Download or read book Correlation and Effect of Process Parameters on the Properties of Inconel 718 Parts Fabricated by Selective Laser Melting Using Response Surface Method written by Bharath Bhushan Ravichander and published by . This book was released on 2020 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inconel 718 (i.e., IN718) is a nickel-based superalloy that exhibits outstanding tensile and impact resistant properties, along with good high-temperature corrosion resistance. However, the machinability is poor due to the high stiffness of IN718. Therefore, additive manufacturing provides an effective solution to overcome the work hardening. Selective laser melting (SLM) is the most common powder-bed additive manufacturing technique designed to use a high power-density laser to melt and fuse the metallic powder to fabricate functional parts with high accuracy. However, the accuracy and the functional properties of the fabricated parts are greatly dependent on the process parameters. Thus, depending on the desired properties,the process parameters for a given material need to be optimized for improving the overall reliability of the SLM devices. The processing parameters that control the SLM process comprise of the laser power, scan speed, hatch spacing, and layer thickness. These process parameters are dependent on each other and therefore making the task of optimizing the process parameters an important one. One of the biggest advantages of optimizing these above-mentioned process parameters is it enables us to control the microstructure as per the requirements. It is important to regulate the microstructure to control the mechanical properties such as tensile strength, yield strength, impact intensity and toughness,as it will directly influence the grain and melt pool distribution in the fabricated parts. As the number of combinations increases, the probability of failure of these additively manufactured parts increases exponentially. As all the process parameters are inter-dependent on each other, finding an optimum value to suit the requirement and render the best build quality both in terms of computer-aided design (CAD) accuracy and desired metallurgical properties is necessary. Thus, it is essential to determine and establish the optimum combination of values for process parameters. Design of Experiments (DOE) methodology was used to construct an experiment that evaluated the CAD deviation, composition, hardness and roughness of SLM fabricated IN718 against the three critical processing parameters: laser power, scanning speed and hatch spacing. This work primarily focuses on the effect of various process parameters on the metallurgical properties and mechanical properties of Inconel 718 parts fabricated on an EOS M290 machine.
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 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 Welding Metallurgy written by Sindo Kou and published by John Wiley & Sons. This book was released on 2003-03-31 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Updated to include new technological advancements in welding Uses illustrations and diagrams to explain metallurgical phenomena Features exercises and examples An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.
Download or read book Effect of Process Parameters on the Surface Roughness and Mechanical Performance of Additively Manufactured Alloy 718 written by Bo Ryan Whip and published by . This book was released on 2018 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal additive manufacturing (AM) is a method to create complex components in a layer-by-layer process. Currently, there is a lack of understanding in the processing-structure-properties-performance relationship, particularly related to defects inherent to the AM process. This work investigates the relationship of process parameters, as-built surface roughness, and mechanical performance for nickel-based superalloy 718 built using laser powder bed fusion. The surface roughness of components built using varied processing parameters was characterized using both nondestructive and destructive measurement techniques. Finite element analysis was used to study the stress concentration on surface profiles. Statistical correlations are presented between contour processing parameters and surface roughness metrics. Results show that destructive measurements are required to expose obstructed features and highly concentrated stress is present on crack-like surface features. The discovered understanding of the surface roughness behavior can be used for further process optimization and to inform the certification and qualification strategy for AM components.
Download or read book Welding Deformation and Residual Stress Prevention written by Ninshu Ma and published by Elsevier. This book was released on 2012-04-26 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Generally, welding produces welding deformation and residual stress in the products, which influences the quality and performance of the products. Although many engineers and researchers have made great effort how to control these incidents, they have still remained unresolved. Welding Deformation and Residual Stress Prevention provides a unique computational approach to the prediction of the effects of deformation and residual stress on materials. The goal is to provide engineers and designers with the ability to create their own computational system for predicting and possibly avoiding the problem altogether. The basic theories including "theory of elastic-plastic analysis" and "inherent strain theory" , and analysis procedures are described using a simple three-bar model Online simulation software to perform basic analysis on welding mechanics Examples of strategic methods and procedures are illustrated to have solved various welding-related problems encountered in the process of construction Appendices present data bases for welding residual stresses, temperature dependent material properties, etc.
