Download or read book Development of a Spectroscopic Process Monitoring System for Multi laser Metal Powder Bed Fusion Additive Manufacturing written by Andrew Przyjemski and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-laser powder bed fusion additive manufacturing (PBFAM) is the answer to the growing demand for faster and larger part production. However, timely and cost-effective part qualification remains a critical hurdle due to the formation of subsurface flaws during the PBFAM process. Spectroscopic inspired monitoring systems has been shown as a promising technique to detect the presence of flaws using the spectral emissions during the laser welding process. However, the use of spectroscopic sensing in PBFAM systems is complicated by the introduction of multiple simultaneously operating lasers. The work presented in this thesis covers the development of an optical emission spectroscopy inspired, photodiode-based system designed for use in multi-laser PBFAM. The objective of this system is to assist in the real time detection of flaws that form during the PBFAM process.

Download or read book Development of an Additive Manufacturing Re coater Monitoring System for Powder Bed Fusion Systems written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the world of research and development, the ability to rapidly manufacture a prototype or part has become a significant part of the manufacturing process. This requirement has given rise to some unique manufacturing technologies. One of these technologies is Additive Manufacturing (AM), or also more commonly known as 3D printing. There are several AM technologies available and can be divided into three major AM categories namely: liquid, powder and solid sheet based. For this research study, the primary focus will be on powder-based technologies. Powder-based technologies make use of materials in powder form and use different fusion techniques to fuse the powder particles together. All the powder bed fusion technologies consist of the same basic components, namely a powder chamber, build chamber, re-coater and a powder fusion system. For each layer of the build, the re-coater applies a new layer of powder from the powder chamber to the build chamber, and then the specific type of powder fusion system will fuse the powder particles together. This process will then be repeated until the entire build has completed.

Download or read book Materials Development and Processing for Biomedical Applications written by Savaş Kaya and published by CRC Press. This book was released on 2022-04-05 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Development and Processing for Biomedical Applications focuses on various methods of manufacturing, surface modifications, and advancements in biomedical applications. This book examines in detail about five different aspects including, materials properties, development, processing, surface coatings, future perspectives and fabrication of advanced biomedical devices. Fundamental aspects are discussed to better understand the processing of various biomedical materials such as metals, ceramics, polymers, composites, etc. A wide range of surface treatments are covered in this book that will be helpful for the readers to understand the importance of surface treatments and their future perspectives. Additional Features Include: Examines various properties of biomedical materials at the beginning in several chapters which will enrich the fundamental knowledge of the readers. Discusses advancements in various fields of biomedical applications. Provides a glimpse of characterization techniques for the evaluation of material properties. Addresses biocompatibility, biocorrosion, and tribocorrosion. This book explores new and novel strategies for the development of materials and their biomedical applications. It will serve as a comprehensive resource for both students and scientists working in materials and biomedical sciences.

Download or read book Process Design in Laser Powder Bed Fusion written by Seyyed Behzad Hosseini Rankouhi and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) has brought about a new age of design and manufacturing where traditional constraints are eased or in some areas completely lifted. The integration of topology optimization (TO) and AM has the potential to revolutionize modern design and manufacturing. However, few instances of manufactured optimized designs are documented, and even fewer examples of experimentally tested designs are available. The lack of validation combined with the influence of AM process on material properties leaves a gap in our understanding of process-microstructure-property relationships that is essential for developing holistic design optimization frameworks. In the first chapter of this thesis, a functional design was topologically optimized and fabricated using both directed energy deposition (DED) and selective laser melting (SLM), also known as powder bed fusion (PBF), methods. It is shown that TO results are sensitive to the AM method, post-processing conditions, and differences in mechanical properties. Thus, a TO for AM framework can be best optimized with the incorporation of microstructure features to account for localized microstructural variations in fabricated components. One of the main challenges facing SLM process is finding suitable process parameters to achieve maximum density (pore-free) parts. In chapter two, two newly discovered dimensionless numbers are presented that correlate process parameters to a part's density allowing for an initial estimation of suitable process parameters without the need for extensive modeling or experimentation. The dimensionless numbers allow for identification of process parameters that will result in a maximum density regime in the as-built part. Finally, a universal scaling law is introduced that can aid in quantitative prediction of process parameters that result in the highest as-built density. Multi-material additive manufacturing using PBF has the potential to revolutionize the manufacturing landscape by producing parts with improved thermophysical properties and enhanced functionality. However, the complex nature of the process requires a case-by-case approach to multi-material characterization. The aim of chapter three is to provide firsthand knowledge of 316L stainless steel (316L) and Hastelloy X (HX) multi-material processing via PBF. Results showed that using the proper process parameters for each individual material led to formation of a compositional gradient at the interface that stretched for 240 ℗æm (10-12 layers) with no evidence of cracking or porosity. Finally, it was concluded that the "naturally" formed interface created a compositional gradient which was defect free due to similar values of coefficient of thermal expansion, energy density, dimensionless number Î 2, and different Marangoni numbers of the materials. The aim of chapter four is to propose a methodology for rapidly predicting suitable process parameters for additive manufacturing of multi-material parts with a compositional gradient by using machine learning and 316L-Cu bi-metal system. Specifically, an algorithm based on a multivariate Gaussian process is developed to predict part density and surface roughness for a given set of laser power, velocity, and hatch spacing values. After the model is validated using leave-one-out cross validation method, process parameter maps are generated for 316L-Cu parts manufactured using selective laser melting with premixed powder at mass fractions of 0.25, 0.50, and 0.75. It is shown that process parameters are a nonlinear function of gradient composition and neither process parameters of 316L or Cu are suitable for the graded region of a 316L-Cu multi-material part. Generated process maps provide a firsthand knowledge of process-property relationships for regions of compositional grading in 316L-Cu parts.

