温度对单晶镁拉伸性能影响的分子动力学研究

本研究主要运用分子动力学的模拟方法,研究了拉伸速率为10~(10) s~(-1)下温度对于单晶镁性能的影响,并对结果进行应力应变分析,势能应变分析,共近邻分析,位错密度分析等。结果表明:随着温度的升高,单晶镁的抗拉强度峰值降低,各峰值点对应的应变值随着温度的升高逐渐减小;在应力峰值出现前hcp首先转化成Other结构且没有位错产生,在应力峰值过后fcc,bcc结构出现,同时产生位错,其中位错主要为1/31100位错和未知结构位错,对应的晶体结构的转化与位错的产生大约滞后应力峰值点0.5%的应变值,并且温度对于滞后值的影响不大,晶体结构的转化和位错的产生也随着温度的升高提前发生。

Molecular dynamics study of the influence of temperature on tensile properties ofsingle crystal Magnesium

As a kind of high quality metal material, magnesium is widely used in various fields. There is little research on the molecular level of magnesium. In this paper, the effect of temperature on the properties of single crystal magnesium at a tensile rate of 10^10s^-1 was studied by using molecular dynamics simulation method, and stress-strain analysis, potential energy strain analysis, common neighbor analysis, dislocation density analysis and other operations were performed on the results. The results show that the peak tensile strength of monocrystalline magnesium decreases with the increase of temperature, and the corresponding strain value of each peak point decreases with the increase of temperature. HCP before the peak stress appears first converted into Other structures without dislocation, after the peak stress in the FCC, BCC structure appeared at the same time produce dislocation, dislocation mainly for 1/3<-1100> dislocation and unknown dislocation structure, the corresponding crystal structure transformation and the generation of dislocation about lag strain values of stress peaks around 0.45%, and the effects of temperature on lag value is not big, crystal structure transformation and the generation of dislocation and with the increase of temperature in advance.