在室温下，采用动电位极化和交流阻抗谱技术（EIS）研究了(Cu47Zr11Ti34Ni8)100-x Mox（x=0, 2;原子百分数）块体非晶合金在1 mol/L H2SO4溶液中的电化学行为。结果表明，非晶合金中添加了2 at％Mo后，材料的钝化膜破裂电位(Eb)显著上升，而致钝化电位(E0) 与维钝电流密度(ip)则明显减小。这主要是由于在稳定的钝化区内，微量Mo的添加增加了基体合金中的“氧空位”和表面活性，抑制了阴离子空位在金属/表面膜（M/F）界面上形成，促使Zr、Ti元素在M/F界面上快速形成相应的氧化物，并增加了钝化层中氧化层的厚度和稳定性。根据该体系在电解质中的电化学反应，基于点缺陷模型（PDM）建立了简单的动力学模型。利用该模型，结合EIS数据，分析了微合金化提高Cu基块体非晶合金耐蚀性能的机理。
(Cu47Zr11Ti34Ni8)100-xMox (x = 0, 2 at.%) bulk metallic glasses (BMGs) were produced by copper mould casting. The amorphous feature of the samples was characterized by X-ray diffraction (XRD). The corrosion resistance and corrosion mechanism of the two BMGs in 1 mol/L H2SO4 solution open to air were studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. It is found that the BMG with 2 at.% Mo exhibited a superior corrosion resistance over the base alloy, as indicated by a considerable increase in pitting potential (Eb) and significant decrease in passive potential (E0) and passive current density (ip) for the Mo-bearing BMG. EIS results revealed that the micro-addition of Mo increased the surface activity and promoted the generation of positive defects (i.e., oxygen vacancies), but suppressed the formation of negative defects at the interfaces between metal/passive film (M/F). As a result, the addition of Mo could speed up the formation of the passive film of Zr-, and Ti-oxides, and stabilize simultaneously the oxides film. Base on point defect model (PDM), a qualitatively kinetic model is established to explain tentatively the effect of micro-additionn of Mo on the improvement of the corrosion resistance of the Cu-based bulk metallic glasses.
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