Influence of pulse repetition rate on morphology and material removal rate of ultrafast laser ablated metallic surfaces

Sedao, Xxx; Lenci, Matthieu; Rudenko, Anton; Faure, Nicolas; Pascale-Hamri, Alina; Colombier, Jean‐Philippe; Mauclair, Cyril

doi:10.1016/j.optlaseng.2018.12.009

Cited by 46 publications

(17 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A strong dependency of Ra on MRR was observed under the given condition that the higher the MRR, the greater the Ra. The dependency of Ra on MRR observed in this part is in good agreement with the conclusion proposed by Sedao et al [30]. It is easy to understand that when adopting high-energy to irradiate the target, the interaction between laser and target becomes more intensive, thus causing the surface smoothness to worsen.…”

Section: Influence Of Pulse Energy On Cvd Diamond Coating Ablationsupporting

confidence: 91%

Study on Femtosecond Laser Processing Characteristics of Nano-Crystalline CVD Diamond Coating

Wei

Han

et al. 2019

Applied Sciences

View full text Add to dashboard Cite

Ultra-short pulse laser interaction with diamond materials has attracted extensive interest in micro- and nano-machining, especially for the fabrication of micro tools, because of the straightforward method and high precision. Thanks to the development of chemical vapor deposition (CVD) technology, high-quality CVD diamonds are employed in more varieties of tools as performance-enhancing coatings. The purpose of the experiments reported here was to explore the machinability of CVD diamond coating under the irradiation of femtosecond (fs) pulsed laser. The factor-control approach was adopted to investigate the influence of scanning speed, single pulse energy and repetition rate on the surface quality and carbon phase transition of CVD diamond coating. The material removal rate and surface roughness were evaluated. The interaction mechanism of scanning speed, single pulse energy, and repetition rate were discussed, and the fs laser ablation threshold of CVD diamond coating was calculated. It was demonstrated that two ablation mechanisms (weak and intensive) were in existence as evidenced by the distinct surface morphologies induced under different processing conditions. A strong dependence on the variation of scanning speed and pulse energy is identified in the examination of surface roughness and removal rate. Lorentzian–Gaussian deconvolution of Raman spectra illustrates that fs laser irradiation yields a strong modification effect on the coating and release the compressive stress in it. Furthermore, a newly defined parameter referring to the fs laser energies applied to unit volume was introduced to depict the degree of ablation and the Taguchi method was used to figure out the significance of different parameters. The ablation threshold of CVD diamond coating at the effective pulses of 90 is calculated to be 0.138 J/cm2.

show abstract

Section: Influence Of Pulse Energy On Cvd Diamond Coating Ablationsupporting

confidence: 91%

Study on Femtosecond Laser Processing Characteristics of Nano-Crystalline CVD Diamond Coating

Wei

Han

et al. 2019

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Their periodicity (Λ LIPSS ) usually ranges from hundreds of nanometers up to some micrometers and it is used to classify them into the general categories as low-spatial frequency LIPSS (LSFL), when Λ LSFL ∼ λ, and high-spatial frequency LIPSS (HSFL) for Λ HSFL λ, where λ is the laser wavelength [2]. Suitable manufacturing strategies have been identified, including the optimization of laser processing parameters (laser fluence, wavelength, repetition rate, angle of incidence, number of pulses per spot area) [3][4][5][6][7][8], material properties (optical, thermal and mechanical properties) [9][10][11], and the ambient medium in which they are generated (air, vacuum, reactive atmospheres) [12][13][14][15] for applications in optics, medicine, fluid transport and tribology among others [1].…”

