论文部分内容阅读
利用分子动力学方法研究超薄Ni/Ni3Al(001)纳米线力学性能和晶体缺陷的拉压不对称,对应力-应变曲线和晶体曲线在不同的温度下进行比较。模拟表明在拉伸载荷作用下不全位错的施密特因子大于压缩载荷下的施密特因子,在10 K温度下的流变应力行为异常,同时超薄Ni/Ni3Al(001)纳米线在不同温度下都表现为抵抗压缩载荷能力比拉伸载荷强。结果显示超薄Ni/Ni3Al(001)纳米线具有显著的拉伸不对称特性。此外,堆积层错提高原子移动,不全位错从堆垛层错处发射。在促进位错发射过程中原子移动扮演着重要的角色;而且在拉-压载荷下不同晶体缺陷主要是点位错和层错,层错主要发生在4个{111}方向。研究拉压不对称与温度之间的关系,可以更准确和全面的理解超薄Ni/Ni3Al(001)纳米线的力学性能。
Molecular dynamics simulation was used to study the mechanical and optical properties of the ultrathin Ni / Ni3Al (001) nanowires. The stress-strain curves and the crystal curves were compared at different temperatures. The simulation shows that the Schmidt factor of incomplete dislocation under tensile load is greater than the Schmitt factor under compressive load, and the flow stress behavior at 10 K is abnormal. Meanwhile, the ultrathin Ni / Ni3Al (001) At different temperatures are shown to resist compression load capacity than tensile load. The results show that the ultrathin Ni / Ni3Al (001) nanowires exhibit significant tensile asymmetry. In addition, stacking faults increase the movement of atoms and incomplete dislocations are emitted from stacking faults. The atomic movement plays an important role in the promotion of dislocation emission. Moreover, the different crystal defects are mainly point dislocations and stacking faults under the tension-compression load. The stacking faults mainly occur in four {111} directions. Studying the relation between tension and pressure asymmetry and temperature can understand the mechanical properties of ultrathin Ni / Ni3Al (001) nanowires more accurately and comprehensively.