Oxidation and Catalytic Efficiency of ZrB2 and HfB2 Based Ultra-High- Temperature Ceramic (UHTC) Composites Exposed to Supersonic Air Plasma

摘要

This report summarizes the activities and results of experimental and modeling activities performed for the Air Force Office of Scientific Research (AFOSR) under Contract F49620-01-C-0026, 'Oxidation and Catalytic Efficiency of ZrB2 and HfB2 Based Ultra-High-Temperature Ceramic (UHTC) Composites Exposed to Supersonic Air Plasma.' The goals of this project were to (1) experimentally investigate UHTC oxidation in a supersonic oxidizing flow environment, (2) develop oxidation models that could be incorporated into aerothermal heating and trajectory codes, and (3) experimentally characterize the catalytic efficiency of UHTC samples for surface recombination of dissociated oxygen and nitrogen. Given the importance of impact damage to the leading edges of hypersonic vehicles, a task was added during the third year of the project to (4) begin preliminary high-velocity impact experiments on UHTC materials. Research efforts and accomplishments in each of these four areas are summarized below. The results of this research have led to eight presentations at various conferences and meetings, and have been written up in three technical publications 1-3. Manuscripts of these technical papers are included in this report as Appendixes I, II, and III.