EAGER: Bulk Nanostructured Metals from Twinned Nanowires

EAGER：来自孪生纳米线的块状纳米结构金属

• 批准号: 1747776
• 负责人: Jiaxing Huang
• 金额: $ 20万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1747776&HistoricalAwards=false
• 关键词: EAGER; Bulk; Nanostructured; Metals; Twinned

Non-technical Abstract:Metals have widespread uses in electronics and infrastructure, and are the material foundation of modern civilization. A continuous piece of metal is made of densely packed, very fine grains. The size and structure of these grains, and the way they pack together determine the macroscopic properties of the bulk material. Typically, these grains are formed during the growth of the entire bulk material, and can be somewhat restructured during further processing. This project explores a contrasting approach, in which discrete metal nanocrystals are first chemically synthesized to yield well-defined structure, then assembled and densified to yield the final bulk nanostructured metal. This new approach allows for much higher degree of freedom to control the size, structure, and orientation of the metal grains, and can potentially create metal materials with novel properties. Technical Abstract:The new approach for creating bulk nanostructured metals departs fundamentally from the current ones, which are based on extensive plastic deformation of coarse-grained metal, atom-by-atom growth through electroplating or sputtering-based techniques, and consolidation of micron-size metal powders. In the new strategy, well-defined metal grains (i.e., nanowires) are first synthesized "atom-by-atom?" and then assembled to construct the final bulk metal "grain-by-grain". This can effectively decouple the tuning of grain microstructures and grain orientations, leading to new bulk nanostructured metals with previously unattainable microstructures (e.g., grain shape, orientation and nano-twinning) and novel properties. The project addresses a long missing connection between bulk nanostructured alloys (metallurgy-oriented) and colloidal nanomaterials (materials chemistry-oriented). If successful, it will inspire and catalyze a long overdue collaboration between these two independent areas of nanomaterials research. Students trained in the project represent a new breed of material scientists that can connect metallurgy with colloidal nanomaterials, bringing fresh mindsets to both areas.

摘要：金属在电子和基础设施中有着广泛的应用，是现代文明的物质基础。一块连续的金属是由密密麻麻的、非常细的颗粒构成的。这些颗粒的大小和结构，以及它们堆积在一起的方式决定了大块材料的宏观特性。通常，这些晶粒是在整个块状材料的生长过程中形成的，并且可以在进一步加工过程中进行某种程度的重构。该项目探索了一种截然不同的方法，其中离散的金属纳米晶体首先被化学合成以产生明确的结构，然后组装和致密化以产生最终的大块纳米结构金属。这种新方法允许更高的自由度来控制金属晶粒的大小、结构和方向，并有可能创造出具有新特性的金属材料。技术摘要：制备大块纳米结构金属的新方法从根本上改变了现有的方法，这些方法基于粗粒度金属的广泛塑性变形，通过电镀或溅射技术实现原子间的生长，以及微米级金属粉末的巩固。在新的策略中，定义明确的金属颗粒（即纳米线）首先“原子一个原子”地合成，然后“一粒一粒”地组装成最终的大块金属。这可以有效地解耦晶粒微观结构和晶粒取向的调谐，从而导致新的大块纳米结构金属具有以前无法实现的微观结构（例如，晶粒形状，取向和纳米孪晶）和新的性能。该项目解决了大块纳米结构合金（冶金方向）和胶体纳米材料（材料化学方向）之间长期缺失的联系。如果成功，它将激发和催化这两个独立的纳米材料研究领域之间期待已久的合作。在该项目中接受培训的学生代表了新一代的材料科学家，他们可以将冶金与胶体纳米材料联系起来，为这两个领域带来新的思维方式。