相场法模拟强迫流场对Mg-Gd系合金中海藻晶及其晶型转变的影响  

Phase Field Simulation of Effect of Forced Flow Field on Seaweed Crystals in Mg-Gd Base Alloy and Transformation of Their Crystal Type

作　　者：王永彪 谢新源 刘新田 张洋 王嘉鑫 关邵康 龙伟民 WANG Yongbiao;XIE Xinyuan;LIU Xintian;ZHANG Yang;WANG Jiaxin;GUAN Shaokang;LONG Weimin(Henan Key Laboratory of Mechanical Equipment Intelligent Manufacturing,Zhengzhou Light Industry University,Zhengzhou Henan 450002,China;Henan Key Laboratory of Advanced Magnesium Alloy,Zhengzhou University,Zhengzhou Henan 450002,China;China Innovation Academy of Intelligent Equipment(Ningbo)Co.,Ltd.,Ningbo Zhejiang 315700,China)

机构地区：[1]郑州轻工业大学河南省机械装备智能制造重点实验室,河南郑州450002 [2]郑州大学河南省先进镁合金重点实验室,河南郑州450002 [3]中机智能装备创新研究院(宁波)有限公司,浙江宁波315700

出　　处：《上海金属》2024年第5期81-88,94,共9页Shanghai Metals

基　　金：国家自然科学基金(51901208);河南省高等学校重点科研项目(20B430020);河南省科技攻关项目(202102210016,202102210272);郑州轻工业大学博士科研启动基金(2019BSJJ001)。

摘　　要：利用相场法模拟了强迫流场作用下Mg-15Gd(质量分数,%)合金中海藻晶生长机制及其晶型转变过程,并定量分析了流速变化对定向凝固过程中海藻晶向树枝晶转变的影响。结果表明:无流场作用下,在抽拉速度为50μm/s时枝晶尖端容易分裂形成海藻晶,而在抽拉速度为90μm/s时发生了海藻晶向树枝晶的转变;引入x方向强迫流场时,流速越大,枝晶向上游方向的生长倾角越大,枝晶尖端继续分裂未发生海藻晶向树枝晶的转变;而引入y方向强迫流场后,流速越大,枝晶生长速度越快、组织越细密,海藻晶向树枝晶的转变提前。Phase field method was used to simulate the growth mechanism of seaweed crystals and transformation of their crystal type in Mg-15Gd(mass fraction,%)alloy under the action of forced flow field,and the effect of flow rate on transition of seaweed to dendrite during directional solidification was quantitatively analyzed.The results showed that(a)in the absence of a flow field,the dendrite tip was prone to splitting and forming seaweed crystals when the pulling velocity was 50μm/s,while the seaweed crystals changed into dendritic crystals when the pulling velocity was 90μm/s;(b)when the forced flow field in x direction was introduced,the larger the flow rate,the greater the inclination angle of the dendrite growth towards the upstream direction,and the dendrite tip continued to split without transition of seaweed to dendrite;and(c)however,when the forced flow field in y direction was introduced,the larger the flow rate,the faster the growth rate of dendrites,the finer the microstructure,and the earlier the transition of seaweed to dendrite was.

关 键 词：Mg-Gd合金 流场 相场模拟 海藻晶 晶型转变 

分 类 号：TG244.3[金属学及工艺—铸造]