Download or read book Handbook of Residual Stress and Deformation of Steel written by George E. Totten and published by ASM International. This book was released on 2002 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Examines the factors that contribute to overall steel deformation problems. The 27 articles address the effect of materials and processing, the measurement and prediction of residual stress and distortion, and residual stress formation in the shaping of materials, during hardening processes, and during manufacturing processes. Some of the topics are the stability and relaxation behavior of macro and micro residual stresses, stress determination in coatings, the effects of process equipment design, the application of metallo- thermo-mechanic to quenching, inducing compressive stresses through controlled shot peening, and the origin and assessment of residual stresses during welding and brazing. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Download or read book Relating Processing microstructure mechanical Properties of Inconel 718 Fabricated by Selective Laser Melting written by Sharniece Holland and published by . This book was released on 2018 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selective laser melting (SLM), uses a computer controlled scanning beam to selectively melt pre-spread powders in a layer by layer fashion. SLM has become a powerful tool to fabricate Inconel 718 due to the ability to obtain a desired microstructure and mechanical properties such as hardness and tensile strength. The combination of rapid melting and solidification in the SLM process, produces a very unique microstructures, which results in different material properties in comparison to conventional routes. Although Inconel 718 has been thoroughly studied, an in-depth analysis of grain boundary (GB) network structures and multiscale correlation of microstructure and mechanical behaviors is lacking. This work aims to relate the processing-microstructure-property relationship of Inconel 718 fabricated by SLM using experimental characterization, computational simulation, and theoretical analysis. These investigations reveal: 1. The as-SLM Inconel 718 exhibits spatial heterogeneity with a typical fast solidification structure with melting pool, columnar and equiaxial grains. In the melt pools, finer dendritic structure and a cellular structure, reflecting micro-segregation due to the laser induced localized thermal history. Upon heat treatment, the unique SLM structures are completely removed. The HT sample displays a fully recrystallized grain structure with appearance of twin boundaries and precipitates along the GBs and within the grain interiors. 2. Effective properties are influenced by the character and connectivity. The GBs diffusivity for both random and crystallographically consistent networks exhibits two types of behaviors, based on the contrast of local diffusivity of individual GBs. The as- SLM samples are occupied by one large connected general cluster reflecting the dominance of J0 triple junctions. While the HT sample multiple special clusters reflecting the interweaving of general and special boundaries. 3. The Vickers hardness of the as-SLM sample is ~ 3.14 GPa and the measured wear rate is ~ 2.16 ©710-6 mm2 while the HT sample had a significant increase in the Vickers hardness to ~ 4.49 GPa, and a reduction of wear rate to 1.75©710-6 mm2. Such enhancement of the mechanical performance can be contributed to the improvement of part quality via lowering the porosity, the removal of residual thermal stress, and the precipitation of nanoscale strengthening phases.
Download or read book Laser Additive Manufacturing of High Performance Materials written by Dongdong Gu and published by Springer. This book was released on 2015-04-21 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book entitled “Laser Additive Manufacturing of High-Performance Materials” covers the specific aspects of laser additive manufacturing of high-performance new materials components based on an unconventional materials incremental manufacturing philosophy, in terms of materials design and preparation, process control and optimization and theories of physical and chemical metallurgy. This book describes the capabilities and characteristics of the development of new metallic materials components by laser additive manufacturing process, including nanostructured materials, in situ composite materials, particle reinforced metal matrix composites, etc. The topics presented in this book, similar as laser additive manufacturing technology itself, show a significant interdisciplinary feature, integrating laser technology, materials science, metallurgical engineering and mechanical engineering. This is a book for researchers, students, practicing engineers and manufacturing industry professionals interested in laser additive manufacturing and laser materials processing. Dongdong Gu is a Professor at College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics (NUAA), PR China.
