室温累积轧制制备致密金属纳米玻璃及其结构和性能研究

项目名称： 室温累积轧制制备致密金属纳米玻璃及其结构和性能研究

项目编号： No.51301080

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 徐远丽

作者单位： 兰州大学

项目金额： 24万元

中文摘要： 纳米玻璃由纳米尺度的玻璃区域和玻璃/玻璃界面组成。与玻璃区域相比，玻璃/玻璃界面区域原子排列更加无序、具有更多自由体积。由于局部增加、在纳米尺度起伏的自由体积，纳米玻璃是一种不同于常规玻璃和纳米晶材料的新型结构材料。本项目基于金属玻璃发生不均匀塑性变形时产生的剪切带上存在更多自由体积，探索完全致密金属纳米玻璃制备技术。将金属玻璃在室温下进行累积轧制变形产生剪切带，当产生的剪切带之间平均间距达到纳米量级（<50 nm）时，即制得完全致密金属纳米玻璃。优化成分和变形参数，制备玻璃/玻璃界面（剪切带）上自由体积稳定的致密金属纳米玻璃。深入分析致密金属纳米玻璃玻璃/玻璃界面上的自由体积分布及其稳定性，描述纳米玻璃的原子排列结构和稳定性。系统研究完全致密金属纳米玻璃的力学、热学等性能，建立纳米玻璃的结构和性能的关系。纳米玻璃的研究将催生纳米玻璃新型材料，开拓材料科学新领域，具有重要的科学和技术意义。

中文关键词： 纳米玻璃；轧制变形；结构；热稳定性；机械性能

英文摘要： Nanoglasses consist of nanometer-sized glassy regions connected by glass/glass interfaces. These "interfaces" between adjacent glassy regions have a reduced atomic density and an enhanced free volume relative to the nanometer-sized glassy regions. Due to their free volume fluctuating on nanoscale, nanoglasses differ structurally and are expected to show different or excellent properties from glassy and nanocrystalline materials (with the same chemical composition). Based on the existence of more amount of free volume in shear bands formed in metallic glasses endured inhomogeneous plastic deformation, we will try a method to fabricate dense metallic nanoglasses. We will perform cumulative room-temperature rolling deformation on metallic glasses to introduce shear bands. Dense metallic nanoglasses can be obtained when enough high density of shear bands with spacing of several tens of nanometers (<50 nm) is introduced into metallic glasses. We will fabricate metallic nanoglasses with stable glass/glass interfaces and study the distribution of free volume as well as the atomic arrangement in these glass/glass interfaces. The mechanical property and thermal stability etc., will be systematically studied and hence the relationship between the microstructure and properties will be analyzed for the dense metallic nanogl

英文关键词： nanoglasses；rolling；structure；thermal stability；mechanical property