Plasma Torch Test of an Ultra-High-Temperature Ceramics Nose Cone Demonstrator

An ultra-high-temperature ZrB2-SiC ceramic nose cone was tested in an arcjet plasma torch facility for 10 min at temperatures above 2000 degrees C. The nose cone model was obtained from a hot-pressed billet via electrical discharge machining. The relevant portions of the models directly exposed to the hot stream were analyzed by scanning electron microscopy and energy-dispersive spectroscopy. The posttest cross sectioning of the model showed a nonnegligible surface recession on the tip of the nose. Nonetheless, the material exhibited a promising potential to withstand severe reentry conditions with temperatures exceeding 2000 degrees C in a single-use application. Spectral directional emissivity evaluations were performed on the fly during the test by means of thermography coupled with dual-color pyrometer. The numerical calculations, which simulated the chemical nonequilibrium flow around the model assuming a low catalytic surface behavior, are in good accordance with the experimental results.