摘要
应用分子动力学方法模拟纳米晶Cu及梯度纳米晶Cu在单向拉伸载荷下的力学性能与微观结构演化过程。模拟结果表明,梯度纳米晶Cu的屈服强度及拉伸塑性变形能力比纳米晶Cu略高。在对梯度纳米晶Cu拉伸模拟过程中,其变形机制较为复杂,粒径较小的区域首先产生裂纹,然后逐渐在粒径较大的区域出现裂纹,单晶区塑性最好,材料遭到破坏时仍然没有裂纹出现,只存在位错运动及堆垛层错。
Classical molecular dynamic simulations were employed to investigate the mechanical properties and deformation mechanism of nanocrystalline copper and gradient nano-grained copper. The results showed that the yield strength and ductility of gradient nano-grained copper are better than nanocrystalline copper. During the simulation, the cracks appeared in smaller grain size area firstly , and then in larger grain size area. The ductility of monocrystalline area is best. When material fails, there is still no cracks appeared in this place, only deformation motion and stacking fault exist.
关键词
分子动力学
梯度纳米晶Cu
位错
晶界
molecular dynamics, gradient nano grained copper, dislocations, grain boundaries
