On the prediction of explosive boiling characteristics in superheated liquid during non-equilibrium heating: Continuum modeling vs. atomistic-continuum modeling

Materials processing using high power pulsed lasers involves complex phenomena including rapid heating, superheating of the laser-melted material, rapid nucleation, and phase explosion. With a heating rate on the order of 109K/s or higher, the surface layer melted by laser irradiation can reach a temperature higher than the normal boiling point. On the other hand, the vapor pressure does not build up as fast and thus falls below the saturation pressure at the surface temperature, resulting in a superheated, metastable state. As the temperature of the melt approaches the thermodynamic critical point, the liquid undergoes a phase explosion that turns the melt into a mixture of liquid and vapor. This article describes heat transfer and phase change phenomena during nanosecond pulsed laser ablation of a metal, with an emphasis on phase explosion and non-equilibrium phase change. The time required for nucleation in a superheated liquid, which determines the time needed for phase explosion to occur, is also investigated from both theoretical and experimental viewpoints.

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A study on thermally controlled bubble growth in a superheated liquid with a thermal non-equilibrium cavitation model based on energy balances on a fixed fluid mass

Computational Methods in Multiphase Flow VIII ◽

10.2495/mpf150331 ◽

2015 ◽

Author(s):

M. Nickaeen ◽

T. Jaskolka ◽

S. Mottyll ◽

R. Skoda

Keyword(s):

Bubble Growth ◽

Superheated Liquid ◽

Cavitation Model ◽

Fluid Mass ◽

Model Based ◽

Energy Balances ◽

Non Equilibrium

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Application of the homogenous nucleation theory to the study of explosive boiling of superheated liquid drops

Journal of Physics Conference Series ◽

10.1088/1742-6596/1683/2/022019 ◽

2020 ◽

Vol 1683 ◽

pp. 022019

Author(s):

V O Mayorov ◽

A K Yastrebov ◽

V Yu Levashov

Keyword(s):

Nucleation Theory ◽

Superheated Liquid ◽

Liquid Drops ◽

Explosive Boiling ◽

Homogenous Nucleation

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Application of analytical electron microscopy to studies of equilibrium and non-equilibrium segregation in materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130705 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1214-1215

Author(s):

Edward A Kenik

Keyword(s):

Electron Microscopy ◽

Analytical Electron Microscopy ◽

Extended Defects ◽

Probe Diameter ◽

Specimen Holder ◽

Analytical Electron ◽

Scanning Transmission ◽

Solute Atoms ◽

Equilibrium Segregation ◽

Non Equilibrium

Segregation of solute atoms to grain boundaries, dislocations, and other extended defects can occur under thermal equilibrium or non-equilibrium conditions, such as quenching, irradiation, or precipitation. Generally, equilibrium segregation is narrow (near monolayer coverage at planar defects), whereas non-equilibrium segregation exhibits profiles of larger spatial extent, associated with diffusion of point defects or solute atoms. Analytical electron microscopy provides tools both to measure the segregation and to characterize the defect at which the segregation occurs. This is especially true of instruments that can achieve fine (<2 nm width), high current probes and as such, provide high spatial resolution analysis and characterization capability. Analysis was performed in a Philips EM400T/FEG operated in the scanning transmission mode with a probe diameter of <2 nm (FWTM). The instrument is equipped with EDAX 9100/70 energy dispersive X-ray spectrometry (EDXS) and Gatan 666 parallel detection electron energy loss spectrometry (PEELS) systems. A double-tilt, liquid-nitrogen-cooled specimen holder was employed for microanalysis in order to minimize contamination under the focussed spot.

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