Nanoscale Interdisciplinary Research Teams (NIRT): Superhard Nanostructured Films

这个纳米级跨学科研究小组（NIRT）项目将由一个团队进行，该团队包括断裂微观力学，结构和界面表征，等离子体技术，气溶胶技术和微细加工的研究人员，以及洛斯阿拉莫斯和桑迪亚国家实验室的合作者。 来自许多研究的证据表明，应该有可能生产出超硬的纳米晶体复合材料，其具有与金刚石相媲美的硬度，并且还具有使其在需要摩擦和耐磨性的应用中上级金刚石的其他性质。 提出了一种新的方法来合成这样的材料，基于等离子体合成和纳米颗粒的沉积。 合成工具将是高超音速等离子体粒子沉积，其中纳米粒子在热等离子体中成核，然后在高超音速膨胀中加速，使它们通过高速撞击存款。 纳米复合膜将被沉积为具有5至10 nm范围内的晶粒尺寸，由元素硼、碳、氮、硅和钛的各种组合组成。 在单独的实验中，空气动力学透镜将用于将纳米颗粒聚焦成准直光束。 这些光束将与微加工技术结合使用，以演示从纳米颗粒制造微机电系统（MEMS）器件。这些合成研究将得到结构-性能关系的基础研究的支持。 合成材料的结构、结晶度、化学组成和变形行为将在从原子水平到单个纳米颗粒、到界面区域、到整个膜的长度尺度上进行表征。 除了这些实验研究，在原子尺度的纳米粒子变形的数值模拟将在处理和随后的机械性能的上下文中进行。 两个学术部门，几个实验室和来自洛斯阿拉莫斯和桑迪亚国家实验室的合作者之间的高度跨学科，高度互动的环境将为研究生和本科生提供纳米制造和纳米材料表征的广泛经验。 此外，参与NSF支持的ScienceWorks计划的K-8学生将有机会体验这一新颖的研究领域。

This Nanoscale Interdisciplinary Research Team (NIRT) project will be conducted by a team that includes researchers on fracture micromechanics, characterization of structure and interfaces, plasma technology, aerosol technology, and microfabrication, together with collaborators at Los Alamos and Sandia National Laboratories. Evidence from a number of studies suggests that it should be possible to produce nano-crystalline composites that are superhard possessing hardness rivaling diamond and that also possess other properties that make them superior to diamond for applications requiring friction and wear resistance. A novel approach is proposed for synthesizing such materials, based on plasma synthesis and deposition of nanoparticles. The synthesis tool will be hypersonic plasma particle deposition, in which nanoparticles nucleate in thermal plasma and are then accelerated, in a hypersonic expansion, causing them to deposit by high-velocity impact. Nanocomposite films will be deposited with grain sizes in the range 5 to 10 nm, comprised of various combinations of the elements boron, carbon, nitrogen, silicon and titanium. In separate experiments, aerodynamic lenses will be used to focus the nanoparticles to collimated beams. These beams will be used in conjunction with microfabrication techniques to demonstrate fabrication of Micro-Electro-Mechanical System (MEMS) devices from nanoparticles.These synthesis studies will be supported by fundamental studies of structure-property relations. The structure, crystallinity, chemical composition and deformation behavior of the synthesized material will be characterized at length scales ranging from the atomic level to individual nanosized grains, to interfacial regions, to the entire film. In addition to these experimental studies, numerical simulations of nanoparticle deformation at the atomistic scale will be performed in the context of both the processing and the subsequent mechanical performance. The highly interdisciplinary, highly interactive environment between two academic departments, several laboratories, and collaborators from Los Alamos and Sandia National Labs will provide graduate and undergraduate students with a breadth of experience in nanomanufacturing and nano-materials characterization. In additions, K-8 students involved in the NSF-supported ScienceWorks Program will be provided the opportunity to experience this novel research area.