利用电化学极化曲线和阻抗图谱(EIS)技术研究了Pr60Fe30Al10块体非晶及其晶化后合金在不同pH值的3.5%(质量分数,下同)NaCl溶液中的腐蚀行为。结果发现,随着pH值的增大2种合金的耐蚀性都增强。即在开路电位Ecorr下,腐蚀电流icorr减小,Ecorr向贵金属方向变化,极化电阻Rp及相应的阻抗图谱等效电阻R'p增大;当pH值一定时,非晶合金和晶化后台金相比,非晶合金的阳极极化曲线出现了宽的钝化区,EIS Nyquist图谱呈现出更大的容抗弧幅值,从而表现出强的耐蚀性。由极化曲线和交流阻抗技术所得到的极化电阻及腐蚀电流具有很好的一致性。
Corrosion behaviors of bulk metallic glass (BMG) Pr60Fe30Al10 and its crystallized sample in 3.5% NaCI aqueous solutions with different pH values were studied by potentiodynamic polarization experiments and electrochemical impedance spectroscopy (EIS). It is found that with the increase in pH, the corrosion resistances of the two kind alloys become larger, i.e., the corrosion current icorr at open-circuit Ecorr decreases, Ecorr is ennobled, the polarization resistance Rp and the equivalent polarization resistance R 'p deduced from EIS increase. Compared with their crystaUized samples, the BMG samples show larger capacitance arcs at Nyquist plots and wider passive regions at anodic polarization curves with significantly low passive current density in the same pH solution. The polarization resistances and corrosion currents deduced from the potentiodynamic polarization and EIS techniques agree well each other in this work.