Microstructure dependence of diusional transport
نویسندگان
چکیده
A simple and eective numerical method is proposed for simulating the temporal diusive mass transport process through a microstructure with arbitrary complexity described by a phase-®eld approach. The mass diusion through a given microstructure is modeled by a diusion equation with a variable diusion coecient, which is solved by an ecient and accurate semi-implicit spectral method. It is shown that it is possible to extract the eective diusion coecient for any given microstructure from the temporal concentration pro®les. The method is used to simulate the grain boundary diusion in a single-phase polycrystalline grain structure and the heterogeneous diusion in a twophase microstructure with dierent diusion coecient in each phase. Results are compared with existing analytical theories and computer simulations. Ó 2001 Elsevier Science B.V. All rights reserved. PACS: 66.30.-h; 02.60.Cb; 66.10.Cb
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