相场模拟中金属固-液热扩散系数比对晶体侧向分支形貌的影响  

Influence of the Ratio of Solid to Liquid Thermal Diffusivity on Dendrite Side-Branch Morphology Within a Phase-Field Simulation

作　　者：田卫星[1] 付海波[2] 王周英 刘建[3] 田学雷[1] 

机构地区：[1]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 [2]济南二机床集团有限公司,山东济南250062 [3]山东大学工程培训中心,山东济南250061

出　　处：《铸造》2007年第5期501-504,共4页Foundry

基　　金：国家自然科学基金项目(50395101)。

摘　　要：采用耦合结构起伏和能量起伏的相场方法,系统地研究了纯金属镍的固-液热扩散系数比(μ=ks/kl)对其过冷熔体树枝晶侧向分支形貌的影响规律。研究发现,金属固-液热扩散系数比μ越大,侧向分支的生长受到强烈的抑制,其百分含量减少,同时晶体的RMS距离Zsb越小,晶体的各向异性强度越小。Dendrite side＇branch growth is studied to examine the effect of the ratio of the thermal diffusivity in the solid .and liquid states （μ=ks/kl） on the side-branching characteristics of the dendrite during the growth of Ni from its undercooled parent melt by simulation of a phase-field model whLch incorporates structural fluctuation and energetic fluctuation of microscopic origin. The calculated results indicate as the ratio is increased the side-branch become strongly Suppressed and meanwhile, the RMS distance at which the mean amplitude of the side-branches is equal to the tip radius becomes little and anisotropy becomes weak.

关 键 词：热扩散系数 树枝晶侧向分支 相场方法 

分 类 号：TG111[金属学及工艺—物理冶金]