Collaborative Research: Fracture Mechanics of Glasses with Nanoscale Phase Separation - A Multiscale Experimental and Computational Study

虽然玻璃具有独特的性能，如高强度和透明度，但其固有的脆性严重限制了其在许多实际应用中的使用。外部处理可以增加玻璃的韧性，但通常会损害其光学透明度。作为一种替代途径，该奖项支持基础研究，以阐明如何控制纳米级成分可用于提高玻璃的抗断裂性。这些知识将加速设计坚韧而透明的玻璃。这项研究的见解将促进玻璃作为更广泛应用的竞争材料，由于玻璃断裂风险导致的安全性和可靠性问题，迄今为止尚未考虑玻璃。 该项目的见解还将改善许多现有应用中的玻璃性能，例如，更轻的汽车挡风玻璃将显著节省能源。因此，这项研究不仅将促进科学的进步，而且由于玻璃的普及，也将促进国民的健康，繁荣和福利。通过整合多个学科，包括物理学，材料科学和机械工程，这项研究将在工程的各个方面培养多样化的学生群体，并有助于形成美国玻璃行业迫切需要的下一代科学家，以在全球范围内竞争。此外，该奖项还将支持：将本科生纳入研究，通过与玻璃制造商康宁公司的广泛合作将研究与教育相结合，通过大学课程招收少数民族学生和推广到K-12学生脆性仍然是眼镜的主要缺点。为了克服这个古老的限制，本研究的目的是阐明纳米异质性和控制相分离的钙铝硅酸盐玻璃，无碱显示玻璃的原型模型的断裂韧性的影响。自下而上的策略依赖于高通量分子动力学模拟，受益于拓扑约束理论，并在动态模拟中达到高潮，以确保所有考虑的空间尺度（原子、微观结构和连续体）的握手。这些预测系统地验证了实验，其中包括结构分析和力学测试。这一跨学科的努力将提供一些新的见解在热力学和动力学的相分离的玻璃。这一新的基础知识将作为指导，阐明原子拓扑结构的独特作用，其异质性，以及纳米级相分离在控制硅酸盐玻璃的纳米延展性和宏观韧性。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Although glasses exhibit unique properties, such as high strength and transparency, their inherent brittleness seriously limits their use in many practical applications. Extrinsic treatments can increase the toughness of glass but typically compromise its optical transparency. As an alternative route, this award supports fundamental research to elucidate how controlled nanoscale composition may be used to enhance the resistance to fracture of glass. This knowledge will accelerate the design of tough, yet transparent glasses. Insights from this study will promote glass as a competitive material for a broader range of applications, for which glasses have not been considered until now due to concerns related to safety and reliability resulting from their risk of fracture. Insights from this project will also lead to improved glass performance in many existing applications,for instance, lighter automotive windshields would result in significant energy savings. Thus, the research will not only promote the progress of science but due to the prevalence of glass will also advance the national health, prosperity, and welfare. By integrating multiple disciplines, including physics, material science, and mechanical engineering, this research will train a diverse group of students in various aspects of engineering and contribute to forming the next generation of scientists that the U.S. glass industry critically needs to compete globally. In addition, this award will support: inclusion of undergraduate students in research, integration of research and education through extensive collaboration with glass manufacturer Corning Inc., and recruitment of minority students and outreach to K-12 students through university programs Brittleness remains the main drawback of glasses. To overcome this age-old limitation, this research aims to elucidate the effects of nanoscale heterogeneities and controlled phase separation on the fracture toughness of calcium aluminosilicate glasses,an archetypical model for alkali-free display glasses. The bottom-up strategy relies on high-throughput molecular dynamics simulations, benefits from topological constraint theory, and culminates in peridynamic simulations to ensure the hand-shake of all the considered spatial scales: atoms, microstructure, and continuum. These predictions are systemically validated by experiments, which comprise structural analysis and mechanical tests. This interdisciplinary effort will offer some new insights in the thermodynamics and kinetics of phase separation in glasses. This new fundamental knowledge will serve as a guide to elucidate the distinct roles of the atomic topology, heterogeneity thereof, and nanoscale phase separation in controlling the nanoductility and macroscopic toughness of silicate glasses.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.