过冷纯金属熔体中结构起伏与能量起伏对树枝晶形貌的影响规律  

Influence of Structure Fluctuation and Energy Fluctuation on Dendrite Morphology in Pure Undercooled Melt

作　　者：刘健[1] 田卫星[2] 郑洪亮 田学雷[2] 陈言俊[1] 

机构地区：[1]山东大学工程训练中心,山东济南250061 [2]山东大学材料液态结构及其遗传性教育部重点实验室,山东济南250061

出　　处：《热加工工艺》2008年第8期8-11,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(50395101)

摘　　要：采用捕获液态界面改进的相场方法,系统地研究了结构起伏、能量起伏对过冷纯金属熔体中树枝晶生长的影响规律。结果表明,过冷熔体中存在的大量结构起伏和能量起伏是促发二次枝晶的重要原因,随着结构起伏和能量起伏水平的增大,晶体中二次枝晶百分含量增加,并在达到一定值时,一次枝晶可能会转变为海藻形态生长。The affecting law of structure fluctuation and energy fluctuation on dendrite growth in pure undercooled melt was studied by simulation of a phase-field method, The calculated results indicate that there is a lot of structure fluctuation and energy fluctuation in undercooled melt, which is the main reason of promoting secondary dendrite. The percentage of secondary dendrite increases with the increase of fluctuation level of the melt structure and melt energy, and a morphological transition takes place with dendrite tip splitting （doubloon formation）, which results in the normal dendrite morphology being replaced by the dendritic ＇seaweed＇ morphology.

关 键 词：起伏 树枝晶 相场方法 

分 类 号：TG113.1[金属学及工艺—物理冶金]