Download or read book Additive Manufacturing Technologies written by Ian Gibson and published by Springer. This book was released on 2014-11-26 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers in detail the various aspects of joining materials to form parts. A conceptual overview of rapid prototyping and layered manufacturing is given, beginning with the fundamentals so that readers can get up to speed quickly. Unusual and emerging applications such as micro-scale manufacturing, medical applications, aerospace, and rapid manufacturing are also discussed. This book provides a comprehensive overview of rapid prototyping technologies as well as support technologies such as software systems, vacuum casting, investment casting, plating, infiltration and other systems. This book also: Reflects recent developments and trends and adheres to the ASTM, SI, and other standards Includes chapters on automotive technology, aerospace technology and low-cost AM technologies Provides a broad range of technical questions to ensure comprehensive understanding of the concepts covered

Download or read book MONITORING OF METAL ADDITIVE MANUFACTURING VIA OPTICAL EMISSIONS SENSING written by Christopher B. Stutzman and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-based, metal additive manufacturing (AM) is a growing manufacturing field where complex components are built by through successive laser depositions. Unfortunately these processes are prone to process drifts and flaw formations. Traditional in-situ sensing methods aim to monitor the melt pool to detect process shifts. However, during these processes, a vapor plume is also formed from vaporized material originating in the melt pool. This plume, under certain circumstances, may affect the laser beam and interfere with direct sensing of the melt pool. Therefore this work seeks to confirm that the vapor plume can affect direct imaging of the melt pool, and describe scenarios where the plume can be the sensing target. First, coaxial melt pool images were compared to solidified track geometry and plume camera images. It was determined that coaxial melt pool images do not correlate well to true deposition geometry, and instead appear strongly correlated to plume geometry. Thereafter, experiments were performed to determine the relationship between processing parameters, plume emissions, and build quality using a high-speed, filtered photodiode sensor designed to measure line emissions from the plume. First, single track coupons were deposited with ramped laser power and one of two scan speeds. A linear relationship between plume emissions and laser power was found and a weak relationship with scan speed was found. Next, single tracks were produced under varied gas flow, scan speed, and laser power. It was found that decreasing gas flow leads to brighter emissions, wider track widths, shorter track depths, and an increase in the apparent surface roughness of the coupons. Additionally, cylinders, each one build layer taller than the prior, were deposited under nominal laser power, scan speed, and gas flow conditions to study the effects of hatch angle on optical emissions and coupon geometry. It was found that coupons oscillated between severe overbuilding, and less severe overbuilding with hatch angle. Coupons exhibiting overbuilding (i.e. close to lack-of-fusion) had dimmer optical emissions similar to lack-of-fusion emissions, while coupons less severely overbuild (and one underbuilt) had optical emissions more similar to keyholing. Further, we consider whether optical emissions from the plume can be used to detect laser misalignment in a multi-laser powder bed fusion system. Here we deposit "X" shaped coupons under nominal conditions. Two conditions were tested, one where both legs of the "X" had the same length, and should cause the lasers to meet in the center of the "X" while, the other had one leg shorter and should thus result in one laser leading the other. We found bright emissions occurred when the two lasers coincidentally intersected at the center of the "X" and dimmer emissions in the scenario where one lead the other. Further, we found that, in the non-coincident case, there was an increased time delay between the laser's minimum Euclidean distance and bright emission from the plume. We use this time difference to distinguish between aligned and misaligned coupons. Finally, we deposited several cylindrical coupons at varied laser power, and gas flow speed to replicate process deviations that may occur during the deposition process. Using the optical emission data acquired during the deposition process, a K-nearest neighbors algorithm was fit and estimated the true laser power and gas flow rate during the process. Root mean squared errors for both laser power and gas flow speed predictions were on the order of typical measurement errors. Based on the results of these experiments, recommendations for future research works are thereafter provided.

