用价电子理论分析Y对Mg-Al合金力学性能的影响  

Effect of Y on Mg-Al Alloy Mechanical Properties in View of Valence Electron Theory

作　　者：张伟[1] 刘伟东[1] 曾莉[1] 屈华[1] 

机构地区：[1]辽宁工业大学材料与化学工程学院,辽宁锦州121001

出　　处：《有色金属》2008年第4期9-12,共4页Nonferrous Metals

基　　金：辽宁省自然科学基金资助项目(20031083);辽宁省教育厅项目(05L185)

摘　　要：基于EET理论,计算Y元素加入Mg-Al合金后形成的Mg-Al-Y固溶体、第二相Al2Y的价电子结构,研究价电子结构与合金固溶强化、第二相强化、高温稳定性的关系。Mg-Al-Y最强键共价电子对数nA值和共价电子密度ρVC值均大于α-Mg的nA值和ρVC值,表明Y元素的固溶有利于基体强度的提高。第二相Al2Y的最强键(nA=0.39704)的键合强度远大于基体α-Mg(nA=0.11199)的键合强度,因此,Al2Y极大的阻碍了位错的运动,提高了合金的强度。Al2Y的单位体积成键能力FVAl2Y值为103.81,与γ-Mg17Al12(FVγ-Mg17Al12=44.22)相比较,Al2Y的高温稳定性更好,其存在有利于改善Mg-Al合金的高温性能。The valence electron structures of Mg-Al-Y solid solution phase, sencond phase Al2Y are calculated based on the empirical electron theory of solids and molecules （EET）, and the relationship between valence electron structures and the alloy solid solution strengthen, sencond phase strengthen, high temperature stability are investigated. The valence electron pairs on the strongest bond nA value and covalent electron density ρv^c value of Mg-Al-Y are bigger than that of α-Mg, which indicates that the solid solution of Y element is advantageous to the substrate intensity enhancement. The strongest bond （ nA = 0. 39704） of Al2Y is far bigger than substrate α- Mg（nA = 0.11199）, therefore, Al2Y is the enormous hinder for the dislocation movement, and the alloy intensity is enhanced. Compared the Fv value of γ-Mg17 Al12 （ Fv^γ-Mg17Al12 = 44.22）, the total bond-forming ability in unit volume Fv^Al2Y value of Al2Y is 103.75, the high temperature stability of Al2Y is better than others, its existence is advantageous to improves the high temperature performance of Mg-Al alloy.

关 键 词：金属材料 MG-AL合金 价电子结构 力学性能 Al2Y 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG146.452[金属学及工艺—金属材料]