物理学报Issue(7)：076101-1-076101-15,15.DOI:10.7498/aps.63.076101
Fe-Pb合金凝固多相体系内偏析形成过程的三维数值模拟
Three-dimensional mo delling and numerical simulation on segregation during Fe-Pb alloy solidification in a multiphase system
摘要
Abstract
The three-dimensional mathematical model for a three-phase flow during its horizontai solidification is studied using fluid dynamics method based on Eulerian-Eulerian and volume of fraction methods, in which the mass, momentum, species, and enthalpy conservation equations of the Fe-Pb alloy solidification process are solved simultaneously. Effects of Pb area quadratic gradient (∇(∇SPb)) and Pb concentration quadratic gradient (∇(∇CPb)) on the segregation formation are investigated. Results show that the segregation mode is manifested as X-segregates in the upper and V-segregates in the lower part during flow-solidification of liquid phase and gas phase. The X-segregates result from the phase transformation driving force of gas phase and”scattering”is due to the orientation of phase transition. When t>tc the lower ∇(∇SPb ) and ∇(∇CPb ) curves cause a larger yielding rate of Pb with a larger down angle of X-segregates and a smaller up angle of X-segregates and V-segregates. All these are favorable for the formation of a well-dispersed microstructure. In addition, the gas-liquid two-phase flow interaction term has an effect on channel segregation, showing that channels occur only in the region where the flow-phase transition interaction term (ul ·∇cl and ug ·∇cg) is negative. With a negative flow-phase transition interaction term the increase in flow velocity due to the flow perturbation and flow-phase transition interaction becomes more negative, thus the channel continues to grow and tends to be stable. Calculated results show good agreement with experimental data.关键词
多相凝固/X形偏析形成/通道偏析/数值模拟Key words
multiphase solidification/formation of X-segregates/channel segregation/numerical simula-tion引用本文复制引用
王哲,王发展,王欣,何银花,马姗,吴振..Fe-Pb合金凝固多相体系内偏析形成过程的三维数值模拟[J].物理学报,2014,(7):076101-1-076101-15,15.基金项目
十二五期间国家科技支撑计划项目(批准号:2011BAE31B02)资助的课题.@@@@Project supported by the National Key Technology R&D Program during the 12th Five-year Plan Period of China (Grant No.2011BAE31B02) （批准号:2011BAE31B02）
