Download or read book Study of Surface Melting of Metals and the Effects in Pulsed Laser Micro Polishing written by Chao Ma and published by . This book was released on 2012 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Study of Pulsed Laser Micro Polishing written by and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fundamental study of pulsed laser micro polishing (PLμP) was conducted as a method for reducing surface roughness of micro/meso-scale metallic parts. Although PLμP was shown to be an effective process at these scales, the knowledge of the process physics lacked thoroughness. The goal of this work, therefore was to improve upon the existing knowledge of PLμP, with focus on developing physics based models, understanding the effects of various process parameters and developing strategies for selection of process parameters and laser scan trajectories. In PLμP, a small area on a surface is irradiated with laser pulses to melt roughness features. The molten features are smoothed out by surface tension and viscous forces. Two polishing regimes for PLμP, namely thermocapillary regime and capillary regime, were defined based on whether the temperature gradient of surface tension driven thermocapillary flows are dominant or negligible. Dominant thermocapillary flows, in the thermocapillary regime, result in significant smoothening of both low and high spatial frequency features, but introduce residual low-amplitude high spatial frequency features. In the capillary regime, thermocapillary flows are negligible and the molten features oscillate as stationary capillary waves that damp out due to the viscosity of the molten metal. The capillary regime is only effective at smoothening higher spatial frequency features. A physics based surface finish prediction model was developed and validated for the capillary regime. The fundamental understanding of the two polishing regimes lead to the development of a two-pass multi-regime PLμP method that takes advantage of both the polishing regimes. In this method, the first pass, in the thermocapillary regime, results in significant reduction of the surface roughness. The second pass, in the capillary regime, removes the residual process features introduced in the first pass. Finally, an artificial potential fields based method was proposed to generate laser scan trajectories for PLμP that can overcome the limitations of a zigzag trajectory. In this method, artificial attractive fields are assigned based on surface condition and repulsive fields assigned to regions where polishing is not desired. The generated trajectories are irregular, smooth and adapt to the changing surface condition of surface being polished.

Download or read book Surface Roughness Prediction and Effects of Initial Surface Textures for Pulsed Laser Micro Polishing of Metal Alloys written by Qinghua Wang and published by . This book was released on 2015 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Surface Treatment of Metals written by C.W. Draper and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Study Institute, San Miniato, Italy, September 2-13, 1985

Download or read book Al Si Alloys written by Francisco C. Robles Hernandez and published by Springer. This book was released on 2017-07-02 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details aluminum alloys with special focus on the aluminum silicon (Al‐Si) systems – that are the most abundant alloys second only to steel. The authors include a description of the manufacturing principles, thermodynamics, and other main characteristics of Al‐Si alloys. Principles of processing, testing, and in particular applications in the Automotive, Aeronautical and Aerospace fields are addressed.

Download or read book A Numerical and Experimental Study of Pulsed Laser Polishing of Metals at the Meso micro Scale written by Tyler L. Perry and published by . This book was released on 2009 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1982 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publications written by United States. National Bureau of Standards and published by . This book was released on 1980 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Modification and Alloying written by J.M. Poate and published by Springer Science & Business Media. This book was released on 2013-11-21 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an outcome of the NATO institute on surface modification which was held in Trevi, 1981. Surface modification and alloying by ion, electron or laser beams is proving to be one of the most burgeoning areas of materials science. The field covers such diverse areas as integrated circuit processing to fabricating wear and corrosion resistant surfaces on mechanical components. The common scientific questions of interest are the microstructures by the different energy deposition techniques. and associated physical properties produced The chapters constitute a critical review of the various subjects covered at Trevi. Each chapter author took responsibility for the overall review and used contributions from the many papers presented at the meeting; each participant gave a presentation. The contributors are listed at the start of each chapter. We took this approach to get some order in a large and diverse field. We are indebted to all the contributors, in particular the chapter authors for working the many papers into coherent packages; to Jim Mayer for hosting a workshop of chapter authors at Cornell and to Ian Bubb who did a sterling job in working over some of the manuscripts. Our special thanks are due to the text processing center at Bell Labs who took on the task of assembling the book. In particular Karen Lieb and Beverly Heravi typed the whole manuscript and had the entire book phototypeset using the Bell Laboratories UNIXTM system.

Download or read book Additive Manufacturing written by Juan Pou and published by Elsevier. This book was released on 2021-05-21 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive Manufacturing explains the background theory, working principles, technical specifications, and latest developments in a wide range of additive manufacturing techniques. Topics addressed include treatments of manufactured parts, surface characterization, and the effects of surface treatments on mechanical behavior. Many different perspectives are covered, including design aspects, technologies, materials and sustainability. Experts in both academia and industry contribute to this comprehensive guide, combining theoretical developments with practical improvements from R&D. This unique guide allows readers to compare the characteristics of different processes, understand how they work, and provide parameters for their effective implementation. This book is part of a four-volume set entitled Handbooks in Advanced Manufacturing. Other titles in the set include Advanced Machining and Finishing, Advanced Welding and Deformation, and Sustainable Manufacturing Processes. Provides theory, operational parameters, and latest developments in 20 different additive manufacturing processes Includes contributions from experts in industry and academia with a wide range of disciplinary backgrounds, providing a comprehensive survey of this diverse and influential subject Includes case studies of innovative additive manufacturing practices from industry

