Arc melting: a novel method to prepare homogeneous solid solutions of transition metal carbides (Zr, Ta, Hf)

摘要

Carbides solid solutions of Zr, Hf and Ta were prepared using arc melting. Seven equimolar compositions of mono, binary and ternary carbides were fabricated by mixing monocarbides in a molten state. The solid solutions had a cubic structure and their homogeneity was confirmed by X-ray diffraction and EDX mapping. Melting was sufficient to prepare a complete solid solutions in a few seconds. Thermogravimetric analysis showed that (Hf,Ta)C had the best oxidation resistance with limited weight (0.4 wt%) gain even at 1000 degrees C. Vickers hardness using 100 g load for (Hf,Ta,Zr)C was 27.1 +/- 2.3 GPa. We report an abnormal Vickers hardness of 34.8 +/- 2.2 GPa for TaC processed using arc melting.