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

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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.