Download or read book Industrializing Additive Manufacturing Proceedings of Additive Manufacturing in Products and Applications AMPA2017 written by Mirko Meboldt and published by Springer. This book was released on 2017-09-05 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings exchange ideas and knowledge among engineers, designers and managers on how to support real-world value chains by developing additive manufactured series products. The papers from the conference show a holistic, multidisciplinary view.

Download or read book Tailoring Mechanical Properties and Porosity in Laser Powder Bed Fusion by Spatial Manipulation of Feedstock Composition written by Bethany Rose Lettiere and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) is capable of forming complex geometries, can build custom products, and offers greater versatility than many conventional manufacturing processes. Metal AM has revolutionized the design and production of rocket engines, enabled lightweight robotics and drones, and created heat exchangers that improve the efficiency of energy conversion systems. Typically, the feedstock for metal AM is a single alloy powder, metal powder, or a stochastic mixture of alloys. The design space of AM can be expanded by techniques for local manipulation of the powder feedstock, thereby enabling the tailoring of composition or microstructure gradients to improve mechanical or thermal properties. Current methods for local manipulation of the feedstock incorporate hopper- or vacuum-based methods with spatial deposition resolution on the order of 500 [mu]m and typically require a secondary recoating step after depositing the material, further limiting the resolution and fidelity of property. In this thesis, a new hybrid AM technique combining inkjet deposition followed by laser powder bed fusion (LPBF) is studied, and the technique is demonstrated in exemplary contexts. To begin, a rapid experimental workflow is developed, whereby etched metal substrates are used as templates for spreading a thin layer of metal powder; spreading is preceded by inkjet deposition onto the wells and is followed by laser scanning to form a solid material with tailored characteristics. This workflow facilitates an understanding of the influence of additive concentration, laser power, and scan speed on the process. Using this workflow, the thesis: (1) assesses the resolution (~ 200 [mu]m) and limitations of the hybrid inkjet-LPBF process; (2) demonstrates the fabrication of porous stainless steel using a polymer-based ink as the deposited additive, achieving spatially controlled porosity upwards of 8% locally with pore sizes of 250-800 [mu]m2 and a spatial resolution of ~ 400 [mu]m; (3) demonstrates spatial tailoring of the hardness of stainless steel using an ink with carbon black as the additive, achieving a local increase in the microhardness from a control of 178 HV to 196.6 HV with a spatial resolution of 250 [mu]m. In the case of porosity control, a scaling model of thermal effects, combined with an understanding of the melt pool's flow and stability, rationalizes the experimental outcomes and the process parameter space. This thesis validates the multi-material inkjet-laser process for high-resolution, spatially graded metal AM. These findings lay the foundation for a hybrid inkjet-LPBF fusion system to develop high-precision components and its use for rapid alloy development in metal AM.

Download or read book Simulation of Metal Grain Growth in Laser Powder Bed Fusion Process Using Phase Field Thermal Coupled Model written by Zhida Huang and published by . This book was released on 2019 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) comparing to traditional manufacture method possess higher flexibility. For metal Additive Manufacturing, approaches to improve products qualities have been intensively studied. Powder Bed Fusion (PBF) is a metal Additive Manufacturing method which manufactures products with high density. The PBF process, involving multiple physical phenomena, is controlled by several parameters such as laser power, scanning speed, material properties, etc. Due to the complexity of the PBF process numerical simulation is very necessary for understanding its mechanism. Simulations of PBF process are categorized depending on their scope of dimension, among which microscopic simulation usually emphasis grain development process and microstructures. Phase Field method is widely employed in microstructure simulation. By solving a set of PDE Phase Field method could represent an interfacial structure using a set of variables called Order Parameters. Models describing the grain growth process in a fixed temperature has been developed. In this work, the Phase Field model is coupled with thermal information to simulate the grain growth process in the melt pool of the PBF process. During the simulation, the computational area for Phase Field calculation and the magnitude of the driving force of Order Parameters are defined using temperature distribution. And the change of Order Parameters also generates latent heat. Finite Element Method is employed in order to execute the simulation on irregular geometry. Operator splitting scheme is applied for higher efficiency and accuracy. The convergence and boundary conditions implement are validated. Columnar shaped cells structures resembling experiment result are simulated.

