Molecular Dynamics Simulation of Microcrack Healing in Copper Nano-Plate

2012 ◽  
Vol 531-532 ◽  
pp. 454-457
Author(s):  
Mei Fen Wang ◽  
Guo Jun Du ◽  
Dong Yu Xia

The molecular dynamics method is used to simulate microcrack healing in copper nano-plate during heating. During microcrack healing, the tip of microcrack is blunted and deforms to round shape, the microcrack becomes smaller and smaller until it is healed through slip bands emitting from the pre-crack tip and expanding to the top and bottom of the copper nano-plate. The healing time is different in different temperature. The healing processes in different temperature present different slip bands for crack healing. When temperature is below 650K, the healing time decreases dramatically with temperature increase. When temperature is above 650K, the healing time decreases smoothly with temperature increase. The critical temperature of microcrack healing in copper nano-plate without pre-existing dislocations is about 400K.

Author(s):  
Qiang Zhao ◽  
Yang Li ◽  
Zheng Zhang ◽  
Xiaoping Ouyang

The sputtering of graphite due to the bombardment of hydrogen isotopes is one of the critical issues in successfully using graphite in the fusion environment. In this work, we use molecular dynamics method to simulate the sputtering by using the LAMMPS. Calculation results show that the peak values of the sputtering yield are located between 25 eV to 50 eV. After the energy of 25 eV, the higher incident energy cause the lower carbon sputtering yield. The temperature which is most likely to sputter is about 800 K for hydrogen, deuterium and tritium. Before the 800 K, the sputtering rates increase when the temperature increase. After the 800 K, they decrease with the temperature increase. Under the same temperature and energy, the sputtering rate of tritium is bigger than that of deuterium, the sputtering rate of deuterium is bigger than that of hydrogen.


2016 ◽  
Vol 18 (26) ◽  
pp. 17461-17469 ◽  
Author(s):  
Z. Y. Hou ◽  
K. J. Dong ◽  
Z. A. Tian ◽  
R. S. Liu ◽  
Z. Wang ◽  
...  

The effect of the cooling rate on the solidification process of liquid aluminium is studied using a large-scale molecular dynamics method.


2015 ◽  
Vol 3 (43) ◽  
pp. 21518-21527 ◽  
Author(s):  
Jingxiang Xu ◽  
Shandan Bai ◽  
Yuji Higuchi ◽  
Nobuki Ozawa ◽  
Kazuhisa Sato ◽  
...  

The effects of the ceramic type and porosity on the sintering and degradation in Ni/YSZ and Ni/ScSZ anodes are unveiled by a recently developed multi-nanoparticle sintering simulation method based on molecular dynamics simulation.


Author(s):  
Y. H. Park ◽  
J. Tang

This paper describes the calculation of material properties of copper (Cu) using the molecular dynamics method. Vacancy formation energy, bulk modulus, surface energy and melting point are calculated using different potentials such as the Morse potential and Embedded Atom Method (EAM). Results obtained from different potentials are discussed and compared with experimental results.


2013 ◽  
Vol 677 ◽  
pp. 130-135
Author(s):  
Feng Yu ◽  
Pu Li ◽  
Zhuo Wang

Predicting squeeze-film air damping of resonators in rare air is crucial in the design of high-Q devices for various applications. In the past, there have been two approaches to treat the squeeze-film air damping in non-continuum regime: using effective viscosity coefficient and using the molecular dynamics method. And most of the previous work focused on devices in which the rarefaction effects of air are not significant. For such cases, continuum theory is often adequate. However, we have investigated the air damping on oscillating structures in the free molecular regime in which classical continuum theory is no longer valid. Based on this premise, Hutcherson (2004 J. Micromesh. Microeng. 14 1726-1733) has developed a molecular dynamics simulation code and used in predicting quality factors of an oscillating micro-plate at low pressures. However, his work is valid only for non-perforated micro-plate. This paper, a brief description of the molecular dynamics method is presented first. Then a molecular dynamics simulation code has been developed and used in predicting quality factors of a perforated oscillating micro-plate in free molecular regime. And we have found that the molecular dynamics simulation results have shown an excellent agreement with the experimental data of Kwok et al. Finally, the limitations of the present molecular dynamics simulation code have been reported.


2008 ◽  
Vol 39-40 ◽  
pp. 49-52
Author(s):  
G.G. Boiko ◽  
G.V. Berezhnoi

The specific features of the dynamics of oxygen ions in Ме2O · SiO2 (Ме = Li, Na, K, Cs) and Na2O·ZnO·P2O5 melts at а temperature of 2000 K were investigated bу the molecular dynamics method. It is demonstrated that, as in the systems studied earlier, the formation of defect complexes is а necessary condition fог an oxygen diffusion event to bе successful. The scenarios of generating defect соmplexes аrе described, and the lifetimes of these complexes are calculated. The structure of the defect complexes is determined. It is shown that two-membered rings, free and threefold-coordinated oxygen ions сап also bе involved in the formation of defect complexes.


2010 ◽  
Vol 105-106 ◽  
pp. 137-141 ◽  
Author(s):  
Dao Yuan Yang ◽  
Hui Yu Yuan ◽  
Fen Ling Qian ◽  
Juan Wu ◽  
Kai Zhu ◽  
...  

After preparing samples (3mm long×4mm wide×36mm high) of Al2O3-MgAlON composites and sintered at 1500°C for 2 h in N2 atmosphere, samples’ cracks were carved by a Vickers hardometer’s pressing head on the center of the sample surface (4 mm×36 mm). Subsequently, the cracks were healed at 1000°C-1550°C for 6 h respectively. Effects of healing temperature on sample’s strength, crack healing dynamics and its molecular dynamics simulation were investigated. The results suggested that: the optimum range of cracks healing temperature was 1300°C-1550°C, and the healing process accelerated at 1300°C, meanwhile, the strength of samples increased significantly. Cracks completely healing finished at 1550°C. The dynamics equation of crack healing was lnν = -Q/kT+lnC. Through characterizing the crack healing rate with the recovering rate of sample’s strength, the diffusion activation energy Q = 4.264 × 10-30 J•K-1 and diffusion constant C=7.359 were claimed. The result of the molecular dynamics simulation suggested that cracks healing process was caused by diffusion could be divided into five stages: passivation of crack tips, formation of salient island, crack shrinkage, generation of secondary crack, and complete healing.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Fancui Meng

The binding mode of sorafenib with VEGFR2 was studied using molecular docking and molecular dynamics method. The docking results show that sorafenib forms hydrogen bonds with Asp1046, Cys919, and Glu885 of VEGFR2 receptor. Molecular dynamics simulation suggests that the hydrogen bond involving Asp1046 is the most stable one, and it is almost preserved during all the MD simulation time. The hydrogen bond formed with Cys919 occurs frequently after 6 ns, while the bifurcated hydrogen bonds involving Glu885 occurs occasionally. Meantime, molecular dynamics simulations of VEGFR2 with 11 other urea-substituted aryloxy compounds have also been performed, and the results indicate that a potent VEGFR2 inhibitor should have lower interaction energy with VEGFR2 and create at least 2 hydrogen bonds with VEGFR2.


2016 ◽  
Vol 14 (1) ◽  
pp. 68-79 ◽  
Author(s):  
Jian-Feng Huang ◽  
Zhong-Lai Wang ◽  
Er-Fu Yang ◽  
Don McGlinchey ◽  
Yuan-Xin Luo ◽  
...  

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