Download or read book Fundamentals of Diffraction based Residual Stress and Texture Analysis of Laser Powder Bed Fused Inconel 718 written by Jakob Schröder 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) processes enable the production of metal structures with exceptional design freedom, of which laser powder bed fusion (PBF-LB) is one of the most common. In this process, a laser melts a bed of loose feedstock powder particles layer-by-layer to build a structure with the desired geometry. During fabrication, the repeated melting and rapid, directional solidification create large temperature gradients that generate large thermal stress. This thermal stress can itself lead to cracking or delamination during fabrication. More often, large residual stresses remain in the final part as a footprint of the thermal stress. This residual stress can cause premature distortion or even failure of the part in service. Hence, knowledge of the residual stress field is critical for both process optimization and structural integrity. Diffraction-based techniques allow the non-destructive characterization of the residual stress fields. However, such methods require a good knowledge of the material of interest, as certain ...
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 Experimental Investigation of Laser Scan Strategy on the Microstructure Mechanical Properties and Residual Stress of Inconel 718 Parts Fabricated by Selective Laser Melting written by Kiriti Mamidi and published by . This book was released on 2020 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inconel 718 (IN718) is a nickel-based superalloy which exhibits excellent tensile and impact resistant properties along with good corrosion resistance at high temperatures. However, due to the high toughness and work hardening, the machinability of this superalloy is low. Therefore, the selective laser melting (SLM) process has been adopted as an efficient technique to fabricate IN718 parts as it overcomes the problems associated with conventional manufacturing of superalloys. SLM is a widely used additive manufacturing technique which offers the possibility to induce multi-functionality into a single component,and thus reduce the number of components that are needed.In the SLM process, various process parameters like scan strategy, laser power, scan speed, and energy density are defined for the fabrication to regulate the microstructure and thus control the mechanical properties like tensile strength, yield strength, impact strength, and hardness. Owing to the nature of the SLM process, there are consistent repetitions of thermal cycles, which in turn induce residual stress into the part. These residual stresses can be detrimental to the microstructure and hence mechanical properties of the part. Residual stresses lead to warping of the part during the fabrication process, thereby leading to failure of the component. Although each process parameter has an independent and definitive effect on theoverall mechanical and metallurgical properties, scan strategy is an independent process parameter which directly affects the level of residual stresses, microstructure, and mechanical properties of the SLM part, as the heat zones in part can be shifted from location to another by varying the scan strategy. This variation of the area of the heat zone changes the temperature gradient, which thereby determines the grain size ranging from equiaxed to elongated. Hence, the scan strategy is the only parameter that is varied for this study. The various scan strategies adopted here are checkered, stripes, FO1, and customized scan strategy, where the angle between the consecutive layers has been changed consistently at an angle of 90°. In this study, the residual stress was deduced using methods like hardness, X-ray powder diffraction(XRD), and direct method (CMM) followed by microstructural and compositional analysis on the parts. Mechanical testing like compression tests, hardness test, and roughness test was performed on the SLM fabricated parts. This effort was undertaken to identify the effect of scan strategy on residual stress and to discuss the metallurgical interactions between the mechanical and microstructural properties within the IN718 superalloy.
Download or read book Study of Gas Flow and Spattering Phenomena of Laser Powder Bed Fusion With Inconel 718 written by 簡成晏 and published by . This book was released on 2020 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Residual Stress Formation in Laser Based Powder Bed Fusion PBF LB of Invar 36 written by Mostafa Yakout and published by . This book was released on 2020 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-based powder bed fusion (PBF-LB), also known as selective laser melting (SLM), is a metal additive manufacturing process associated with residual stress formation due to rapid heating and cooling. This paper aims at investigating residual stresses and deflections of Invar 36 parts produced using a selective laser melting machine that is equipped with a 400-W ytterbium fiber laser source. Invar 36 has been used in the aerospace industry for the past decade because it is known for its ferromagnetic property, high strength, and improved toughness. Invar 36 has a very low coefficient of thermal expansion below its Curie temperature (279C); therefore, it is a good candidate for the PBF-LB process because it shows low thermal stresses and small deflections. Parts manufactured by the PBF-LB process usually experience void formation, internal cracks, metallurgical changes, vaporization of alloying elements, and residual stress formation. In this paper, evolution of residual stresses and deflections of Invar 36 parts is analyzed using a coupled thermal-mechanical finite element model in ANSYS Additive 19.2 software. The numerical results are validated experimentally. Residual stresses are measured using an X-ray diffraction (XRD) instrument, and part deflections are measured using a coordinate measuring machine (CMM). Parts are produced at the optimum process parameters for Invar 36 in order to eliminate the formation of excessive residual stresses during the PBF-LB process. These optimum process parameters that give the smallest deflections and lowest residual stresses are tested using the finite element model. In addition, the relationships between the thermal properties of Invar 36 and the process-induced residual stresses and deflections are discussed.
