1 edition of A model for laser produced material surface evaporation found in the catalog.
A model for laser produced material surface evaporation
Geoffrey Lance Travers
|Contributions||Naval Postgraduate School (U.S.)|
|The Physical Object|
|Pagination||1 v. :|
The multi-component evaporation model described herein considers medium to strong evaporation from a molten alloy in high vacuum (less than about Fluid dynamics within the vapour phase is ignored, so that only the effect of the expanding vapour plume upon the molten surface is taken into account in terms of the recoil pressure as well as the. The structuring of materials by ultrashort laser pulses demonstrated new morphologies in nanotexturing of the surface and volume by self-organized quasi-periodic structures—ripp .
the spatial period less than the incident laser wavelength was produced on various solids mainly by femtosecond lasers. The origin of HSFL is still under discussion. One mechanism proposed is the interaction of incident laser light with laser-produced surface . The choice of the right laser marking system is very important and strongly depends on the material to be processed. Read our knowledge base to learn a little more about laser types pairing with metals, plastics, glass, ceramics and other organic materials. We cover fiber lasers, CO2 lasers and UV lasers.
The coupling of the aluminum surface breakdown model with the computational fluid dynamics model developed for pulse laser supported propulsion system allows the simulation to start without the assumption of using a spark ignition heat source. Benchmark testing of the present model for laser Lightcraft model has shown the effectiveness of. A theoretical model for simulating the pulsed laser evaporation (PLE) process has been developed. This model considers an anisotropic three-dimensional expansion of the laser-generated plasma, initially at high temperature and pressure.
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This study is to assess the feasibility of using a laser's radiation to remove masses on the order of milligrams from a target surface and to form a vapor jet Skip to.
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The common physical process involved with these applications is the phase change that takes place during the heating process and it is complicated due to rapid interactions during high power heating pulse. As the beam power increases, surface evaporation dominates over the melting, in which case ablation governs the heating : Bekir Sami Yilbas, Shahzada Zaman Shuja.
Modelling of surface evaporation by laser ablation Article (PDF Available) in Applied Surface Science s –– February with 34 Reads How we measure 'reads'.
Using this assumption, we developed a mesoscopic model to see what happens to the surface of a target with grain boundaries, assuming a faster evaporation of these parts of the target. In this other model, the laser is incident from a direction that makes an angle of 45° with the vertical and the evaporation is assumed to be proportional, on each point, to the energy deposited per unit by: Modeling of plasma-controlled surface evaporation and condensation of Al target under pulsed laser irradiation in the nanosecond regime Applied Surface Science, Vol.
No. 19 A comparative study of the residual deformation of an automotive gear-case assembly due. The laser beam is deflected by galvano mirrors, which control the movement of the laser source over the surface of the powder bed. In each layer the laser beam follows a certain scanning path.
Upon absorption of the laser radiation, the powder particles heat up and after melting and solidifying, a solid structure is by: A volume heat source model is used for laser/powder interaction considering the material absorption coefficient.
A surface heat source is used to take into account the high laser energy absorption. The absorption of laser intensity at any point in a substrate material can be written in terms of Beer-Lambert’s law.
Irradiated energy is absorbed in the surface skin of the substrate material. Consideration of surface heat source minimizes this problem. Surface evaporation is the dominant mechanism during key-hole formation.
The framework combines a powder packing model based on Discrete Element Method and a 3-D transient heat and fluid flow simulation. The latter, i.e., the molten pool model, captures the interaction. Evaporation plays an important role in many technical applications including beam-based additive manufacturing processes, such as selective electron beam or selective laser melting (SEBM/SLM).
In this paper, we describe an evaporation model which we employ within the framework of a two-dimensional free surface lattice Boltzmann method. Pulsed laser deposition (PLD) uses high-energy laser pulses on the order of a few nanoseconds to ablate the target material.
The laser radiation is focused on the target surface, is absorbed, and rapidly evaporates the material, resulting in the ablation of atoms. The laser-induced vaporization process of a metallic surface is incorporated into a simple model which describes the phase transformation and the expansion of the metal vapour against the ambient air as a function of the laser intensity and material properties.
A special mode of laser action—the surface evaporation—has been experimentally studied on a large number of various materials. Characteristic features of the pure evaporation mode have been established, and some possible applications of the method for modifying surfaces and clean-cutting of biopolymers are indicated.
of a laser characterized by pulse duration and laser frequency interacts with a bulk material [1–3]. As a result, material is removed from the bulk depending on the absorption properties of the target materials.
The principle of PLD is shown in Figa. A laser pulse is focused onto the surface. InKlassen et al built a 2D evaporation model using lattice Boltzmann free surface method, solving the hydrodynamics as well as the thermodynamics of the molten material, taking into account the mass and energy losses due to evaporation and the recoil pressure acting on the melt pool in the selective electron beam melting process.
Magnetic Iron Oxide Nanopowders Produced by CO2 Laser Evaporation—‘In Situ’ Coating and Particle Embedding in a Ceramic Matrix material bound to the particles surface the proportion of. Films of polymers or biomaterials can be produced by an alternative technique, known as matrix-assisted pulsed laser evaporation (MAPLE).
In MAPLE, a guest molecule, e.g. a polymer, usually with a concentration of –2 wt% is dissolved and subsequently frozen into a light absorbing matrix. The evaporation behavior of band-gap materials (semiconductors and oxides) under laser illumination will be presented, taking into account the change of the surface optical properties of these.
The role of surface melting and vaporization during laser ablation of several metals is investigated, presenting results from a numerical model and experimental determinations.
The model takes into account the laser–solid interaction, melt-pool development and evaporation of the target material, followed by vaporization and plume expansion in 1 atm He background gas, plasma formation, and. The laser−induced vaporization of iron was studied using a quadrupole mass spectrometer detector.
Neutral atoms emitted by thermal processes at the surface were of interest; energetic ions produced by a plasma near the surface were not. Conventional mode laser pulses served as a heat source and the characteristics of the pulses of vaporized atoms reaching the mass spectrometer were.PLD.
PVD Products, Inc. is the premier manufacturer of Pulsed Laser Deposition Systems for R&D, pilot production, and full production capabilities for a variety of applications.
PVD Products has sold pulsed laser deposition systems to Fortune companies, national laboratories, start-up companies, and universities around the world.Pulsed-laser-induced size reduction of plasmonic nanoparticles in solution has long been known for a drawback resulting from polydispersed products.
Recently, by adjusting external pressure, laser intensity, and excitation wavelength, the nanosecond pulsed-laser excitations of colloidal gold nanoparticles in pressurized aqueous solution were found to enable tuning of the particle size and size.