Comparison of pair potential and thermochemical models of the heat of formation of BCC and FCC alloys

Data bases covering the thermochemical properties of solid solution phases are being assembled for a wide variety of applications. Such activities are often hampered by limitations on available experimental data and fundamental methods for estimating missing information. To bridge this gap the pair potential model has been developed and refined and is compared here with results drawn from thermochemical and phase diagram analysis of the heat of formation of bcc and fcc alloys. A computer program is presented providing a means for calculating the heat of formation for binary systems composed of twenty-seven elements. The results are compared with thermochemical values for sixty-six binary systems composed of all combinations of aluminum, cobalt, chromium, copper, iron, manganese, molybdenum, niobium, nickel, silicon, titanium and tungsten. The level of agreement provides a good measure of confidence in the usefulness of this pair potential model to obtain estimates for data which is otherwise available.