Segregation of Mg-6Gd alloy under natural convection:From macro solute distribution to micro dendrite growthOACSTPCDEI
Segregation is a serious defect in alloy ingots which severely deteriorates materials performance.The segregation defect in Mg-6Gd alloy is studied by coupling macro thermal-solutal-convection transport and micro dendrite growth.The macroscopic fluid dynamics and mass transfer equations are resolved to forecast the segregation behavior under conditions of continuous temperature variation during the solidification process.The numerical model is validated by testing double-diffusive natural convection in a closed square cavity.A phase field model is then applied to simulate the micro dendrite growth,using macro undercooling and liquid flow velocity as boundary conditions.Results show that the multiscale segregation behavior,including macro solute distribution and micro dendritic morphology,is strongly dependent on the temperature condition and the liquid convection,which provides guidance for reducing and eliminating the segregation defect.
Hong-xu Chen;Ang Zhang;Hao Li;Yu Gao;Yu-hong Cui;Guang-sheng Huang;Bin Jiang;Fu-sheng Pan;
National Engineering Research Center for Magnesium Alloys,National Key Laboratory of Advanced Casting Technologies,College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China
金属材料
magnesium alloysegregationnumerical simulationphase-field simulationmultiscale
《China Foundry》 2024 (005)
P.613-624 / 12
supported by the National Key Research and Development Program of China(Grant No.2021YFB3701000);the National Natural Science Foundation of China(Grant Nos.52101125,52471118,U2037601,and U21A2048);the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(CAST)(Grant No.2022QNRC001).
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