کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1447186 988638 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phase-field simulation of micropores constrained by the dendritic network during solidification
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Phase-field simulation of micropores constrained by the dendritic network during solidification
چکیده انگلیسی

A phase-field model has been developed to describe the morphology of pores constrained by a dendritic solid network, and are forced to adopt complex non-spherical shapes. The distribution of the solid, liquid and gas phases was calculated with a multiphase-field approach which accounts for the pressure difference between the liquid and the gas. The model considers the partitioning of the dissolved gas at interfaces, gas diffusion and capillary forces at the solid/liquid, liquid/gas and gas/solid interfaces. The model was used to study the influence of the dendrite arm spacing (DAS) and the solid fraction on the state of a pore. The calculations show that a pore constrained to grow in a narrow liquid channel exhibits a substantially higher mean curvature, a larger pressure and a smaller volume than an unconstrained pore. Comparisons with simple geometrical models indicate that analytical approaches show a good trend but tend to underestimate the pore curvature, in particular at high solid fractions, where pores have to penetrate the thin liquid channels. For pores spanning over distances larger than the average DAS, the simulations showed that the radius of curvature can vary between two limits, which are given by the size of the narrowest section that the pore needs to pass in order to expand and by the largest sphere that can be fitted in the interdendritic liquid. The pore curvature is therefore a complex non-monotonic function of the DAS, the solid fraction, the hydrogen content and statistical variations of the liquid channel width.


► Direct description of the complex morphology of micropores in using phase-field.
► Presence of solid substantially influences the pressure and volume of the pores.
► Hydrogen content is an influencing factor that was not considered previously.
► Pore curvature depends on the statistical distribution of liquid channel widths.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 59, Issue 8, May 2011, Pages 3032–3040
نویسندگان
, ,