Binary and ternary metal carbides based upon Ti, Zr and Hf

Ab initio electronic structure calculations are employed to study the behavior of ternary alloy carbides based upon the metals Ti, Zr and Hf. Significant variations of the bulk modulus are found. The relative importance of each of the metals in influencing the cohesive properties of both binary and ternary metal carbides is discussed. A miscibility concept of ternary systems relative to the binary counterparts is considered at length and where it is argued that miscibility of the equilibrated or stable system is far different than for the metastable system as would be the case, for example, in a pressure synthesized alloy. From comparisons of two extremes of stable and metastable miscibility, speculation is made of extreme conditions as to how the ternary alloys can be achieved.