易切削锌-铜-镁-铝-稀土锌合金表面电镀光亮镍

以新型易切削Zn-Cu-Mg-Al-RE锌合金为基体,电镀得到光亮镍镀层。其工艺流程主要包括化学除油、活化、预镀镍、光亮镀镍和干燥。研究了温度、pH、电流密度、电镀时间等工艺条件对在以硫酸镍、氯化镍、硼酸和光亮剂为主要成分的镀液中所得光亮镍镀层外观的影响。电镀光亮镍的最佳工艺为:0.045～0.050A/cm2,40～45℃,pH=3.9～4.1,10min。在最佳工艺下得到的镀层总厚度约为80μm,镀层光滑、致密、光泽度好,无针孔、麻点、起泡等缺陷,与基体结合紧密,界面存在ZnNi过渡层。

Bright nickel plating on surface of machinable zinc-copper-magnesium-aluminum-rare earth zinc alloy

Bright nickel coating was electroplated on Zn-Cu-Mg-Al-RE zinc alloy substrate through the following process flow:chemical degreasing,activating,nickel pre-plating,bright nickel plating,and drying.The effects of temperature,pH,current density and plating time on the appearance of bright nickel coating prepared from a bath mainly composed of nickel sulfate,nickel chloride,boric acid,and brightener were studied.The optimal process parameters for bright nickel plating are as follows:0.045-0.050 A/cm 2,40-45℃,pH 3.9-4.1,and 10min.The coating with a thickness of ca.80μm is obtained under the optimal parameters,which is smooth,compact and of good glossiness,without defects such as pinholes,pits,and bubbles.The nickel coating is tightly bonded to zinc alloy substrate,and there is a ZnNi transition layer close to the zinc alloy substrate.