NIRT: Deformation Mechanisms and Manufacturing of Nanostructured Materials Processed by Severe Plastic Deformation (SPD)

本提案旨在获得对纳米结构金属和合金中的变形机制的基本理解，特别是那些由严重塑性变形（SPD）方法产生的金属和合金。基于这些知识，它进一步旨在开发以高质量散装形式制造这些材料的全部能力。这些材料的机械性能（高强度，延展性，抗疲劳性）和可制造性的极具吸引力（和罕见）的组合导致了一种新型的结构用途的高性能合金。据了解，这种性能的结合是由于这些材料中纳米级颗粒的形成，但导致高强度和高延性结合的机制尚不清楚。这对这些材料的优化或这些材料在应用中的性能预测提出了一个根本性的障碍。提出了一种强调制造业的综合方法。在理论方面，变形机制将用晶体塑性集合体模型和晶粒和晶界的详细模型来模拟。实验程序涵盖了广泛的应变速率和温度范围，纹理发展，以及原位透射电子显微镜和原子力显微镜，以直接验证变形机制。实验结果将为理论建模和制造过程仿真提供验证。最后，制造过程的仿真将使工艺参数优化成为可能。一个完整的，微型的，但完全可扩展的制造设施将被设计和实施。通过对变形机制的基本理解，以及批量生产这些非常理想的材料的制造技术的进步，所提出的研究的重大影响成为可能。微型制造设备将成为大量纳米结构合金的来源。最后，该提案将为加州大学圣地亚哥分校和当地K-12学校的学生提供前沿研究领域的跨学科教育。

This proposal aims to gain fundamental understanding of thedeformation mechanisms that operate in nanostructured metals andalloys, in particular in those produced by severe plastic deformation(SPD) methods. Based on this knowledge it further aims to develop fullcapability to manufacture these materials in high quality bulk forms.The extremely attractive (and rare) combination of mechanicalproperties (high strength, ductility, fatigue resistance) andmanufacturability of these materials leads to a new class of highperformance alloys for structural uses. It is understood that thiscombination of properties is due to the formation of nano-scale grainsizes in these materials, but the mechanisms responsible for the highstrength combined with high ductility are not well understood. Thispresents a fundamental obstacle to the optimization of thesematerials, or to predictions of the performance of these materials inapplications.An integrated approach with strong emphasis on manufacturing isproposed. On the theoretical side, deformation mechanisms will besimulated with crystal-plasticity aggregate models and with detailedmodels of the grains and grain boundaries. The experimental programcovers a wide a range of strain rates and temperatures, texturedevelopment, and in situ transmission electron microscopy and atomicforce microscopy to directly verify deformation mechanisms. Theexperimental results will provide validation to the theoreticalmodeling and manufacturing process simulations.Finally, simulations of the manufacturing processes will enableprocess parameter optimization. A complete, miniature, yet fullyscalable, manufacturing facility will be designed and implemented.The significant impacts of the proposed research are made possible bythe acquired fundamental understanding of the deformation mechanisms,and include advances in manufacturing techniques to produce thesehighly desirable materials in bulk. The miniature manufacturingfacility will become a source of significant quantities ofnano-structured alloys. Finally, the proposal will provide students atthe UCSD and at local K-12 schools with interdisciplinary education ina cutting-edge area of research.