Download or read book Development of Feedback Control Loops for the Laser Powder Bed Fusion Machine written by and published by . This book was released on 2021 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Demonstration of Closed Loop Control for Laser Powder Bed Fusion LPBF written by David Maass and published by . This book was released on 2020 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, AM processes such as LPBF are performed open loop, using a fixed, preprogrammed definition of material deposition (path, speed, laser power, and so on). Actual layer and part formation details, even when measured, are not fed back to the print controller to account for actual, as-made layer conditions. Unanticipated layer and part deviations occur frequently that, in the worst case, can result in print failure, part rejection, higher scrap rate, lower yield, and more expensive parts. Process anomalies are sometimes detected manually by the operator. In-process inspection methods such as melt pool monitoring typically do not provide accept/reject guidance. When anomalies are noted, no instructions are provided to the operator or the machine to repair or compensate for the flaw and to salvage the build, in cases where this is possible. We demonstrate development of a closed-loop control capability using a nonthermal in-process inspection method on every layer. Layer Topographic Mapping (LTM) is an in-process inspection method using an optical profilometer to generate a dense, precise map of layer surface height. Algorithms process this data to detect melt flaws with excellent performance. Demonstrated detection of lack of fusion flaws in more than 1,800 Inconel 625 layers is 98.2% probability of detection (POD) and 1.0% probability of false detection (POFD). Optimum repair/rework processes were developed for lack of fusion flaw regions one to three layers thick. LTM software was modified to not only detect flaws but also to define the optimum repair process to employ upon detection based on the number of flaw layers present. Intentionally created (or seeded) lack of fusion flaws were restored to less than 0.1% porosity for one- to three-layer flaws. Porosity in the flaw regions was reduced by up to 98% as verified by CT scans.

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 Laser Powder Bed Fusion of Additive Manufacturing Technology written by Di Wang and published by Springer Nature. This book was released on 2023-10-06 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book systematically introduces the powder bed laser melting technology and its application and summarizes the author's team's experience in scientific research, engineering development, and data accumulation in recent 15 years. It includes in-depth theoretical analysis and a lot of engineering experience in equipment debugging, process development, and material testing. The book takes the powder bed laser melting technology as the object and divides the content into 15 chapters. It is used as technical learning materials for researchers and engineering development personnel engaged in metal 3D printing.

Download or read book Transactions on Intelligent Welding Manufacturing written by Shanben Chen and published by Springer Nature. This book was released on 2020-01-11 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary aim of this volume is to provide researchers and engineers from both academic and industry with up-to-date coverage of new results in the field of robotic welding, intelligent systems and automation. The book is mainly based on papers selected from the 2019 International Workshop on Intelligentized Welding Manufacturing (IWIWM’2019) in USA. The articles show that the intelligentized welding manufacturing (IWM) is becoming an inevitable trend with the intelligentized robotic welding as the key technology. The volume is divided into four logical parts: Intelligent Techniques for Robotic Welding, Sensing of Arc Welding Processing, Modeling and Intelligent Control of Welding Processing, as well as 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 2021-05-27 with total page 676 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 Virtual and Rapid Manufacturing written by Ljubomir Tanchev and published by CRC Press. This book was released on 2007-09-17 with total page 866 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection of 120 peer-reviewed papers that were presented at the 3rd International Conference on Advanced Research in Virtual and Rapid Prototyping, held in Leiria, Portugal in September 2007. Essential reading for all those working on V&RP, focused on inducing increased collaboration between industry and academia. In addition to key

