电场作用下Al_6CuMg_4准晶相自由能的计算  

Free Energy Calculation of Quasicrystal Phase Al_6CuMg_4 under Electric Field

作　　者：张建军[1] 王永欣[1] 陈铮[1] 刘兵[1] 

机构地区：[1]西北工业大学,陕西西安710072

出　　处：《稀有金属材料与工程》2007年第9期1578-1583,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50671084);陕西省自然基金

摘　　要：基于Thomas-Fermi模型,系统定量地计算研究了在电场作用下Al6CuMg4准晶相对于Al-Cu-Mg固溶体及普通化合物的自由能和吉氏自由能的变化趋势。结果表明:Al6CuMg4准晶相、Al2CuMg及Al-Cu-Mg固溶体的自由能与吉氏自由能,均随着电场强度的增大而升高。正电场作用要高于负电场作用,但差距不大。Al6CuMg4准晶相的自由能与吉氏自由能相对于固溶体对电场的变化更为敏感,随着电场的升高,Al6CuMg4与固溶体间的自由能与吉氏自由能的差值迅速增加。电场作用使得准晶相的不稳定性增加,Al2CuMg的稳定性显著高于Al6CuMg4的电场稳定性。对于Al-Cu-Mg固溶体,随着Mg含量的增加,合金对电场的敏感性增强,但增大幅度要远远小于化合物与准晶相的增大幅度。Based on Thomas-Fermi model, the change trend of free energy and Gibbs free energy of quasicrystal Al6CuMg4 against Al-Cu-Mg solid solution and compound Al2CuMg were calculated systematically and quantitatively. The main conclusion was following： free energy and Gibbs free energy of quasicrystal phase Al6CuMg4, Al2CuMg and Al-Cu-Mg solid solution increased with increasing of electric field. The effect of positive electric field was more intensive than the negative electric field, but their different was not big. The change trend of free energy and Gibbs free energy of quasicrystal Al6CuMg4 with the electric field was more sensitive than that of solid solution. With increasing of electric field, the differences of free energy and Gibbs free energy between Al6CuMg4 and solid solution increased quickly. The instability of quasicrytal increased under electric field. The stability of Al2CuMg under electric field was obviously higher than that of Al6CuMg4. For Al-Cu-Mg solid solution, the sensitivity increased with increasing of the Mg content, but the amplitude was far lower than those of the compound and quasicrystal.

关 键 词：自由能 吉氏自由能 电场 Al6CuMg4准晶 Thomas-Fermi模型 

分 类 号：TG111[金属学及工艺—物理冶金]