摘要
基于耦合流场的相场模型,采用有限差分法,研究了各相场参数对纯金属凝固过程中的枝晶生长的影响。结果表明,对流作用下枝晶形貌发生了很大变化,上游枝晶的枝晶臂最长,下游枝晶臂最短,水平方向枝晶臂介于两者之间;过冷度越大,上游及水平方向侧枝越发达;各向异性系数越大,主枝晶枝晶臂越瘦长,二次枝晶间距越小;对流速度越大,上游枝晶生长越快。
The phase-field model based on the Tong and Bechemann model which couples the flow field was developed to simulate the effects of phase-field parameters on dendrite growth in microstructure of pure metal by the finite difference method (FDM). The results show that the dendritic morphology obviously changes under the condition of convection, in which the branch of upper dendrite is the longest and that of down dendrite is the shortest and the length of the branch in horizontal direction is middle. The higher the undercooling rate is, the more development the side-branches in upper and in horizontal direction are; the larger the anisotropy parameters is, the thinner the branch of main dendrites is, and the smaller the second dendrite spacing is. In addition, the dendrite tip velocity is accelerated with the increase of convection velocity.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2008年第7期513-515,共3页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金重点资助项目(50331040)
关键词
强迫对流
热噪声
侧枝
相场参数
Forced Convection, Thermal Noise, Side-branching, Phase-field Parameters
