Oxyacetylene torch testing and microstructural characterization of tantalum carbide

Abstract

Summary Tantalum carbide samples have been subjected to high‐temperature testing at ∼2300°C using an oxyacetylene torch to evaluate their potential for ultra‐high temperature applications. While large samples cracked during the rapid heating, indicating their inability to withstand thermal shock, small samples survived the severe test conditions. The oxidation products formed were characterized and found to comprise different phases of Ta2O5. The ultra‐high temperature experienced by the samples resulted in the formation of many interesting microstructures, including the formation of submicron sized grains, which has not been reported previously in the literature, as well as the expected evidence of melting.

Evaluation of the high temperature performance of HfB2 UHTC particulate filled Cf/C composites

“…The carbon fibers underwent severe degradation and the UHTC particles showed partial oxidation; they were not exposed to the jet for long enough to undergo complete oxidation, Figure D. Similar partial oxidation behavior was reported for TaC during high temperature testing …”

“…Similar partial oxidation behavior was reported for TaC during high temperature testing. 41,42 AJ10-10 sample experienced a higher temperature and heat flux compared to AJ5-20, but the test duration was shorter. The oxide particles were melted and, on solidification, formed a dense layer as shown in Figure 8A.…”

High Temperature Oxidation Study of Tantalum Carbide-Hafnium Carbide Solid Solutions Synthesized by Spark Plasma Sintering

“…Oxidation is another key factor for designing UHTC for ultrahigh temperature applications. TaC has a relatively poor oxidation behavior [14][15][16][17][18][19][20]; it begins to oxidize at around 400 o C. The melting point of its oxide: Ta2O5 is ~1872 o C and will liquefy in oxygen rich environments [14]. However, when TaC is used in an oxygen deficient environment, such as an aluminized propellant solid rocket motor, TaC has been identified as the best performing ceramic lining material [21].…”

Arc-jet wind tunnel characterization of ultra-high-temperature ceramic matrix composites

“…Capability of surviving the exposition to harsh environments without significant oxidation/ablation is one of the key features of ceramic materials for TPS applications and a proper experimental characterization is needed in this sense. A primary evaluation of hightemperature ablation resistance can be performed by means of relatively cheap techniques like high power laser beams [10], plasma [11,12] or oxyacetylene torch [13,14,15], which can produce significant heat fluxes on materials. However, as also suggested in [16], to test the materials survivability in an environment representative of hypersonic flight conditions, a realistic combination of heat fluxes, pressures, flow velocity and chemical composition around the test articles needs to be reproduced.…”