Download or read book Additive Manufacturing Handbook written by Adedeji B. Badiru and published by CRC Press. This book was released on 2017-05-19 with total page 928 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical and practical interests in additive manufacturing (3D printing) are growing rapidly. Engineers and engineering companies now use 3D printing to make prototypes of products before going for full production. In an educational setting faculty, researchers, and students leverage 3D printing to enhance project-related products. Additive Manufacturing Handbook focuses on product design for the defense industry, which affects virtually every other industry. Thus, the handbook provides a wide range of benefits to all segments of business, industry, and government. Manufacturing has undergone a major advancement and technology shift in recent years.

Download or read book A V Model Framework to Support Qualification of Metal Additive Manufacturing Parts Made with Laser Powder Bed Fusion written by Byeong Min Roh and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a novel framework for monitoring metal additive manufacturing (AM) processes for quality assurance using process signatures occurring during the laser powder bed fusion process. The framework offers a structured approach based on the Systems Engineering V-model to translate part requirements into process signatures that can be monitored using in situ sensing technologies. A method for selecting sensors based on the process signatures of interest is also developed to address a related shortcoming in the field. Information gathered from the selected sensors during the build is used to ascertain build quality with respect to the microstructure and mechanical properties of the resulting metal AM part. This information can then be used for quality assurance, validating that the requirements are met by the metal AM part. The V-model framework and sensor selection method for laser powder bed fusion are demonstrated and tested using existing Ti-6Al-4V and IN625 test data from the literature to validate traceability and requirements for density and ultimate tensile strength. The contributions of the work are discussed in this dissertation, along with limitations and future work.

Download or read book High Speed Stereovision in Situ Monitoring of Spatter During Laser Powder Bed Fusion written by Christopher Barrett and published by . This book was released on 2019 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal laser powder bed fusion (LPBF) Additive Manufacturing (AM) affords new design freedoms for metallic structures with complex geometries. The aerospace industry has identified the inherent benefits of AM not just in terms of shape creation but also with regard to producing replacement parts for an aging fleet of aircraft. However, for these parts to be deployed, the quality must be well established given the lack of heritage for this manufacturing process. As additive manufacturing is executed layerwise, opportunities exist to non-destructively verify the fabrication in situ with a qualify-as-you-go methodology. A proposed solution is presented, which utilizes a pair of low cost, high speed cameras that are integrated and synchronized together to provide stereovision in order to identify the size, speed, direction and age of spatter ejected from the laser melt pool. The driving hypothesis of the effort is that the behavior of spatter can be reliably measured in order to determine the health of the laser process and ensure that spatter is not contaminating the build.

Download or read book Multi sensor Approach to Determine the Effect of Geometry on Microstructure in Additive Manufacturing written by Joseph R. Walker and published by . This book was released on 2019 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser powder bed fusion (LPBF) is an additive manufacturing technique used for making complex parts through a layer-by-layer process with fine feature resolution. However, the layer-by-layer process, with complex scanning patterns within each layer, introduces variability in thermal behavior leading to inconsistent microstructure and defects. The in- situ process monitoring approach in this work uses sensors including a high-speed visible camera, thermal camera, and spectrometer to evaluate each location in the LPBF process. Each sensor focuses on a different process phenomenon such as the melt pool or thermal behavior. An experimental study, using metallographic analysis and collection of sensor data, is used to determine the influence of processing parameters and geometric changes on the final microstructure of Alloy 718. The multi-sensor approach creates a comprehensive view of the microstructural changes. Combining in-situ process monitoring with process control allows for the prediction of part quality and reliable material properties.

Download or read book Additive Manufacturing of Metals written by John O. Milewski and published by Springer. This book was released on 2017-06-28 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: This engaging volume presents the exciting new technology of additive manufacturing (AM) of metal objects for a broad audience of academic and industry researchers, manufacturing professionals, undergraduate and graduate students, hobbyists, and artists. Innovative applications ranging from rocket nozzles to custom jewelry to medical implants illustrate a new world of freedom in design and fabrication, creating objects otherwise not possible by conventional means. The author describes the various methods and advanced metals used to create high value components, enabling readers to choose which process is best for them. Of particular interest is how harnessing the power of lasers, electron beams, and electric arcs, as directed by advanced computer models, robots, and 3D printing systems, can create otherwise unattainable objects. A timeline depicting the evolution of metalworking, accelerated by the computer and information age, ties AM metal technology to the rapid evolution of global technology trends. Charts, diagrams, and illustrations complement the text to describe the diverse set of technologies brought together in the AM processing of metal. Extensive listing of terms, definitions, and acronyms provides the reader with a quick reference guide to the language of AM metal processing. The book directs the reader to a wealth of internet sites providing further reading and resources, such as vendors and service providers, to jump start those interested in taking the first steps to establishing AM metal capability on whatever scale. The appendix provides hands-on example exercises for those ready to engage in experiential self-directed learning.

