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On the mathematical modelling of cellular (discontinuous) precipitation

  • Author Bio: E-mail address: O.Penrose@hw.ac.uk
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  • Cellular precipitation is a dynamic phase transition in solid solutions (such as alloys) where a metastable phase decomposes into two stable phases : an approximately planar (but corrugated) boundary advances into the metastable phase, leaving behind it interleaved plates (lamellas) of the two stable phases.

    The forces acting on each interface (thermodynamic, elastic and surface tension) are modelled here using a first-order ODE, and the diffusion of solute along the interface by a second-order ODE, with boundary conditions at the triple junctions where three interfaces meet. Careful attention is paid to the approximations and physical assumptions used in formulating the model.

    These equations, previously studied by approximate (mostly numerical) methods, have the peculiarity that $v,$ the velocity of advance of the interface, is not uniquely determined by the given physical data such as $c_0$, the solute concentration in the metastable phase. It is hoped that our analytical treament will help to improve the understanding of this.

    We show how to solve the equations exactly in the limiting case where $v=0$. For larger $v$, a successive approximation scheme is formulated. One result of the analysis is that there is just one value for $c_0$ at which $v$ can be vanishingly small.

    Mathematics Subject Classification: Primary:74N20 Dynamicsofphaseboundaries; Secondary:34B15Nonlinearboundaryvalueproblems, 74A50 Structuredsurfacesandinterfaces, coexistentphases, 74G15Numericalapproximationofsolutions, 74N25Transformationsinvolvingdiffusion.

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  • Figure 1.  Schematic cross-section of a cellular precipitation front, advancing upwards at velocity $v$. The as yet undisturbed metastable phase is labelled 0; the two (relatively) stable phases into which it separates after the front has passed are labelled $\alpha$ and $\beta$

    Figure 2.  Notation for the coordinate axes and for angles and arc lengths

    Figure 3.  The thermodynamic construction for phase equilibrium. The common tangent has slope $\mu_{TJ}$ and touches the curve at the points with abscissas $ c_\alpha^{eq}$ and $c_\beta^{eq}.$

    Figure 4.  Dihedral angles $\delta$, inclinations of arcs $\theta$ and surface tensions $\gamma$ at a triple junction

  • [1] L. Amirouche and M. Plapp, Phase-field modeling of the discontinuous precipitation reaction, Acta materialia, 57 (2009), 237-247.  doi: 10.1016/j.actamat.2008.09.015.
    [2] R. W. Balluffi and J. W. Cahn, Mechanism for diffusion induced grain boundary migration, Acta Met., 29 (1981), 493-500.  doi: 10.1016/0001-6160(81)90073-0.
    [3] E. A. Brener and D. Temkin, Theory of diffusional growth in cellular precipitation, Acta Materialia, 47 (1999), 3759-3765.  doi: 10.1016/S1359-6454(99)00238-4.
    [4] E. A. Brener and D. Temkin, Theory of discontinuous precipitation: Importance of the elastic strain, Acta Materialia, 51 (2003), 797-803.  doi: 10.1016/S1359-6454(02)00471-8.
    [5] J. W. Cahn, The kinetics of cellular segregation reactions, Acta Met, 7 (1959), 18-28.  doi: 10.1016/0001-6160(59)90164-6.
    [6] J. W. CahnP. C. Fife and O. Penrose, A phase-field model for diffusion-induced grain boundary motion, Acta Mater., 45 (1997), 4397-4413.  doi: 10.1016/S1359-6454(97)00074-8.
    [7] P. C FifeJ. W. Cahn and C. M. Elliott, A free-boundary model for diffusion-induced grain boundary motion, Interfaces and Free Boundaries, 3 (2001), 291-336.  doi: 10.4171/IFB/42.
    [8] P. FratzlO. Penrose and J. L. Lebowitz, Modeling of phase separation in alloys with coherent elastic misfit, J. Stat Phys, 95 (1999), 1429-1503.  doi: 10.1023/A:1004587425006.
    [9] M. Hillert, On the driving force for diffusion induced grain-boundary migration, Scripta Met., 17 (1983), 237-240.  doi: 10.1016/0036-9748(83)90105-9.
    [10] L. M. KlingerY. J. M. Brechet and G. R. Purdy, On velocity and spacing selection in discontinuous precipitation. 1. simplified analytical approach, Acta Mater., 45 (1997), 5005-5013.  doi: 10.1016/S1359-6454(97)00171-7.
    [11] F. C. Larché and J. W. Cahn, The effect of self-stress on diffusion in solids, Acta Metall., 30 (1982), 1835-1845. 
    [12] IUPAC Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford, 1997. XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi: notenoalianjie. Last update: 2014-02-24; version: 2. 3. 3. DOI of this term: doi: notenoalianjie.
    [13] W. W. Mullins, The effect of thermal grooving on grain boundary motion, Acta Metall., 6 (1958), 414-427.  doi: 10.1016/0001-6160(58)90020-8.
    [14] O. Penrose and J. W. Cahn, A mathematical model for diffusion-induced grain boundary motion, Proceedings of conference on free boundary problems, Trento 2002, International Series of Numerical Mathematics (ISNM), 147 (2004), 237-254. 
    [15] O. Penrose, On the elastic driving force in diffusion-induced grain boundary motion, Acta Materialia, 52 (2004), 3901-3910.  doi: 10.1016/j.actamat.2004.05.004.
    [16] http://mathworld.wolfram.com/GreensFunction.html
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