Recent experiments have shown that fracture resistance or toughness of certain high-temperature ceramic SiC/SiC composites may be substantially elevated by incorporation of very thin ceramic fibers or nanowires into the matrix. Properties of the nanowire-matrix interface control crack bridging and fiber pullout, which are recognized as sources of the elevated toughness. To describe and explain this response, the project focuses on atomistic simulations of the deformation mechanisms at both internal core-shell interfaces and at interfaces of the nanowires with the matrix. Optimization of the interface composition is expected to provide guidelines for design of nanowire-based ceramic composites for strength, dimensional stability, and fracture and irradiation resistance in applications to nuclear reactors.
Societal benefits include both technology advancement and graduate education. The results will enable the development of toughened composites for applications at extreme temperatures, intense radiation and corrosion. Involvement of a graduate student will contribute to manpower needs in the revival of the nuclear industry.
