High-Speed Fabrication of Microchannels Using Line-Based Laser Induced Plasma Micromachining

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Ishan Saxena ◽  
Rajiv Malhotra ◽  
Kornel Ehmann ◽  
Jian Cao
Keyword(s):  
Process Parameters ◽  
Optical System ◽  
Pulse Energy ◽  
High Speed ◽  
Microfluidic Devices ◽  
Pulse Frequency ◽  
Free Form ◽  
Laser Induced Plasma ◽  
Circular Spot ◽  
Energy Pulse

Microtexturing of surfaces has various applications that often involve texturing over large (macroscale) areas with high precision and resolution. This demands scalability and speed of texturing while retaining feature sizes of the order of a few microns. Microchannels are a versatile microfeature, which are often used in microfluidic devices and can be arrayed or joined to form patterns and free-form geometries. We present a technique to fabricate microchannels on surfaces with high-speed and by using a multimaterial process, namely, laser induced plasma micromachining (LIPMM). The process has the potential to machine metals, ceramics, polymers, and other transparent, brittle, and hard-to-machine materials. The presented technique uses an optical system to modify the laser spot into the shape of a line, to fabricate microchannels directly without scanning as in the case of a regular circular spot. The process schematics are shown, and micromachining experiments on polished aluminum are discussed. Moreover, it is shown that the depth and width of the channels may be varied by changing process parameters like the pulse energy, pulse frequency, and number of exposures.

scholarly journals Numerical Response Surfaces of Volume of Ablation and Retropulsion Amplitude by Settings of Ho:YAG Laser Lithotripter

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Jian J. Zhang ◽  
Jonathan Rutherford ◽  
Metasebya Solomon ◽  
Brian Cheng ◽  
Jason R. Xuan ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Pulse Width ◽  
High Speed ◽  
Operation Time ◽  
Laser Lithotripsy ◽  
Pulse Number ◽  
Response Surfaces ◽  
Ho:Yag Laser ◽  
Energy Pulse ◽  
Best Fit

Objectives.Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate, the optimal laser settings for URS (ureteroscopic lithotripsy) for less operation time remain unclear. The aim of this study was to look for quantitative responses of calculus ablation and retropulsion by performing operator-independent experiments to determine the best fit versus the pulse energy, pulse width, and the number of pulses.Methods.A lab-built Ho:YAG laser was used as the laser pulse source, with a pulse energy from 0.2 J up to 3.0 J and a pulse width of 150 μs up to 1000 μs. The retropulsion was monitored using a high-speed camera, and the laser-induced craters were evaluated with a 3-D digital microscope. The best fit to the experimental data is done by a design of experiment software.Results.The numerical formulas for the response surfaces of ablation speed and retropulsion amplitude are generated.Conclusions.The longer the pulse, the less the ablation or retropulsion, while the longer pulse makes the ablation decrease faster than the retropulsion. The best quadratic fit of the response surface for the volume of ablation varied nonlinearly with pulse duration and pulse number.

scholarly journals Effect of Process Parameters on the Quality of Laser-Cut Stainless Steel Thin Plates

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1224
Author(s):  
Irene Buj-Corral ◽  
Lluís Costa-Herrero ◽  
Alejandro Domínguez-Fernández
Keyword(s):  
Process Parameters ◽  
Laser Cutting ◽  
Pulse Width ◽  
High Speed ◽  
Linear Models ◽  
Dimensional Accuracy ◽  
Pulse Frequency ◽  
Thin Plates ◽  
Dimensional Error ◽  
Frequency Pulse

At present, laser cutting is currently employed to cut metallic plates, due to their good finish and dimensional quality, as well as because of the flexibility of the process to obtain different shapes. In the present paper, surface roughness, dimensional accuracy, and burr thickness of thin plates of 0.8 mm are studied as functions of different process parameters: pulse frequency, pulse width, and speed. Eight different experiments were performed according to a full 23 factorial design, with two replicates each. Square specimens of 10 mm × 10 mm were cut. Arithmetical mean roughness Ra was measured with a contact roughness meter, and the dimensions and burr thickness with a micrometer. Ra values ranged between 1.89 and 3.86 µm, dimensional error values between 0.22 and 0.93%, and burr thickness between 2 and 34 µm. Regression analysis was performed, and linear models were obtained for each response. Results showed that roughness depends mainly on frequency, on the interaction of frequency and pulse width and on pulse width. The dimensional error depends on pulse width, frequency, and the interaction between pulse width and speed. Burr thickness is influenced by frequency, pulse width, and the interaction between frequency and speed. Multi-objective optimization showed that, in order to simultaneously minimize the three responses, it is recommended to use high frequency (80 Hz), high pulse width (0.6 ms), and high speed (140 mm/min). The present study will help to select appropriate laser cutting conditions in thin plates, in order to favor good surface finish and dimensional accuracy, as well as low burr thickness.

