摘要
通过高压扭转工艺(HPT)对两个半圆盘的纯铝和纯锌进行合金化处理以及合金化后的退火处理(PDA)。通过扫描电子显微镜、透射电子显微镜和分子动力学(MD)模拟研究Al-Zn合金的微观结构演变过程。结果表明,高压扭转处理的Al/Zn组件由纳米晶相和非晶相混合组成。变形产生的(0001)Al//(111)Zn特殊晶面取向促进了原子扩散,高固溶度的钉扎效应使位错密度达到2.17×10^(17)m^(-2)。Al-Zn合金中的晶体向非晶的转变可能主要归因于纳米晶、高扩散度和高局部位错密度。此外,结果表明,退火后结构呈现150~250 nm和500~900 nm的双峰粒度分布,并且在后续的PDA中晶界处出现锌原子富集。这种异质微观结构使材料的伸长率达到160%,展现出优良的塑性。
Two half-disk samples of pure Al and pure Zn were mechanically alloyed via high-pressure torsion(HPT)processing,followed by post-deformation annealing(PDA).The microstructure evolution of the Al-Zn alloy was studied by scanning electron microscopy,transmission electron microscopy and molecular dynamics(MD)simulations.The results indicated that the HPT-processed Al/Zn assembly was presented as a mixture of nanocrystalline and amorphous phases.The deformation-induced special orientation of(0001)Al//(111)Zn facilitated the interatomic diffusion,and the dislocation density reached 2.17×10^(17) m^(-2) under the pinning effect of high solid solubility.Nanocrystalline,high diffusion degree,and high local dislocation density may primarily accounted for the crystalline-to-amorphous transformation in Al-Zn alloy.Moreover,the results indicated a bimodal grain size distribution of 150-250 nm and 500-900 nm,and Zn atoms were enriched at the grain boundaries,upon subsequent PDA.Under the effect of this special heterogeneous microstructure,the prepared alloy exhibited an excellent plasticity with 160%of tensile elongation.
作者
陈琛
花安平
于俊杰
陈昱林
吉卫喜
钱陈豪
Chen CHEN;An-ping HUA;Jun-jie YU;Yu-lin CHEN;Wei-xi JI;Chen-hao QIAN(Department of Mechanical Engineering,Jiangnan University,Wuxi 214122,China;Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology,Wuxi 214122,China;School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China)
基金
supported by the National Natural Science Foundation of China(No.51905215)
the Major Scientific and Technological Innovation Project of Shandong Province,China(No.2019JZZY020111)。
关键词
铝锌合金
高压扭转
分子动力学模拟
固态非晶化
位错密度
Al−Zn alloy
high-pressure torsion
molecular dynamics simulation
solid-state amorphization
dislocation density
