The thermodynamic properties of ternary zirconium-hafnium carbide, ZrxHf1-xCy, having the sodium-chloride type structure were studied, using the time-of-flight mass spectrometer. The ratios of the activities of the components were measured as a function of composition at 2440 deg K. From the variation of the ratio of activities with composition, the pairwise interaction energies were obtained. The metal-metal interaction energy E12-E11E222 1.9 plus or minus 0.3 kcalmole, similar to that in the body-centered cubic zirconium-hafnium metallic system. The difference between the zirconium-carbon and hafnium-carbon interaction energy E13-E23 is a function of composition and can be expressed as E13-E23 9.8 plus or minus 0.05-7.5 plus or minus 0.2x in kcalmole.
Technical Report,01 Jul 1967,30 Jun 1969
01 Jan 0001, 01 Jan 0001, See also Part 4, AD0700766