动态多向塑性变形制备高强韧纳米结构铝合金的微/纳观机理及其热稳定性研究

项目名称： 动态多向塑性变形制备高强韧纳米结构铝合金的微/纳观机理及其热稳定性研究

项目编号： No.51274245

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 矿业工程

项目作者： 杨扬

作者单位： 中南大学

项目金额： 80万元

中文摘要： 纳米金属材料的制备和优异性能探索研究是当下材料学界的热点。为揭示这一贯穿不同结构层次的过程本质，本项目拟探索制备铝合金体纳米结构材料的动态多向锻压DMF新技术；综合运用SEM/EBSD、TEM/HREM、APT等先进的实验技术，在不同尺度尤其是在原子尺度上进行实验研究。探究高应变速率动载下绝热剪切变形诱导的纳米结构形成过程中析出相低温瞬间溶解以及晶粒瞬间急剧细化的机制；揭示DMF变形过程中微结构纳米化的演变过程与机理；研究纳米结构特征尤其是纳米结构中溶质原子团簇的成分、分布、偏析等的原子量级特征，探索纳米结构强韧化的物理本质、以及纳米结构热稳定性的控制因素和机制。 力图发展出金属纳米结构材料制备新技术和性能优化途径，进而为纳米结构设计原理和制备技术的工程应用奠定基础。

中文关键词： 动态多向塑性变形；高应变速率；超细晶/纳米结构；热稳定性；铝合金

英文摘要： The preparation of nano-structured metallic materials and the exploration of their excellent performance are the research focuses in the current materials academic fields. The dynamic multiple forging technique for preparing nano-structural aluminum alloy will be explored in the present application. Advanced experimental techniques such as SEM/EBSD、TEM/HREM and APT will be comprehensively used to study the achieved nanostructure at different scales especially on the atomic scale. The mechanisms of precipitates dissolved instantaneously at low temperature and grains sharp refined instantly during the nano-structure forming process induced by adiabatic shear deformation at high strain rate, and the nano-miniaturization evolution mechanism of the micro-structure during the dynamic multiple forging deformation will be explored. The characteristics of the nano-structures especially the composition、distribution、segregation of the solute atom clusters will also be investigated. The physical essence of the nanostructure's strengthening/toughening and the mechanism of the nanostructure's thermal stability will be studied. New techniques for preparing metallic nano-structural materials and optimizing of their performance will try to be developed, and then the foundation for engineering applications and the design pr

英文关键词： dynamic multiple forging；high strain rate；ultra-fine grained structure/nanostructure；thermal stability；aluminum alloy