Фазовая диаграмма системы Al-Te

К оглавлению: Другие диаграммы (Others phase diargams)

Al-Te (Aluminum-Tellurium) N. Prabhu and J.M. Howe The assessed phase diagram for the Al-Te system is based on the data of [81Sai] , and differs significantly from the phase diagram of [Hansen], which was based mainly on thermal analysis data from relatively impure alloys. The assessed phase diagram exhibits liquid immiscibility at 957 с 8 C and 41 с 5 at.% Te, and there is a congruently melting intermediate phase Al2Te3 (895 C), which is a normal valency compound, with no solubility for the components [ 84Des]. There are two eutectics on the Al- and Te-rich sides of the phase diagram at ~2 at.% Te and 651 с 2 C and ~90 at.% Te and 432 с 2 C [84Des]. There is a monotectic reaction at ~54 at.% Te and 843 с 5 C [84Sai]. The maximum solubility of Al2Te3 acting as a component in solid Al or Te has not been reported, but appears to be extremely small. The maximum solubility of Al in solid (Te) was calculated to be 0.03 at.% [65Kuj] and Te appears to be insoluble in (Al) [72Ell]. The form of the phase diagram may be considered well defined for 0 to 60 at.% Te; however, the liquidus surface from 60 to 100 at.% Te requires better definition and has been difficult to evaluate due to the high vapor pressure of Te [81Sai]. A thermal arrest at 462 с 5 C indicates the possible existence of a compound richer in Te than Al2Te3 [81Sai]. Although not yet documented, this compound is probably not due to solid-state transformation of Al2Te3, because a corresponding thermal arrest was not observed on the Al-rich side. A peritectoid reaction Al + Al2Te3 = Al5Te that was previously reported at 551 C in alloys with 0 to 60 at.% Te [Hansen] has been strongly questioned using recent data [81Sai] collected by differential calorimetric analysis, which shows no thermal arrest at this temperature. Formation and crystallization of an Al2Te77 glass were examined [79Col]. 65Kuj: R.V. Kujawa, Phys. Status Solidi, 12, 169-180 (1965). 79Col: J. Colemenero and J.M. Barandiaran, J. Noncrystallogr. Solids, 30, 263- 271 (1979). 81Sai: H. Said, R. Chastel, C. Bergman, and R. Castanet, Z. Metallkd., 72, 360- 365 (1981). 84Des: N.U. Deshpande, K.K. Ray, and A.K. Mallik, Trans. Ind. Inst. Met., 37(6) , 715-719 (1984). Published in Bull. Alloy Phase Diagrams, 11(2), Apr 1990. Complete evaluation contains 5 figures, 3 tables, and 11 references. 1