双极性现象及其应用

Bipole Phenomena and its Application

双极性是指通过电流绕道或电场叠加的原因,使同一金属上出现正负两种极性,并同时发生阳极氧化和阴极还原反应。在电镀过程中一旦产生双极性现象,常会导致发生一些莫名其妙的电镀故障。对此,本文例举了四个实例,分析了产生的原因并提出了解决的办法。但是若懂得了双极性的原理,也可利用它来进行双极性电镀,特别适用于要求单面镀的工件,操作简单、效率高。为此,本文介绍了双极性酸性镀锡用于电镀火锅的内壁,以及齿轮轴眼的防渗碳镀铜。

Bipole phenomenon means that two opposite poles, positive pole and negative pole present on the same metal and anode oxidation and cathode reduction take place simutaneously on the same metal, due to the current detour and the superposition of electric field. Once this bipole phenomenon occurs in plating, it will lead to a series of inexplicable electroplating troubles. In this paper, four examples are given, the causes of the trouble are analyzed, and how to solve them is discussed. However. if the principle of bipole phenomenon is well understood, it could be utilized to carry on bipole electroplating, particularly suitable for the workpiece, which requires single face plating. Owing to its simple operation and high efficiency, it is recommened to be used in acid Sn plating for the inner wall of chafing dish, and in anti-carburisa- tion Cu plating for the spindle hole gear.