DESIGN AND EVALUATION OF RARE-EARTH CO-STABILIZED CUBIC ZIRCONIA FOR HYPERSONIC FLIGHT
Abstract
Development of vehicles that can fly in excess of five times the speed of sound is key for developing next generation hypersonic aircraft. During hypersonic flight, a substantial amount of energy is transferred to the vehicle leading edge by two forms of heating: convective heating and chemical heating. Both processes can heat the leading edge to greater than 1800oC. It is advantageous to reduce the surface temperature of leading edges during hypersonic flight. One way to reduce the surface temperature, and therefore, improve the performance of any control surface, would be to radiate heat away from the surface. The relevant material property is emissivity, with a value approaching one desired. In ongoing work at Purdue, an emittance of 0.9 at 1600C was measured for a coating comprised of small amounts Sm3+ with a balance of zirconium diboride. That coating would reduce the surface temperature by more than two hundreddegrees centigrade during flight. Furthermore, the Sm dopant improved ablation performance by forming a stable cubic-zirconia scale. This cubic-zirconia phase has a melting point of greater than 2600C depending on the amount of Sm3+ stabilizing the zirconia, and can thus withstand temperature extremes expected during hypersonic flight. In this work, we are proposing to prepare and investigate solid solutions of cubic zirconia co-stabilized using different rare-earth ions to tailor and tune the emissivity of this phase for hypersonic flight applications. We will also investigate the ablation and emittance of the cubic zirconias investigated as a function of temperature up to 2200oC. We will use studies of the microstructure before and after testing to determine those cubic zirconia compositions that are best for hypersonic flight.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 08, 2020
- Source ID
- N000142012262
Entities
People
- Rodney W. Trice
Organizations
- Office of Naval Research
- United States Navy
- University of Virginia