Section: Introductionmentioning

confidence: 99%

The Role of the Laser-Induced Oxide Layer in the Formation of Laser-Induced Periodic Surface Structures

et al. 2020

View full text Add to dashboard Cite

Laser-induced periodic surface structures (LIPSS) are often present when processing solid targets with linearly polarized ultrashort laser pulses. The different irradiation parameters to produce them on metals, semiconductors and dielectrics have been studied extensively, identifying suitable regimes to tailor its properties for applications in the fields of optics, medicine, fluidics and tribology, to name a few. One important parameter widely present when exposing the samples to the high intensities provided by these laser pulses in air environment, that generally is not considered, is the formation of a superficial laser-induced oxide layer. In this paper, we fabricate LIPSS on a layer of the oxidation prone hard-coating material chromium nitride in order to investigate the impact of the laser-induced oxide layer on its formation. A variety of complementary surface analytic techniques were employed, revealing morphological, chemical and structural characteristics of well-known high-spatial frequency LIPSS (HSFL) together with a new type of low-spatial frequency LIPSS (LSFL) with an anomalous orientation parallel to the laser polarization. Based on this input, we performed finite-difference time-domain calculations considering a layered system resembling the geometry of the HSFL along with the presence of a laser-induced oxide layer. The simulations support a scenario that the new type of LSFL is formed at the interface between the laser-induced oxide layer and the non-altered material underneath. These findings suggest that LSFL structures parallel to the polarization can be easily induced in materials that are prone to oxidation.

show abstract

“…As mentioned in Section 2, the AS can be achieved on aluminum but not stainless steel; a typical comparison can be viewed in Figure 2a,b, with the cross-sections of these two materials treated at a fluence of 18 J/cm 2 and a 250-kHz repetition rate. The laser processing is shown to be strongly material-dependent in the ~100 kHz repetition rate regime [16,17], resulting either in material accumulation on the side of the ablation groove in the aluminum case, or to significant roughness development in the case of stainless steel. The laser plasma hydrodynamics and ablation particles shielding may be taken account of in these observations.…”

Section: Resultsmentioning

confidence: 99%

“…Thermal effects might be at the origin of further ablation crater degradation, as the diffusivity of stainless steel D=ki/ρCi≈5×10−6 m2/normals (ki is the lattice thermal conductivity, Ci is the lattice heat capacity, and ρ is the lattice density), which is six times lower than the diffusivity of aluminum D≈3×10−5 m2/normals. For aluminum, the material accumulates only at the corners of the laser-processed area, leaving the central part inside the ablation crater free from micro-debris [16], and facilitating the proposed technique of additive surface structuring.…”

Section: Resultsmentioning

confidence: 99%

Additive and Substractive Surface Structuring by Femtosecond Laser Induced Material Ejection and Redistribution

et al. 2018

View full text Add to dashboard Cite

A novel additive surface structuring process is devised, which involves localized, intense femtosecond laser irradiation. The irradiation induces a phase explosion of the material being irradiated, and a subsequent ejection of the ablative species that are used as additive building blocks. The ejected species are deposited and accumulated in the vicinity of the ablation site. This redistribution of the material can be repeated and controlled by raster scanning and multiple pulse irradiation. The deposition and accumulation cause the formation of µm-scale three-dimensional structures that surpass the initial surface level. The above-mentioned ablation, deposition, and accumulation all together constitute the proposed additive surface structuring process. In addition, the geometry of the three-dimensional structures can be further modified, if desirable, by a subsequent substractive ablation process. Microstructural analysis reveals a quasi-seamless conjugation between the surface where the structures grow and the structures additively grown by this method, and hence indicates the mechanic robustness of these structures. As a proof of concept, a sub-mm sized re-entrant structure and pillars are fabricated on aluminum substrate by this method. Single units as well as arrayed structures with arbitrary pattern lattice geometry are easily implemented in this additive surface structuring scheme. Engineered surface with desired functionalities can be realized by using this means, i.e., a surface with arrayed pillars being rendered with superhydrophobicity.

show abstract

Influence of pulse repetition rate on morphology and material removal rate of ultrafast laser ablated metallic surfaces

Cited by 46 publications

References 35 publications

Study on Femtosecond Laser Processing Characteristics of Nano-Crystalline CVD Diamond Coating

Study on Femtosecond Laser Processing Characteristics of Nano-Crystalline CVD Diamond Coating

The Role of the Laser-Induced Oxide Layer in the Formation of Laser-Induced Periodic Surface Structures

Additive and Substractive Surface Structuring by Femtosecond Laser Induced Material Ejection and Redistribution

Contact Info

Product

Resources

About