块体金属玻璃在微观尺度下弹性变形及失效机制研究

项目名称： 块体金属玻璃在微观尺度下弹性变形及失效机制研究

项目编号： No.51461026

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 谭军

作者单位： 昆明理工大学

项目金额： 48万元

中文摘要： 随着对大块金属玻璃研究的逐渐深入，人们发现玻璃结构的本征脆性所导致的塑性变形能力的缺失成为金属玻璃工程化应用的瓶颈问题，只有突破与玻璃态结构、形变机理相关的关键科学问题，与金属玻璃相关的新材料研究开发才能够在强大应用背景的推动下得到持续的发展。了解非晶相结构随应变的演化规律，是理解大块金属玻璃塑性和强度起源所急需解决的科学问题。本课题将采用高能X射线同步辐射光源在恒定或变化温度情况下对金属玻璃进行原位观察，同时利用数字散斑相关方法原位测量弹性应变场在弹性变形中的分布及大小。研究内容包括：（1）在宽温度范围内（98K至720K之间）短程序畴和中程有序畴随弹性变形至屈服点的演化规律；（2）探讨力链传递的形成机制，并利用其阐述塑性流变过程中的应变和应力的传递过程，以及变形及失效机制。以此为基础，在原子尺度上建立金属玻璃的变形本构模型。

中文关键词： 非晶合金；微观结构；塑性变形；同步辐射技术；力学行为

英文摘要： With further research on bulk metallic glass (BMG), it has been discovered that the intrinsic brittleness of glass structure, which cause it almost impossible to endure plastic deformation, become bottlenecks in engineering applications. Only a key breakthrough of scientific issues between glassy structure and deformation mechanism, the development of new materials in BMG can be driven in engineering applications. Understanding the structure of the amorphous phase with the evolution of strain is an important scientific problem to solve the origin of plasticity and strength of BMG. In this work, high-energy X -ray synchrotron radiation source at a constant or changeable temperature conditions will be utilized to observe the structure evolution of metallic glasses; while digital scattering correlation method (DSCM) will be adopted to obtain an in-situ measurement of elastic strain in the elastic deformation field distribution and size. This project include following 2 subjects: (1) understanding the evolution rule of short- and medium-range ordered domains from elastic deformation to the yield point over a wide temperature range (between 98K to 720K); (2) exploring the formation mechanism of power transmission chains, of its elaborate plastic flow during the transfer process of strain and stress, as well as the deformation and failure mechanisms. On this basis, the establishment of the deformation constitutive model of metallic glasses under atomic scale will come to a target.

英文关键词： amorphous alloy;microstructure;plastic deformation;synchrotron radiation technology;mechanical behaviour