EAGER/DMREF: In-Situ Thermomechanical Processing and Measurement in the Scanning Electron Microscope

改善工程合金的性能有着广泛的应用，但在这一领域的创新需要在微观尺度上对这些材料的行为进行精确的了解。这一早期概念探索性研究(EARGER)/设计材料革命性和设计我们的未来(DMREF)奖项支持加快工程合金加工方法优化的努力。将在电子显微镜内建立一个“微模拟器”，以复制金属合金在从原材料到加工形式的加工步骤中经历的温度和应力。该设备将提供在加工过程中对材料的详细内部结构进行成像的能力。该系统还将集成一台用于测量材料机械性能的仪器。这种能力的结合将提供前所未有的能力，将加工条件与材料的结构和性能相关联，并帮助有效地确定改善的加工条件，以提高性能。参与该项目的研究生将接受设计和制造复杂仪器的培训，这是提高国家技术竞争力的关键技能。本研究的主要目标是在扫描电子显微镜中实现相关的热机械加工和测量条件，使金属合金在实时热机械加工过程中的应力和温度条件与组织演变和力学性能相关联。将开发一种自适应微型模拟器，该模拟器将在显微镜内运行，并集成在与商业金属合金加工相关的条件下对样品进行加热和应力的能力，以及使用集成的纳米压头测量局部机械性能的能力。该仪器将允许访问包括该系统中的相和微结构演变的温度范围，以及接近或超过屈服应力的拉应力的施加，同时以纳米级分辨率成像。此外，集成的纳米压头被设计成将局部微结构与机械性能相关联。这种独特的功能组合将为在热机械加工条件下不断演变的组织和性能提供广泛的新见解。

Improving the performance of engineering alloys has a great many applications, but innovation in this area requires precise knowledge of the behavior of these materials at the microscopic scale. This EArly-concept Grant for Exploratory Research (EAGER)/Designing Materials to Revolutionize and Engineer our Future (DMREF) award supports efforts to accelerate the optimization of processing methods for engineering alloys. A "micro-simulator" will be built within an electron microscope to replicate the temperatures and stresses that a metallic alloy experiences during the processing steps from raw materials to a manufactured form. This device will provide the ability to image the detailed internal structure of the material as it is processed. An instrument for measuring the mechanical properties of the material will also be integrated into the system. This combination of capabilities will provide unprecedented ability to correlate processing conditions to the structure and properties of the material, and help efficiently identify improved processing conditions for improved performance. The graduate students involved in this project will receive training in designing and building complex instrumentation, a key skill for national technological competitiveness.The primary goal of this research is to implement relevant thermo-mechanical processing and measurement conditions within a scanning electron microscope, to enable correlation of stress and temperature conditions to microstructural evolution and mechanical properties during real time thermo-mechanical processing of metal alloys. An Adaptive Microscale Simulator will be developed that will operate within the microscope and integrate the ability to heat and stress samples under conditions relevant to commercial metal alloy processing, combined with the ability to measure local mechanical properties using an integrated nano-indenter. The instrumentation will allow access to the range of temperatures that encompass phase and microstructural evolution in this system, and application of tensile stresses that approach or exceed the yield stress, while imaging at nanometer-scale resolution. Further the integrated nano-indenter is designed to correlate local microstructure to mechanical properties. This unique combination of capabilities will provide broad new insight into evolving microstructure and properties under thermo-mechanical processing conditions.