Materials World Network: Processing-Structure-Property Relationships in Ultra-Fine Grained and Nanostructured Bulk Cu and Cu-Zn Alloys

这项研究是基于北卡罗来纳州州立大学（NCSU），奥地利维也纳大学（UV）和IFW-Dresden，德国（IFW-D）之间的合作。 该研究的科学目标是利用一系列加工和表征技术和专业知识来研究金属和合金的机械行为，作为其晶粒尺寸和堆垛层错能的函数。 特别是，Cu和Cu-Zn合金是通过各种机构的加工技术制备的，当这些技术结合在一起时，可以生产出无伪影的块状样品，其粒度范围从超细（1000 nm）到纳米级（~ 10 nm）的最细粒度。需要NCSU、UV和IFW-D的联合努力和设施来实现处理目标。临界机械性能通过NCSU的拉伸、剪切和纳米压痕测试，IFW-D的压缩、拉伸和扭转测试，以及UV的疲劳和断裂韧性来确定。 在不同的晶粒尺寸和堆垛层错能量的变形机制，是在原位的X射线衍射线展宽的应力下，在UV和NCSU与合作者的研究进行了探讨。 原位透射电子显微镜（TEM）应变研究由IFW-D和NCSU进行，原位扫描电子显微镜（SEM）在IFW-D进行。 一套广泛的密度泛函理论（DFT）计算和大规模分子动力学（MD）模拟也在NCSU完成，而基于机制和相关的建模在NCSU，UV和IFW-D完成。 研究生的交流和教师之间的互动NCSU，UV和IFW-D构成了该项目的一个重要组成部分。

This research is based on collaboration among North Carolina State University (NCSU), the University of Vienna, Austria (UV), and IFW-Dresden, Germany (IFW-D). The scientific objectives of the research are to exploit a range of processing and characterization techniques and expertise to investigate the mechanical behavior of metals and alloys as a function of their grain size and stacking fault energy. In particular, Cu and Cu-Zn alloys are prepared by processing techniques at the various institutions that, when combined, produce artifact-free bulk samples with a grain size range from ultra-fine ( 1000 nm) down to the finest achievable at the nanoscale (~ 10 nm). The combined effort and facilities at NCSU, UV, and IFW-D are needed to achieve the processing objectives. The critical mechanical properties are determined by tensile, shear and nanoindentation tests at NCSU, compression, tensile and torsion tests at IFW-D, and fatigue and fracture toughness at UV. The deformation mechanisms that are operative at the various grain sizes and stacking fault energies are probed by in situ x-ray diffraction line broadening studies under stress at UV and NCSU with collaborators. In situ transmission electron microscopy (TEM) straining studies are done by IFW-D and NCSU, and in situ scanning electron microscopy (SEM) is done at IFW-D. An extensive set of density functional theory (DFT) calculations and large-scale molecular dynamics (MD) simulations are also done at NCSU, while mechanism-based and related modeling is done at NCSU, UV, and IFW-D. The exchange of graduate students and the faculty interactions among NCSU, UV and IFW-D constitute a major part of the project.