——微观结构演化
(中南大学 材料科学与工程学院, 长沙 410083)
摘 要: 采用相场模型对共格沉淀析出过程微观结构演化进行模拟研究。 模拟结果表明， 应力场的存在将会对相变过程中析出相形态产生显著的影响，通过界面能与弹性应变能的相互竞争析出相在不同阶段呈现不同的形态如模量结构、 网格结构、 三明治多畴结构、 沉淀宏观点阵结构以及板条状等； 此外， 点阵错配度中等(2%~4%)时， 粒子的粗化过程将出现应力诱导反向粗化现象， 这种粗化现象取决于粒子的点阵错配度与体积分数。
关键字: 点阵错配度； 微观结构演化； 相分离； 计算机模拟
coherent particles
──Microstructure evolution
（ School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The effect of elasticity on the microstructure evolution of alloys containing coherent precipitates was studied by phase field model. The simulation results indicate that morphological evolutions are controlled by a transformation-induced elastic strain during a solid state precipitation and various types of coherent two-phase morphologies such as modulated structure, basket-weave structure, sandwich-like multi-domain structure, precipitate macrolattices structure and plate-like structure are predicted. Moreover, the stress-induced reverse coarsening phenomenon, which depends on the lattice misfit and volume fraction of precipitates, is found for medium lattice misfit in the stage of coarsening.
Key words: lattice misfit; microstructure evolution; phase separation; computer simulation
