Fabrication of high-aspect-ratio grooves with high surface quality by using femtosecond laser

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ru Zhang ◽  
Chuanzhen Huang ◽  
Jun Wang ◽  
Hongtao Zhu ◽  
Hanlian Liu
Keyword(s):  
Laser Ablation ◽  
Aspect Ratio ◽  
Femtosecond Laser ◽  
Process Parameters ◽  
Laser Fluence ◽  
High Aspect Ratio ◽  
High Surface ◽  
Content Type ◽  
High Surface Quality ◽  
Fs Laser

Purpose The purpose of this study is to fabricate high-aspect-ratio grooves with high surface quality by femtosecond laser (FS) to improve the machinability of silicon carbide (SiC) and optimize the process parameters in micromechanical applications. Design/methodology/approach Four contrast experiments are reported to characterize the FS laser grooving process for SiC with polarization direction, crystal orientation, multi-pass scanning and z layer feed, respectively. The effects of different experimental conditions on the groove characteristics, material removal rate (MRR), aspect ratio, heat affected zone (HAZ) and surface roughness Ra are analyzed. Findings The influence of increasing laser fluence and multi-scanning pass on the groove depth is greater than on the groove width. The MRR, aspect ratio, HAZ and Ra increased with the increase of laser fluence and multi-scanning pass. The direction of laser polarization affects the direction of hot electron injection but has little effect on the material characteristics. FS laser ablation is an isotropic process and there is no obvious change in different crystal orientations. The z-layer feed can significantly increase the groove width and depth and reduce HAZ and Ra. The maximum aspect ratio of 82.67% was fabricated. Originality/value The results contribute to the understanding of the removal mechanism and reduce the friction of the microfluidic device and improve the flowability in the FS laser ablation of SiC. This paper provides suggestions for the selection of suitable process parameters and provides a wider possibility for the application of micro-texture on SiC.

The Interactions of Microhole Sidewall With Plasma induced by Femtosecond Laser Ablation in High-Aspect-Ratio Microholes

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Benxin Wu ◽  
Sha Tao ◽  
Shuting Lei
Keyword(s):  
Laser Ablation ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Material Removal ◽  
Laser Energy ◽  
Spatial Scales ◽  
Femtosecond Laser Ablation ◽  
Plasma Energy ◽  
Direct Laser ◽  
Fs Laser

High-aspect-ratio microholes have many important applications, but their drilling is very challenging. Femtosecond (fs) laser ablation provides a potential solution, but involves many complicated physical processes that have not been well understood, which have hindered its practical application. One of these is that the plasma induced by laser ablation at the hole bottom will transfer some of its energy to the hole sidewall as it expands in the microhole. The plasma–sidewall interaction has been rarely studied in literature, and it is still not clear if or not the energy transferred from the plasma is sufficient to cause significant material removal from the sidewall. Direct time-resolved observations are extremely difficult due to the small temporal/spatial scales and the spatial constraint inside the hole, while the sidewall characterization after laser ablation is difficult to distinguish between the possible material removal due to plasma energy transfer and that due to direct laser energy absorption by the sidewall. In this paper, a physics-based model is applied as the investigation tool to study the plasma–sidewall interaction in fs laser drilling of high-aspect-ratio microholes. It has been found that for the studied conditions the energy transferred from the plasma is not sufficient to cause significant material removal from the sidewall through any thermally induced phase change process.

Non-diffraction-length Bessel-beam femtosecond laser drilling of high-aspect-ratio microholes in PMMA

Optik ◽  
2021 ◽  
Vol 229 ◽  
pp. 166295
Author(s):  
Haoran Wang ◽  
Fan Zhang ◽  
Kaiwen Ding ◽  
Ji'an Duan
Keyword(s):  
Aspect Ratio ◽  
Femtosecond Laser ◽  
High Aspect Ratio ◽  
Bessel Beam ◽  
Laser Drilling

scholarly journals Investigation on the Surface Quality Obtained during Trochoidal Milling of 6082 Aluminum Alloy

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 75
Author(s):  
Nikolaos E. Karkalos ◽  
Panagiotis Karmiris-Obratański ◽  
Szymon Kurpiel ◽  
Krzysztof Zagórski ◽  
Angelos P. Markopoulos
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Manufacturing Industry ◽  
High Surface ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Surface Quality ◽  
Trochoidal Milling

Surface quality has always been an important goal in the manufacturing industry, as it is not only related to the achievement of appropriate geometrical tolerances but also plays an important role in the tribological behavior of the surface as well as its resistance to fatigue and corrosion. Usually, in order to achieve sufficiently high surface quality, process parameters, such as cutting speed and feed, are regulated or special types of cutting tools are used. In the present work, an alternative strategy for slot milling is adopted, namely, trochoidal milling, which employs a more complex trajectory for the cutting tool. Two series of experiments were initially conducted with traditional and trochoidal milling under various feed and cutting speed values in order to evaluate the capabilities of trochoidal milling. The findings showed a clear difference between the two milling strategies, and it was shown that the trochoidal milling strategy is able to provide superior surface quality when the appropriate process parameters are also chosen. Finally, the effect of the depth of cut, coolant and trochoidal stepover on surface roughness during trochoidal milling was also investigated, and it was found that lower depths of cut, the use of coolant and low values of trochoidal stepover can lead to a considerable decrease in surface roughness.

Fabrication and Characterization of Si Nano-Columns by Femtosecond Laser

2012 ◽  
Vol 16 ◽  
pp. 15-20 ◽  
Author(s):  
Omid Tayefeh Ghalehbeygi ◽  
Vural Kara ◽  
Levent Trabzon ◽  
Selcuk Akturk ◽  
Huseyin Kizil
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Laser Beam ◽  
Chemical Etching ◽  
Silicon Surface ◽  
Laser Pulses ◽  
Laser Beam Profile ◽  
Fs Laser ◽  
Fabrication And Characterization

We fabricated Si Nano-columns by a femtosecond laser with various wavelengths and process parameters, whilst the specimen was submerged in water. The experiments were carried out by three types of wavelengths i.e. 1030 nm, 515nm, 343nm, with 500 fs laser pulses. The scales of these spikes are much smaller than micro spikes that are constructed by laser irradiation of silicon surface in vacuum or gases like SF6, Cl2. The Si nano-columns of 300 nm or less in width were characterized by SEM measurements. The formation of these Si Nano-columns that were revealed by SEM observation, indicates chemical etching with laser ablation occurred when surface exposed by laser beam. We observed 200 nm spikes height at the center of laser beam profile and the ones uniform in height at lateral incident area.

High aspect ratio, high-quality microholes in PMMA: a comparison between femtosecond laser drilling in air and in vacuum

2014 ◽  
Vol 119 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Bo Xia ◽  
Lan Jiang ◽  
Xiaowei Li ◽  
Xueliang Yan ◽  
Weiwei Zhao ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Femtosecond Laser ◽  
High Aspect Ratio ◽  
Laser Drilling ◽  
High Quality

A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

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