On the Existence of Our Metals-Based Civilization
On the Existence of Our Metals-Based Civilization
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DOI：
10.1149/1.2195877
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发表时间：
2006-02
影响因子：
3.9
通讯作者：
D. Macdonald
中科院分区：
文献类型：
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作者：
D. Macdonald
双层钝化膜，形成在金属和合金表面上的阻挡层的稳定性，当接触氧化性水环境中，探索的点缺陷模型的框架内使用相空间分析，其中的阻挡层的生长速度的金属，和阻挡层的溶解速率，同时绘制对阻挡层的厚度。与的交点表示存在具有大于零的稳态厚度的亚稳态势垒层。如果是，则阻挡层不能存在，即使是作为亚稳相，因为所得厚度将为负值。在这些条件下，表面被去钝化，金属可能以快速的速度腐蚀。由于潜在的增强溶解（过渡到过钝化状态）和酸攻击的屏障层（“酸去钝化”）的去钝化进行了探讨。去钝化的边界可以在电位-pH空间中绘制，以开发动力学稳定性图作为经典Pourbaix图的替代品，用于描述金属或合金以钝化状态存在的条件。
The stability of the barrier layers of bilayer passive films that form on metal and alloy surfaces, when in contact with oxidizing aqueous environments, is explored within the framework of the point defect model using phase-space analysis, in which the rate of growth of the barrier layer into the metal, and the barrier layer dissolution rate, are plotted simultaneously against the barrier layer thickness. A point of intersection of with indicates the existence of a metastable barrier layer having a steady-state thickness greater than zero. If, the barrier layer cannot exist, even as a metastable phase, as the resulting thickness would be negative. Under these conditions, the surface is depassivated and the metal may corrode at a rapid rate. Depassivation due to potential-enhanced dissolution (transition to the transpassive state) and to acid attack on the barrier layer (" acid depassivation") are explored. The boundaries for depassivation may be plotted in potential-pH space to develop kinetic stability diagrams as alternatives to the classical Pourbaix diagrams for describing the conditions under which metals or alloys exist in the passive state.