Download or read book Nickel Cobalt and Their Alloys written by Joseph R. Davis and published by ASM International. This book was released on 2000-01-01 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive guide to the compositions, properties, processing, performance, and applications of nickel, cobalt, and their alloys. It includes all of the essential information contained in the ASM Handbook series, as well as new or updated coverage in many areas in the nickel, cobalt, and related industries.
Download or read book Introduction to the Characterization of Residual Stress by Neutron Diffraction written by M.T. Hutchings and published by CRC Press. This book was released on 2005-02-28 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past 25 years the field of neutron diffraction for residual stress characterization has grown tremendously, and has matured from the stage of trial demonstrations to provide a practical tool with widespread applications in materials science and engineering. While the literature on the subject has grown commensurately, it has also remained
Download or read book Comparison of Residual Stresses in Inconel 718 Simple Parts Made by Electron Beam Melting and Direct Laser Metal Sintering written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Residual stress profiles were mapped using neutron diffraction in two simple prism builds of Inconel 718: one fabricated with electron beam melting and the other with direct laser sintering. Spatially indexed stress-free cubes were obtained by EDM sectioning equivalent prisms of similar shape. The (311) interplanar spacing examined for the EDM sectioned sample was compared to the interplanar spacings calculated to fulfill force and moment balance. We have shown that Applying force and moment balance is a necessary supplement to the measurements for the stress-free cubes with respect to accurate stress calculations in additively manufactured components. In addition, our work has shown that residual stresses in electron beam melting parts are much smaller than that of direct laser metal sintering parts.
Download or read book Additively Manufactured Inconel 718 written by Dunyong Deng and published by Linköping University Electronic Press. This book was released on 2018-01-24 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM), also known as 3D printing, has gained significant interest in aerospace, energy, automotive and medical industries due to its capabilities of manufacturing components that are either prohibitively costly or impossible to manufacture by conventional processes. Among the various additive manufacturing processes for metallic components, electron beam melting (EBM) and selective laser melting (SLM) are two of the most widely used powder bed based processes, and have shown great potential for manufacturing high-end critical components, such as turbine blades and customized medical implants. The futures of the EBM and SLM are doubtlessly promising, but to fully realize their potentials there are still many challenges to overcome. Inconel 718 (IN718) is a nickel-base superalloy and has impressive combination of good mechanical properties and low cost. Though IN718 is being mostly used as a turbine disk material now, the initial introduction of IN718 was to overcome the poor weldability of superalloys in 1960s, since sluggish precipitation of strengthening phases ?’/?’’ enables good resistance to strain-age cracking during welding or post weld heat treatment. Given the similarity between AM and welding processes, IN718 has been widely applied to the metallic AM field to facilitate the understandings of process-microstructure-property relationships. The work presented in this licentiate thesis aims to better understand microstructures and mechanical properties EBM and SLM IN718, which have not been systematically investigated. Microstructures of EBM and SLM IN718 have been characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and correlated with the process conditions. Monotonic mechanical properties (e.g., Vickers microhardness and tensile properties) have also been measured and rationalized with regards to the microstructure evolutions before and after heat treatments. For EBM IN718, the results show the microstructure is not homogeneous but dependant on the location in the components, and the anisotropic mechanical properties are probably attributed to alignment of porosities rather than texture. Post heat treatment can slightly increase the mechanical strength compared to the as-manufactured condition but does not alter the anisotropy. SLM IN718 shows significantly different microstructure and mechanical properties to EBM IN718. The as-manufactured SLM IN718 has very fine dendritic microstructure and Laves phases in the interdendrites, and is “work-hardened” by the residual strains and dislocations present in the material. Mechanical properties are different between horizontally and vertically built samples, and heat treatment can minimize this difference. Results from this licentiate thesis provide the basis for the further research on the cyclic mechanical properties of EBM and SLM IN718, which would be the focus of following phase of the Ph.D. research.
