-
合金铸锭凝固过程中经常伴随着游离枝晶在运动的同时生长运动及相互碰撞等现象，其对铸锭的温度场、流场、溶质场及微观组织等具有不可忽视的影响，是研究铸锭凝固组织形成的关键问题之一. 元胞自动机-格子玻尔兹曼(CA-LB)耦合模型近年来在处理运动枝晶方面发展迅速，该模型不仅可以很好地维持运动枝晶的形貌，还可以合理地计算出枝晶间的相互碰撞. 本文改进了模拟游离枝晶运动生长的元胞自动机-格子玻尔兹曼模型，采用交替方向隐式迭代法求解导热微分方程，模拟参数不会受稳定性条件限制. 文中分别验证了流场与固相和温度场耦合的准确性. 随后采用该模型分别模拟了Fe-0.34%C合金铸锭中等轴晶运动与否的凝固过程. 模拟结果表明，等轴晶的运动会增大与临近枝晶的接触概率，会使铸锭中的晶粒尺寸更加均匀；枝晶的运动还会改变熔体中心部位的溶质分布，特别是增大了顶部正偏析的大小以及范围；等轴晶的运动会受到柱状晶的阻碍，所以CET区域受枝晶运动的影响不大.The solidification process of alloy ingot is often accompanied by the phenomena of free dendrites growing and colliding with each other while in motion, which has a non-negligible influence on the temperature field, flow field, solute field and microstructure of the ingot, and it is one of the key issues in the study of ingot solidification organization formation. The cellular automata-lattice Boltzmann (CA-LB) coupling model has been developed rapidly in recent years in dealing with the moving dendrites, which can not only maintain the morphology of the moving dendrites well, but also calculate the mutual collisions between the dendrites reasonably. In this paper, the cell-automata-lattice Boltzmann model for simulating the growth of free dendrites is improved. Alternating direction implicit method is used to solve the differential heat conduction equation, and the simulation parameters are not limited by stability conditions in this method. In the paper, the accuracy of the flow-solid coupling of the model is verified by using the flow around a circular cylinder example, and the temperature field of the model is well coupled under the natural convection condition. Finally, the solidification process of Fe-0.34%C alloy ingots with or without equiaxed grains movement was simulated using the model. The simulation results show that the movement of equiaxed grains increases the contact probability with the neighboring dendrites, which leads to a more uniform grain size in the ingot; the movement of dendrites also alters the solute distribution in the center of the melt, especially increasing the size and range of the hot-top segregation; the movement of equiaxed grains is impeded by the columnar crystals, and therefore the CET region is not much affected by the movement of dendrites.
-
Keywords:
- ingot /
- macroscopic segregation /
- numerical simulation /
- dendrite movement
-
[1] Qi X B, Chen Y, Kang X H, Li D Z, Gong T Z 2017Sci Rep 7 45770
[2] Rátkai L, Pusztai T, Gránásy L 2019npj Comput Mater 5 113
[3] Zhang S J, Wang Y M, Wang Q, Li C Y, Li R 2021Acta Phys. Sin. 70 238101(in Chinese)[张士杰,王颖明,王琦,李晨宇,李日2021 70 238101]
[4] Sakane S, Takaki T, Ohno M, Shibuta Y, Aoki T 2020Computational Materials Science 178 109639
[5] Ren J kun, Chen Y, Cao Y fei, Sun M yue, Xu B, Li D zhong 2020Journal of Materials Science& Technology 58 171
[6] Yamanaka N, Sakane S, Takaki T 2021Computational Materials Science 197 110658
[7] Zhang S, Zhu B, Li Y, Zhang Y, Li R 2024Computational Materials Science 245 113308
[8] Liu L, Pian S, Zhang Z, Bao Y, Li R, Chen H 2018Computational Materials Science 146 9
[9] Wang Q, Wang Y, Zhang S, Guo B, Li C, Li R 2021Crystals 11 1056
[10] Sakane S, Aoki T, Takaki T 2022Computational Materials Science 211 111542
[11] Meng S, Zhang A, Guo Z, Wang Q 2020Computational Materials Science 184 109784
[12] Takaki T 2023IOP Conf. Ser.:Mater. Sci. Eng. 1274 012009
[13] Flemings M C, Mehrabian R, Nereo G E 1968Transactions of the Metallurgical Society of AIME 2391449
[14] Bennon W D, Incropera F P 1987International Journal of Heat& Mass Transfer 30 2161
[15] Bennon W D, Incropera F P 1987International Journal of Heat and Mass Transfer 30 2171
[16] Beckermann C, Viskanta R 1988Physicochemical Hydrodynamics 10195
[17] Gu J P, Beckermann C 1999Metallurgical& Materials Transactions A 30 1357
[18] Wu M, Ludwig A, Kharicha A 2016Applied Mathematical Modelling 41 102
[19] Zhang Z, Bao Y, Liu L, Pian S, Li R 2018Metall Mater Trans A 49 2750
[20] Zhang S, Li Y, Zhang S, Zhu B, Li R 2025International Journal of Thermal Sciences 211 109737
[21] Rappaz M, Thévoz P H 1987Acta Metallurgica 35 2929
[22] Zhu M F, Lee S Y, Hong C P 2004Phys. Rev. E 69 061610
[23] Sun D K, Zhu M F, Pan S Y, Yang C R, Raabe D 2011Computers& Mathematics with Applications 61 3585
[24] Zhu M, Stefanescu D 2007Acta Materialia 55 1741
[25] Wen B, Zhang C, Tu Y, Wang C, Fang H 2014Journal of Computational Physics 266 161
[26] Mei R, Yu D, Shyy W, Luo L S 2002Phys. Rev. E 65 041203
[27] Drummond J E, Tahir M I 1984International Journal of Multiphase Flow 10 515
[28] ZHANG Z 2020M.S. Thesis(Tianjin:Hebei University of Technology)(in Chinese)[张照2020硕士学位论文(天津:河北工业大学)]
[29] Shan X 1997Phys. Rev. E 55 2780
[30] Clever R M, Busse F H 1974J. Fluid Mech. 65 625
[31] Wu M, Könözsy L, Ludwig A, Schützenhöfer W, Tanzer R 2008steel research international 79 637
[32] Luo S, Wang W, Zhu M 2018International Journal of Heat and Mass Transfer 116 940
[33] Ge H, Li J, Guo Q, Ren F, Xia M, Yao J, Li J 2021Metall Mater Trans B 52 2992
计量
- 文章访问数: 138
- PDF下载量: 0
- 被引次数: 0
下载:
