Preparation of tantalum carbide from an organometallic precursor

In this work we have synthesized an organometallic oxalic precursor from ta ntalum oxide. This oxide was solubilized by heating with potassium hydrogen sulfate. In order to precipitate Ta2O5.nH(2)O, the fused mass obtained was dissolved in a sulfuric acid solution and neutralized with ammonia. The hy drated tantalum oxide precipitated was dissolved in an equimolar solution o f oxalic acid/ammonium oxalate. The synthesis and the characterization of t he tantalum oxalic precursor are described. Pyrolysis of the complex in a m ixture of hydrogen and methane at atmospheric pressure was studied. The gas -solid reaction made it possible to obtain tantalum carbide, TaC, in the po wder form at 1000 degrees C. The natural sintering of TaC powder in an iner t atmosphere at 1400 degrees C during 10 hours, under inert atmosphere made it possible to densify the carbide to 96% of the theoretical value.