Фазовая диаграмма системы Al-Mo

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Al-Mo

Al-Mo (Aluminum-Molybdenum) N. Saunders The assessed Al-Mo phase diagram is based on review of the data of [64Wal], [ 69Pet], and [71Rex], on the previous assessment in [Molybdenum], and on thermodynamic calculations. The Al-rich liquidus is well established up to 1000 C. Based on this and on the solid solubility of Mo in (Al), the most Al-rich reaction is a peritectic between the (Al) solid solution and Al12Mo. This differs from the eutectic reaction assumed in [Molybdenum]. There is uncertainty concerning the stability of and the exact sequence of reactions involving the Al-rich intermetallic compounds. Further experimental work is needed to confirm many features in this region of the assessed diagram. [Molybdenum] included two other phases, Al17Mo4 and Al22Mo5, in their phase diagram. However, they co-existed with at least three other phases and therefore cannot be unambiguously identified as equilibrium phases. The solubility of Al in (Mo) in the temperature range 1200 to 1800 C is well established, with the results of various studies in good agreement. The solvus line proposed by [Molybdenum] is used in the assessed diagram. Early work on splat quenched alloys [69Pol] showed that the (Al) solid solution could be supersaturated by up to 2.7 at.% Mo. Later work by [89Log] showed that melt spun ribbon containing up to 1.3 at.% Mo formed homogeneous supersaturated solid solutions of (Al). Above this composition, ribbons comprised a mixture of structures. In the supersaturated regions, up to 2.45 at.% Mo was measured, in good agreement with [69Pol]. Above this composition, all areas of the ribbon contained intermetallic phases. Icosahedral phase formation was reported by [85Dun] and [86Ban] in alloys of 7.7 and 14 at.% Mo, respectively. 64Wal: L.K. Walford, Philos. Mag., 9, 513-516 (1964). 69Pet: G. Petzow and J. Rexer, Z. Metallkd., 60, 449-453 (1969). 69Pol: A.F. Polesya and A.I. Stepina, Phys. Met. Metallogr., 27(5), 122-126 ( 1969). 71Rex: J. Rexer, Z. Metallkd., 62, 844-848 (1971). 85Dun: R.A. Dunlap, Phys. Status Solidi (a), 92, K11-K13 (1985). 86Ban: P.A. Bancel and P.A. Heiney, Phys. Rev. B, 33, 7917-7222 (1986). 89Log: E.A. Logan, J.N. Pratt, and M.H. Loretto, Mater. Sci. Technol., 5, 123- 130 (1989). Submitted to the APD Program. Complete evaluation contains 4 figures, 8 tables, and 40 references. Special Points of the Al-Mo System