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Solvus

Precipitation hardening consists of solutioning, quenching, and aging. Solutioning entails heating above the solvus temperature in order to form a homogeneous soHd solution. [Pg.234]

In aging, the alloy is heated below the solvus to permit precipitation of fine particles of a second phase 9 (CuAl ). The solvus represents the boundary on a phase diagram between the soHd-solution region and a region consisting of a second phase in addition to the soHd solution. [Pg.234]

Fig. 27. Projection of solvus surface of Al—Li—Mg system, where L is liquid and T is temperature. Fig. 27. Projection of solvus surface of Al—Li—Mg system, where L is liquid and T is temperature.
The solute concentrations at the reaction front were not the equilibrium values (the co and C03W solvus are marked in Figure 5.22(B)), in contrast to the value approximately 300 nm from the reaction front. [Pg.161]

Figure 3,10 Solvus and spinodal decomposition fields in regular (B) and subregular (D) mixtures. Gibbs free energy of mixing curves are plotted at various T conditions in upper part of figure (A and C, respectively). The critical temperature of unmixing (or consolute temperature ) is the highest T at which unmixing takes place and, in a regular mixture (B), is reached at the point of symmetry. Figure 3,10 Solvus and spinodal decomposition fields in regular (B) and subregular (D) mixtures. Gibbs free energy of mixing curves are plotted at various T conditions in upper part of figure (A and C, respectively). The critical temperature of unmixing (or consolute temperature ) is the highest T at which unmixing takes place and, in a regular mixture (B), is reached at the point of symmetry.
Let us again consider a solid mixture (A,B)N with a solvus field similar to the one outlined in the T-Xplot in figure 3. lOB, and let us analyze in detail the form of the Gibbs free energy of mixing curve in the zone between the two binodes (shaded area in figure 3.10A). [Pg.178]

Figure 3J2 Energy relationships between solvus and spinodal decompositions. (A) Portion of Gibbs free energy of mixing curve in zone between binodal (X ) and spinodal (X ) points. (B) Gibbs free energy variation as a consequence of compositional fluctuations around intermediate points X and X(2). ... Figure 3J2 Energy relationships between solvus and spinodal decompositions. (A) Portion of Gibbs free energy of mixing curve in zone between binodal (X ) and spinodal (X ) points. (B) Gibbs free energy variation as a consequence of compositional fluctuations around intermediate points X and X(2). ...
Figure 3.16 Solvus and spinodal decomposition fields as a function of elastic strain, (a) Strain-free or chemical solvus (b) strain-free spinodal (c) coherent solvus (d) coherent spinodal. From Ganguly and Saxena (1992). Reprinted with permission of Springer-Verlag, New York. Figure 3.16 Solvus and spinodal decomposition fields as a function of elastic strain, (a) Strain-free or chemical solvus (b) strain-free spinodal (c) coherent solvus (d) coherent spinodal. From Ganguly and Saxena (1992). Reprinted with permission of Springer-Verlag, New York.
The energy of elastic strain modifies the Gibbs free energy curve of the mixture, and the general result is that, in the presence of elastic strain, both solvus and spinodal decomposition fields are translated, pressure and composition being equal, to a lower temperature, as shown in figure 3.16. [Pg.184]

To our knowledge, direct experimental data on amphibole mixtures have been obtained only for the (pseudo)binary system actinolite-cummingtonite (Cameron, 1975) at Ptotai = -Phjo = 2 kbar and for the (pseudo)binary system tremolite-pargasite at Ptotai = PhjO = 1 kbar (Oba, 1980). In both cases, an extended miscibility gap (or solvus field in the second case), is evident at low T(i.e., 600 to 800 °C), which is indicative of strong positive interactions in the solid mixtures. Unmixing of other compositional terms is also evident in microprobe investigations (see Ghose, 1982 for an appropriate discussion). [Pg.315]

The compositional relations of the sodic and potassic phases in perthites depend on whether the phases are coherent or not. If the perthitic phases are non-coherent (or if the rock consists of separate grains of sodic and potassic feldspar) their equihbrium compositions are given by the strain-free solvus. This is the solvus which has been studied extensively in the past. These sentences. [Pg.363]

Solvus thermobarometry uses the unmixing phenomena of crystalline compounds, retrieving the T and P conditions of unmixing from the compositions... [Pg.388]

Note that the isoactivity condition of equation 5.258 is valid only for all the loci of the solvus limb (see, for instance, figure 3.10) but not for a spinodal limit or for a miscibihty gap limb, because in these cases the structural state of unmixes is different, so that equation 5.257 does not hold. [Pg.391]

Reaction 6. This reaction was investigated in detail by Finnerty and Boyd (1978) and was more recently recahbrated by Kohler and Brey (1990). Because the Ca content in olivine is R-dependent, due essentially to a large solvus between monticellite and forsterite that expands with pressure (cf. section 5.2.5), this reaction should act as a sensitive barometric function. However, the enthalpy of reaction is quite high and the effect of T on the equilibrium is also marked. The calibrated P-T slope has an inflection, the origin of which is not clear at first glance. [Pg.398]


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See also in sourсe #XX -- [ Pg.522 ]

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Chemical solvus

Coherent solvus

Determination of solvus curves (disappearing-phase method)

Determination of solvus curves (parametric method)

Solidus, Solvus Surfaces

Solvus diagrams

Solvus line

Strain-free solvus

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