Theoretical and Experimental Investigations of Gum Metal

胶质金属的理论与实验研究

• 批准号: 0706554
• 负责人: Daryl Chrzan
• 金额: $ 40.5万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0706554&HistoricalAwards=false
• 关键词: Theoretical; Experimental; Investigations; Gum; Metal

TECHNICAL: PIs will pursue a transformative research program to study in detail the mechanical properties of the recently discovered class of Ti-Nb alloys known as Gum Metals. Gum Metals display super-elasticity, high strength, and significant ductility all in the absence of traditional, dislocation mediated plasticity. In an effort previously funded (in part) through an NSF NIRT, PIs have conducted a rudimentary analysis of the mechanical properties of these materials. Specifically, PIs have demonstrated that Gum Metals are deforming near their ideal strength limit. Further, PIs demonstrated that the dislocations may be pinned easily, even at stresses approaching the ideal strength. Using nanoindentation experiments, PIs showed that the material deforms through (apparently) continuous rotations of nanoscale volume elements. All of these properties have been linked to an electron-filling-induced transition from a body-centered cubic to a hexagonal close packed structure. PIs will expand substantially their prior investigations of Gum Metal behavior in two directions. First, PIs will develop a more detailed understanding of the mechanical properties of Gum Metals. These studies will expand to include the study of dislocation cores, as well as more detailed mapping of the nanoscale deformation patterns associated with nanoindentation. PIs will use theory to identify new alloys that are candidates for Gum Metal behavior. PIs will synthesize the alloys in thin film form and explore directly their mechanical properties. NON-TECHNICAL: Gum Metal behavior presents several exciting opportunities for materials theorists and metallurgists. Since the mechanical properties of these materials are linked to quantities that can be computed directly using the best available quantum mechanical based total energy methods, there is a genuine opportunity for rapid, computer aided, advanced engineering of these alloys. Further, theory will be used to identify other candidates for Gum Metal behavior. PIs' work is aimed at exploiting these opportunities, and it will advance the understanding of Gum Metal behavior and, more generally, an understanding of metallurgical possibilities. The project will have a broad impact in a number of ways. First, there will be two graduate students working directly on the project, and their research conducted within this program will advance their Ph.D. studies. Each student will be encouraged to write papers and to attend meetings of professional societies in order to disseminate their research results. Second, the research results will be incorporated directly into the graduate level Computational Materials Science course taught at Berkeley. Third, the PIs will recruit undergraduates to work on the project using programs at Berkeley aimed at engaging students from underrepresented groups in research. Within a much broader perspective, the existence of alloys with mechanical properties that conflict with 80 years of metallurgical wisdom is truly exciting. The potential for the engineering of advanced materials is clear. The research program may lead to a broad new class of alloys with "super" properties and numerous technological applications.

技术：PIS将追求一项变革性研究计划，详细研究最近发现的Ti-NB合金类的机械性能。在没有传统的脱位介导的可塑性的情况下，牙龈金属表现出超弹性，高强度和明显的延展性。在以前（部分）通过NSF NIRT资助的努力中，PI对这些材料的机械性能进行了基本分析。具体而言，PI已证明胶金属在其理想强度极限附近变形。此外，PIS证明，即使在接近理想强度的压力下，也可以轻松固定错位。 PI使用纳米引导实验表明，材料通过纳米级体积元素的连续旋转（显然）连续旋转而变形。所有这些属性都与电子填充引起的从体内的立方体到六角形近距离堆积结构有关。 PI将在两个方向上大大扩展对牙龈金属行为的先前研究。首先，PI将对胶金属的机械性能有更详细的了解。这些研究将扩展到包括脱位核心的研究，以及与纳米识别相关的纳米级变形模式的更详细的映射。 PI将使用理论识别新的合金，这些合金是牙龈金属行为的候选。 PIS将以薄膜形式合成合金并直接探索其机械性能。非技术：牙龈金属行为为材料理论家和冶金学家带来了一些激动人心的机会。由于这些材料的机械性能与可以使用基于最佳量子机械的总能量方法直接计算的数量有关，因此这些合金的快速，计算机辅助，高级工程确实有一个真正的机会。此外，理论将用于识别其他牙龈金属行为的候选者。 PIS的工作旨在利用这些机会，它将促进对牙龈金属行为的理解，更普遍地了解冶金可能性。该项目将以多种方式产生广泛影响。首先，将有两名直接从事该项目的研究生，他们在该计划中进行的研究将推进他们的博士学位。研究。将鼓励每个学生写论文并参加专业社会的会议，以传播他们的研究结果。其次，研究结果将直接纳入伯克利教授的研究生水平计算材料科学课程。第三，PI将使用伯克利计划招募本科生从事该项目，旨在吸引来自代表性不足的团体的学生参与研究。从更广泛的角度来看，具有机械性能的合金的存在与80年的冶金智慧冲突确实令人兴奋。高级材料工程的潜力很明显。该研究计划可能会导致具有“超级”特性和众多技术应用的广泛合金类。