Principal Investigator:  John J. Moore

Partners:  Guigné International, Ltd., BioServe Space Technologies, Hewlett-Packard, ITN Energy Systems, Inc., CoorsTek

Introduction:  Self-propagating high temperature synthesis (SHS) is a viable alternative to conventional methods of producing ceramics, glass-ceramics, ceramic-composites and intermetallic compounds. The basis for the process is the ability of highly exothermic reactions in a powder to be self-sustaining.  In the typical SHS reaction, pre-mixed powders are pressed into a pellet of a certain "green" density and ignited. The products are intrinsically porous, typically 50% of the theoretical density.  The porosity can be controlled by the incorporation of gasifying agents and the generation of liquid of a certain viscosity at the reaction front. The SHS products can also be densified by incorporating hot pressing, in-situ with the SHS reaction. CCACS researchers have recently demonstrated that high-quality glass-ceramics can be synthesized by SHS. When these materials are produced in microgravity, larger amorphous areas result because the absence of convection currents inhibits formation of microcrystals.

Market:  Examples of materials produced by SHS to date include: borides, carbides, nitrides, silicides, aluminides, and other more complex intermetallics and compounds.  Some of the applications include: abrasives, cutting tools and polishing powders (TiC), resistive heating elements (MoSi₂) shape-memory alloys (NiTi), electrodes (TiN, TiB₂), ceramic raw starting powders (Si₃N₄), thin films (MoSi₂, TiB₂), functionally-graded materials (TiC + Ni), composites (TiC+Al₂0₃), high-temperature filters (B₄C+Al₂O₃), bone replacements (Ti+TiB₂), and a variety of glass-ceramics based on Al₂O₃ + SiO₂ + MgO/BaO/CaO systems.
Markets for glass-ceramics include optical and other fiber applications where high temperature capability is important, high-temperature fiber insulation and dental implants.

Project Status and Plans:  Microgravity experiments are currently underway in NASA's KC-135 and are planned for the International Space Station (ISS).  Current plans are to install processing facilities on ISS in January, 2004.  After that, routine microgravity measurements will be possible for extended periods of time.  It will be possible to adjust the experimental parameters for optimal processing of porous materials with prescribed properties.  Knowledge gained from these experiments will be brought back to earth for incorporation into more cost-effective processes.

To Get Involved:  Interested companies may join CCACS now for a nominal fee to participate in these experiments.  Intellectual property rights to commercial applications are protected.

For More Information Contact:  John Moore, Trustees Professor and Head, Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO 80401, Ph. (303) 273-3771, email:  jjmoore@mines.edu.