Nanosecond laser-metal ablation at different ambient conditions

Elsied, Ahmed M. M.; Dieffenbach, Payson; Diwakar, Prasoon K.; Hassanein, A.

doi:10.1016/j.sab.2018.02.012

Cited by 30 publications

(9 citation statements)

References 25 publications

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“…Surface structuring of aluminum with nanosecond laser pulses at a reduced pressure has been investigated in literature. [44] The ablation depth is significantly increased by a factor of two for the fluence of 10 J cm À 2 applied here at high vacuum and at 13 hPa in an inert gas atmosphere in comparison to 1013 hPa at air. [44] With the standard parameter set applied here at 20 hPa, a pronounced surface structure has been observed ( Figure 3h).…”

Section: Resultsmentioning

confidence: 76%

From Femtosecond to Nanosecond Laser Microstructuring of Conical Aluminum Surfaces by Reactive Gas Assisted Laser Ablation

Rauh

Wöbbeking

et al. 2020

ChemPhysChem

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A conical microstructure is one of the most versatile surface textures obtained by ultrashort laser micromachining. Besides an increased surface area, unique surface properties such as superhydrophilicity, increased absorptivity; and thermal emissivity can be tailored. On metals, usually ultrashort laser pulses in the femtosecond to low picosecond range are used to obtain these surface structures, whereas nanosecond laser pulses favor melting processes. Herein, we report on an investigation of reactive gas atmospheres such as oxygen, steam, and halogens during laser micromachining of aluminum with 6 ns laser pulses. At a reduced pressure of 20 hPa (air) with additional iodine vapor as reactive species, we found a perfectly microconical structured surface to be formed with nanosecond laser pulses. The resulting surface structures were proven to be free of residual halogens. The application of nanosecond instead of femtosecond laser pulses for the surface structuring process allows to apply significantly less complex laser sources.

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Section: Resultsmentioning

confidence: 76%

From Femtosecond to Nanosecond Laser Microstructuring of Conical Aluminum Surfaces by Reactive Gas Assisted Laser Ablation

Rauh

Wöbbeking

et al. 2020

ChemPhysChem

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“…When defocus was increased from 30 mm to 50 mm, the porosity was reduced from 16.2% to 11.2%. On the one hand, the reduction of defocus leads to the formation of strong Gaussian heat flow, which leads to the ablation of part of the coating and the formation of ablation pits [ 25 ]. The formation of ablation pits can be confirmed by SEM images, as shown in Figure 3 .…”

Section: Resultsmentioning

confidence: 99%

Tuning the Surface Characteristics and Mechanical Properties of Y2O3 Coatings on a Graphene Matrix via Laser Micro Melting

Líu

Chen

et al. 2022

Materials

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The effects of laser parameters on the microstructure and properties of plasma-sprayed yttrium oxide coating on the graphite matrix were investigated. Tensile strength, porosity, roughness, and scratch meter tests were carried out to evaluate the critical load and mechanical properties of the coating after spraying and laser micro-melting. When the porosity and surface roughness of the coating are minimum, the critical load of the coating is 7.85 N higher than that of the spraying surface. After laser micromelting, the crystal phase of Y2O3 coating surface does not change, the crystallinity is improved, and fine grain strengthening occurs. When the laser power density is 75 W/mm2, the scanning speed is 30 mm/s, and the defocusing distance is 40 mm, the film base bonding performance and wear resistance of the material reach the maximum value. The failure of Y2O3 coating is mainly due to the degradation of mechanical properties such as film base bonding strength, surface porosity, and surface roughness, which leads to the local collapse of the material. The coating after laser micro-melting only presents particle disintegration at the end of the scratch area.

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“…Depending on the pulse duration and other process variables, different types of laser-matter interaction dominate the material removal. In case of short laser pulses (microsecond to nanosecond range), the heated target material is melted, followed by its vaporization if the liquid-vapor critical temperature is exceeded (Elsied, 2018). Subsequently, the metal vapor can be ionized by the remaining laser pulse, resulting in a plasma plume.…”

Section: Introductionmentioning

confidence: 99%

Novel strategy for quality improvement of up-facing inclined surfaces of LPBF parts by combining laser-induced shock waves and in situ laser remelting

Metelková

Ordnung

Kinds

et al. 2021

Journal of Materials Processing Technology

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Nanosecond laser-metal ablation at different ambient conditions

Cited by 30 publications

References 25 publications

From Femtosecond to Nanosecond Laser Microstructuring of Conical Aluminum Surfaces by Reactive Gas Assisted Laser Ablation

From Femtosecond to Nanosecond Laser Microstructuring of Conical Aluminum Surfaces by Reactive Gas Assisted Laser Ablation

Tuning the Surface Characteristics and Mechanical Properties of Y2O3 Coatings on a Graphene Matrix via Laser Micro Melting

Novel strategy for quality improvement of up-facing inclined surfaces of LPBF parts by combining laser-induced shock waves and in situ laser remelting

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