circulating Flow of Plating Bath on Ni-SiC Composite Coating in Closed and Bath Recyclable Electroplating Device

目的研究封闭式镀液循环装置中不同镀液循环流量对Ni-SiC复合镀层的影响规律,优化镀液循环流量参数。方法以Q235管状工件为待镀基体,以添加SiC颗粒的改良瓦特镀液为母液,在自主研发的封闭式镀液循环电镀装置中以0.3、0.5、0.7 m3/h的镀液循环流量于管件内壁制备Ni-SiC复合镀层,通过SEM检测、XRD测试、硬度测试和摩擦磨损性能测试等手段,对各Ni-SiC复合镀层宏微观形貌、厚度、成分、结构、硬度和耐磨性进行分析研究。结果在0.5 m^(3)/h流量条件下,镀层厚度为32.98μm,SiC颗粒含量为15.37%,镀层晶粒尺寸和硬度分别为10.84 nm和704HK_(0.245),该条件下制备的Ni-SiC复合镀层具有最佳耐磨性,摩擦系数为0.41,体积磨损率仅2.83×10^(-5) mm^(3)/Nm。结论在不同镀液循环流量参数下,采用该封闭式循环电镀装置,均可制得均匀完整的Ni-SiC复合镀层。随镀液循环流量的升高,镀层厚度和SiC颗粒体积含量均降低,镀层颜色金属光泽增强,镀层晶粒尺寸先减小、后增大,镀层硬度则先升高、后降低。

This study is aimed to analyze the effects of different circular-flow velocities of plating solutions,which is based on the Ni-SiC composite coating in a self-designed and closed electrolyte-circulating plating apparatus and optimize circular-flow parameters.The Q235 tubular workpiece is seemed as the plated substrate and the plating solution has been solved by modified Watt bath containing SiC particles in this article.Ni-SiC composite coatings were prepared by circulating flow with three different rates(0.3 m3/h,0.5 m3/h and 0.7 m3/h)on the internal wall of the tube in the mentioned electroplating device.Ad-ditionally,the macro-microscopic morphology,thickness,composition,structure,hardness and wear resistance of each Ni-SiC composite coating were measured and the results indicated that uniform and complete Ni-SiC composite coatings could be generated under the mentioned circulation flow.The color of the coating is affected by the SiC content,which reflects that the higher the SiC content,the weaker the metallic luster of the coating.With the circulating flow rate increases,the plating solution,the coating’s thickness and volume content of SiC particles were going to decrease.At first,the grain size of the coating decreases and then raised up,while the hardness showed oppositely.At the flow rate of 0.5 m^(3)/h,the coating thickness,SiC particle content,grain size and hardness are 32.98μm,15.37%,10.84 nm and 704HK0.245,respectively.Furthermore,the Ni-SiC composite coating prepared under this condition has the best wear resistance with a friction coefficient of 0.41 and a volume wear rate of only 2.83×10^(-5) mm^(3)/Nm.The circulating flow rate of the plating solution has a significant effect on the Ni-SiC composite coating.When the circulating flow rate of the plating solution is 0.5 m^(3)/h,the Ni-SiC composite coating obtained the best comprehensive performance.