Thermodynamic Modeling of the (Mg, Al)-Ca-Zn Systems

Download or read book Thermodynamic Modeling of the (Mg, Al)-Ca-Zn Systems written by Sk. Wasiur Rahman and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Critical assessment of the experimental data and re-optimization of the binary Mg-Zn, Ca-Zn, Al-Zn, Al-Ca systems and the Laves phase in the Mg-Ca system have been performed. A Comprehensive thermodynamic database of the Mg-Ca-Zn and Al-Ca-Zn ternary systems is presented from the constituent binary systems using suitable extrapolation methods. All available as well as reliable experimental data both for the thermodynamic properties and phase boundaries are reproduced within experimental error limits. In the present assessment, the Modified Quasichemical Model in the pair approximation is used for the liquid phase to account for the presence of the short-range ordering properly. The intermediate solid solutions are modeled using the compound energy formalism. Since the literature included contradicting information regarding the ternary compounds in both ternary systems, thermodynamic modeling of phase equilibria is used to determine the most likely description of the two ternary systems and to exclude the self-contradicting experimental observations. The constructed database is used to calculate both the integral and partial thermodynamic properties of the constituent binary systems. Moreover, the liquidus projections, isothermal sections and vertical sections of the ternary systems are also calculated and the invariant reaction points are predicted using the constructed database.