超声振动作用下非晶态合金的结构非均匀性响应规律及其对变形行为影响研究

The structural heterogeneity of amorphous alloys is closely correlated with plastic deformation, but how to understand its structural heterogeneity and relationship with micro-properties is always one of difficult issues in the research field of amorphous alloys. In this project,  structural relaxation of amorphous alloys is induced by ultrasonic vibration. Different from stress and temperature, ultrasonic vibration certainly have different effects on structural heterogeneity of amorphous alloys due to the difference of input energy. The influences of structural heterogeneity on relaxation, plastic deformation and mechancial properties of amorphous alloys are systematacially investigated. The structural evolution and plastic deformation behaviors of amorphous alloys can be directly observed by high-resolution method on structure characterization combined with a statistical method based on auto-correlation function which enables to traverse and quantify the ordered clusters in amorphous alloy systems. The correlations between the plasticity of amorphous alloys and relaxation as well as plastic deformation units are established by dynamic mechanical analysis. The results will help to further understand structural heterogeneity and mechanism of plastic deformation of amorphous alloys and provide theoretical basis and method to enhance its plasticity at room temperature.

非晶合金的塑性变形能力与其结构的非均匀性密切相关，但是如何认识非晶合金的结构非均匀性并建立微观结构与宏观性能之间的关联一直是非晶合金研究领域的难度问题之一。本项目研究从弛豫方式入手，通过超声振动诱导非晶合金发生结构弛豫，由于能量输入方式的差异，必然对其结构非均匀性产生不同影响，系统研究结构的非均匀性对非晶合金弛豫、塑性变形和力学性能的影响。利用高分辨结构表征技术，结合基于自相关函数的能遍历量化纳米尺度有序团簇的方法，直接观察不同能量形式激励下非晶合金的微观结构演化规律和塑性变形行为；通过动态力学分析建立非晶合金塑性变形能力与弛豫、塑性变形单元之间的关系。研究结果将有助于加深对非晶合金结构非均匀性和微观塑性变形机制的理解，为提高其室温宏观塑性提供理论依据和方法。

非晶合金的塑性变形与其结构的非均匀性密切相关，但是如何认识非晶合金的结构非均匀性并建立微观结构与宏观性能之间的关联一直是非晶合金研究领域亟待解决的问题之一。本项目从施加外场和微合金化的角度出发，系统研究了超声振动和微量添加Ag和O对Zr基非晶合金的微观结构不均匀性、热力学行为、力学性能和变形行为的影响规律；基于第二相增强方式设计了新型Zr基非晶复合材料，并考察其力学性能和界面特征。取得的创新性成果如下：（1）添加微量Ag和O在ZrCuNiAl块体非晶合金中调控非晶有序度以及纳米晶的分布和形态，实现了强度和塑性协同提升；（2）基于自相关函数和电子衍射技术，发展了一种可定量化描述非晶合金有序化程度的新方法；（3）揭示了超声振动对非晶的弛豫、结构不均匀性、强度以及塑性变形行为的影响规律；（4）提出了一种改善Zr基非晶合金脆性的超声振动方法；（5）开发出兼具强度和塑性的Zr基非晶复合材料，并探讨了其强化机制。以上发现对于理解非晶合金结构不均匀性和微观塑性变形机制具有重要科学意义，为提高非晶合金强度和塑性提供了新的思路和方法。