Elastically Coherent Binary Alloys

We have investigated phase separation of coherent binary alloy systems with elastic fields, resulting from lattice mismatch, crystallographic anisotropy and inhomogeneities in the elastic constants. We were the first to extend this work to the experimentally important 3-d case, aimed at understanding Ni-based superalloys, and other systems. Here, we have shown that all of the complex microstructures of the alloy systems can be understood in terms of a basic observation -- namely, that it is the matrix that holds most of the elastic distortions. The physical consequences of this fact lead to a selection criterion for the shape and/or orientation of the domains based on the different shear moduli present in the system.

References

   C. Sagui, A.M. Somoza and R.C. Desai, Spinodal decomposition in an order-disorder phase transition with elastic fields, Phys. Rev. E. 50, 4865 (1994).(pdf)

   C. Sagui, D. Orlikowski, A. Somoza and C. Roland, Three-Dimensional Simulations of Ostwald Ripening with Elastic Effects, Phys. Rev. E. 58, Rapid Communication 4092 (1998).(pdf)

   D. Orlikowski, C. Sagui, A. Somoza and C. Roland, Three-Dimensional Simulations of Phase Separation in Model Alloy Systems with Elasticity, Mat. Res. Soc. Symp. Proc. 481, 255 (1998).

   D. Orlikowski, C. Sagui, A. Somoza and C. Roland, Large-scale Simulations of Phase Separation in Elastically Coherent Binary Alloy Systems, Phys. Rev. B 59, 8646 (1999).(pdf)

    D. Orlikowski, C. Sagui, A. Somoza and C. Roland, t Two and Three-Dimensional Simulations of phase separation of elastically coherent binary alloys subject to external stresses, Phys. Rev. B 62, 3160 (2000).(pdf)

    D. Orlikowski, C. Sagui, A. Somoza and C. Roland, Phase Separation and Elastic Fields: Three-Dimensional Simulations of a Phase Field Model, Mat. Res. Soc. Symp. Proc. 580, 21 (2000).

Picture Gallery

  Elastically coherent binary alloys The two top panels represent phase separation in a binary alloy without elastic effects. The two bottom panels represent phase separation in an elastically inhomogeneus binary alloy with dilational misfit and cubic anisotropy.

2D and 3D systems with elastic effects Sample configurations for systems with dilational misfit. The systems may be elastically homogeneus or inhomogeneus, and elastically isotropic or anisotropic. Panels (a) and (b) in the 2D systems and (b) and (c) in the 3D systems represent a binary alloy without elastic effects.