The Experts below are selected from a list of 3387 Experts worldwide ranked by ideXlab platform
Vinod Yadava - One of the best experts on this subject based on the ideXlab platform.
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Laser Beam Machining—A review
International Journal of Machine Tools & Manufacture, 2008Co-Authors: Avanish Kumar Dubey, Vinod YadavaAbstract:Abstract Laser Beam Machining (LBM) is one of the most widely used thermal energy based non-contact type advance Machining process which can be applied for almost whole range of materials. Laser Beam is focussed for melting and vaporizing the unwanted material from the parent material. It is suitable for geometrically complex profile cutting and making miniature holes in sheetmetal. Among various type of Lasers used for Machining in industries, CO2 and Nd:YAG Lasers are most established. In recent years, researchers have explored a number of ways to improve the LBM process performance by analysing the different factors that affect the quality characteristics. The experimental and theoretical studies show that process performance can be improved considerably by proper selection of Laser parameters, material parameters and operating parameters. This paper reviews the research work carried out so far in the area of LBM of different materials and shapes. It reports about the experimental and theoretical studies of LBM to improve the process performance. Several modelling and optimization techniques for the determination of optimum Laser Beam cutting condition have been critically examined. The last part of this paper discusses the LBM developments and outlines the trend for future research.
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Laser Beam Machining a review
International Journal of Machine Tools & Manufacture, 2008Co-Authors: Avanish Kumar Dubey, Vinod YadavaAbstract:Abstract Laser Beam Machining (LBM) is one of the most widely used thermal energy based non-contact type advance Machining process which can be applied for almost whole range of materials. Laser Beam is focussed for melting and vaporizing the unwanted material from the parent material. It is suitable for geometrically complex profile cutting and making miniature holes in sheetmetal. Among various type of Lasers used for Machining in industries, CO2 and Nd:YAG Lasers are most established. In recent years, researchers have explored a number of ways to improve the LBM process performance by analysing the different factors that affect the quality characteristics. The experimental and theoretical studies show that process performance can be improved considerably by proper selection of Laser parameters, material parameters and operating parameters. This paper reviews the research work carried out so far in the area of LBM of different materials and shapes. It reports about the experimental and theoretical studies of LBM to improve the process performance. Several modelling and optimization techniques for the determination of optimum Laser Beam cutting condition have been critically examined. The last part of this paper discusses the LBM developments and outlines the trend for future research.
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experimental study of nd yag Laser Beam Machining an overview
Journal of Materials Processing Technology, 2008Co-Authors: Avanish Kr. Dubey, Vinod YadavaAbstract:Abstract Since last four decades Laser Beams are being used in various manufacturing processes. CO2 and Nd:YAG Lasers are most widely used in Machining of engineering materials. In recent years the researchers have explored the number of ways to improve the quality of cutting, drilling and microMachining of different materials (metals, alloys, ceramics and composites) using Nd:YAG Lasers. This paper reviews the experimental investigations carried out to study the effect of various factors/process parameters on the performance of Nd:YAG Laser Beam Machining. The importance of different design of experiments (DOE) methodologies used by various investigators for achieving the optimum value of different quality characteristics has also been discussed in paper.
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Experimental study of Nd:YAG Laser Beam Machining—An overview
Journal of Materials Processing Technology, 2007Co-Authors: Avanish Kr. Dubey, Vinod YadavaAbstract:Abstract Since last four decades Laser Beams are being used in various manufacturing processes. CO2 and Nd:YAG Lasers are most widely used in Machining of engineering materials. In recent years the researchers have explored the number of ways to improve the quality of cutting, drilling and microMachining of different materials (metals, alloys, ceramics and composites) using Nd:YAG Lasers. This paper reviews the experimental investigations carried out to study the effect of various factors/process parameters on the performance of Nd:YAG Laser Beam Machining. The importance of different design of experiments (DOE) methodologies used by various investigators for achieving the optimum value of different quality characteristics has also been discussed in paper.
Bert Lauwers - One of the best experts on this subject based on the ideXlab platform.
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prediction of local sintering in Laser Beam Machining of green y tzp ceramic
Cirp Annals-manufacturing Technology, 2020Co-Authors: Francois Ducobu, Edouard Rivierelorphevre, Anthonin Demarbaix, Bert LauwersAbstract:Abstract Laser Beam Machining of Y-TZP engineering ceramic material is carried out in green stage to increase the material removal rate. The generation of hot spots may cause local sintering of the ceramic material leading to a decrease of the mechanical properties of the final sintered component. This paper presents the implementation of alternative Laser Beam paths to reduce the hot spots occurrence. A thermal finite element model has been developed to support the experimental analysis as well as the prediction of local sintering. The experimental validation of the newly developed toolpath strategies confirmed the reduction of local sintering.
