Experimental set up for characterization of carbide-based materials in propulsion environment

This paper summarizes our achievements in the development of an experimental set up for the characterization of ultra-high-temperature carbide-based material ceramics under conditions representative of a propulsion environment. A segmented converging diverging (de Laval) nozzle was manufactured and tested in a lab-scaled hybrid rocket engine. The converging and diverging sections are manufactured from high temperature tolerant graphite. A straight section of the graphite nozzle throat was replaced with a low-eroding tantalum carbide composite. The experimental setup enables to carry test with different combination of solid propellants and gas oxidizers. The purpose of this study was to prepare and test, under typical operating conditions in the hybrid rocket engine, i.e. very high temperature, high oxygen partial pressure and total pressure, a nozzle throat insert of a Tantalum Carbide-based composite, fabricated with hot-pressing technique and characterized in terms of strength and fracture toughness, thermal shock, high temperature oxidation behavior.