Download or read book Transactions on Intelligent Welding Manufacturing written by Shanben Chen and published by Springer. This book was released on 2017-08-01 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary aim of this volume is to provide researchers and engineers from both academia and industry with up-to-date coverage of recent advances in the fields of robotic welding, intelligent systems and automation. It gathers selected papers from the 2017 International Workshop on Intelligentized Welding Manufacturing (IWIWM’2017), held June 23-26, 2017 in Shanghai, China. The contributions reveal how intelligentized welding manufacturing (IWM) is becoming an inescapable trend, just as intelligentized robotic welding is becoming a key technology. The volume is divided into four main parts: Intelligent Techniques for Robotic Welding, Sensing in Arc Welding Processing, Modeling and Intelligent Control of Welding Processing, and Intelligent Control and its Applications in Engineering.

Download or read book Fundamentals of Laser Powder Bed Fusion of Metals written by Igor Yadroitsev and published by Elsevier. This book was released on 2021-05-23 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser powder bed fusion of metals is a technology that makes use of a laser beam to selectively melt metal powder layer-by-layer in order to fabricate complex geometries in high performance materials. The technology is currently transforming aerospace and biomedical manufacturing and its adoption is widening into other industries as well, including automotive, energy, and traditional manufacturing. With an increase in design freedom brought to bear by additive manufacturing, new opportunities are emerging for designs not possible previously and in material systems that now provide sufficient performance to be qualified in end-use mission-critical applications. After decades of research and development, laser powder bed fusion is now enabling a new era of digitally driven manufacturing. Fundamentals of Laser Powder Bed Fusion of Metals will provide the fundamental principles in a broad range of topics relating to metal laser powder bed fusion. The target audience includes new users, focusing on graduate and undergraduate students; however, this book can also serve as a reference for experienced users as well, including senior researchers and engineers in industry. The current best practices are discussed in detail, as well as the limitations, challenges, and potential research and commercial opportunities moving forward. - Presents laser powder bed fusion fundamentals, as well as their inherent challenges - Provides an up-to-date summary of this advancing technology and its potential - Provides a comprehensive textbook for universities, as well as a reference for industry - Acts as quick-reference guide

Download or read book Metal Additive Manufacturing written by Dyuti Sarker and published by John Wiley & Sons. This book was released on 2021-10-26 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: METAL ADDITIVE MANUFACTURING A comprehensive review of additive manufacturing processes for metallic structures Additive Manufacturing (AM)—also commonly referred to as 3D printing—builds three-dimensional objects by adding materials layer by layer. Recent years have seen unprecedented investment in additive manufacturing research and development by governments and corporations worldwide. This technology has the potential to replace many conventional manufacturing processes, enable the development of new industry practices, and transform the entire manufacturing enterprise. Metal Additive Manufacturing provides an up-to-date review of all essential physics of metal additive manufacturing techniques with emphasis on both laser-based and non-laser-based additive manufacturing processes. This comprehensive volume covers fundamental processes and equipment, governing physics and modelling, design and topology optimization, and more. The text adresses introductory, intermediate, and advanced topics ranging from basic additive manufacturing process classification to practical and material design aspects of additive manufacturability. Written by a panel of expert authors in the field, this authoritative resource: Provides a thorough analysis of AM processes and their theoretical foundations Explains the classification, advantages, and applications of AM processes Describes the equipment required for different AM processes for metallic structures, including laser technologies, positioning devices, feeder and spreader mechanisms, and CAD software Discusses the opportunities, challenges, and current and emerging trends within the field Covers practical considerations, including design for AM, safety, quality assurance, automation, and real-time control of AM processes Includes illustrative cases studies and numerous figures and tables Featuring material drawn from the lead author’s research and professional experience on laser additive manufacturing, Metal Additive Manufacturing is an important source for manufacturing professionals, research and development engineers in the additive industry, and students and researchers involved in mechanical, mechatronics, automatic control, and materials engineering and science.