Matrix and interphase design of geopolymer composites

Geopolymers offer significant advantages for the processing of ceramic matrix composites (CMCs), such as low-cost near-net shape processing, tailored coefficient of thermal expansion (CTE), and corrosion resistance in acids. Ceramatec and its R&D partners, Brown University and Rutgers University are developing functional geopolymer systems for improved hydrothermal corrosion resistance and/or mechanical properties. It has been demonstrated that a hydrothermally stable matrix phase can be formed using the geopolymer processing approach. In order to obtain improved mechanical properties and/or facilitate graceful failure in the geopolymer CMCs, a distinct functional layer (interphase) can be incorporated at the fiber/matrix interfaces. Mechanical behaviors of a new type of geopolymer-steel mesh composite with enhanced strength and ductility have been studied.