A New Class of Functionally Graded Ceramic-Metal Composites for Next Generation, Very High Temperature Reactors

Generation IV power generating nuclear reactors, which will operate at temperatures greater than 900 C, need new multi-functional refractory materials that presently are not available. Some of the functional performance criteria for the materials include low thermal coefficient of expansion, high creep resistance, good thermal conductivity, and resistance to thermal cycling. Conventional composite concepts have fallen short in delivering the desired performance, and new microstructures and associated processing technologies are needed. This project will develop a functionally-graded composite material that combines the attributes of non-oxide ceramic materials and fine-grained refractory metal alloys in ways never done before. Phase I will demonstrate that the mechanical and thermal properties of the proposed functionally graded composite material are superior to presently available composites, including SiC-based materials. Accordingly, test samples will be fabricated and tested, and structure-property correlations will be drawn. Comparisons with the properties state-of-the-art materials will be made. Commercial Applications and Other Benefits as described by the awardee: . The technology should advance the state-of-the-art of materials technology for next generation nuclear reactors such as the Very High Temperate Reactor. Other applications for functionally-graded materials would include high speed cutting tools, oil and natural gas drilling, and tank armors.