Nanoscale Sintering Understanding

纳米级烧结的理解

• 批准号: 1461516
• 负责人: Kathy Lu
• 金额: $ 30.07万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1461516&HistoricalAwards=false
• 关键词: Nanoscale; Sintering; Understanding

Sintering is an important materials consolidation and densification strategy. It is used to make components with complex shapes, in near net-shapes, and with relatively simple equipment. Also, different compositions and structures can be flexibly tailored using sintering. However, sintering is also a complex process. With the progress of nanoparticle-based materials, many conventional sintering theories cannot predict new sintering behaviors; relying on existing sintering knowledge to guide nanoparticle-based material processing has led to numerous failures and contradictory results. This award supports fundamental research to build our understanding of the sintering process, to test the scalability of sintering equations from nanometers up, and to quantify the function of pores in nanostructure evolution and shrinkage. Successful nano-sintering represents exciting possibilities in improved structural, electrical, optical, and other functional properties and unprecedented nanostructures. The application areas are numerous, including energy storage/conversion, nanophotonic devices, microfluidic devices, catalysts, microreactor devices, and optical components. This program also includes extensive outreach activities (such as HBCU, local schools, camps) to increase the participation of underrepresented groups in engineering, especially in the area of nanomaterials. This award supports research to build direct and quantitative sintering shrinkage-nanostructure evolution correlations, test the scalability of sintering equations from nanoscale and up, and quantify the function of pores in nanostructure evolution and shrinkage. There are three key components to this research. The first is to demonstrate that below a critical density, shrinkage extrapolation from grain neck size is dependent on coarsening-induced grain-reconfiguration; microstructure scalability is only valid for homogenous microstructures. The second is to show that above the critical density, pore size, distribution, and shape are critical factors for decoupling grain boundary diffusion from grain boundary migration and 3D microstructure reconstruction is a unique technique to provide such quantitative data. The third component is to illustrate that sintering of particle packing in unusual configurations is dependent on the balance between packing structures and diffusion mechanisms. The research will provide the much needed linkage between nanoparticle arrangement, microstructural evolution, and shrinkage by using small features that can track individual to multiple nanoparticles and reconstructing 3D nanostructures. The sintering knowledge gained will provide not only effective solutions to nanoparticle-based sintering but also never-before conduits for net-shape sintering, novel nanostructures, and a vast array of complex material design capabilities.

烧结是一种重要的材料固结和致密化策略。它用于用相对简单的设备制造形状复杂、近净形状的部件。此外，可以使用烧结灵活定制不同的成分和结构。然而，烧结也是一个复杂的过程。随着纳米颗粒材料的进步，许多传统的烧结理论无法预测新的烧结行为；依靠现有的烧结知识来指导基于纳米粒子的材料加工已经导致了许多失败和矛盾的结果。该奖项支持基础研究，以加深我们对烧结过程的理解，测试纳米级以上烧结方程的可扩展性，并量化纳米结构演变和收缩中孔隙的功能。成功的纳米烧结代表了改善结构、电学、光学和其他功能特性以及前所未有的纳米结构的令人兴奋的可能性。应用领域众多，包括能量存储/转换、纳米光子器件、微流体器件、催化剂、微反应器器件和光学元件。该计划还包括广泛的外展活动（例如 HBCU、当地学校、营地），以增加代表性不足的群体在工程领域的参与，特别是在纳米材料领域。该奖项支持建立直接和定量的烧结收缩与纳米结构演化相关性的研究，测试纳米级及以上烧结方程的可扩展性，并量化纳米结构演化和收缩中孔隙的功能。这项研究由三个关键组成部分组成。首先是证明在临界密度以下，从晶颈尺寸推断的收缩取决于粗化引起的晶粒重构；微观结构可扩展性仅对均质微观结构有效。第二个目的是表明，在临界密度之上，孔径、分布和形状是将晶界扩散与晶界迁移解耦的关键因素，而 3D 微观结构重建是提供此类定量数据的独特技术。第三个组成部分是为了说明异常结构中颗粒堆积的烧结取决于堆积结构和扩散机制之间的平衡。该研究将通过使用可以跟踪单个到多个纳米颗粒并重建 3D 纳米结构的小特征，提供纳米颗粒排列、微观结构演化和收缩之间急需的联系。获得的烧结知识不仅将为基于纳米颗粒的烧结提供有效的解决方案，而且还将为净形状烧结、新型纳米结构和大量复杂材料设计能力提供前所未有的途径。