脉冲电镀在复合镀中的应用及其复合镀机理模型

Application of Pulse Plating on Composite Plating and Composite Plating Model

复合镀是在金属或合金电镀过程中,将不溶性的单质、氧化物、碳化物、纤维等固体微粒共沉积在基底表面,并夹杂到金属沉积层中而形成的镀层的过程。复合镀层既有镀层金属的性质,又保留了夹杂颗粒的原有性质,因此,通过复合镀,可获得优良的耐高温性、耐腐蚀性,耐磨性、装饰性以及其他特殊的表面性能的镀层。目前常用的复合镀是直流电镀,需采用特殊的辅助手段使不溶性颗粒与电镀金属共沉积。脉冲电镀是通过电流的通断模式使电镀进行间断式地工作,通过脉冲频率、占空比、电流密度等工艺参数的设置,能有效降低电镀过程中的浓差极化,增强镀层与基底的结合力,提高夹杂颗粒在镀层的分布均匀性等。概述了复合镀的机理研究,对脉冲电镀在复合镀中的研究现状及其发展趋势进行了归纳总结。

Composite plating is a process in which insoluble solid particles such as simple substance,oxides,carbides,fibers,etc.are deposited on the matrix surface and mixed into the metal deposit layer in electroplating process of metal or alloy.Composite coating not only has the nature of the coated metal and also keeps the original nature of the inclusion particles.Therefore,the coating with excellent high temperature resistance,corrosion resistance,wear resistance,decorative and other special surface properties can be obtained by composite plating.At present,the common composite plating is DC plating.It needs special auxiliary means to co-deposit the insoluble particles with the electroplating metal.Pulse plating is to work intermittently through the on-off mode of current.By setting the process parameters of pulse frequency,duty cycle,current density and other,it can effectively reduce the concentration difference polarization in the electroplating process,enhance the binding force of the coating and the matrix,and improve the distribution uniformity of the inclusion particles in the coating.In this paper,the mechanism of composite plating is summarized,and the research status and development trend of pulse plating in composite plating are summarized.