魏双磊,褚浩男,韩帅,等.高应变率下温度对单晶铜拉伸微观变形的影响机理[J].精密成形工程,2023,15(4):143-152.
WEI Shuang-lei,CHU Hao-nan,HAN Shuai,et al.Effect Mechanism of Temperature on Microscopic Tensile Deformation of Single Crystal Copper at High Strain Rate[J].Journal of Netshape Forming Engineering,2023,15(4):143-152. |
| 高应变率下温度对单晶铜拉伸微观变形的影响机理 |
| Effect Mechanism of Temperature on Microscopic Tensile Deformation of Single Crystal Copper at High Strain Rate |
| |
| DOI：10.3969/j.issn.1674-6457.2023.04.016 |
| 中文关键词: 分子动力学 单晶铜 晶体结构 应力应变 孔洞分析 |
| 英文关键词: molecular dynamics single crystal copper crystal structure stress-strain void analysis |
| 基金项目: |
|
| 摘要点击次数: 1563 |
| 全文下载次数: 918 |
| 中文摘要: |
| 目的 以单晶铜为研究对象，探究5×109 s–1高应变率下温度对单晶铜的应力及微观变形的影响，为设计、制备高性能单晶铜导线提供理论依据。方法 运用分子动力学模拟技术，构建尺寸为10.8 nm×10.8 nm×10.8 nm的单晶铜模型，在应变率为5×109s–1，温度为100~1 100 K范围内对单晶铜进行x、y、z三轴拉伸，模拟其应力应变、位错密度、晶体结构转变规律，对晶体的有序性和孔洞体积分数的微观结构变化进行研究。结果 随着温度的升高，单晶铜的屈服强度降低，在温度为1 100 K时单晶铜的屈服强度比100 K时降低了约55%，与屈服强度相对应的应变数值会提前约5%。得到了100~1 100 K温度范围内应力−应变曲线，该曲线包括3个阶段，即弹性变形阶段、塑性变形阶段和应力下降阶段。对应力变化的原因进行分析，当应力达到屈服点后，单晶铜内部出现孔洞形核，孔洞快速长大并合并;在变形的同时，晶格结构发生转变，在1 100 K温度时FCC结构全部转变为Other结构;利用径向分布函数对晶格有序性进行分析，发现在高应变下会产生非晶结构。结论 随着温度的升高，单晶铜的屈服强度降低，屈服强度的下降主要是位错密度增大、孔洞形核、快速长大和合并以及晶格转变共同作用的结果。 |
| 英文摘要: |
| The work aims to investigate the effects of temperature on stress and microscopic deformation of single crystal copper at high strain rate of 5×109 s–1 with single crystal copper as the research object, and to provide a theoretical basis for design and preparation of high performance single crystal copper wires. The molecular dynamics simulation technology was used to construct a single crystal copper model with a size of 10.8 nm×10.8 nm×10.8 nm, and the single crystal copper was triaxially stretched along x-axis, y-axis and z-axis at a high strain rate of 5×109 s–1 in the temperature range of 100-1 100 K to simulate its stress-strain, dislocation density, crystal structure transformation rules, and research on the microstructure changes of crystal order and void volume fraction. As the temperature increased, the yield strength of the single crystal copper decreased. At 1 100 K, the yield strength of the single crystal copper was about 55% lower than that at 100 K, and the strain value corresponding to the yield strength would be about 5% earlier. The stress-strain curve at 100-1 100 K was obtained, and the curve included three stages:the elastic deformation stage, the plastic deformation stage, and the stress drop stage. The reason for the stress change was analyzed. When the stress reached the yield point, voids nucleated inside the single crystal copper, and the holes grew rapidly and merged. The lattice structure changed while deforming, and all FCC transformed into other structure at 1 100 K. Analysis of the lattice order through the radial distribution function revealed that an amorphous structure occurred at high strains. With the increase of temperature, the yield strength of the single crystal copper decreases mainly due to the combined effect of the increase of dislocation density, void nucleation, rapid growth and merging, and lattice transformation. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
渝公网安备 50010702501719号