Ag晶体的力学稳定性和理论强度  

Mechanical Stability and Theoretical Strength of Crystal Ag

作　　者：杨艳[1] 许丽萍[1] 

机构地区：[1]中北大学理学院物理系,太原030051

出　　处：《材料导报》2009年第12期78-81,共4页Materials Reports

基　　金：山西省自然科学基金资助项目(200611010)

摘　　要：把MAEAM与Milstein改进的Born力学稳定性判据相结合,讨论了fcc晶体Ag在单轴载荷下的力学稳定性和理论强度。结果表明,在压缩过程中,晶体结构首先转变为无应力不稳定的bcc相,随后通过消耗内能自发地转变为另一个无应力的bct亚稳相。计算的bcc和fcc相的结构能量差与实验值很符合,其力学稳定性范围为-2.076～4.390GPa,相应的应变范围为-7.972%～8.672%。The mechanical stability and theoretical strength of fcc crystal Ag under uniaxial loading are investigated by combining MAEAM with Milstein modified Born stability criteria. The results reveal that, under compression, there exists a stress-free bcc phase which is unstable and slips spontaneously to a stress-free metastable bet phase by consuming internal energy. The calculated structural energy difference between the bcc and fcc phase is in good agreement with the experimental value. The stable region ranges from -2. 076GPa to 4. 390GPa in the theoretical strength or -7. 972% to 8. 672% in the strain correspondingly.

关 键 词：力学稳定性 理论强度 AG MAEAM 

分 类 号：TG139.7[一般工业技术—材料科学与工程] TQ127.2[金属学及工艺—合金]