锆基非晶合金的氧化过程与氧化机理研究

Due to their outstanding mechanical, physical and chemical properties, amorphous alloys have been considered as highly important engineering materials and functional materials for the future. Many properties of amorphous alloys are strongly dependent on their surface conditions, in particular, the formation of a surficial oxide layer and its evolution under service conditions. However, a systematic investigation of the oxidation of amorphous alloys has hitherto been lacking. Detailed knowledge and fundamental understanding of the structure, composition, growth kinetics and growth mechanism of the oxide layers formed on amorphous alloys are largely missing. ..In this project, by using binary amorphous alloys as the model system, the oxidation behaviors and mechanisms of Zr-based amorphous alloys will be investigated systematically under various environments. Attentions will particularly be focused on:.(1).The diffusion behaviors and diffusion mechanism of oxygen atoms in amorphous alloys, and the differences as compared to those in the corresponding crystalline alloys..(2). The solubility of oxygen in amorphous alloys and its dependence on the amorphous alloy composition; internal oxidation processes in amorphous alloys..(3).The effect of the absence of structural defects, such as grain boundaries and dislocations, in amorphous alloys on their oxidation process..(4).The effect of the absence of the lattice-mismatch-induced stress between the oxide and the amorphous alloy on the oxidation process of the alloy. ..On this basis, the general features of the oxidation of amorphous alloys will be summarized and a fundamental scientific understanding of the oxidation of amorphous alloys will be derived from this project. The reached fundamental understanding may then provide guidelines for the development of strongly corrosion-resistant amorphous alloys.

非晶合金以其优异的力学、物理和化学特性被认为是新一代的重要的结构材料与功能材料。非晶合金的许多性能直接取决于其表面情况，尤其是表面氧化层的生长以及在服役条件下的演化。至今，国际上尚未系统开展关于非晶合金氧化的研究，对非晶合金表面氧化层的成分、结构、生长动力学以及形成机制等的认识与理解目前还存在着大量空白。.本项目从二元非晶合金体系出发，系统研究锆基非晶合金在不同环境下的氧化行为，重点阐明：.(1).氧在非晶合金中的扩散行为和扩散机制，以及与在相应晶态合金中的区别。.(2).氧在非晶合金中的溶解度与组分的关联；非晶合金的内氧化过程。.(3).非晶合金中晶界、位错等缺陷的缺失对氧化行为的影响。.(4).表面氧化物与非晶合金之间晶格失配应力的缺失对氧化行为的影响。.在此基础上，本项目将全面总结非晶合金氧化的共性特征，力图从基础科学层面实现对非晶合金氧化的根本认识，为强耐腐蚀非晶合金开发提供指导。

非晶合金以其优异的力学、物理和化学特性而成为新一代重要的结构材料与功能材料。非晶合金的许多性能直接取决于其表面情况，尤其是表面氧化层的生长及其在服役条件下的演化情况。非晶合金通常具有比较复杂的成分，包含多种（大于三种）具有不同氧亲和势的元素组元，其氧化行为因同时受到这些不同组元的影响而变得极为复杂，故而难以探索其中的普遍科学规律。本项目从简单二元非晶合金体系（Zr-Al和Zr-Cu）入手，系统研究了非晶合金的氧化过程与氧化机理，并重点通过与同化学成分晶态合金的氧化过程的细致对比，全面而深入地澄清了非晶合金的无序结构对其氧化过程中的微结构演变、动力学、热力学以及物理机制等的影响。在获得对二元非晶合金氧化规律认识的基础上，进一步研究了多组分Zr-Cu-Al非晶合金的氧化过程，揭示了合金的原子结构以及不同元素的氧亲和势与活度对非晶合金选择性氧化和同步氧化过程的深刻影响。通过全面总结非晶合金氧化的共性特征，从基础层面获得了对非晶合金氧化过程系统且深入的认识。以上研究成果对发展表面预氧化/热处理工艺和开发强耐腐蚀耐氧化非晶合金具有重要的理论指导意义。