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Shaping of engineering ceramics by electro, chemical and physical processes
CIRP Annals - Manufacturing Technology, 2016Co-Authors: Eleonora Ferraris, Jean‐pierre Kruth, Yuebin Guo, David L Dl Bourell, Jozef Vleugels, Bert LauwersAbstract:Thanks to the favourable combination of outstanding mechanical, thermal and chemical properties, engineering ceramics find widespread applications in the modern industry. Nevertheless, their extensive use is still hindered by the implementation of a labour and cost intensive manufacturing chain. Electro, chemical and physical shaping techniques, like electrical discharge Machining, additive manufacturing and Laser Beam Machining, have recently been investigated to offer efficient alternatives. This work provides a comprehensive overview of the current technological trends and main perspectives on electro, chemical and physical shaping of engineering ceramics with a focus on experimental works. The literature data trace back to the 80s.
Chong Nam Chu - One of the best experts on this subject based on the ideXlab platform.
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Long-Lasting Superhydrophilic and Instant Hydrophobic Micropatterned Stainless Steel Surface by Thermally-Induced Surface Layers
International Journal of Precision Engineering and Manufacturing-Green Technology, 2020Co-Authors: Doogon Kim, Janggil Kim, Taekyum Kim, Chong Nam ChuAbstract:We present a novel method of realizing instant hydrophobic and long-lasting superhydrophilic states on stainless steel (SS) surfaces by micropatterning and thermally-induced surface layers (TISL). Heat treatment of SS surfaces in the air for 6 h yields hydrophobic TISLs at 140 °C and hydrophilic TISLs at 300 °C. The result of X-ray photoelectron spectroscopy reveals the correlation of chromium depletion with the hydrophilic TISLs, as well as surface oxidation with the hydrophobic TISLs. We fabricated superhydrophilic SS surfaces holding the wettability over 40 days, and hydrophobic SS surfaces realized in an hour-scale period via the fabrication process comprised of Laser Beam Machining, electrochemical etching, and heat treatment in serial.
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Fabrication of various shaped tungsten micro pin arrays using micro carving technology
Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology, 2016Co-Authors: Jong Wuk Park, Janggil Kim, Haan Kim, Chong Nam ChuAbstract:Abstract This paper describes a state of the art in micro-structuring high strength metallic materials. Tungsten micro pin arrays in a variety of shapes are fabricated using a micro carving technology, which combines Laser Beam Machining and electrochemical etching processes. First, micro pin arrays were rough-shaped by Laser Beam Machining along a pre-defined scanning path to control their structural shape. The micro pin array in this stage had near-conical shape of structures due to a recast layer. Next, the genuine shape of micro pin arrays came to the surface via electrochemical etching process to elute the recast layer into electrolyte. Quantitative elemental analysis with energy-dispersive spectroscopy (EDS) was implemented to characterize the formation of recast layer on a micro pin structure after the Laser Beam Machining process. The atomic percentage EDS maps indicated that higher percentage of tungsten was detected on the core micro pin structure, whereas relatively large percentage of oxygen was found on the recast layer (O 9%, W 91% in the center area, and O 53%, W 47% in the outer area).
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Fabrication of an oil–water separation copper filter using Laser Beam Machining
Journal of Micromechanics and Microengineering, 2016Co-Authors: Chong Nam ChuAbstract:In this study, oil and water are successfully separated using a copper filter that is fabricated using only Laser Beam Machining. Even though copper is hydrophilic and recast copper material, which inevitably results during Laser Beam Machining, is super-hydrophilic, the filter can prevent the water from penetrating and allow oil to flow based on surface tension of the liquids at the hole exit. For practical uses of the filter, both the pressure differences at which the filter is able to retain its ability to separate and the oil penetration rate of the filter are revealed. The fabrication process is simple and time-saving, and the filter has high durability because of lack of surface coating or surface chemical modification.
