Laser Controlled Dynamic Self-Assembly of Nanostructure

2017 ◽  
Vol 49 ◽  
pp. 225-231 ◽  
Author(s):  
Li Nan Zhang ◽  
Wei Zheng ◽  
Cong Xiu Cheng ◽  
Li Qun Wu

This paper presents a three-dimensional dynamic model of laser controlled dynamic self-assembly of nanostructure. A phase field model is employed to study the surface fabrication of silicon which is induced by the laser. The mechanism of the surface fabrication is that the heating effect enhances surface diffusion mobility results in atoms outward flow. The computational model systematically integrate for high reliability of the whole analysis, the experimental and simulated measurements have been quantitatively investigated. A semi-implicit Fourier spectral scheme is applied for high efficiency and numerical stability. The performed simulations suggest a substantial potential of the presented model, which provides a reliable technology of nanostructure fabrications on the surface of silicon.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Min Yang ◽  
Lu Wang ◽  
Wentao Yan

AbstractA three-dimensional phase-field model is developed to simulate grain evolutions during powder-bed-fusion (PBF) additive manufacturing, while the physically-informed temperature profile is implemented from a thermal-fluid flow model. The phase-field model incorporates a nucleation model based on classical nucleation theory, as well as the initial grain structures of powder particles and substrate. The grain evolutions during the three-layer three-track PBF process are comprehensively reproduced, including grain nucleation and growth in molten pools, epitaxial growth from powder particles, substrate and previous tracks, grain re-melting and re-growth in overlapping zones, and grain coarsening in heat-affected zones. A validation experiment has been carried out, showing that the simulation results are consistent with the experimental results in the molten pool and grain morphologies. Furthermore, the grain refinement by adding nanoparticles is preliminarily reproduced and compared against the experimental result in literature.


2010 ◽  
Vol 97-101 ◽  
pp. 3769-3772 ◽  
Author(s):  
Chang Sheng Zhu ◽  
Jun Wei Wang

Based on a thin interface limit 3D phase-field model by coupled the anisotropy of interfacial energy and self-designed AADCR to improve on the computational methods for solving phase-field, 3D dendritic growth in pure undercooled melt is implemented successfully. The simulation authentically recreated the 3D dendritic morphological fromation, and receives the dendritic growth rule being consistent with crystallization mechanism. An example indicates that AADCR can decreased 70% computational time compared with not using algorithms for a 3D domain of size 300×300×300 grids, at the same time, the accelerated algorithms’ computed precision is higher and the redundancy is small, therefore, the accelerated method is really an effective method.


2007 ◽  
Vol 558-559 ◽  
pp. 1177-1181 ◽  
Author(s):  
Philippe Schaffnit ◽  
Markus Apel ◽  
Ingo Steinbach

The kinetics and topology of ideal grain growth were simulated using the phase-field model. Large scale phase-field simulations were carried out where ten thousands grains evolved into a few hundreds without allowing coalescence of grains. The implementation was first validated in two-dimensions by checking the conformance with square-root evolution of the average grain size and the von Neumann-Mullins law. Afterwards three-dimensional simulations were performed which also showed fair agreement with the law describing the evolution of the mean grain size against time and with the results of S. Hilgenfeld et al. in 'An Accurate von Neumann's Law for Three-Dimensional Foams', Phys. Rev. Letters, 86(12)/2685, March 2001. Finally the steady state grain size distribution was investigated and compared to the Hillert theory.


2015 ◽  
Vol 12 (11) ◽  
pp. 4289-4296 ◽  
Author(s):  
Li Feng ◽  
Jinfang Jia ◽  
Changsheng Zhu ◽  
Yang Lu ◽  
Rongzhen Xiao ◽  
...  

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