ZA27合金中Y及Fe的晶界偏聚电子理论研究  

Segregation and interaction of yttrium and iron elements at grain boundaries in ZA27 alloy

作　　者：郭玉福[1] 李荣德[1] 刘贵立[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110023

出　　处：《沈阳工业大学学报》2006年第5期486-489,共4页Journal of Shenyang University of Technology

基　　金：国家自然科学基金资助项目(50571071);辽宁省教育厅科学研究计划资助项目(05L297);沈阳市科技计划基金资助项目(1041020-1-04-6)

摘　　要：根据分子动力学理论建立了液态ZA27合金的原子集团,结合计算机编程构造出ZA27合金α相与液相共存时的原子构形及α相大角度重位点阵晶界模型.利用递归法计算了Fe、Y固溶于晶粒内,游离于固液相界面及其在α相晶界处的环境敏感镶嵌能.由此得出:Fe、Y处于固液相界区时比在晶内更稳定,并解释了Fe、Y在α相内溶解度很小,结晶时富集于固液相界前沿液体中,从而导致凝固结束后Fe、Y偏聚于晶界,形成成分复杂的稀土化合物的事实.The model of the liquid-phase ZA27 cast alloy was set up based on the molecular dynamics simulation. The atomic structural models for the α-liquid phase interface and the grain boundary of a phase with coincidence-site lattice were constructed by computer programming. The environment-sensitive embedding energy （ESE） of yttrium （or iron） atom inside grains, at grain boundary and α-liquid phase interface was calculated by the recursion method. The bond order integrals （BOI） between Fe, Y and Al atoms were also estimated. The results show that yttrium and iron elements are more stable at the α-liquid phase interface than inside grains, which explains such facts as very small solid solubility of yttrium and iron elements in a phase, and the enrichment of yttrium and iron elements in the solid-liquid growth front at the end of solidification. This leads to the segregation of yttrium and iron atoms at grain boundaries and the formation of compounoss containing RE element.

关 键 词：锌铝合金 晶界 递归法 电子结构 原子集团 

分 类 号：TG111.1[金属学及工艺—物理冶金]