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采用元胞自动机(cellular automaton,CA)模型研究了界面能各向异性对二维定向凝固枝晶生长的影响.模拟结果显示当晶体的择优生长方向与热流方向一致时,随着界面能各向异性强度的增大,凝固组织形态由弱界面能各向异性时的海藻晶转变为强界面能各向异性时的树枝晶.同时,界面能各向异性强度会影响稳态枝晶尖端状态的选择,界面能各向异性越强,定向凝固稳态枝晶尖端半径越小,尖端界面前沿的液相浓度和过冷度越小.稳态枝晶生长的尖端状态选择参数与界面能各向异性强度也存在标度律的指数关系,而枝晶一次间距则受界面能各向异性强度影响较弱.当晶体的择优生长方向与热流方向呈40夹角时随着界面能各向异性强度的增大,凝固组织形态由海藻晶逐渐转变为退化枝晶,后又逐渐转变为倾斜枝晶.
The cellular automaton (CA) model was used to study the influence of interfacial anisotropy on the growth of two-dimensional directional solidification dendrites. The simulation results show that when the preferred growth direction of the crystal is in the same direction as the heat flow, The anisotropy intensity increases, the solidified microstructure changes from seaweed crystal with weak interfacial anisotropy to dendrite with strong interfacial anisotropy, meanwhile, the interfacial anisotropy intensity will affect the steady state dendrite tip state , The stronger the anisotropy of the interface, the smaller the tip radius of the directionally solidified dendrite, the smaller the concentration of the liquid phase and the degree of undercooling at the leading edge of the tip interface.The tip state selection parameters and interface energy The anisotropy intensity also has the exponential relationship of scale law, while the dendrite primary spacing is less affected by the strength of the interface anisotropy.When the preferred orientation of the crystal and the heat flow direction is at an included angle of 40, with the interfacial energy anisotropy Increasing the strength, the solidified tissue morphology gradually changes from seaweed degenerated dendrites, and then gradually transformed into oblique dendrites.