Thermodynamics Of Vanadium Alloys Part Ii Mass Spectrometric Determination Of Thermodynamic Properties Of Vanadium Titanium Chronium Alloys PDF Download

The Knudsen effusion method was combined with a mass spectrometer sensing technique in order to measure theremodynamic quantities of solid solution alloys of V-Ti-Cr in the b.c.c. (beta) phase. The technique makes use of the regular solution model in order to treat the vaporization data in terms of ion current ratios obtained from the mass spectrometer. The incipient melting points of twenty two ternary alloys were determined. The temperature range of the vaporization experiments was limited from 1400 to 1700C for alloy compositions ranging from 10 to 66 atomic percent of each of the three components of the ternary system. Within the experimental temperature range, a regular solution model modified for ternary interactions represented the thermodynamic behavior in the b.c.c. (beta) phase. Interaction parameters for Ti-C, V-Cr, and Ti-Cr were found to be temperature independent. However, a temperature dependent interaction parameter was determined for the Ti-Cr system when the ternary alloy data and data on the binary system in the literature were combined. An expression for the temperature dependent interaction parameter for the Ti-Cr system was obtained using both binary and ternary alloy data. The experimental results on the interaction parameters agree with calculated estimates from phase diagrams and theoretically calculated values. (Author).