Materials World Network: Mechanisms leading to nanometer-sized materials

材料世界网络：纳米材料的形成机制

• 批准号: 73725602
• 负责人: Professor Dr.-Ing. Jürgen Eckert
• 金额: --
• 依托单位: Lehrstuhl für Materialphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/73725602?language=en
• 关键词: Materials; World; Network; Mechanisms; leading

Deformation induced grain refinement has been revealed in pure Cu by rolling at ambient and cryogenic temperature and low temperature annealing. In addition, Zn decreases the stacking fault energy (SFE) from 78 (for pure Cu) to 14 mJ/m2 (Cu-30 wt.% Zn) and enhances the grain refinement. In this project, nano-/ultrafine grained Cu-/Cu-Zn alloys will be synthesized by rolling and low temperature annealing, in order to overcome dimension limitations of specialized critical mechanical tests for strength and ductility, which are poorly understood for such NC/UFG materials. Characterization of the microstructure will be performed down to the atomic level by thorough and systematic analysis; and mechanical properties of these materials will be studied under tension, compression and torsion. In-situ deformation studies under scanning and transmission electron microscopic observation will be performed to reveal the deformation mechanisms at different length-scales. The nano-/ultrafine structures obtained by various processing routes (rolled/annealed samples prepared at IFW and specimens produced by ball milling (NCSU) and equal channel angular pressing/ high pressure torsion (UV)) will be compared in order to reveal the influence of processing induced structural defects on the ease of grain refinement in Cu-/Cu-Zn alloys with different SFE and deformation mechanisms as a function of grain size and SFE. The influence of alloy composition and processing conditions, i.e., rolling temperature, severity of deformation, on nanostructure development, and final grain size will be compared in these Cu/Cu-Zn alloys with different SFE.

通过室温和低温轧制以及低温退火，发现纯铜中变形诱导的晶粒细化。此外，Zn将堆垛层错能（SFE）从78（对于纯铜）降低到14 mJ/m2（Cu-30 wt.% Zn）并增强晶粒细化。在这个项目中，纳米/超细晶Cu-/Cu-Zn合金将通过轧制和低温退火来合成，以克服强度和延展性的专门关键机械测试的尺寸限制，这对于这种NC/UFG材料来说知之甚少。微观结构的表征将通过彻底和系统的分析进行到原子水平;这些材料的机械性能将在拉伸，压缩和扭转下进行研究。在扫描和透射电子显微镜观察下进行原位变形研究，以揭示不同长度尺度的变形机制。通过各种工艺路线获得的纳米/超细结构（在IFW制备的轧制/退火样品和通过球磨（NCSU）和等通道角挤压/高压扭转（UV）制备的试样）进行比较，以揭示加工引起的结构缺陷对Cu-/Cu-合金中晶粒细化容易性的影响。锌合金具有不同的超临界流体和变形机制作为晶粒尺寸和超临界流体的函数。合金成分和加工条件的影响，即，轧制温度、变形程度、纳米结构发展和最终晶粒尺寸将在具有不同SFE的这些Cu/Cu-Zn合金中进行比较。