Fundamental Understanding of Superplasticity in Nanocrystalline Metals

对纳米晶金属超塑性的基本理解

• 批准号: 9630881
• 负责人: Amiya Mukherjee
• 金额: $ 49.09万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9630881&HistoricalAwards=false
• 关键词: Fundamental; Understanding; Superplasticity; Nanocrystalline; Metals

9630881 Mukherjee This grant provides fundamental understanding of superplastic behavior in nanocrystalline materials. Ultrafine-grained nanocrystalline materials contain a very large density of interfaces and, therefore, offer unique opportunities for studying the structural state of grain boundaries and their role on grain boundary sliding during superplasticity. Combining methods for synthesis as well as consolidation of nanopowders, the experimental program examines superplastic deformation behavior of nanometals, nanointermetallics, and nanocomposites with nanoscale oxides dispersed in the nanoscale metallic matrix. The scientific goal is to correlate in the context of theoretical models of superplasticity new microstructural information with mechanical data obtained from nanoscale materials. Special emphasis is given to the difficulty of intragranular dislocation generation inside the matrix in truly nanoscale structure and its consequences to slip accommodation in current models of superplasticity. The nanostructure before and after deformation is investigated using transmission electron microscopy, X-ray diffraction and internal friction methods. %%% The research could lead to new processing techniques for deformation processing of nanocrystalline materials and could impact future metal alloy processing in the metal forming industries. ***

小行星9630881 这项资助提供了对纳米晶材料超塑性行为的基本理解。 超细晶纳米晶材料含有非常大的界面密度，因此，提供了独特的机会，研究晶界的结构状态及其在超塑性过程中晶界滑动的作用。 结合纳米粉末的合成和固结方法，实验程序研究了纳米金属，纳米金属间化合物和纳米复合材料的超塑性变形行为，纳米氧化物分散在纳米金属基体中。 科学目标是在超塑性理论模型的背景下，从纳米材料获得的力学数据与新的微观结构信息相关联。 特别强调的是，在真正的纳米级结构和其后果的滑动住宿在目前的超塑性模型的矩阵内的晶内位错生成的困难。利用透射电子显微镜、X射线衍射和内耗方法对变形前后的纳米结构进行了研究。 这项研究可能会导致新的加工技术的变形加工的纳米晶材料，并可能影响未来的金属合金加工在金属成型工业。 ***