Heat transport analysis for femtosecond laser ablation with molecular dynamics-two temperature model method

AbstractAn improved two-temperature model to describe femtosecond laser ablation of metal target was presented. The temperature-dependent heat capacity and thermal conductivity of the electron, as well as electron temperature-dependent absorption coefficient and absorptivity are all considered in this two-temperature model. The tailored two-temperature model is solved using a finite difference method for copper target. The time-dependence of lattice and electron temperature of the surface for different laser fluence are performed, respectively. The temperature distribution of the electron and lattice along with space and time for a certain laser fluence is also presented. Moreover, the variation of ablation rate per pulse with laser fluence is obtained. The satisfactory agreement between our numerical results and experimental data indicates that the temperature dependence of heat capacity, thermal conductivity, absorption coefficient and absorptivity in femtosecond laser ablation of metal target must not be neglected. The present model will be helpful for the further experimental investigation of application of the femtosecond laser.

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An improved three-dimensional two-temperature model for multi-pulse femtosecond laser ablation of aluminum

Journal of Applied Physics ◽

10.1063/1.4907990 ◽

2015 ◽

Vol 117 (6) ◽

pp. 063104 ◽

Cited By ~ 17

Author(s):

Jinping Zhang ◽

Yuping Chen ◽

Mengning Hu ◽

Xianfeng Chen

Keyword(s):

Laser Ablation ◽

Femtosecond Laser ◽

Three Dimensional ◽

Femtosecond Laser Ablation ◽

Temperature Model ◽

Two Temperature

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Multiscale Investigation of Thickness Dependent Melting Thresholds of Nickel Film Under Femtosecond Laser Heating

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2018-86947 ◽

2018 ◽

Author(s):

Pengfei Ji ◽

Mengzhe He ◽

Yiming Rong ◽

Yuwen Zhang ◽

Yong Tang

Keyword(s):

Molecular Dynamics ◽

Femtosecond Laser ◽

Multiscale Simulation ◽

Nickel Film ◽

Atomic Scale ◽

Dynamics Simulation ◽

Model Description ◽

Temperature Model ◽

Laser Material Processing ◽

Two Temperature

A multiscale modeling that integrates electronic scale ab initio quantum mechanical calculation, atomic scale molecular dynamics simulation, and continuum scale two-temperature model description of the femtosecond laser processing of nickel film at different thicknesses is carried out in this paper. The electron thermophysical parameters (heat capacity, thermal conductivity, and electron-phonon coupling factor) are calculated from first principles modeling, which are further substituted into molecular dynamics and two-temperature model coupled energy equations of electrons and phonons. The melting thresholds for nickel films of different thicknesses are determined from multiscale simulation. Excellent agreement between results from simulation and experiment is achieved, which demonstrates the validity of modeled multiscale framework and its promising potential to predict more complicate cases of femtosecond laser material processing. When it comes to process nickel film via femtosecond laser, the quantitatively calculated maximum thermal diffusion length provides helpful information on choosing the film thickness.

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Molecular Dynamics Study of Mechanism of Ablation Induced by a Femtosecond Laser Pulse

Heat Transfer, Volume 1 ◽

10.1115/imece2003-55236 ◽

2003 ◽

Author(s):

Changrui Cheng ◽

Xianfan Xu

Keyword(s):

Molecular Dynamics ◽

Laser Ablation ◽

Laser Pulse ◽

Femtosecond Laser ◽

Critical Point ◽

Change Process ◽

Femtosecond Laser Ablation ◽

Md Simulations ◽

Femtosecond Laser Irradiation ◽

Transient Temperature

In this work, molecular dynamics (MD) simulations are carried out to study femtosecond laser ablation of a metal, with an emphasis on the understanding of the mechanism of laser ablation. Theoretically, it has been shown that under intense femtosecond laser irradiation, the material can undergo a volumetric phase change process; its temperature can be close to or even above the critical point. MD simulations allow us to determine the transient temperature of the irradiated material as well as the transient thermodynamic state, which explain the mechanisms of femtosecond laser ablation.

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Molecular Dynamics Study of Phase Change Mechanisms During Femtosecond Laser Ablation

Journal of Heat Transfer ◽

10.1115/1.1797011 ◽

2004 ◽

Vol 126 (5) ◽

pp. 727-734 ◽

Cited By ~ 35

Author(s):

Xianfan Xu ◽

Changrui Cheng ◽

Ihtesham H. Chowdhury

Keyword(s):

Molecular Dynamics ◽

Laser Ablation ◽

Femtosecond Laser ◽

Phase Change ◽

Change Process ◽

Femtosecond Laser Ablation ◽

Femtosecond Laser Irradiation ◽

Maximum Temperature ◽

Transient Temperature ◽

Phase Change Process

In this work, Molecular Dynamics (MD) simulation is employed to investigate femtosecond laser ablation of copper, with an emphasis on the understanding of the mechanism of phase change during laser ablation. Laser induced heat transfer, melting, surface evaporation, and material ablation are studied. Theoretically, it has been suggested that under intense femtosecond laser irradiation, the material undergoes a volumetric phase change process; its maximum temperature can be close to or even above the thermodynamic critical point. The MD simulations allow us to determine the transient temperature history of the irradiated material and to reveal the exact phase change process, which explains the mechanisms of femtosecond laser ablation. A finite difference calculation is also performed, which is used to compare results of heating and melting prior to a significant amount of material being ablated.

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