Experimental Study of Chemo-Thermal Micromachining of Glass

2016 ◽  
Author(s):  
Arham Ali ◽  
Murali Sundaram
Keyword(s):  
Laser Beam ◽  
Thermal Ablation ◽  
Carbon Dioxide Laser ◽  
Aqueous Sodium Hydroxide ◽  
Chemical Degradation ◽  
Target Point ◽  
Micro Machining ◽  
Machined Surface ◽  
Laser Target ◽  
Naoh Solution

Chemo-thermal micro-machining is a hybrid method of micro fabrication achieved by integrating laser based thermal ablation and chemical etching. Material removal in this process involves focussing laser beam on a glass specimen submerged in aqueous sodium hydroxide (NaOH) solution that causes chemical degradation of glass along with thermal ablation at the laser target point. Though laser by itself is capable of machining numerous materials, it often causes micro fractures radially along the machined surface, especially when used on glass. In the proposed process, continuous waves of carbon dioxide laser (10.6 μm wavelength) with varying power are irradiated on the surface of borosilicate glass slide immersed in 1M NaOH solution for varying duration of exposure. This resulted in smaller hole diameter and better surface finish in the micro machining of glass, as compared to machining by laser beam alone.

scholarly journals Complex Micro Machining of an Injection Mold Surface for a Conductive Polymeric Composite Product

2019 ◽  
Vol 290 ◽  
pp. 03015
Author(s):  
Daniiel Serban ◽  
Constantin Gheorghe Opran
Keyword(s):  
Laser Beam ◽  
Polymeric Composite ◽  
Micro Milling ◽  
Surface Pattern ◽  
Injection Mold ◽  
Mold Surface ◽  
Micro Machining ◽  
Machined Surface ◽  
Research Activities ◽  
Composite Product

Hydrogen and fuel cell technologies were identified amongst new renewable energy technologies which contribute strongly to mitigating climate change. Important research activities were directed to the injection molded bipolar plates made by conductive polymeric composites. The mold surface quality can help obtaining better conductivity. In this paper are presented the experiments regarding complex micro-machining of the surfaces of an injection mold for a conductive polymeric composite product by micro-milling and for finishing and cleaning by laser beam micro-machining. The laser ablation consists in removing material from a solid surface by irradiating it with a laser beam, in successive layers in order to achieve complex geometries with accuracy of about micrometres. Injection moulding experiments evidenced the very good replication of the micro-machined surface pattern.

Carbon Dioxide Laser Beam Control for Corneal Surgery

1981 ◽  
Vol 12 (2) ◽  
pp. 117-122
Author(s):  
Richard H Keates ◽  
Leno S Pedrotti ◽  
Hugo Weichel ◽  
William H Possel
Keyword(s):  
Carbon Dioxide ◽  
Laser Beam ◽  
Carbon Dioxide Laser ◽  
Corneal Surgery ◽  
Beam Control

Effect of Laser Beam Diameter on Cut Edge of Steel Plates Obtained by Laser Machining

2013 ◽  
Vol 467 ◽  
pp. 227-232 ◽  
Author(s):  
Imed Miraoui ◽  
Mouna Zaied ◽  
Mohamed Boujelbene
Keyword(s):  
Laser Beam ◽  
Laser Cutting ◽  
Steel Plates ◽  
Beam Diameter ◽  
Power Laser ◽  
Laser Beam Diameter ◽  
Machined Surface ◽  
Cut Edge ◽  
Thermal Influence ◽  
Cut Surface

Laser cutting is a thermal process which is used contactless to separate materials. In the present study, high-power laser cutting of steel plates is considered and the thermal influence of laser cutting on the cut edges is examined. The microstructure and the microhardness of the cut edge are affected by the input laser cutting parameter: laser beam diameter. The aim of this work is to investigate the effect of the laser beam diameter on the microhardness beneath the cut surface of steel plates obtained by CO2 laser cutting. The cut surface was studied based on microhardness depth profiles beneath the machined surface. The results show that laser cutting has a thermal effect on the surface microstructure and on the microhardness beneath the cut section. Also the microhardness of the hardening zone depends on the laser beam diameter.

