相场晶体法模拟过冷熔体中的晶体生长

利用相场晶体(phase-field crystal)模型,采用有限差分法,模拟了过冷熔体中晶体生长过程,研究了不同相区、不同过冷度对晶体生长过程的影响.结果表明,在共存区中,随着演化的进行,晶体生长被抑制,液-晶边界层逐渐变厚;在单相区中,随着过冷度的增大,晶态区面积显著增加,液-晶边界层逐渐变薄.晶体生长速度和过冷度成近似线性的关系. 关键词： 相场晶体 自由能函数 过冷熔体 晶体生长

Simulation of crystal growth using phase-field crystal method

The phase-field crystal (PFC) model is used to simulate crystal growth from undercooled liquid by the finite difference method. The effects of phase region and undercooling on crystal growth process are analyzed. The simulation results show that crystal growth is inhibited in the region of liquid-crystal coexistence where liquid-crystal boundary becomes thicker gradually. In the single crystal phase region, crystallization is enhanced with undercooling increasing,while liquid-crystal boundary becomes thinner. It is found that there is a linear relationship between crystal growth velocity and undercooling.