利用分子动力学模拟方法分别研究了空位、自间隙杂质原子、杂质He原子等缺陷对金属Ti样品的力学性能的影响. 对完整晶格的金属Ti在不同拉伸应变速率下的应力-应变曲线进行计算, 发现拉伸过程可分为弹性形变、塑性形变及断裂3个阶段. 分别研究了含有不同浓度的空位、自间隙杂质原子、杂质He原子缺陷的金属Ti样品在2×10⁹ s^-1拉伸应变速率下的应力-应变曲线, 并对不同情况下的Young's模量进行了统计. 还分别对含有自间隙杂质原子和杂质He原子的金属Ti的拉伸断裂过程进行了观察与分析.

The effect of defects in metal Ti such as vacancies, self-interstitial atoms and impurity He atoms on mechanical properties of metal Ti sample was studied using molecular dynamics simulation. First, the stress-strain curves of perfect Ti sample at different strain rates were calculated. The results show that the stretching process can roughly be divided into three stages, elastic deformation, plastic deformation and fracturing. For comparison the stress-strain curves of metal Ti samples with vacancies, self-interstitial atoms and impurity He atoms were researched, respectively, in which the strain rate was set as 2×10⁹ s^-1. Finally the corresponding Young's moduli were calculated. It is found that after carefully investigating that the mechanical properties of metal Ti are degraded by each of these effects in it and the degradation degree increases with increasing defect concentration. However, the stretching process of samples is not essentially affected by these effects (the stress-strain curves of Ti samples with defects have still 3 stages). In this process, self-interstitial atoms in samples always exist for they to be bonded by metal Ti atoms, but impurity He atoms in samples are released due to their extraordinarily low solution in metal Ti.