Thermodynamic description of the Al-Fe-Zr system

The Fe-Zr and Al-Fe-Zr systems were critically assessed by means of the CALPHAD technique. The solution phases, liquid, face-centered cubic, body-centered cubic and hexagonal close-packed, were described by the substitutional solution model. The compounds with homogeneity ranges, hex.-Fe2Zr, Fe2Zr, FeZr2 and FeZr3 in the Fe-Zr system, were described by the two-sublattice model in formulas such as hex.-Fee (Fe, Zr), (Fe, Zr)(2)(Fe, Zr), (Fe, Zr)Zr-2 and (Fe, Zr)(Fe, Zr)(3) respectively. The compounds AlmZrn except Al2Zr in the Al-Zr system were treated as line compounds (Al, Fe)(m)Zr-n in the Al-Fe-Zr system. The compounds FeZr2 and FeZr3 in the Fe-Zr system were treated as (Al, Fe, Zr)Zr-2 and (Al, Fe, Zr)(Fe, Zr)(3) in the Al-Fe-Zr system, respectively. All compounds in the Al-Fe system and hex.-Fe2Zr in the Fe-Zr system have no solubilities of the third components Zr or AI, respectively, in the Al-Fe-Zr system. The ternary compounds),, with C14 structure and lambda(2) with C15 structure in the Al-Fe-Zr system were treated as X,(Al, Fe, Zr)(2)(Fe, Zr) with Al2Zr in the Al-Zr system and lambda(2)-(Al, Fe, Zr)(2)(Fe, Zr) with Fe2Zr in the Fe-Zr system, respectively. And the ternary compounds tau(1), tau(2) and tau(3) in the Al-Fe-Zr system were treated as (Al, Fe)(12)Zr, Fe(Al, Zr)(2)Zr-6 and Fe7Al67Zr26, respectively. A set of self-consistent thermodynamic parameters of the Al-Fe-Zr system was obtained. (C) 2008 Elsevier Ltd. All rights reserved.