Robotic Navigated Laser Craniotomy for Depth Electrode Implantation in Epilepsy Surgery: A Cadaver Lab Study

2020 ◽  
Author(s):  
Karl Roessler ◽  
Fabian Winter ◽  
Tobias Wilken ◽  
Ekaterina Pataraia ◽  
Magdalena Mueller-Gerbl ◽  
...  
Keyword(s):  
Laser Beam ◽  
Epilepsy Surgery ◽  
Entry Point ◽  
Occipital Bone ◽  
Electrode Placement ◽  
Target Point ◽  
Twist Drill ◽  
Electrode Implantation ◽  
Depth Electrodes ◽  
Depth Electrode

Abstract Objective Depth electrode implantation for invasive monitoring in epilepsy surgery has become a standard procedure. We describe a new frameless stereotactic intervention using robot-guided laser beam for making precise bone channels for depth electrode placement. Methods A laboratory investigation on a head cadaver specimen was performed using a CT scan planning of depth electrodes in various positions. Precise bone channels were made by a navigated robot-driven laser beam (erbium:yttrium aluminum garnet [Er:YAG], 2.94-μm wavelength,) instead of twist drill holes. Entry point and target point precision was calculated using postimplantation CT scans and comparison to the preoperative trajectory plan. Results Frontal, parietal, and occipital bone channels for bolt implantation were made. The occipital bone channel had an angulation of more than 60 degrees to the surface. Bolts and depth electrodes were implanted solely guided by the trajectory given by the precise bone channels. The mean depth electrode length was 45.5 mm. Entry point deviation was 0.73 mm (±0.66 mm SD) and target point deviation was 2.0 mm (±0.64 mm SD). Bone channel laser time was ∼30 seconds per channel. Altogether, the implantation time was ∼10 to 15 minutes per electrode. Conclusion Navigated robot-assisted laser for making precise bone channels for depth electrode implantation in epilepsy surgery is a promising new, exact and straightforward implantation technique and may have many advantages over twist drill hole implantation.

A Preliminary Study of the Erosion Process in Micro-Machining of Glasses with a Low Pressure Slurry Jet

2008 ◽  
Vol 389-390 ◽  
pp. 375-380 ◽  
Author(s):  
Thai Nguyen ◽  
King Pang ◽  
Jun Wang
Keyword(s):  
Fluid Flow ◽  
High Surface ◽  
Low Pressure ◽  
Outer Diameter ◽  
Micro Machining ◽  
Erosion Process ◽  
Machined Surface ◽  
High Surface Quality ◽  
Accumulation Zone ◽  
Micro Hole

The erosion process in micro-machining of brittle glasses using a low pressure slurry jet is discussed. The process capability of the technique is assessed by examining the machined surface integrity in relation to fluid flow dynamics in micro-hole generations. The holes produced are characterised by a “W” shape in the cross section, while the surface morphology is distinguished by three zones associated with the fluid flow behaviour, i.e. a direct impact zone, a wavy zone and an accumulation zone. The surfaces appear to be smooth and without cracks, indicating a predominance of the ductile mode erosion process. With the increase of pressure, the erosion rates can be enhanced as a result of the expending of the accumulation zone while the outer diameter of the holes remains unchanged. This study shows that this technique can be used for micro-machining with high surface quality, and provides an essential understanding for further research in the avenue.

scholarly journals Laser surface texturing of tool steel: textured surfaces quality evaluation

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Peter Šugár ◽  
Jana Šugárová ◽  
Martin Frnčík
Keyword(s):  
Laser Beam ◽  
Tool Steel ◽  
Surface Texturing ◽  
Scanning Speed ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Fibre Laser ◽  
Textured Surfaces ◽  
Machined Surface ◽  
Ytterbium Fibre Laser

Abstract In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

Laser beam micro-machining under water immersion

2015 ◽  
Vol 83 (9-12) ◽  
pp. 1671-1681 ◽  
Author(s):  
Abdulrehman M. Alahmari ◽  
Naveed Ahmed ◽  
Saied Darwish
Keyword(s):  
Laser Beam ◽  
Water Immersion ◽  
Micro Machining

Laser-Induced Reactive Evaporation and Condensation

1988 ◽  
Vol 129 ◽  
Author(s):  
Gan-Moog Chow ◽  
Peter R. Struti
Keyword(s):  
Laser Beam ◽  
Carbon Dioxide Laser ◽  
Chemical Vapor ◽  
Analytical Techniques ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
Evaporation And Condensation ◽  
Reactive Evaporation ◽  
Silica Fibers ◽  
Reducing Environment

ABSTRACTA study of laser-induced reactive evaporation-condensation is presented. This considers coevaporation of metallic, and non-metallic species, by a cw carbon dioxide laser beam, within a reducing environment (98.5% hydrogen, 1.5% methane). A heated W filament placed in proximity of the laser beam-substrate interaction zone produces W for deposition via chemical vapor transport reactions. Composite thin films of a W matrix containing amorphous silica fibers have been deposited on nickel alloy substrates. These films form at rates of about 1 micron/sec, and are found to be adherent to the substrates. The diameter of the fibers is between 25 nm and 120 nm, depending on the interaction time. Various analytical techniques have been employed to characterize as-synthesized layers. Mechanisms of this process are discussed.

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