块体热电材料的热变形诱导再结晶与性能优化

项目名称： 块体热电材料的热变形诱导再结晶与性能优化

项目编号： No.51271165

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： 赵新兵

作者单位： 浙江大学

项目金额： 83万元

中文摘要： 结构纳米化是提高块体热电材料性能的最有效途径之一。发展热电性能空间分布均一的千克级纳米结构块体热电材料可控制备技术是实现热电材料规模化应用的关键性需求和挑战。热变形诱导再结晶（HDIR）是一种不依赖于固态相变、具有可放大应用潜力的块体热电材料原位纳米化制备新技术。本项目选择分别具有典型晶体结构的碲化铋基合金和镁硅基合金热电材料，通过对百克级至千克级大块体材料在HDIR过程中的微结构形成演变规律、变形应力和微结构空间分布特征及其对热电性能影响的系统研究，阐明金属间化合物热电材料的热变形行为和10纳米级微结构形成机制，揭示HDIR处理对纳米结构大块体材料中合金元素在界面处的分布特征以及对有效载流子浓度的影响，探索通过HDIR处理实现大块体热电材料中电声输运协同调控和热电性能突破的途径，并在此基础上发展具有局部性能分布均一的高性能千克级大块体纳米结构热电材料可控制备技术。

中文关键词： 热电材料；热变形；点缺陷；多尺度微结构；热电性能

英文摘要： Nanostructurization is one of the most efficient routes to improve the properties of bulk thermoelectric materials. The fabrication of nanostructured thermoelectric materials with a homogeneous property distribution in kilogram large bulks is one of the most crucial demands and challenges for the scale applications of thermoelectric materials. Hot-deformation induced recrystallization (HDIR) is a new, facile, phase transformation independent and scalable technique to make bulk thermoelectric materials nanostructured in-situ. Here we propose to investigate the microstructure formation during HDIR in large bulk thermoelectric materials, the spacial distribution of the deformation stress and microstructures, and their effects on the thermoelectric properties, using bismuth telluride and magnesium silicide based alloys, as both represent two typical crystal structures. The proposed investigation is aimed at revealing the hot-reformation behaviors and the formation of 10-nm structures in thermoelectric intermetallic compounds, exploring the possibility of improving thermoelectric figure of merits of large bulk materials with HDIR treatment, and developing scalable, controllable fabrication techniques for high-ZT large bulk thermoelectric materials with a homogeneous property distribution.

英文关键词： thermoelectric materials；hot deformation；point defects；multiscale microstructures；thermoelectric properties