Miscibility of binary VC-MC carbides in quaternary Fe-V-M-C alloys

A series of quaternary (Fe, V, M, C) alloys with different additions (Ti, Zr, Nb, Ta, Mo and W) were prepared. The phases were characterised by scanning electron microscopy. Quantitative electron probe microanalysis was used to analyse the carbides. As in ternary systems, MCx carbides formed in quaternary alleys are carbon deficient. TiC and VC formed a continuous solid solution, while Zr, which belongs to the same group, showed a solubility below 0.1% Zr in VC and V is less than 1% in ZrC. VC-TaC and VC-NbC formed a continuous solid solution at high temperature, but decomposed during cooling. In the presence of Mo, continuous variations of M and C levels are observed between VC and Mo2C, while in the presence of W. the formation of an intermediate carbide of M6C type limits the solubility of W in VC. (C) 2001 Elsevier Science B.V. All rights reserved.