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用分子动力学模拟研究了Cu熔体以不同速率冷却微观结构的演变规律.结果表明,冷却速率在10~(12.6)K/s到10~(14.5)K/s之间时,Cu熔体凝固后形成了非晶体与晶体的混合体;Cu熔体中的原子团簇、临界晶核及凝固后晶体的结构均是由hcp和fcc结构层状镶嵌排列构成,这说明Cu凝固后形成的层状镶嵌结构起源于形核阶段;冷却速率小于10~(13.3)K/s时,Cu层状镶嵌结构中具有fcc结构的原子数多于hcp结构的原子数,而冷却速率大于10~(13.3)K/s后,hcp结构的原子数多于fcc结构的原子数;Cu非晶基体中晶态结构原子团簇的尺寸小于临界晶核尺寸时,虽然用HA键型指数法能确定出一定数量晶态结构原子键对的存在,但径向分布函数反映不出其晶态结构的特征.
The evolution of microstructure of Cu melt cooled at different rates was studied by molecular dynamics simulation. The results show that when the cooling rate is between 10 ~ (12.6) K / s and 10 ~ (14.5) K / s, After solidification, a mixture of amorphous and crystal was formed. The atomic clusters, critical nuclei and solidified crystals in the Cu melt were all arranged in a layered mosaic structure with hcp and fcc structures, indicating that the layer formed after Cu solidification Like mosaic structure originated in the nucleation stage. When the cooling rate was less than 10 ~ (13.3) K / s, the number of atoms with fcc structure in Cu layered inlay structure was more than that in hcp structure, while the cooling rate was more than 10 ~ (13.3 ) K / s, the number of atoms in the hcp structure is larger than the number of atoms in the fcc structure. When the size of the crystalline structure in the Cu amorphous matrix is smaller than the critical nucleus size, although the HA bond index method can determine a certain amount However, the radial distribution function does not reflect the characteristics of its crystalline structure.