Phase Field Modelによる過冷却凝固のシミュレーション
Phase Field Modelによる過冷却凝固のシミュレーション
复制标题
使用相场模型模拟过冷凝固
DOI：
10.1299/kikaib.64.463
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
邦夫 土方
中科院分区：
文献类型：
--
作者：
修 中別府;邦夫 土方
为了阐明枝晶生长的机理，采用与热力学相一致的相场模型（PFM）对过冷凝固过程进行了数值模拟。在模型中，固体和液体的状态被识别的相变量，它连续变化的界面区域。该模型由包含潜热源项的热传导方程和包含表面张力效应、过冷非平衡效应和动力学凝固速度的相方程组成。该模型能定量再现过冷凝固过程中的Gibbs-Thomson效应和固液界面形态不稳定性。在原子尺度下，根据晶体结构，考虑表面张力、非平衡性和各向异性，对枝晶凝固过程进行了模拟。通过改变表面张力、过冷度和各向异性等条件，研究了PFM在凝固过程中的各种图案形成。金属烤瓷显微镜有望从根本上解释过冷凝固的物理行为和枝晶形貌的形成机理。
Numerical simulation of supercooling solidification was conducted by phase field model (PFM) derived consistently to thermodynamics to clarify a mechanism of dendritic crystal growth. Solid and liquid states are identified in the model by phase variable, which changes continuously over interfacial region. The PFM is composed of heat conduction equation with a source term of latent heat and phase equation including surface tension effect, nonequilibrium effect by supercooling and kinetic solidification speed. The derived model can quantitatively reproduce Gibbs-Thomson effect and morphological instability of solid-liquid interface during supercooling solidification. Dendritic solidification was also simulated by considering surface tension, nonequilibrium and anisotropy based on crystal structure in atomic scale. Various pattern formations in solidification were studied through the PFM by changing conditions such as surface tension, degree of supercooling and anisotropy. It is expected that the PFM entirely explain physical behavior of supercooling solidification and mechanism of dendritic pattern formation.