Download or read book Model Learning and Predictive Control of Laser Powder Bed Fusion written by Yong Ren and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) provides a transformative approach for industrial applications, enabling the fabrication of near-net-shape components directly from computer-aided design files. As a subcategory of metal AM processes, Laser Powder Bed Fusion (L-PBF) utilizes a high-speed, fine-diameter laser heat source to melt layers of powder that have been evenly distributed by a recoater. While L-PBF has emerged as the most widely-used commercial metal AM technology, numerous critical challenges still persist in process modeling and control of this approach. Addressing these issues is crucial for enhancing the geometric accuracy and overall quality of additive manufactured components. The objective of this research is to employ machine learning and numerical techniques for the development of comprehensive multiscale models, facilitating prediction and control in the L-PBF process across various process conditions. Using machine learning algorithms allows for constructing robust computational models based on training data, offering accurate predictions and informed decision-making for a wide range of physical systems. In this research, a variety of machine learning techniques were primarily used for fine-scale modeling and control of L-PBF processes. This was demonstrated through single-layer multi-track cases as a proof-of-concept study. In order to accurately model the relationship between process parameters and melt-pool sizes, a physics-informed method was adopted to identify critical input features for machine learning models. A two-level architecture was implemented for both model training and validation. Notably, the initial temperature at the melting point was recognized as a crucial variable in characterizing the thermal history for precise melt-pool size predictions. To achieve consistent melt-pool distribution during multi-track laser processing, a physics-informed optimal control method was devised to adjust laser power based on Gaussian process regression. The study's findings demonstrate that nonlinear regression analysis techniques, such as Gaussian process regression, are effective in predicting melt-pool geometry. When these techniques are further combined with optimal control, they can regulate the melt-pool size to a desired reference value. Regarding the evolution of temperature at the part-scale level, a novel finite-difference model was introduced, providing fast predictions of interlayer temperature and facilitating model-based thermal control. Interlayer temperature, defined as the layer temperature after powder spreading but before scanning a new layer, serves as the initial condition for the subsequent scan and thus plays an important role in the melt-pool morphology and the final build quality. The effectiveness of the proposed modeling method was evaluated through thermal analysis of a square-canonical geometry made from Inconel 718. Based on the part-scale thermal model, an optimal control utilizing layer-wise laser power adjustments was further developed to regulate the interlayer temperature below a preset threshold, thereby mitigating excessive heat buildup during the build process. The optimized laser power profiles, initially obtained by solving a convex program based on the finite-difference model, were then programmed on the EOS M280 system for a feedforward control to build the square-canonical parts. In-situ, real-time measurements of interlayer temperature were collected using infrared (IR) thermal imaging during the build process to validate the model and control. Post-process optical micrographs were also captured to compare the melt-pool morphology under optimized laser power profiles with that obtained under the default constant laser power. The control performance was evaluated through numerical simulations and experimental studies. Research findings confirm the efficacy of the proposed optimal thermal control in reducing overheating during the L-PBF build process.

Download or read book Predictive Theoretical and Computational Approaches for Additive Manufacturing written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-12-21 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) methods have great potential for promoting transformative research in many fields across the vast spectrum of engineering and materials science. AM is one of the leading forms of advanced manufacturing which enables direct computer-aided design (CAD) to part production without part-specific tooling. In October 2015 the National Academies of Sciences, Engineering, and Medicine convened a workshop of experts from diverse communities to examine predictive theoretical and computational approaches for various AM technologies. While experimental workshops in AM have been held in the past, this workshop uniquely focused on theoretical and computational approaches and involved areas such as simulation-based engineering and science, integrated computational materials engineering, mechanics, materials science, manufacturing processes, and other specialized areas. This publication summarizes the presentations and discussions from the workshop.

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 Analysis of the Laser Powder Bed Fusion Additive Manufacturing Process Through Experimental Measurement and Finite Element Modeling written by Alexander Dunbar and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective in this work is to provide rigourous experimental measurements to aid in the development of laser powder bed fusion (LPBF) additive manufacturing (AM). A specialized enclosed instrumented measurement system is designed to provide in situ experimental measurements of temperature and distortion. Experiments include comparisons of process parameters, materials and LPBF machines. In situ measurements of distortion and temperature made throughout the build process highlight inter-layer distortion effects previously undocumented for laser powder bed fusion. Results from these experiments are also be implemented in the development and validation of finite element models of the powder bed build process. Experimental analysis is extended from small-scale to larger part-scale builds where experimental post-build measurements are used in analysis of distortion profiles. Experimental results provided from this study are utilized in the validation of a finite element model capable of simulating production scale parts. The validated finite element model is then implemented in the analysis of the part to provide information regarding the distortion evolution process. A combination of experimental measurements and simulation results are used to identify the mechanism that results in the measured distortion profile for this geometry. Optimization of support structure primarily focuses on the minimization of material use and scan time, but no information regarding failure criteria for support structure is available. Tensile test samples of LPBF built support structure are designed, built, and tested to provide measurements of mechanical properties of the support structure. Experimental tests show that LPBF built support structure has only 30-40\% of the ultimate tensile strength of solid material built in the same machine. Experimental measurement of LPBF built support structure provides clear failure criteria to be utilized in the future design and implementation of support structure.

Download or read book Framework to Accelerate Parameter Development for Laser Powder Bed Fusion written by Benjamin C. Graybill and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Laser Powder Bed Fusion (M-LPBF) is a method of additive manufacturing that enables the fabrication of complex components that would not be possible through conventional manufacturing methods. M-LPBF is well suited for aerospace applications not only because of its ability to fabricate complex and efficient components, but it also can enable the reduction of cost and the schedule of programs. The recent advancements in material development could open the design space even further for aerospace applications, but the initial development process of evaluating a new material on a M-LPBF printer can be time consuming and costly. In this work, a framework to improve the efficiency and structure of M-LPBF process development is proposed. First, simulations of the melt pool were performed to understand the impact of primary process parameters on the dimensions of the melt pool. Then, tools to model the melt pool were tested and used in combination with analytical equations to identify an acceptable processing window for the M-LPBF process. Following this process parameter filtering, physical experiments were executed that investigated the impact of process and design parameters on various outputs connected to the melt pool, density, dimensional accuracy, and surface roughness of the coupons printed. Optimal parameter ranges can then be determined according to different design and process priorities. The framework developed in this project enables a material and machine agnostic approach to process parameter selection in less time and at a lower cost.

