Determination of thermodynamic properties in full composition range of Ti-Al binary melts based on atom and molecule coexistence theory

• Published in: Transactions of Nonferrous Metals Society of China Vol. 28; no. 6; pp. 1256 - 1264
• Main Authors: DUAN, Sheng-chao, SHI, Xiao, YANG, Wen-sheng, GUO, Han-jie, GUO, Jing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2018
• Subjects: activity coefficient; atom and molecule coexistence theory; mass action concentration; thermodynamic model; Ti-Al binary system; activity coefficient; Ti; Ti-Al binary system; thermodynamic model; mass action concentration; atom and molecule coexistence theory; Al
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(18)64764-8

The results of predicting thermodynamic properties in the full composition range of Ti-Al binary melts in a temperature range from 1973 to 2273 K were obtained by coupling with the developed thermodynamic model for calculating mass action concentration Ni of structural units in Ti-Al system based on the atom and molecule coexistence theory (AMCT). Temperature dependence of the activity coefficients of Ti and Al in natural logarithmic form in the infinitely dilute solution (0>xTi<0.01) of Ti-Al binary melts was also determined from the calculated activity coefficients of Ti and Al at temperatures of 1973, 2073, 2173, and 2273 K. The standard molar Gibbs free energy change of dissolving pure liquid element i(l) for forming 1% (mass fraction) element i in Ti-Al binary melts further was deduced. With the aid of this model, meanwhile, the determined excess thermodynamic properties, such as the excess molar mixing Gibbs free energy/entropy/enthalpy were also calculated.