摘要
利用分子动力学的方法模拟钼单晶纳米丝在拉伸作用下的力学性能和微观结构的演化过程。在不同温度下的模拟结果表明,位错和滑移是钼单晶拉伸变形的主要机制。其中从100 K到500 K,随着温度的增加,钼单晶纳米丝拉伸过程中屈服应力逐渐降低,断裂应力逐渐增加;屈服应变逐渐减小,断裂应变在常温300 K时达到最大。此外,100 K和300 K时纳米丝的结构在拉伸过程中出现明显的屈服变形,内部变形以滑移为主;在500 K时没有出现明显的屈服变形,原子排列不规则呈无序状态,结构内部伴有大量的位错和滑移现象。
The mechanical properties and micro structure of single-crystalline Mo nanowires under uniaxial tension are investigated using molecular dynamics （MD） simulations. The results show that dislocations and slips are main mechanisms of the tension deformation of single-crystalline Mo nanowires. When the temperature is increased from 100 K to 500 K, the yield strength and strain decrease, and the fracture strength and strain increase, respectively. The maximum fracture strength is at room temperature （300 K）. Furthermore, the structures of the stretched single-crystalline Mo nanowires at 100 K and 300 K have apparent yield deformation and the interior deformation is caused by slips. At 500 K, the structures of the stretched single- crystalline Mo nanowires have no apparent yield deformation, and the atomic arrangement of the interior is irregular and disordered and mixed with a large number of dislocations and slips.
出处
《机械强度》
CAS
CSCD
北大核心
2012年第5期683-686,共4页
Journal of Mechanical Strength
基金
重庆市科技攻关计划项目院士专项(CQCSTC2009AB4089)项目资助
关键词
分子动力学模拟
钼单晶
应力-应变曲线
Molecular dynamics simulations
Single-crystalline Mo
Stress-strain curve
