Arc jet testing

Figure 14. (a) Schematic representation of a typical arc-jet testing set-up [Zhang, 2008]. Experimental set-up for arc-jet testing (a) before the test (b) during the test (c) hemispherical HfB sample used for arc-jet testing, radius of curvature R = 7.5 mm [Savino, 2008]... 

Savino, R., Fumo, M. D. S., Silvestroni, L., Sciti, D. (2008). Arc-jet testing on HfBj and HfC-hased ultra-high temperature ceramic materials. Journal of the European Ceramic Society, 28,1899-1907. doi 10.1016/j.jeurceramsoc.2007.11.021. 

Plasma arc-jet and oxyacetylene torch ablation tests are much more convenient for operations and with much lower cost, which therefore are often used for primary evaluations of materials about their thermal shock resistance and ablation resistance properties . The difference between these two methods is their gaseous composition and flow speed. A plasma of air may exhibit ultra high temperatures above 5000°C and high velocities of 2 Mach but with ionized air atmosphere. On the other hand, the generally used oxyacetylene torch is of combustion gaseous products of carbon mono/dioxide, water vapor, OH and active hydrocarbon species with gas velocity less than 1 Mach and temperatures above 3000°C. A HVOF torch exhibits... 

The performance of ARC AII was studied with tracers of Zr, Nb, Hf, Ta, Pa, and some lanthanides produced on line and transported to ARCA n with a He(KCl) jet. To this end, the effluents from the TiOA mini columns were collected in fractions of three drops in small test tubes and were assayed for y-ray activities using two Ge detectors. In agreement with earlier tracer studies, chemical yields for Nb, Ta, and Pa were consistently found to be 85 5%. 

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