Relevant Geometric Features in the Percussion Laser Microdrilling of Different Alloys

Volume 3 ◽  
2004 ◽  
Author(s):  
Paola Bassani ◽  
Edoardo Capello ◽  
Enrico Gallus ◽  
Elisabetta Gariboldi ◽  
Luca Longoni ◽  
...  
Keyword(s):  
Process Parameters ◽  
Pulse Energy ◽  
Pulse Length ◽  
Pulse Frequency ◽  
Laser Drilling ◽  
Laser Source ◽  
Drilling Process ◽  
Geometric Features ◽  
Hole Shape ◽  
Laser Sources

In the recent decade the laser drilling process has continually attracted new interests and has found increasing applications in the industry. Nowadays the most common industrial laser sources for laser drilling are the solid state ones with pulse length of the order of milliseconds, even if nanosecond and femtosecond pulse sources can also be found in industrial applications. The latter, short and ultrashort laser sources, are very promising since they are expected to generate the hole directly by vaporisation, leaving the hole surfaces free of molten and resolified layer, as well as very low amount of spatter. This paper reports an experimental study on microhole laser machining and on influence of some process parameters on the hole shape. The laser source used in the study was a pulsed, diode pumped, Q-switched Nd:YAG laser. The materials investigated were four different alloys (AISI 304 stainless steel, cp titanium, CuZn35 brass and IN718 alloy), provided as 0.5 mm thick commercial sheets. Since an experimental approach has been here preferred, the performed experimental plan has been designed by the analysis of variance technique. The influence of material type, as well as laser process parameters, like pulse frequency and pulse energy, have been investigated. Relevant geometrical features, like top and bottom hole diameter, taper angle, top and bottom aspect ratio, have been measured and analysed. Moreover, the geometric features of the top spatter as well as the metallurgical characteristics of heat affected zone has been investigated. The results have shown that pulse energy strongly affects both geometric and metallurgical hole features. On the other hand, pulse frequency does not seem to influence the hole shape in all material. The presence of spatter and metallographic analysis confirmed the production of molten layers in all material mainly around the hole entrance.

scholarly journals Investigation on the Electrochemical Micromachining of Micro Through-Hole by Using Micro Helical Electrode

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 118 ◽  
Author(s):  
Baohui Liu ◽  
Hang Zou ◽  
Haixuan Luo ◽  
Xiaoming Yue
Keyword(s):  
Process Parameters ◽  
High Speed ◽  
Pulse Frequency ◽  
Machining Process ◽  
Electrochemical Micromachining ◽  
Good Effect ◽  
Machining Accuracy ◽  
High Speed Rotation ◽  
Helical Electrode ◽  
Through Hole

The instability of machining process caused by the difficulty of the electrolyte refresh in electrochemical micromachining (EMM) of micro through-hole has been an unsolved problem. Thus, this paper investigates the electrochemical micromachining of micro through-hole by using a micro helical electrode combining with the jetting electrolyte. With the help of high-speed rotation of micro helical electrode and its spiral shape, the internal electrolyte can be stirred while the external jetting electrolyte can flow into the hole along the spiral groove to refresh the electrolyte effectively, thereby, improving the machining stability of EMM. Firstly, the influence of the process parameters on the fabrication of micro through-hole in the EMM by using micro helical electrode without non-conductive mask is investigated. Based on the optimization of the process parameters, a micro through-hole with an inlet dimension of 121.6 μm and an outlet dimension of 114.9 μm is obtained successfully. Furthermore, this paper also tries to use the micro helical electrode coated with the non-conductive mask to decrease the bad influence of the stray corrosion attack. It is found that the non-conductive mask coated on the surface of micro helical electrode can improve the machining accuracy significantly under the condition of low pulse frequency (≤1 KHz). However, its good effect on preventing the stray corrosion decreases along with the increase of the pulse frequency.

scholarly journals Analysis and optimization of laser drilling process during machining of AISI 303 material using grey relational analysis approach

