曲率驱动晶界迁移的晶体相场研究

Phase field crystal study of curvature driven grain boundary migration

采用晶体相场方法模拟U形半环双晶的演化过程,讨论晶界曲率对体系自由能及晶界迁移的影响。结果表明:在双晶演化过程中体系自由能不断降低直至演变成单晶,且晶界曲率越大自由能降低越快;半环晶粒在收缩过程中晶界迁移具有稳态性质,且迁移速度正比于晶界曲率。

The evolution process of a U-shaped half-loop bicrystal was simulated by the phase field crystal method. Also,the effect of grain boundary curvature on system free energy and grain boundary migration was discussed. The results show that the system free energy decreases continuously until the crystal evolves from bicrystal to a single one. In addition,the greater the grain boundary curvature is,the faster the free energy decreases. The grain boundary migration has a steady state nature during the half-loop grain retraction and grain boundary migration velocity is proportional to grain boundary curvature.