Phase-field simulation of dendritic sidebranching induced by thermal noise

• 作者: 朱昌盛 柳百成 王智平 荆涛
• 来源期刊: 中国有色金属学会会刊（英文版）
• 学科: 工学
• 关键词: phase-field method undercooling thermal noise dendritic sidebranching numerical simulation
• 年，卷（期）: 2004,（6）
• 页码范围: 1106-1110
• 页数: 5页
• 分类号: TG248|TG244
• 语种: 英文

摘要

The influence of undercooling and noise magnitude on dendritic sidebranching during crystal growth was investigated by simulation of a phase-field model which incorporates thermal noise. It is shown that, the sidebranching is not influenced with inclusion of the nonconserved noise, therefore, in order to save the computational costs it is often neglected; while conserved noise drives the morphological instability and is dominant origin of sidebranching. The dependence of temperature field on magnitude of thermal noise is apparent, when Fu gets an appropriate value, noise can induce sidebranching but not influence the dendritic tip operating state. In the small undercooled melt, the thermal diffusion layer collected around the dendrite is thick, which suppresses the growth of its sidebranching and makes the dendrite take on the morphology of no sidebranching, but when the undercooling is great,the thermal diffusion layer is thin, which is advantageous to the growth of the sidebranching and the dendrite presents the morphology of the developed sidebranching.