全硫酸盐体系三价铬电镀铬的研究

Study of Electroplating with Thrivalent Chromium in Sulfate System

研究了全硫酸盐体系三价铬电镀铬的工艺.实验表明:溶液的pH值、温度、搅拌、电流密度等工艺条件都会影响镀层质量及外观,其中pH值升高是铬结晶层无法增厚的一个主要原因.当Cr(Ⅵ)的浓度≥10mg/L时会对镀层的外观及质量产生影响,甚至无镀层.加入稳定剂能抑制Cr(Ⅲ)向Cr(Ⅵ)的转化.在全硫酸盐体系三价铬电镀铬中,加入光亮剂前后铬的电结晶机理不会改变,均遵循瞬时成核机理.

A new process of electroplating with thrivalent chromium from sulfate solution is introduced in this paper. The technology parameters that the pH of solution, temperature, stiring way and the cathode current densities can affect the quality of plating. Furthermore, the parameter of pH is one of the main reasons that cause plating not to become thicker. When the concentration of sexivalent chromium in electrolyte attains a definite value, it can lead to inferior, even no plating. Stablizer can inhibit thrivalent chromium converting to sexivalent chromium. The mechanism of electrodeposition in sulfate system adheres to instantaneous nucleation, and brighterer can not change the machanism.