Download or read book Investigation of Laser Assisted Modification of Silicon Nitride Ceramic for Enhanced Surface Integrity written by Li Sun and published by . This book was released on 2000 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Numerical Investigation of Laser Assisted Milling of Silicon Nitride Ceramics written by Budong Yang and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study experimentally and numerically investigates laser assisted milling (LAMill) of silicon nitride ceramics. Experiments are conducted to study the machinability of Si3N4 under LAMill. The effects of temperature on cutting forces, tool wear, surface integrity, edge chipping and material removal mechanisms are investigated. It is shown that when temperature increases, cutting force and tool wear are significantly decreased, surface integrity is improved, chip size is increased and material removal demonstrates more plastic characteristics. The mechanisms of edge chipping at elevated temperature are investigated theoretically and experimentally. When temperature is above the softening point and below the brittle/ductile transition temperature, the mechanism is mainly through softening. When temperature is above the brittle/ductile transition temperature, toughening mechanism contributes significantly to the reduced edge chipping. The coupled effect of softening and toughening mechanisms shows that temperature range between 1200 to 1400°C has the most significant effect to reduce edge chipping. Distinct element method (DEM) is applied to simulate the micro-mechanical behavior of Si3N4. First, quantitative relationships between particle level parameters and macro-properties of the bonded particle specimens are obtained, which builds a foundation for simulation of Si3N4. Then, extensive DEM simulations are conducted to model the material removal of machining Si3N4. The simulation results demonstrate that DEM can reproduce the conceptual material removal model summarized from experimental observations, including the initiation and propagation of cracks, chip formation process and material removal mechanisms. It is shown that material removal is mainly realized by propagation of lateral cracks in machining of silicon nitride. At the elevated temperature under laser assisted machining, lateral cracks are easier to propagate to form larger machined chips, there are fewer and smaller median cracks therefore less surface/subsurface damage, and crushing-type material removal is reduced. The material removal at elevated temperature demonstrates more plastic characteristics. The numerical results agree very well with experimental observations. It shows that DEM is a promising method to model the micro-mechanical process of machining Si3N4.
Download or read book SME Technical Paper written by Society of Manufacturing Engineers and published by . This book was released on 2005 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of Laser Assisted Milling of Silicon Nitride Ceramic written by Shuting Lei PhD and published by . This book was released on 2000 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Study of Laser assisted Machining on Silicon Nitride Hollow Ceramic Cylinder Using Finite Element Method written by Mohammed Mudassar Hussain Ansari and published by . This book was released on 2018 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most commonly used technique for machining ceramics is diamond grinding. It accounts for up to 75% of the manufacturing costs resulting in high cost of the product. An LED bulb offering increased brightness, energy saving and long life by using ceramic integration to LED chips costs around 10 times to a normal LED bulb. Complex geometries used in electronics, medical surgeries, aerospace, and automobile industries require the use of costly molds or powder metallurgy for low batch production which does not justify the cost. Laser Assisted Machining (LAM) is a process that uses a laser to locally heat the surface of a component (made of ceramic), making it more ductile and machinable using conventional machine tools. Recent studies have shown that LAM gives improved material removal rate and surface finishing, and reduces the cost of machining, i.e. around 50% reduction in the manufacturing costs. Physical experiments require the use of advanced instruments and specialized tools making it a difficult and time-consuming process. It is necessary to have a predicting thermal study to help design more efficient physical experiments. In this study, Finite Element Analysis (FEA) has been used to analyze the thermal distribution of a workpiece under rotating and translating moving heat source. In LAM, there are many variables that greatly affect the temperature, such as laser size, laser power, translational velocity, etc. Extensive research has been performed on solid cylinders however many new applications such as thermocouple protection tube, cylinder lining, blasting nozzles, bone fusion in surgeries, etc., require application of hollow cylinders. Therefore, this work intends to perform a thermal study on a ceramic tube when a laser beam moving on its outer surface. As the generated heat due to the machining is insignificant compared to the heat created by the laser heat source, this study doesn't consider the mechanical removal of the material. The ceramic chosen for this study is Silicon Nitride as it is widely used due to its excellent wide range of properties making it suitable for all industries. The FEA method and assumptions that will be used on this research has been verified with previous experimental and numerical research on a solid cylinder.
Download or read book Understanding Laser Superheating in Lam of Silicon Nitride written by SriHarsha Panuganti and published by LAP Lambert Academic Publishing. This book was released on 2010-10 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of advanced ceramics like silicon nitride can be found in many high-tech engineering applications in various fields such as aerospace, defense and automotive. In order for these ceramics to become more prevalent in industry, development of better and cheaper methods of manufacturing ceramic parts is essential. Laser-assisted machining (LAM) of ceramics is one tool that can enable this growth while maintaining reasonable costs of manufacturing parts in small quantities. This book contains the research conducted on LAM of ceramics that helps develop a complete understanding of various laser and machining parameters in LAM of ceramics, and makes some important conclusions that help in continuing the research for a fully developed LAM of ceramics system. A fiber-coupled diode laser - which has the highest wall plug efficiencies and offers more flexibility, cheaper equipment costs, and smaller footprint than others - has been used.
