金属玻璃及其液相的微观结构和热力学的核磁共振表征

项目名称： 金属玻璃及其液相的微观结构和热力学的核磁共振表征

项目编号： No.51271082

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 吴跃

作者单位： 华中科技大学

项目金额： 90万元

中文摘要： 非晶合金的形变机理是凝聚态物理的一大基本科学问题。基本流变单元的存在与特征是当前金属玻璃领域研究的焦点之一。如何从微观上认识流变单元的结构特征、从实验上直接捕捉到流变单元是本领域的一大挑战。本项目提出利用滞弹性变形的方法使流变单元处于剪切变形的过程中，利用核磁共振的结构测试方法捕捉到流变单元，识别流变单元剪切变形后的微观结构特征。通过选择不同激活能和脆度的体系，系统研究流变单元、弛豫和微观结构的关系，为从微观上认识非晶合金的形变机理提供关键的实验与理论依据。同时，用高温核磁共振对非晶合金液态结构、热力学及动力学的研究会从金属玻璃的源头认识金属玻璃的结构、形成能力、和力学性能。通过研究合金成份（包括共晶点成份）对液态特性的影响认识液态微观特征与玻璃形成能力的关系，与玻璃态纳米尺度结构及力学性能和弛豫的关系。这些有关液态微观性质的研究为认识非晶合金形变、形成能力、及玻璃转变提供了重要信息。

中文关键词： 金属玻璃；金属液体；核磁共振；力学性能；微结构

英文摘要： Deformation mechanism of metallic glasses is a fundamental problem of condensed matter physics. The existence of flow units and their characteristics in metallic glasses are currently one of the research focuses in the field of metallic glasses.Unlike dislocations in crystalline systems, flow units in metallic glasses lack obviously recognizable characters in microscopic structures. Therefore, it is very challenging to detect and recognize flow units in experiments. This project proposes to utilize anelastic deformation to activate the shear flow of flow units and freeze the flow units in an intermediate state which could assume recognizable unique microscopic structures. Such unique microscopic structures could be detected and characterized by nuclear magnetic resonance (NMR). By choosing metallic glass systems with different activation energies of flow units, different fragilities, the relationships between flow units, the characteristics of α and β relaxations, and microscopic structures could be established.In addition, the structures, thermodynamics，and dynamic properties of glass forming liquids will be studied. This could offer important information on the relationship between the characteristics of liquid properties and the structure, glass forming ability (GFA), and mechanical properties of the glassy s

英文关键词： metallic glasses；metallic liquids；NMR；mechanical properties；microstructures