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
V. Chengal Reddy ◽  
Thota Keerthi ◽  
T. Nishkala ◽  
G. Maruthi Prasad Yadav
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Pulse Frequency ◽  
Laser Drilling ◽  
Simultaneous Optimization ◽  
Fibre Laser ◽  
Drilling Process ◽  
Relational Analysis ◽  
Grey Relational

AbstractSurface roughness and heat-affected zone (HAZ) are the important features which influence the performance of the laser-drilled products. Understanding the influence of laser process parameters on these responses and identifying the cutting conditions for simultaneous optimization of these responses are a primary requirement in order to improve the laser drilling performance. Nevertheless, no such contribution has been made in the literature during laser drilling of AISI 303 material. The aim of the present work is to optimize the surface roughness (Ra) and HAZ in fibre laser drilling of AISI 303 material using Taguchi-based grey relational analysis (GRA). From the GRA methodology, the recommended optimum combination of process parameters is flushing pressure at 30 Pa, laser power at 2000 W and pulse frequency at 1500 Hz for simultaneous optimization of Ra and HAZ, respectively. From analysis of variance, the pulse frequency is identified as the most influenced process parameters on laser drilling process performance.

scholarly journals Influence of process parameters on thermal cycle and intermetallic compounds formation in high speed laser weld-brazing of aluminium-steel angle joints

2018 ◽  
Vol 26 ◽  
pp. 690-699 ◽  
Author(s):  
Guillaume Filliard ◽  
Mohamed El Mansori ◽  
Mathieu De Metz-Noblat ◽  
Christian Bremont ◽  
Anthony Reullier ◽  
...  
Keyword(s):  
Intermetallic Compounds ◽  
Process Parameters ◽  
Thermal Cycle ◽  
High Speed ◽  
Laser Weld ◽  
Influence Of Process Parameters ◽  
Steel Angle

Influence of Process Parameters and Geometry of the Spraying Nozzle on the Properties of Titanium Deposits Obtained in Wire Arc Spraying

2015 ◽  
Vol 1111 ◽  
pp. 211-216
Author(s):  
Bogdan Florin Toma ◽  
Iulian Ionita ◽  
Diana Antonia Gheorghiu ◽  
Lucian Eva ◽  
Costică Bejinariu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Process Parameters ◽  
High Speed ◽  
Electrical Current ◽  
Electric Arc ◽  
Arc Spraying ◽  
Oxide Content ◽  
Spray Parameters ◽  
Influence Of Process Parameters ◽  
Wire Arc Spraying

Influence of the process parameters and geometry of the spraying nozzle on the properties of titanium deposits obtained in wire arc spraying. Wire arc spraying is a process in which through minor modifications of the spray parameters, they can have a major impact on the coatings properties. In this paper there is presented a study on the influence of process parameters and fluid dynamics of the atomization gas on the properties of titanium deposits (14T - 99.9% Ti). For this there were used three different frontal spraying nozzles, having different geometries, and were varied the spraying gas pressure and the electrical current on three levels. There were evaluated the particles velocity, coating density, chemical composition and characteristic interface between deposition and substrate. Obviously, the high speed of the atomization gas determinate the improving of all properties, but in the same time increased the oxide content in the layer. However, the oxidation can be drastically reduced if the melting and atomization of the wire droplets is produced at the point of formation of the electric arc, and the spraying jet is designed to constrain the electric arc. The assessment of deposits adherence allowed the observation of process parameters that contribute to its improvement.

scholarly journals High-Speed Epitaxy Using Supersonic Molecular Jets

1990 ◽  
Vol 201 ◽  
Author(s):  
Djula Eres
Keyword(s):  
Thin Film ◽  
Growth Rates ◽  
High Speed ◽  
Film Growth ◽  
Thin Film Growth ◽  
Free Form ◽  
Electrical Measurements ◽  
Growth Technique ◽  
Pulsed Jets ◽  
Gaseous Source

AbstractThis paper discusses the use of supersonic jets of gaseous source molecules in thin film growth. Molecular jets in free form with no skimmers or collimators in the nozzle-substrate path were used in the investigation of basic film growth processes and in practical film growth applications. The Ge growth rates were found to depend linearly on the digermane jet intensity. Furthermore, the film thickness distributions showed excellent agreement with the distribution of digermane molecules in the jet. High epitaxial Ge growth rates were achieved on GaAs (100) substrates by utilizing high-intensity pulsed jets. The practical advantages and limitations of this film growth technique are evaluated, based on the results of microstructural and electrical measurements of heteroepitaxial Ge films on GaAs (100) substrates.

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