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Indexed by:期刊论文

Date of Publication:2009-11-01

Journal:APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING

Included Journals:SCIE、EI、Scopus

Volume:97

Issue:3

Page Number:595-605

ISSN No.:0947-8396

Abstract:A method for geometrical and topological modeling the evolution of close-cell metallic foams based on the Voronoi tessellation in three-dimensional space is presented. Numerical computations were carried out to examine the evolution of the bubble size distribution and topological and geometric properties of aluminum foams in the liquid state, which were implemented by using McPherson's new theory on coarsening of microstructures as well as the topological transition rules (T1 and T2 processes) in 3D foams, accounting for remarkable effects of both the gas diffusion and surface tension. Computational results show that the bubble size distributions of metallic foams are strongly coupled to the evolution of the cellular structure and dependent on the gas diffusivity and surface tension. The way of foam coarsening can be expressed as RR (32)=-mt (2)+1 approximately, and gas diffusion between bubbles dominates the evolution of bubble sizes and foam structures. It is found that the average number of faces per bubble is aOE (c) f >=13.8, which is in good agreement with the values reported in the literature.