Advanced Nanocrystalline Ceramic Matrix Composites with Improved Fracture Toughness: Processing, Characterization & Modeling

拟议项目的目标是对氧化铝基纳米复合材料的加工、表征和建模进行广泛的调查，以充分了解加工、结构和机械性能之间的相互作用。一般来说，陶瓷纳米复合材料中的常规和特殊增韧机制与发生在各种长度尺度上的过程相关，因此需要在多尺度材料力学方面进行理论描述。后者是分析多尺度建模的主要目标，这是拟议研究项目的一部分。低密度、化学惰性和高强度/硬度使陶瓷成为结构应用的非常有前途的候选者。然而，陶瓷相对较低的断裂韧性阻碍了其在此类应用中的应用。因此，拟议的研究的重点是提高氧化铝的断裂韧性，通过纳入第二相，以创建陶瓷基复合材料[CMC]适合于结构应用。智力的优点在于使用的微观结构和力学性能数据收集的PI？研究以及其他分析模型内的纳米晶陶瓷基复合材料的增韧机制？提出的研究活动的更广泛的影响是开发准确的建模ofCMC，这将有助于科学界在某一天预测CMC的理论力学性能和主要的增韧机制。这些模型可用于教育各级学生，并将促进工程科学中代表性不足的人的教学。

The goal of the proposed project is to conduct an extensive investigation into processing, characterization and modeling of alumina-based nanocomposites in order to fully understand the interplay between processing, structure, and mechanical properties. In general, the conventional and special toughening mechanisms in ceramic nanocomposites are associated with processes occurring on various length scales and thereby need to be theoretically described in terms of multiscale mechanics of materials. The latter is the main aim of analytical multiscale modeling, a part of the proposed research project. The low density, chemical inertness, and high strength/hardness make ceramics a very promising candidate for structural applications. However, utilization of ceramics for such applications is impeded by their relatively low fracture toughness. Thus, the focus of the proposed research is to improve the fracture toughness of alumina by incorporation of second phases to create ceramic matrix composites [CMCs] suitable for structural applications. The intellectual merit lies in the use of microstructural and mechanical properties data collected from PIs? research as well as others to analytically model the toughening mechanisms within nanocrystalline ceramic matrix composites ? a size regime in which interfacial toughening mechanisms are dominant.The broader impacts of the proposed research activity is to develop accurate modeling ofCMCs which would help the scientific community at large to someday predict the theoretical mechanical properties and dominant toughening mechanisms of CMCs. These models can be used to educate students of all levels and will facilitate teaching of underrepresented people in engineering sciences.