Hot Stuff

Present position: Assistant Professor, Department of Ceramic Engineering, University of Missouri-Rolla

Degrees: B.S. and M.S. Ceramic Engineering, University of Illinois at Urbana-Champaign; Ph.D. Chemical Engineering, University of New Mexico

Area of research: I study what happens when you bring ceramics and metals together and processing techniques that take advantage of exothermic reactions.

Biggest breakthrough: By extending reaction-based processing techniques, we've learned how to make multi-phase materials, such as AL2O3 with unique combinations of properties. Right now we're focused on strength and fracture toughness.

What about your work on high-temperature ceramics? Dr. Greg Hilmas and I are co-principal investigators on a three-year, $300K grant from the Air Force Office of Scientific Research to develop high-temperature (over 3,500F) ceramic materials, such as zirconium diboride, for military applications. One application for these ceramics is for use in thermal protection systems for wing leading and trailing edges on the next-generation reusable launch vehicles.

Don't NASA's current carbon-based tiles survive re-entry temperatures now? The current shuttle has a very blunt nose and blunt leading and trailing edges on the wings. This design causes a boundary layer to form during re-entry, protecting the vehicle surface from the highest temperatures. The coated carbon-carbon composites currently used have a maximum use temperature of 3,000F. Above that temperature, the SiC coating degrades and allows the underlying carbon to oxidize. Many advanced, hypersonic vehicle designs have sharp leading and trailing edges, which will allow for laminar flow across aerodynamic surfaces. While these vehicles will be much more aerodynamically efficient (i.e., maneuverable), the surface temperatures will be above the operation limit for the thermal protection materials in use today.