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 of CMCs 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.