Download or read book Modeling and Characterization of Mechanical Properties in Laser Powder Bed Fusion Additive Manufactured Inconel 718 written by Senthamilaruvi Moorthy and published by . This book was released on 2018 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parametric Investigation and Optimization for Inconel 718 Nickel based Superalloy in Laser Powder Bed Fusion written by Thinh Huu Huynh and published by . This book was released on 2020 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excellent weldability and high temperature stability make Inconel 718 (IN718) one of the most desired alloys to be produced by additive manufacturing (AM). Within the flourishing field of AM technology, laser powder bed fusion (LPBF) is a popular prospective candidate capable of fabricating complex and near net-shape engineering components that traditional manufacturing methods cannot accomplish. In this study, the effects of processing parameters on the relative density and microstructure was investigated. Gas atomized IN718 powders were used to fabricate cuboidal specimens via LPBF for metallographic characterization. The specimens were printed with independently varied laser power (125 - 350W), laser scan speed (200 - 2200 mm/s), and laser scan rotation (0° - 90°). Archimedes’ method, optical microscopy, and scanning electron microscopy were employed to assess the influence of LPBF parameters on part density and microstructure, respectively. In general, relative density greater than 99.5% was achieved for a wide range of energy density between 50 and 100 J/mm3. At higher laser powers, larger processing windows to produce high density parts were documented. Microstructural features including melt pool geometry, lack of fusions defects, keyhole porosity, and grain structure were examined and correlated to a wide range of LPBF parameters. The cellular microstructure within grains was observed to decrease with increasing laser scan speed. Based on the measurement of cellular structures and Rosenthal models, cooling rate in LPBF was estimated to be in the order of 105 – 105 K/s.
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.
Download or read book Practical Residual Stress Measurement Methods written by Gary S. Schajer and published by John Wiley & Sons. This book was released on 2013-09-23 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introductory and intermediate level handbook written in pragmatic style to explain residual stresses and to provide straightforward guidance about practical measurement methods. Residual stresses play major roles in engineering structures, with highly beneficial effects when designed well, and catastrophic effects when ignored. With ever-increasing concern for product performance and reliability, there is an urgent need for a renewed assessment of traditional and modern measurement techniques. Success critically depends on being able to make the most practical and effective choice of measurement method for a given application. Practical Residual Stress Measurement Methods provides the reader with the information needed to understand key residual stress concepts and to make informed technical decisions about optimal choice of measurement technique. Each chapter, written by invited specialists, follows a focused and pragmatic format, with subsections describing the measurement principle, residual stress evaluation, practical measurement procedures, example applications, references and further reading. The chapter authors represent both international academia and industry. Each of them brings to their writing substantial hands-on experience and expertise in their chosen field. Fully illustrated throughout, the book provides a much-needed practical approach to residual stress measurements. The material presented is essential reading for industrial practitioners, academic researchers and interested students. Key features: • Presents an overview of the principal residual stress measurement methods, both destructive and non-destructive, with coverage of new techniques and modern enhancements of established techniques • Includes stand-alone chapters, each with its own figures, tables and list of references, and written by an invited team of international specialists
Download or read book Determination of Residual Stress in Components Manufactured Using Laser Powder Bed Fusion L PBF written by Rodrigo Magana Carranza and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimizing Quality of Additively Manufactured Inconel 718 Using Powder Bed Laser Melting Process written by Magda Dominique Sadowski and published by . This book was released on 2016 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superalloys II written by Chester T. Sims and published by Wiley-Interscience. This book was released on 1987-09-07 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of the latest developments in the pursuit of superalloys.
Download or read book Analysis of Residual Stress by Diffraction using Neutron and Synchrotron Radiation written by M.E. Fitzpatrick and published by CRC Press. This book was released on 2003-02-06 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: While residual stress can be a problem in many industries and lead to early failure of component, it can also be introduced deliberately to improve lifetimes. Knowledge of the residual stress state in a component can be critical for quality control of surface engineering processes or vital to performing an accurate assessment of component life unde
