摘要
采用基于密度泛函理论的第一性原理赝势平面波方法计算了Mg5Al8和Mg2Si的生成焓,结合能和弹性常数。结果表明:Mg2Si具有更强的合金化能力和更好的结构稳定性;Mg2Si的弹性常数满足Born稳定性判据,而Mg5Al8不满足。构建了3个固溶体相:Al100Mg3Si1,Al67Mg2Si1和Al46Mg1Si1(at%),计算研究了其态密度和弹性常数。态密度的计算结果表明:3者都具有典型的金属特征;Al46Mg1Si1费米能级附近的赝带隙宽度和深度最大,结构最稳定。体模量(B),剪切模量(G),弹性模量(E)和泊松比(v)的计算结果表明:Al46Mg1Si1的强度和刚度最大,Al100Mg3Si1的塑性最好,3个固溶体相均为韧性相。
The formation enthalpy,binding energy and elastic constant of Mg5Al8 and Mg2 Si were calculated by the first-principle with pseudopotential plane wave method based on density functional theory. The results show that the Mg2 Si has stronger alloying ability and better structural stability,and the elastic constant of the Mg2 Si satisfies the Born stability criterion,while Mg5Al8 does not. Three solid solution phases,Al100 Mg3 Si1,Al67 Mg2 Si1 and Al46 Mg1 Si1 ( at%),were constructed,and their state density and elastic constant were calculated and studied. The calculation results of state density show that all three solid solution phases have typical metal characteristics, and the pseudo-band gap width and depth near the Fermi energy level of Al46Mg1 Si1 are the largest and the structure is the most stable. The calculation results of bulk modulus( B),shear modulus ( G),elastic modulus ( E) and Poisson's ratio ( v) show that the strength and stiffness of Al46Mg1 Si1 are the highest,the plasticity of Al100Mg3 Si1 is the best,and the three solid solution phases are ductile phases.
作者
万杨杰
钱晓英
曾迎
王良辉
杨秋荣
张英波
蒋斌
WAN Yang-jie;QIAN Xiao-ying;ZENG Ying;WANG Liang-hui;YANG Qiu-rong;ZHANG Ying-bo;JIANG Bin(School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;National Engineering Research Center for Magnesium Alloys,Chongqing University,Chongqing 400044,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2019年第10期158-165,共8页
Transactions of Materials and Heat Treatment
基金
国家重点基础研究发展计划(2018YFB1105803)
关键词
生成焓
结合能
弹性常数
电子态密度
formation enthalpy
cohesive energy
elastic constants
DOS
