纳米Fe颗粒对液态Fe凝固过程影响的分子动力学研究  

Molecular Dynamics Study of Effect of Fe Nanoparticle on Solidification Process of Liquid Fe

作　　者：吴永全[1] 张宁[1] 沈通[1] 赖莉珊[1] 高帅[1] 

机构地区：[1]上海大学上海市现代冶金及材料制备重点实验室,上海200072

出　　处：《热加工工艺》2013年第3期1-4,共4页Hot Working Technology

基　　金：国家自然科学基金项目(50974083,51174131);国家自然科学基金钢铁联合基金项目(50774112);上海市青年科技启明星计划项目(07QA4021);上海市教育委员会科研创新计划资助课题(09YZ24)

摘　　要：采用分子动力学方法研究了纯Fe材料中嵌入固相Fe纳米团簇后的凝固过程。结果表明,嵌入的纳米团簇能够显著降低过冷度,凝固得到的Fe的结构为γ-Fe。当凝固发生时,嵌入的Fe纳米团簇能够保持其形状。凝固过程首先从纳米团簇与Fe液的界面处开始发生,其形核长大阶段会交替出现稳定的FCC层和亚稳的FCP层。随后在结构弛豫阶段,大部分亚稳态FCP结构会逐渐转变成稳态的FCC结构。嵌入纳米团簇的结构能决定Fe液在凝固过程中的晶格取向和结构演化以及凝固的最终结构。Solidification process of liquid pure Fe embedded with a solid Fe nanoparticle was studied by molecular dynamics method. The results show that the embedded Fe nanoparticle can significantly reduce the undercooling temperature and the structure of solid Fe is 3,-Fe. When solidification happens, the embedded Fe nanoparticle is able to maintain its shape. The solidification process first begins at the interface between Fe nanoparticle and liquid. And during nucleation and growth stage, stable FCC layers and metastable FCP layers grow alternatively. During structural relaxation stage, most of the metastable FCP structure can gradually change into the stable FCC structure. Structure of embedded Fe nano-particle can decide the orientation and microstructure evolution of liquid Fe as well as eventual structure of liquid Fe in solidification process.

关 键 词：嵌入纳米团簇 Fe液 微观结构 分子动力学 

分 类 号：TG244.3[金属学及工艺—铸造]