Numerical simulation of three-dimensional dendritic growth of alloy part II—model application to Fe-0.82WtPctC alloy
Numerical simulation of three-dimensional dendritic growth of alloy part II—model application to Fe-0.82WtPctC alloy
复制标题
合金三维枝晶生长的数值模拟第二部分——模型在Fe-0.82WtPctC合金中的应用
DOI：
10.1007/s11661-015-3305-6
复制
发表时间：
2016
影响因子：
2.8
通讯作者：
Miaoyong Zhu
中科院分区：
文献类型：
--
作者：
Weiling Wang;Sen Luo;Miaoyong Zhu
In the second part (Part II) of the present simulation work, the three-dimensional (3D) dendritic growth of Fe-0.82wtpctC alloy is investigated with the 3D CA-FVM cellular automaton-finite volume method model developed in Part I. The influences of the melt undercooling, the interfacial anisotropy, and the forced flow on the equiaxed dendritic growth, especially the formation of secondary arms, are discussed. The comparisons of equiaxed dendritic growth in 3D and two-dimensional (2D) are also carried out. Finally, the columnar dendritic growth under different cooling conditions is investigated including the morphology and the secondary dendrite arm spacing (SDAS). The results show that the high undercooling can promote the formation of secondary arms as the anisotropy parameter is 0.04. With the increase of the anisotropy parameter, the secondary arms first reduce and then well develop again; meanwhile the tertiary arms are gradually developed. However, the secondary arms vanish at the undercooling of 5 K as the anisotropy parameter increases to 0.04. With the introduction of the forced flow with the inlet velocity of 0.001 m/s along thexaxis, the secondary arms at the left (upstream) arm become more developed. However, they become slightly less developed with the forced flow intensifying. Secondary arms at the left side (upstream) of the perpendicular arms and in they-zsymmetrical plane become more and more developed as the inlet velocity increases. The competition of the secondary arms at the right side (downstream) of the perpendicular arms and at the right (downstream) arm becomes significant as the undercooling increases from 10 to 15 K. The solute-enriched envelope in 2D is much thicker than in the 3D case, so that the dendritic growth in 2D is influenced more by the melt flow and the undercooling; moreover, the secondary arms in 2D are hard to form even at the undercooling of 15 K and with the forced convection in the present article. Meanwhile, the variation tendency of the movement of columnar dendritic tip and the decrement of the average SDAS with every 0.025-MW/m2increment of the heat flux are quite different.
