Collaborative Proposal: Manufacturing of Nanocrystalline Bulk Materials by Field Activated Sintering

将为纳米颗粒材料的现场加工建立一个科学框架。具体而言，将执行一项详细的理论-实验方案，其具体目标是：(A)评估和澄清纳米粉末的材料特性、微结构几何形状和工艺参数之间的相互依赖关系；(B)量化通过烧结纳米粉末压坯的电流传导并将其与制造和性能相关联；以及(C)开发适用于大尺寸和净形状零件的纳米晶材料的工艺设计/表征方法。该项目将：(A)产生关于尺寸在现场加工中的作用的基本知识，(B)阐明现场烧结性能增强的具体机制，(C)为该工艺的工艺设计和优化提供合理的依据；(D)从当前应用的优化以及模具设计的角度，为开发复杂形状加工设计的新模型提供指导。此外，我们将产生大量的纳米晶体材料样品，这些样品将广泛表征结构、缺陷和机械性能。晶粒度小于100 nm的结构材料具有异常高的强度、硬度和耐磨性，以及良好的抗疲劳性能。本项目致力于利用场辅助烧结技术生产块体纳米晶材料，这种材料可以从纳米粉末开始生产出近净形状的块体成分，并在加工过程中保持微结构的尺度。开发用于制造块状纳米材料的科学加工基地将是这类令人兴奋的新材料商业化的重要一步，这种材料保留了纳米级的颗粒尺寸并具有独特的性能。这项两所大学之间的合作提案将提供协同效应，以增强在德雷克塞尔大学进行的建模和在加州大学戴维斯大学通过实验对纳米过程的理解。教育和培训在研究计划中的整合将通过为Drexel和UCD的学生开发一个研讨会课程来实现，课程主题是“块状纳米材料的制造”。我们将继续让本科生参与REU补充剂的研究。

A scientific framework will be established for field processing of nanosize particulate materials. In particular, a detailed theoretical-experimental program will be pursued with specific goals to: (a) evaluate and clarify the interdependence of material properties, geometry of microstructure and processing parameters of nanosize powders, (b) quantify the conduction of electric current through sintering nanopowder compacts and relate them to manufacturing and properties, and (c) develop a process design/characterization methodology for this technology that is applicable to nanocrystalline materials for large and net shape parts.This project will: (a) generate fundamental knowledge of the role of size scale in field processing, (b) elucidate specific mechanisms responsible for the enhanced performance of field sintering, (c) provide a rational basis for process design and optimization of this process, (d) provide guidance for the development of new models for design of complex shape processing in terms of optimization of current application, as well as die design. In addition, we will generate sizable specimens of nanocrystalline materials that will be extensively characterized for structure, defects and mechanical properties.Structural materials with grain size less than 100 nm are characterized by unusually high strength, hardness and wear resistance, as well as good fatigue resistance. This project focuses on the manufacturing and characterization of bulk nanocrystalline materials produced by field assisted sintering that can produce near net-shape bulk components starting from nanosize powders, and retains the scale of the microstructure during processing. The development of a scientific processing base for manufacturing of bulk nanoscale materials will be a major step towards commercialization of this exciting new class of materials which preserve nanometric grain size and combine unusual properties. This collaborative proposal between two Universities will provide a synergistic effect to enhance both modeling performed at Drexel University and nano-process understanding by experiments at University of California Davis. The integration of education and training within the research program will be achieved by developing a seminar course for Drexel and UCD students on "Manufacturing of bulk nanomaterials". We will continue involving undergraduate students in research by REU supplements.