Aluminum phase diagram

Copper-aluminum phase diagram. Reprinted with permission of ASM International from ASM Handbook, vol. 8, 8th ed. (Materials Park, OH ASM, 1973), p. 259. All rights reserved. www.asminternational.org. 

Examine the copper-aluminum phase diagram and predict whether cgb /c o is larger for copper segregating to grain boundaries in aluminum or aluminum segregating to grain boundaries in copper. 

Figure 1. Uranium-aluminum phase diagram. (From P. Chiotti, V. V. Akhachinskij, I. Ansara, M. H. Rand, The Chemical Thermodynamics of Actinide Elements and Compounds, Part 5, The Actinide Binary Alloys, International Atomic Energy Agency, Vienna, 1981, Fig. 5.22, with permission.)...

Kor76] Kornilov, I.I., Nartova, T.T., and Chernyshova, S.P., The Titanium-Aluminum Phase Diagram in the Titanium-Rich Part, Russ. Met. (Met-ally), Vol 6,1976, p. 192-198... 

Figure 9.37 is a portion of the copper-aluminum phase diagram for which only single-phase regions are labeled. Specify temperature-composition points at which all eutectics, eutectoids, peritectics, and congruent phase transformations occur. Also, for each, write the reaction upon cooling. 

Figpre 9.37 The copper-aluminum phase diagram. (From Metals Handbook, Vol. 8,8th edition. Metallography, Structures and Phase Diagrams, 1973. Reproduced by permission of ASM International, Materials Park, OH.)... 

Fig. 14. Aluminum-rich portion of alurninum—copper-phase diagram.

Binary Alloys. Aluminum-rich binary phase diagrams show tliree types of reaction between liquid alloy, aluminum solid solution, and otlier phases eutectic, peritectic, and monotectic. Table 16 gives representative data for reactions in tlie systems Al—Al. Diagrams are shown in Figures 10—19. Compilations of phase diagrams may be found in reference 41. 

Fig. 1. Aluminum chloride phase diagram. The triple poiat occurs at 192.5°C at 33 kPa. To convert to psi, multiply by 0.145.

Silicon is soluble in aluminum in the solid state to a maximum of 1.62 wt % at 577°C (2). It is soluble in silver, gold, and 2inc at temperatures above their melting points. Phase diagrams of systems containing silicides are available (2,3). 

Phase diagrams for the systems silver/copper (limited solubility in the solid) and aluminum/silicon (formation of an eutectic mixture)... 

The phase diagram for aluminum/silicon (Fig. 4.5) is a typical example of a system of two components that form neither solid solutions (except for very low concentrations) nor a compound with one another, but are miscible in the liquid state. As a special feature an acute minimum is observed in the diagram, the eutectic point. It marks the melting point of the eutectic mixture, which is the mixture which has a lower melting point than either of the pure components or any other mixture. The eutectic line is the horizontal line that passes through the eutectic point. The area underneath is a region in which both components coexist as solids, i.e. in two phases. 

In order to examine the possible relationship between the bulk thermodynamics of binary transition metal-aluminum alloys and their tendency to form at underpotentials, the room-temperature free energies of several such alloys were calculated as a function of composition using the CALPHAD (CALculation of PHAse Diagrams) method [85]. The Gibbs energy of a particular phase, G, was calculated by using Eq. (14),... 

Magnesium (Mg), 15 320-381. See also Aluminum— magnesium phase diagram Aluminum-magnesium- zinc phase diagram MgB2 entries activated, 12 835 analytical methods for, 15 348 atmospheric exposures of, 15 369 beer as dietary source of, 3 588 behavior on contact with chemicals, 15 372t... 

Aluminum—magnesium—zinc phase diagram Magnesium—zinc phase... 

If the desired catalyst is to consist of two or more catalytic metals after leaching or if a promoter metal is to be included, the precursor alloy becomes even more complicated with respect to phase diagrams. The approximate proportion of reactive metal (aluminum) in these ternary and higher alloys usually remains the same as for the binary metal system for the best results, although the different catalytic activities, leaching behavior and strengths of the various intermetallic phases need to be considered for each alloy system. 

Holdaway M. J. and Mukhopadhyay B. (1993). A reevaluation of the stability relations of andalusite Thermochemical data and phase diagram for the aluminum silicates. Amer Mineral, 78 298-315. 

Silica and aluminum phosphate have much in common. They are isoelec-tronic and isostructural, the phase diagrams being nearly identical even down to the transition temperatures. Therefore, aluminum phosphate can replace silica as a support to form an active polymerization catalyst (79,80). However, their catalytic properties are quite different, because on the surface the two supports exhibit quite different chemistries. Hydroxyl groups on A1P04 are more varied (P—OH and A1—OH) and more acidic, and of course the P=0 species has no equivalent on silica. The presence of this third species seems to reduce the hydroxyl population, as can be seen in Fig. 21, so that Cr/AP04 is somewhat more active than Cr/silica at the low calcining temperatures, and it is considerably more active than Cr/alumina. 

The production of corrosion-resistant materials hy alloying is well established, hut the mechanisms are noi lull) understood. It is known, of course, that elements like chromium, mckcl. titanium, and aluminum depend for their corrosion resistance upon a tenacious surface oxide layer (passive film). Alloying elements added for the purpose of passivation must be in solid solution. The potential of ion implantation is promising because restrictions deriving from equilibrium phase diagrams frequently do not applv li e., concentrations of elements beyond tile limits of equilibrium solid solubility might he incorporated). This can lead to heretofore unknown alloyed surfact-s which are very corrosion resistant... 

Recently Franken and Ponec (44) have published photoelectric work functions of Ni-Al alloy films. Since the phase diagram contains many inter-metallic compounds, the surface composition will now be determined by that compound which yields the lower surface energy, in this case the compound having the largest amount of aluminum. Indeed after an initial steep decrease in work function over a limited concentration range, a plateau of constant work function is found. 

A portion of the isothermal section of an aluminum-iron-manganese phase diagram at 600 °C is shown in Figure 6.10. Assuming equilibrium, list the phases present, give their compositions, and calculate the relative amounts of them for... 

The melting point of pure aluminum is 660 °C and aluminum and silicon form a eutectic, the eutectic temperature is 577 °C, the eutectic composition is 12% Si, and the maximum solubility of of silicon in solid aluminum is 1.65%. Assume the phase diagram consists of straight lines. If aluminum containing 0.15 wt% Si were solidified, what would be the composition of the first solid to form ... 

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