The Variation of Lattice Parameter with Carbon Content of TaC-WC Solid Solution in High Carbon Range

TaC-WC solid solutions in high carbon range, containing up to 30 mol % WC, were prepared by heating single carbide mixtures in vacuum. And the variations of lattice parameter with carbon content were studied. The results are as follows.1) The lattice parameter of TaC-WC solid solutions increased linearly with carbon content.2) Fitted equations of these solid solutions were obtained by applying the least-squares as follows.(Ta0.9W0.1)C:a0=4.337+0.101X(Ta0.8W0.2)C:a0=4.311+0.116X(Ta0.7W0.3)C:a0=4.328+0.085X X=C/(Ta+W)3) The slopes of these equations are smaller than that of TaC obtained by other investigators. But the recalculated value of the slope employing Bowman's results in high carbon range agreed with the values of solid solutions within the range of experimental errors.