The Effect of Volume Fraction on γ’ (Ni3Si) Precipitate Coarsening In Ni-Si Alloys
During precipitate coarsening large particles grow at the expense of smaller ones such that the average particle size increases with increasing aging time. Lifshitz and Slyozov1, and Wagner2 published one of the earliest theories of diffusion-controlled coarsening, now known as the LSW theory, wherein the rate of solute transfer from the smaller to the larger particles is controlled by the rate of solute diffusion in the matrix. One of its predictions is the familiar asymptotic rate law 〈r〉3 ≈ kt, where 〈r〉 is the average particle radius and t is the aging time. The rate constant k is related to the material constants of the alloy system.
KeywordsNickel Quartz Argon Expense Alan
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- 2.C. Wagner, Theorie der alterung von niederschlagen durch umlösen, Z. Electrochem.65:581 (1961).Google Scholar
- 4.A.J. Ardell, Precipitate coarsening in solids: modern theories, chronic disagreement with experiment, in: “Phase Transformations’ 87,” G.W. Lorimer, ed., The Institute of Metals, London (1988).Google Scholar
- 6.A. Maheshwari and A.J. Ardell, Anomalous coarsening behavior of small volume fractions of Ni3Al precipitates in binary Ni-Al alloys, Acta Metall. et Mater.,in press (1992).Google Scholar
- 9.E. Hornbogen and M. Roth, The distribution of coherent particles in nickel alloys, Z. Metallkde58:842 (1967).Google Scholar
- 18.H. Chen, S. Polat, and J.E. Epperson, Kinetics of phase separation and dynamical scaling in a supersaturated Ni-Si alloy, in: “Phase Transformations’ 87,” G.W. Lorimer, ed., The Institute of Metals, London (1988).Google Scholar