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利用Voronoi几何法搭建了纳米多晶金属铝,对初始结构进行弛豫和退火来降低由大角度晶界带来的高应力和高能量。在弛豫和退火过程中监测了体系结构、平均内应力、平均能量等在各个过程的变化情况,最终获得了稳定的结构。随后利用经典分子动力学模拟方法计算了不同晶粒大小纳米金属铝的弹性常数和一些热力学参数。计算结果表明,金属铝的弹性常数随着晶粒的增大有所变化,C11、C44随着晶粒的增大而增大,C12则是减小的,模拟结果与其他计算数据和实验数据进行了对比;随后计算了不同晶粒大小体系的杨氏模量、体弹模量、剪切模量等热力学参量,并与实验数据对比分析。
The Voronoi geometry was used to construct nano-poly aluminum, which relaxed and annealed the original structure to reduce the high stress and high energy caused by the large-angle grain boundaries. In the process of relaxation and annealing, the changes of the structure, average internal stress and average energy in each process were monitored, finally the stable structure was obtained. Then, the elastic constants and some thermodynamic parameters of nano-sized aluminum with different grain sizes were calculated by classical molecular dynamics simulation. The calculated results show that the elastic constant of aluminum increases with the increase of the grain size, while C11 and C44 increase with the increase of grain size, while C12 decreases. The simulation results are in agreement with other calculated and experimental data The thermodynamic parameters such as Young’s modulus, bulk modulus and shear modulus of different grain size systems were calculated and compared with the experimental data.