Comprehension of oxidation processes under the influence of an external polarization is still a challenge, despite numerous past studies. In this study, thermogravimetric analysis technique coupled with in situ application of an electric voltage was used to investigate oxidation of zirconium. The first technical challenge was to modify the thermobalance to integrate it with polarization equipment without perturbation of measurement and of oxidation behavior. Surprisingly, the oxidation rate was found to remain independent on the applied voltage, despite a large range of applied potentials, ± 200 V. Modeling of oxidation rates according to diffusion mechanism combined with investigation of polarization curves of the metal/oxide/electrode system has shown that a high electrical resistance appears at the oxide/electrode interface, even with addition of an intermediate gold layer. This resistance prevents from generating sufficient voltage drop through the oxide layer (> 10 V), necessary to modify the kinetics. Nevertheless, meaningful electrochemical properties using analogy with solid-oxide fuel cells have been observed, allowing to propose a comprehensive approach of oxidation phenomena under polarization.

中文翻译：

---

850 °C 氧化锆过程中金属/氧化物系统电行为的原位测量

尽管过去有许多研究，但理解外部极化影响下的氧化过程仍然是一个挑战。在这项研究中，热重分析技术与原位施加电压相结合，用于研究锆的氧化。第一个技术挑战是修改热天平以将其与极化设备集成，而不会干扰测量和氧化行为。令人惊讶的是，尽管施加的电压范围很大，± 200 V，氧化速率仍被发现与施加的电压无关。 根据扩散机制的氧化速率建模结合金属/氧化物/电极系统的极化曲线研究具有表明在氧化物/电极界面出现高电阻，即使添加了中间金层。这种电阻会阻止通过氧化层 (> 10 V) 产生足够的电压降，这是修改动力学所必需的。然而，已经观察到使用与固体氧化物燃料电池类比的有意义的电化学特性，允许提出极化下氧化现象的综合方法。