Download or read book Fundamental Study on Laser Interaction with Metal Matrix Nanocomposites written by Chao Ma and published by . This book was released on 2015 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study is to significantly advance the fundamental understanding of laser interaction with metal matrix nanocomposites (MMNCs) and to overcome the fundamental limits of current laser processing techniques by tuning heat transfer and fluid flow using nanoparticles. Ultrasonic assisted electrocodeposition was used to prepare MMNCs samples (e.g., Ni/Al2O3) for laser melting experiments. Microstructural study showed that uniform distribution and dispersion of nanoparticles were achieved. The effects of nanoparticles on the optical and thermophysical properties were studied experimentally and theoretically. The viscosity was greatly increased while the surface tension and thermal conductivity were slightly decreased by nanoparticles. The knowledge of these properties would provide valuable insights to fundamentally understand how laser interacts with MMNCs. To understand the influences of the changes in the thermophysical properties on the laser melting process, an analytical model was developed and used to predict the melt pool flows. The study indicated that thermocapillary flows were tremendously suppressed because of the increased viscosity. As an emerging application of laser melting, laser polishing could significantly benefit from this phenomenon because it would result in improved surface finish. Systematic laser polishing experiments at various laser pulse energies were conducted on Ni/Al2O3 and pure Ni. The normalized surface roughness was decreased by nearly a factor of two with the help of Al2O3 nanoparticles. The proposed methodology of controlling heat transfer and fluid flow by nanoparticles successfully overcame the fundamental limit in laser polishing. Microstructural study on the laser processed region also revealed interesting features. By the addition of the Al2O3 nanoparticles, the laser melted depth was increased while the heat affected zone was, surprisingly, largely reduced. It would be of great significance if this phenomenon can be utilized to other manufacturing processes such as laser welding and laser additive manufacturing where a minimal HAZ is highly desired. In summary, the work in this dissertation has significantly advanced the fundamental knowledge on how laser interacts with MMNCs. Under the guidance of the fundamental knowledge, some existing limits of laser melting have been successfully overcome, which will broaden its processing capability and application space.

Download or read book Post Processing Techniques for Metal Based Additive Manufacturing written by Hao Wang and published by CRC Press. This book was released on 2023-09-04 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book shares insights on post-processing techniques adopted to achieve precision-grade surfaces of additive manufactured metals including material characterization techniques and the identified material properties. Post-processes are discussed from support structure removal and heat treatment to the material removal processes including hybrid manufacturing. Also discussed are case studies on unique applications of additive manufactured metals as an exemplary of the considerations taken during post-processing design and selection. Addresses the critical aspect of post-processing for metal additive manufacturing Provides systematic introduction of pertinent materials Demonstrates post-process technique selection with the enhanced understanding of material characterization methods and evaluation Includes in-depth validation of ultra-precision machining technology Reviews precision fabrication of industrial-grade titanium alloys, steels, and aluminium alloys, with additive manufacturing technology The book is aimed at researchers, professionals, and graduate students in advanced manufacturing, additive manufacturing, machining, and materials processing.

Download or read book 4M 2006 Second International Conference on Multi Material Micro Manufacture written by Stefan Dimov and published by Elsevier. This book was released on 2006-09-15 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: 4M 2006 - Second International Conference on Multi-Material Micro Manufacture covers the latest state-of-the-art research results from leading European researchers in advanced micro technologies for batch processing of metals, polymers, and ceramics, and the development of new production platforms for micro systems-based products. These contributions are from leading authors at a platform endorsed and funded by the European Union R&D community, as well as leading universities, and independent research and corporate organizations. Contains authoritative papers that reflect the latest developments in micro technologies and micro systems-based products

Download or read book Publications of the National Bureau of Standards Catalog written by United States. National Bureau of Standards and published by . This book was released on 1979 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Publications of the National Bureau of Standards 1978 Catalog written by United States. National Bureau of Standards and published by . This book was released on 1979 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applicability of a Picosecond Laser for Micro polishing of Metallic Surfaces written by Abdullah Mohammad Khalid Hafiz and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An increasing number of recent technological advancements is linked to the adoptions of ultra-short pulsed picosecond (ps) lasers in various material processing applications. The superior capability of this laser is associated with precise control of laser-material interaction resulted from extremely short interaction time. In this context, the present study explored the applicability of a ps laser in laser micro-polishing (LæP) of Inconel 718 (IN718) and AISI H13 tool steel. The melting regime-a mandatory phase for LæP-was determined experimentally by the variation of focal offset to attain desired laser fluence. The finite element formulation of heat transfer equation and its solution were also estimated in order to develop a theoretical foundation for the heat transfer mechanism in ps laser-material interaction. The initial one dimensional (1D) line polishing experiments were performed on ground IN718 and H13 tool steel samples with the parameters related to the melting regime of corresponding material. The knowledge of this initial experimental investigation was later utilized to prepare the surface topography by micromilling with a specific step-over and scallop height, followed by LæP experiments with the same set of aforementioned parameters. The performance of LæP was evaluated by average surface roughness (Ra) spectrum at different spatial wavelength intervals along the laser path trajectory. Additionally, statistical measures, such as power spectral density (PSD) function, transfer function (TF) and material ratio (MR) curve were analyzed in order to establish the process parameters resulting the best possible surface quality. From the analysis of this experimental investigation, surface quality improvement up to 78.5% and 75.7% were reported for the spatial wavelength interval of 50-100 æm for IN718 and H13 tool steel respectively. As a next step, two dimensional (2D) areal polishing of micromilled IN718 and H13 tool steel were performed, where surface quality improvement up to 69.32% and 77.28% were observed for the spatial wavelength interval of 50-100 æm for IN718 and H13 tool steel, respectively. Overall, ps LæP was found to be an effective way of enhancing desired surface quality as demonstrated by the reduction of surface asperities as well as their volumetric uniform redistributions.