Download or read book Laser assisted Surface Engineering of Silicon Nitride to Minimize the Surface Defects Generated During Grinding Operation written by Palaniappan Chinnakaruppan and published by . This book was released on 2000 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stress Mapping Studies on Silicon Nitride Ceramic Using a Laser Raman Microprobe written by Steven Lawrence Ernst and published by . This book was released on 1992 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Assisted Waterjet Microgrooving of Silicon Nitride Ceramics with near Damage Free written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Material Processing written by William M. Steen and published by Springer Science & Business Media. This book was released on 2013-04-18 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: New chapters on bending and cleaning reflect the changes in the field since the last edition, completing the range of practical knowledge about the processes possible with lasers already familiar to users of this well-known text. Professor Steen's lively presentation is supported by a number of original cartoons by Patrick Wright and Noel Ford, which will bring a smile to your face and ease the learning process. From the reviews: "...well organized, and the text is very practical...The engineering community will find this book informative and useful." (OPTICS AND PHOTONICS NEWS, July/August 2005)
Download or read book Thermal Machining Processes written by Society of Manufacturing Engineers and published by . This book was released on 1979 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1993 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ceramic Processing and Sintering written by Mohamed N. Rahaman and published by CRC Press. This book was released on 2017-12-19 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the field's premiere source, this reference is extensively revised and expanded to collect hard-to-find applications, equations, derivations, and examples illustrating the latest developments in ceramic processing technology. This book is concerned primarily with the processing of polycrystalline ceramics and focuses on the widespread fabrication of ceramics by the firing of consolidated powders forms. A brief treatment of sol-gel processing is also included. Ceramic Processing and Sintering, Second Edition provides clear and intensive discussions on colloidal and sol-gel processing, sintering of ceramics, and kinetic processes in materials. From powder synthesis and consolidation to sintering and densification behavior, this latest edition emphasizes the impact of each processing procedure on ceramic properties. The second edition also contains new and extended discussions on colloid stability, polymer growth and gelation, additives in ceramic forming, diffusion and defect strucutre, normal and abnormal grain growth, microwave sintering, Rayleigh instability effects, and Ostwald ripening. Illustrating the interconnectedness between the various steps in the overall fabrication route, Ceramic Processing and Sintering, Second Edition approaches the fundamental issues of each process and show how they are applied to the practical fabrication of ceramics.
Download or read book Semiconductor Laser Engineering Reliability and Diagnostics written by Peter W. Epperlein and published by John Wiley & Sons. This book was released on 2013-01-25 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference book provides a fully integrated novel approach to the development of high-power, single-transverse mode, edge-emitting diode lasers by addressing the complementary topics of device engineering, reliability engineering and device diagnostics in the same book, and thus closes the gap in the current book literature. Diode laser fundamentals are discussed, followed by an elaborate discussion of problem-oriented design guidelines and techniques, and by a systematic treatment of the origins of laser degradation and a thorough exploration of the engineering means to enhance the optical strength of the laser. Stability criteria of critical laser characteristics and key laser robustness factors are discussed along with clear design considerations in the context of reliability engineering approaches and models, and typical programs for reliability tests and laser product qualifications. Novel, advanced diagnostic methods are reviewed to discuss, for the first time in detail in book literature, performance- and reliability-impacting factors such as temperature, stress and material instabilities. Further key features include: practical design guidelines that consider also reliability related effects, key laser robustness factors, basic laser fabrication and packaging issues; detailed discussion of diagnostic investigations of diode lasers, the fundamentals of the applied approaches and techniques, many of them pioneered by the author to be fit-for-purpose and novel in the application; systematic insight into laser degradation modes such as catastrophic optical damage, and a wide range of technologies to increase the optical strength of diode lasers; coverage of basic concepts and techniques of laser reliability engineering with details on a standard commercial high power laser reliability test program. Semiconductor Laser Engineering, Reliability and Diagnostics reflects the extensive expertise of the author in the diode laser field both as a top scientific researcher as well as a key developer of high-power highly reliable devices. With invaluable practical advice, this new reference book is suited to practising researchers in diode laser technologies, and to postgraduate engineering students.
Download or read book Machining of Titanium Alloys written by J. Paulo Davim and published by Springer. This book was released on 2014-07-05 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a collection of examples illustrating the resent research advances in the machining of titanium alloys. These materials have excellent strength and fracture toughness as well as low density and good corrosion resistance; however, machinability is still poor due to their low thermal conductivity and high chemical reactivity with cutting tool materials. This book presents solutions to enhance machinability in titanium-based alloys and serves as a useful reference to professionals and researchers in aerospace, automotive and biomedical fields.
Download or read book Engineering Ceramics written by M. Bengisu and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 629 pages. Available in PDF, EPUB and Kindle. Book excerpt: A handy reference for technicians who want to understand the nature, properties and applications, of engineering ceramics. The book meets the needs of those working in the ceramics industry, as well as of technicians and engineers involved in the application of ceramic materials.
