MRI: Acquisition of High-Resolution X-Ray Computed Tomography System for Real-Time, In Situ Studies of Various Effects on Microstructure of Materials

该主要研究仪器（MRI）奖支持获得高分辨率，四维（4D） x射线计算机断层扫描（XCT）系统，以实现广泛的基础材料研究。所获得的知识将推动新型和高性能材料设计的进步，从而导致智能和更有弹性的结构，更好的医疗，并提高能源效率。XCT系统还将支持密苏里州立大学及其合作机构的教育、培训和推广活动，包括历史上的黑人林肯大学（Lincoln University）和塔斯基吉大学（Tuskegee University）。这些活动包括培训K-12学生和教师，将仪器纳入课程，跨学科培训和指导研究生和本科生，包括伙伴机构中代表性不足的少数民族的个人。材料微观结构的特征决定了它的性能（如机械性能和传输性能）。任何使材料微观结构发生变化的外部或内部刺激，例如机械负荷或化学反应，都必然导致其性质发生变化。了解材料中这种内在的微观结构-性能联系可以揭示材料物理化学行为的起源，随后可以利用这些行为来优化其性能。由于XCT系统能够对各种类型的材料进行原位、实时的三维微观结构表征，它将推动许多与新材料设计相关的领域的研究（例如，新型胶凝材料和形状记忆合金），以及现有材料性能的优化（例如，玻璃和陶瓷、用于组织修复的生物材料、数字制造材料以及能量储存和转换材料）。有了这样的能力，XCT系统将为追求高风险高回报的研究提供支持，例如，研究机械/热载荷或不期望的反应如何导致非均质多孔材料中微裂纹的产生和扩展，以及裂纹将在多大程度上影响材料的传输特性。值得注意的是，XCT系统将促进揭示微观结构-性能联系的研究，并弥合基础知识空白：表征新型二氧化碳高效胶凝粘合剂的早期反应和微观结构发展；模拟增材制造金属零件中气孔、缺乏熔合和其他缺陷的发展；制造定制的镍钛形状记忆合金组件，用于刚度匹配的生物医学应用，精密力致动器和能量吸收器；阐明核废料玻璃表面蚀变层中的变质反应和输运现象基于氧反应性聚合物纳米颗粒治疗外伤性脑损伤的研究揭示了锂离子电池电极内部三维微观结构网络（亚微米分辨率）与离子和电子输运的基本关系，以及相应的电池性能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Major Research Instrumentation (MRI) award supports the acquisition of a high-resolution, four-dimensional (4D) X-Ray Computed Tomography (XCT) system to enable a broad range of fundamental materials research. The knowledge gained will enable advances in the design of novel and high-performance materials – leading to smart and more resilient structures, better medical treatments, and to enhanced energy efficiency. The XCT system will also support education, training, and outreach activities at Missouri S&T and partner institutions, including historically black Lincoln University and Tuskegee University. These activities include training of K-12 students and teachers, integration of the instrumentation into courses and interdisciplinary training and mentoring of graduate and undergraduate students, including individuals from underrepresented minorities at the partner institutions. Features of a material’s microstructure dictate its performance (e.g., mechanical and transport properties). Any external or internal stimulus that imparts changes to microstructure of a material – for example, mechanical load, or chemical reaction – invariably causes its properties to change. Knowledge of such intrinsic microstructure-property links in materials can reveal the origins of the materials’ physicochemical behavior, which can subsequently be capitalized on to optimize their performance. The XCT system – owing to its ability to perform in-situ, real-time characterization of 3D microstructure of materials of various types – will advance research in many areas relevant to design of new materials (e.g., novel cementitious materials; and shape memory alloys), and optimization of performance of prevailing materials (e.g., glasses and ceramics; biomaterials for tissue repair; digitally-fabricated materials; and energy storage-and-conversion materials). With such capabilities, the XCT system will empower the pursuit of high-risk-high-reward research – for instance, to study how mechanical/thermal loads or undesired reactions lead to initiation and propagation of microcracks in a heterogeneous porous material, and to what extent the cracks will affect the material’s transport properties. Significantly, the XCT system will facilitate research geared towards revealing microstructure-property links, and bridging fundamental knowledge-gaps in: characterizing the early stage reactions and microstructure developments in novel CO2-efficient cementitious binders; modeling the development of porosity, lack of fusion, and other defects in additively-manufactured metallic parts; fabricating bespoke components of nickel-titanium shape memory alloys for stiffness-matched biomedical applications, precision force actuators, and energy absorbers; elucidating the deteriorative reactions and transport phenomena in nuclear waste glass surface alteration layer; developing oxygen reactive polymer nanoparticle-based therapeutics to treat traumatic brain injury; and revealing the fundamental relationship between 3D internal microstructural network (with sub-micron resolution) of lithium-ion battery electrodes and the transport of ions and electrons, and correspondingly the battery’s performance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.