——微觀結(jié)構(gòu)演化
(中南大學(xué) 材料科學(xué)與工程學(xué)院, 長沙 410083)
摘 要: 采用相場模型對共格沉淀析出過程微觀結(jié)構(gòu)演化進行模擬研究。 模擬結(jié)果表明， 應(yīng)力場的存在將會對相變過程中析出相形態(tài)產(chǎn)生顯著的影響，通過界面能與彈性應(yīng)變能的相互競爭析出相在不同階段呈現(xiàn)不同的形態(tài)如模量結(jié)構(gòu)、 網(wǎng)格結(jié)構(gòu)、 三明治多疇結(jié)構(gòu)、 沉淀宏觀點陣結(jié)構(gòu)以及板條狀等； 此外， 點陣錯配度中等(2%~4%)時， 粒子的粗化過程將出現(xiàn)應(yīng)力誘導(dǎo)反向粗化現(xiàn)象， 這種粗化現(xiàn)象取決于粒子的點陣錯配度與體積分數(shù)。
關(guān)鍵字: 點陣錯配度； 微觀結(jié)構(gòu)演化； 相分離； 計算機模擬
coherent particles
──Microstructure evolution
LI Jian, ZHOU Ming, CHEN Zhi-guo
（ 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