Download or read book Towards Design Automation for Additive Manufacturing written by Anton Wiberg and published by Linköping University Electronic Press. This book was released on 2019-10-14 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, the development of computer-controlled manufacturing by adding materiallayer by layer, called Additive Manufacturing (AM), has developed at a rapid pace. The technologyadds possibilities to the manufacturing of geometries that are not possible, or at leastnot economically feasible, to manufacture by more conventional manufacturing methods. AMcomes with the idea that complexity is free, meaning that complex geometries are as expensiveto manufacture as simple geometries. This is partly true, but there remain several design rulesthat needs to be considered before manufacturing. The research field Design for Additive Manufacturing(DfAM) consists of research that aims to take advantage of the possibilities of AMwhile considering the limitations of the technique. Computer Aided technologies (CAx) is the name of the usage of methods and software thataim to support a digital product development process. CAx includes software and methodsfor design, the evaluation of designs, manufacturing support, and other things. The commongoal with all CAx disciplines is to achieve better products at a lower cost and with a shorterdevelopment time. The work presented in this thesis bridges DfAM with CAx with the aim of achieving designautomation for AM. The work reviews the current DfAM process and proposes a new integratedDfAM process that considers the functionality and manufacturing of components. Selectedparts of the proposed process are implemented in a case study in order to evaluate theproposed process. In addition, a tool that supports part of the design process is developed. The proposed design process implements Multidisciplinary Design Optimization (MDO) witha parametric CAD model that is evaluated from functional and manufacturing perspectives. Inthe implementation, a structural component is designed using the MDO framework, which includesComputer Aided Engineering (CAE) models for structural evaluation, the calculation ofweight, and how much support material that needs to be added during manufacturing. Thecomponent is optimized for the reduction of weight and minimization of support material,while the stress levels in the component are constrained. The developed tool uses methodsfor high level Parametric CAD modelling to simplify the creation of parametric CAD modelsbased on Topology Optimization (TO) results. The work concludes that the implementation of CAx technologies in the DfAM process enablesa more automated design process with less manual design iterations than traditional DfAM processes.It also discusses and presents directions for further research to achieve a fully automateddesign process for Additive Manufacturing.

Download or read book Additive Manufacturing written by Amit Bandyopadhyay and published by CRC Press. This book was released on 2015-09-08 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of additive manufacturing has seen explosive growth in recent years due largely in part to renewed interest from the manufacturing sector. Conceptually, additive manufacturing, or industrial 3D printing, is a way to build parts without using any part-specific tooling or dies from the computer-aided design (CAD) file of the part. Today, mo

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 To Orbit and Back Again written by Davide Sivolella and published by Springer Science & Business Media. This book was released on 2013-08-27 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Space Shuttle has been the dominant machine in the U.S. space program for thirty years and has generated a great deal of interest among space enthusiasts and engineers. This book enables readers to understand its technical systems in greater depth than they have been able to do so before. The author describes the structures and systems of the Space Shuttle, and then follows a typical mission, explaining how the structures and systems were used in the launch, orbital operations and the return to Earth. Details of how anomalous events were dealt with on individual missions are also provided, as are the recollections of those who built and flew the Shuttle. Many photographs and technical drawings illustrate how the Space Shuttle functions, avoiding the use of complicated technical jargon. The book is divided into two sections: Part 1 describes each subsystem in a technical style, supported by diagrams, technical drawings, and photographs to enable a better understanding of the concepts. Part 2 examines different flight phases, from liftoff to landing. Technical material has been obtained from NASA as well as from other forums and specialists. Author Davide Sivolella is an aerospace engineer with a life-long interest in space and is ideally qualified to interpret technical manuals for a wider audience. This book provides comprehensive coverage of the topic including the evolution of given subsystems, reviewing the different configurations, and focusing on the solutions implemented.

Download or read book Additive Manufacturing of Metals The Technology Materials Design and Production written by Li Yang and published by Springer. This book was released on 2017-05-11 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a unique guide to the three-dimensional (3D) printing of metals. It covers various aspects of additive, subtractive, and joining processes used to form three-dimensional parts with applications ranging from prototyping to production. Examining a variety of manufacturing technologies and their ability to produce both prototypes and functional production-quality parts, the individual chapters address metal components and discuss some of the important research challenges associated with the use of these technologies. As well as exploring the latest technologies currently under development, the book features unique sections on electron beam melting technology, material lifting, and the importance this science has in the engineering context. Presenting unique real-life case studies from industry, this book is also the first to offer the perspective of engineers who work in the field of aerospace and transportation systems, and who design components and manufacturing networks. Written by the leading experts in this field at universities and in industry, it provides a comprehensive textbook for students and an invaluable guide for practitioners