Methods of forming composite bodies and materials including a metal oxide, such as, uranium dioxide, and silicon carbide are disclosed. The composite materials may be formed from a metal oxide powder, a silicon carbide powder and, optionally, a carbon powder. For example, the metal oxide powder, the silicon carbide powder and the carbon powder, if present, may each be combined with a binder and may be deposited in succession to form a precursor structure. Segments of the precursor structure may be removed and pressed together to form a multi-matrix material that includes interlaced regions of material including at least one of the metal oxide powder, the silicon carbide powder and, optionally, the carbon powder. The segments may be extruded or coextruded with another material, such as, a silicon carbide material, to form a green body. The green body may be sintered to form the composite bodies and materials having a desired final density.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Contract Number DE-AC07-051D14517 awarded by the United States Department of Energy. The government has certain rights in the invention.