摘要
本文利用相场方法对过冷镍熔体中枝晶生长过程进行了模拟,发现在过冷度低于 200 K时,生长速度与过冷度之间近似呈幂函数关系,当过冷度高于 200 K时,生长速度与过冷度之间基本呈线性关系。伴随着速度/过冷度之间关系的变化,枝晶尖端半径/过冷度的关系则呈现先减小后增加的趋势,并在 200 K时达到最小。本文还将模拟结果与实验值和经典LKT理论进行了比较,对上述关系转变的物理机制进行了分析。
Phase field model (PFM) is used to simulate the dendrite growth of pure nickel in un-
dercooled melts. The simulation results show that the relationship between the dendrite tip velocity
and the bulk undercooling undergoes a transformation from a power law to a linear one around 200
K, where the tip radius reaches its lowest value. This PFM simulated results are compared with
the experimental results and the LKT prediction. The possible reason that causes the transition of
velocity-undercooling relationship is proposed and the accompanied grain morphology change is also
included.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2004年第3期487-489,共3页
Journal of Engineering Thermophysics
基金
自然科学基金(No.50395101)
关键词
过冷熔体
枝晶生长
相场模型
undercooling melts
dendrite growth
phase field model