摘要
采用连续噪声电阻计算(CNRC)技术在线测定经锆预处理后镁合金的化学镀镍速率。为此,计算化学镀液中预处理合金表面的噪声电阻(R_n)随时间的变化。采用能量色散X射线谱仪(EDS)和扫描电镜(SEM)技术对CNRC结果进行解释。同时,用动电位极化法和重量法测定同一时间区间内的化学沉积速率,并与CNRC结果进行比较。R_n随施镀时间的变化表明,化学镀是由具有不同沉积速率的几个阶段组成的。由于极化法在线监测沉积速率的局限性,CNRC结果和极化法的结果并不一致。然而,重量法的结果与CNRC结果完全一致。因此可以认为CNRC是一种合适的化学沉积速率在线评估工具。
Continuous noise resistance calculation(CNRC)technique was used for online determination of the electroless nickel deposition rate on zirconium pretreated magnesium alloy.For this purpose,the noise resistance(R_n) variation with time was calculated for the pretreated alloy surface in the electroless plating solution.The CNRC results were described by energy dispersive X-ray spectroscopy(EDS)and scanning electron microscopy(SEM)techniques.Also,potentiodynamic polarization and gravimetric measurements were used for determination of the electroless deposition rate at the same time period and the results were compared with the CNRC results.The Rn variation with plating time shows that the electroless plating consists of different stages with various deposition rates.The results of the CNRC and polarization methods were not in acceptable agreement due to the limitations of the polarization method for online monitoring of the deposition rate.However,the results of the gravimetric measurements were in complete agreement with the CNRC technique and so,the CNRC can be considered as suitable tool for online evaluation of the electroless deposition rate.
关键词
镁合金
化学镀
沉积速率
电化学噪声
SEM
EDS
magnesium alloy
electroless plating
deposition rate
electrochemical noise
SEM
EDS