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Fabrication of a micro-hole array on metal foil by nanosecond pulsed Laser Beam Machining using a cover plate
Journal of Micromechanics and Microengineering, 2015Co-Authors: Won Lee, Janggil Kim, Won Young Jee, Chong Nam ChuAbstract:A novel Laser Beam Machining (LBM) method is proposed to achieve higher precision and better quality beyond the limits of a commercialized nanosecond pulsed Laser system. The use of a cover plate is found to be effective for the precision Machining of a thin metal foil at micro scale. For verifying the capability of cover plate Laser Beam Machining (c-LBM) technology, a 30 by 30 array of micro-holes was fabricated on 8 µm-thick stainless steel 304 (STS) foil. As a result, thermal deformation and cracks were significantly reduced in comparison with the results using LBM without a cover plate. The standard deviation of the inscribed and circumscribed circle of the holes with a diameter of 12 µm was reduced to 33% and 81%, respectively and the average roundness improved by 77%. Moreover, the smallest diameter obtainable by c-LBM in the given equipment was found to be 6.9 µm, which was 60% less than the minimum size hole by LBM without a cover plate.
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Fabrication of micro-pin array with high aspect ratio on stainless steel using nanosecond Laser Beam Machining
Applied Surface Science, 2012Co-Authors: Won Lee, Hong Shik Shin, Chong Nam ChuAbstract:Abstract In this paper, a micro-pin array with a high aspect ratio was fabricated on AISI 304 using Laser Beam ablation for attachment to a vertical wall. In recent times, there has been research in various fields, including robotics and bio-MEMS, regarding attachment to vertical walls, and micro-pin arrays may offer the best solution. For vertical wall attachment, the micro-pin should have a high aspect ratio, long length, and sharp tip. The recast layer could be piled due to the chromium oxide with high surface tension and viscosity of chromium oxide, and it composed the micro-pins with high aspect ratio. X-ray photoelectron spectroscopy (XPS) was used to identify the characteristics of the piled recast layer. The Machining characteristics for a high aspect ratio micro-pin array were investigated according to Laser Beam Machining parameters. In addition, experiments for attaching force relative to the surface roughness of the subject plane were carried out.
Gaasuren Davaasuren - One of the best experts on this subject based on the ideXlab platform.
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fabrication of transparent superhydrophobic surface on thermoplastic polymer using Laser Beam Machining and compression molding for mass production
Cirp Annals-manufacturing Technology, 2014Co-Authors: Dooman Chun, Gaasuren DavaasurenAbstract:Abstract Superhydrophobic surface has unique characteristics such as water repellence and self-cleaning, and especially transparent superhydrophobic surfaces have wide applications for self-cleaned solar cells, protective optics, and building windows. In this research, Laser Beam Machining with ultra-violet (UV) nanosecond pulse Laser was utilized for fabrication of the surface textured metal mold, and the replica of thermoplastic polymer was fabricated using compression molding for mass production. Water droplet contact angle and transmittance were measured to confirm the superhydrophobicity and transparency. By controlling pattern size, the transparent superhydrophobic surface was fabricated, and the effect of pattern size was studied with wetting states.
Avanish Kr. Dubey - One of the best experts on this subject based on the ideXlab platform.
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experimental study of nd yag Laser Beam Machining an overview
Journal of Materials Processing Technology, 2008Co-Authors: Avanish Kr. Dubey, Vinod YadavaAbstract:Abstract Since last four decades Laser Beams are being used in various manufacturing processes. CO2 and Nd:YAG Lasers are most widely used in Machining of engineering materials. In recent years the researchers have explored the number of ways to improve the quality of cutting, drilling and microMachining of different materials (metals, alloys, ceramics and composites) using Nd:YAG Lasers. This paper reviews the experimental investigations carried out to study the effect of various factors/process parameters on the performance of Nd:YAG Laser Beam Machining. The importance of different design of experiments (DOE) methodologies used by various investigators for achieving the optimum value of different quality characteristics has also been discussed in paper.
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Experimental study of Nd:YAG Laser Beam Machining—An overview
Journal of Materials Processing Technology, 2007Co-Authors: Avanish Kr. Dubey, Vinod YadavaAbstract:Abstract Since last four decades Laser Beams are being used in various manufacturing processes. CO2 and Nd:YAG Lasers are most widely used in Machining of engineering materials. In recent years the researchers have explored the number of ways to improve the quality of cutting, drilling and microMachining of different materials (metals, alloys, ceramics and composites) using Nd:YAG Lasers. This paper reviews the experimental investigations carried out to study the effect of various factors/process parameters on the performance of Nd:YAG Laser Beam Machining. The importance of different design of experiments (DOE) methodologies used by various investigators for achieving the optimum value of different quality characteristics has also been discussed in paper.
