Atomic Simulation of the Bending Deformation of a Single-Crystal Simply Supported Nano-Beam

2009 ◽  
Vol 79-82 ◽  
pp. 1185-1188 ◽  
Author(s):  
Wen Bin Ni ◽  
Jian Wei Zhao ◽  
Yun Hong Liu ◽  
Feng Ying Wang ◽  
Xing Yin
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Deformation Behavior ◽  
Surface Effect ◽  
Dynamics Simulation ◽  
Nanoelectromechanical Systems ◽  
Atomic Simulation ◽  
Simply Supported ◽  
Distributed Load ◽  
Uniformly Distributed Load

Advanced fabrication techniques to miniaturize electromechanical systems have brought us into the regime of nanoelectromechanical systems (NEMS). Understanding the mechanical properties of NEMS components is of fundamental importance in the operation of these devices. In this paper, we have reported the deformation behavior of a single-crystal simply supported nano-beam under the uniformly distributed load. By using the molecular dynamics simulation, we have investigated the influence of span the nano-beam on the bending characters. Due to surface effect, the nano-beam shows a different behavior under the uniformly distributed load.

scholarly journals The Effect of Phase Separation on the Mechanical Behavior of the Co–Cr–Cu–Fe–Ni High-Entropy Alloy

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6523
Author(s):  
Heling Liu ◽  
Chuanxiao Peng ◽  
Xuelian Li ◽  
Shenghai Wang ◽  
Li Wang
Keyword(s):  
Mechanical Properties ◽  
Phase Separation ◽  
Grain Boundaries ◽  
Deformation Behavior ◽  
Grain Boundary Sliding ◽  
Dynamics Simulation ◽  
Uniaxial Tensile ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Critical Resolved Shear Stress

Phase separation phenomena in high-entropy alloys (HEAs) have attracted much attention since their discovery, but little attention has been given to the dynamics of the deformation mechanism of this kind of HEA during uniaxial tension, which limits their widespread and practical utility. In this work, molecular dynamics simulation was used to study the effect of phase separation on the mechanical properties of an HEA under uniaxial tensile loading. Moreover, the associated deformation behavior of the Co–Cr–Cu–Fe–Ni HEA was investigated at the nanoscale. Models with Cu-rich grain boundaries or grains were constructed. The results showed that Cu-rich grain boundaries or grains lowered the strength of the Co–Cr–Cu–Fe–Ni HEA, and Cu-rich grain boundaries significantly reduced ductility. This change of mechanical properties was closely associated with a deformation behavior. Furthermore, the deformation behavior was affected by the critical resolved shear stress of Cu-rich and Cu-depleted regions and the uneven stress distribution caused by phase separation. In addition, dislocation slipping and grain boundary sliding were the main mechanisms of plastic deformation in the Co–Cr–Cu–Fe–Ni HEA.

scholarly journals Size Effect on Mechanical Properties and Deformation Behavior of Pure Copper Wires Considering Free Surface Grains

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4563
Author(s):  
Yu Hou ◽  
Xujun Mi ◽  
Haofeng Xie ◽  
Wenjing Zhang ◽  
Guojie Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Free Surface ◽  
Size Effect ◽  
Single Crystal ◽  
Deformation Behavior ◽  
Pure Copper ◽  
Critical Value ◽  
Wire Diameter ◽  
Surface Model

The size (grain size and specimen size) effect makes traditional macroscopic forming technology unsuitable for a microscopic forming process. In order to investigate the size effect on mechanical properties and deformation behavior, pure copper wires (diameters range from 50 μm to 500 μm) were annealed at different temperatures to obtain different grain sizes. The results show that a decrease in wire diameter leads to a reduction in tensile strength, and this change is pronounced for large grains. The elongation of the material is in linear correlation to size factor D/d (diameter/grain size), i.e., at the same wire diameter, more grains in the section bring better plasticity. This phenomenon is in relationship with the ratio of free surface grains. A surface model combined with the theory of single crystal and polycrystal is established, based on the relationship between specimen/grain size and tensile property. The simulated results show that the flow stress in micro-scale is in the middle of the single crystal model (lower critical value) and the polycrystalline model (upper critical value). Moreover, the simulation results of the hybrid model calculations presented in this paper are in good agreement with the experimental results.

Atomic simulation of mechanical properties of irradiated iron

2019 ◽  
Vol 31 (02) ◽  
pp. 2050027
Author(s):  
Lei Ma ◽  
Changsheng Li ◽  
Ailong Zhang ◽  
Wangyu Hu
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Tensile Test ◽  
Room Temperature ◽  
Stacking Faults ◽  
Dynamics Simulation ◽  
Stress And Strain ◽  
Micro Structure ◽  
Atomic Simulation

The mechanical properties of irradiated iron are studied by molecular dynamics simulation. The initial models are irradiated with the energy of primary knocked-on atoms (PKA) of 10[Formula: see text]keV at 100, 300, 500 and 600 K, and then all the irradiated models are subjected to tensile test. The results reveal that the mechanical properties of irradiated iron are changed compared with un-irradiated iron, the yield stress and strain decrease after irradiation, and the irradiation causes the hardening of micro-structure at low temperature and high temperature, but it results in the softening of structure at room temperature. The plastic reduces for irradiated iron under tensile test, more stacking faults are formed in the crystal structure as the temperature increases.

Atomistic Investigation of Thermal Effect on the Shear Deformation of Single Crystal Copper

2011 ◽  
Vol 486 ◽  
pp. 155-158
Author(s):  
Xiao Chun Ma ◽  
Ji Hui Yin
Keyword(s):  
Single Crystal ◽  
Thermal Effect ◽  
Shear Deformation ◽  
Deformation Behavior ◽  
Mechanical Response ◽  
Strong Dependence ◽  
Dynamics Simulation ◽  
Small Length ◽  
Single Crystal Copper ◽  
Small Length Scale

The thermal effect has pronounced influence on deformation behavior of materials at nanoscale due to small length scale. In current paper, shear deformation of single crystal copper is simulated by molecular dynamics simulation, and special attention is paid to the thermal effect on the deformation behavior of material and mechanical response. The result shows that the plastic deformation of material during shear deformation is dominated by dislocation activities. Both the yield strength and shear strength have strong dependence on temperature due to thermal effect.

Sign in / Sign up

Export Citation Format

Share Document