Download or read book Additive Manufacturing written by T.S. Srivatsan and published by CRC Press. This book was released on 2015-09-25 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Get Ready for the Future of Additive ManufacturingAdditive Manufacturing: Innovations, Advances, and Applications explores the emerging field of additive manufacturing (AM)-the use of 3D printing to make prototype parts on demand. Often referred to as the third industrial revolution, AM offers many advantages over traditional manufacturing. This pr
Download or read book Laser Additive Manufacturing written by Milan Brandt and published by Woodhead Publishing. This book was released on 2016-09-01 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser Additive Manufacturing: Materials, Design, Technologies, and Applications provides the latest information on this highly efficient method of layer-based manufacturing using metals, plastics, or composite materials. The technology is particularly suitable for the production of complex components with high precision for a range of industries, including aerospace, automotive, and medical engineering. This book provides a comprehensive review of the technology and its range of applications. Part One looks at materials suitable for laser AM processes, with Part Two discussing design strategies for AM. Parts Three and Four review the most widely-used AM technique, powder bed fusion (PBF) and discuss other AM techniques, such as directed energy deposition, sheet lamination, jetting techniques, extrusion techniques, and vat photopolymerization. The final section explores the range of applications of laser AM. Provides a comprehensive one-volume overview of advances in laser additive manufacturing Presents detailed coverage of the latest techniques used for laser additive manufacturing Reviews both established and emerging areas of application
Download or read book Characterisation of Areal Surface Texture written by Richard Leach and published by Springer Science & Business Media. This book was released on 2013-04-03 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: The function of a component part can be profoundly affected by its surface topography. There are many examples in nature of surfaces that have a well-controlled topography to affect their function. Examples include the hydrophobic effect of the lotus leaf, the reduction of fluid drag due to the riblet structure of shark skin, the directional adhesion of the gecko foot and the angular sensitivity of the multi-faceted fly eye. Surface structuring is also being used extensively in modern manufacturing. In this way many properties can be altered, for example optical, tribological, biological and fluidic. Previously, single line (profile) measurements were adequate to control manufacture of surfaces, but as the need to control the functionality of surfaces increases, there is a growing need for three-dimensional (areal) measurement and characterisation techniques. For this reason there has been considerable research, development and standardisation of areal techniques. This book will present the areal framework that is being adopted by the international community. Whereas previous books have concentrated on the measurement aspects, this book concentrates on the characterisation techniques, i.e. how to interpret the measurement data to give the appropriate (functional) information for a given task. The first part of the book presents the characterisation methods and the second part case studies that highlight the use of areal methods in a broad range of subject areas - from automobile manufacture to archaeology. Contents Introduction to Surface Topography The Areal Field Parameters The Areal Feature Parameters Areal Filtering Methods Areal Form Removal Areal Fractal Methods Choosing the Appropriate Parameter Characterisation of Individual Areal Features Multi-Scale Signature of Surface Topography Correlation of Areal Surface Texture Parameters to Solar Cell Efficiency Characterisation of Cylinder Liner Honing Textures for Production Control Characterisation of the Mechanical Bond Strength for Copper on Glass Plating Applications Inspection of Laser Structured Cams and Conrods Road Surfaces
Download or read book Welding Metallurgy and Weldability of Nickel Base Alloys written by John C. Lippold and published by John Wiley & Sons. This book was released on 2011-09-20 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most up-to-date coverage of welding metallurgy aspects and weldability issues associated with Ni-base alloys Welding Metallurgy and Weldability of Nickel-Base Alloys describes the fundamental metallurgical principles that control the microstructure and properties of welded Ni-base alloys. It serves as a practical how-to guide that enables engineers to select the proper alloys, filler metals, heat treatments, and welding conditions to ensure that failures are avoided during fabrication and service. Chapter coverage includes: Alloying additions, phase diagrams, and phase stability Solid-solution strengthened Ni-base alloys Precipitation strengthened Ni-base alloys Oxide dispersion strengthened alloys and nickel aluminides Repair welding of Ni-base alloys Dissimilar welding Weldability testing High-chromium alloys used in nuclear power applications With its excellent balance between the fundamentals and practical problem solving, the book serves as an ideal reference for scientists, engineers, and technicians, as well as a textbook for undergraduate and graduate courses in welding metallurgy.
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 Selective Laser Melting Materials and Applications written by Prashanth Konda Gokuldoss and published by . This book was released on 2020 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing (AM) is one of the manufacturing processes that warrants the attention of industrialists, researchers, and scientists. AM has the ability to fabricate materials to produce parts with complex shapes without any theoretical restrictions combined with added functionalities. Selective laser melting (SLM), also known as laser-based powder bed processing (LPBF), is one of the main AM process that can be used to fabricate wide variety of materials that are Al-, Ti-, Fe-, Ni-, Co-, W-, Ag-, and Au-based, etc. However, several challenges need to be addressed systematically, such as development of new materials that suit the SLM process conditions so the process capabilities can be fully used to produce new properties in these materials. Other issues in the field are the lack of microstructure-property correlations, premature failure, etc. Accordingly, this Special Issue (book) focuses mainly on the microstructure-correlation in three different alloys: AlSi10Mg, Ti6Al4V, and 304L stainless steel, where six articles are presented. Hence, this Special Issue outlines microstructure-property correlations in the SLM processed materials and provides a value addition to the field of AM.
Download or read book Surface Integrity and Energy Consumption in Machining of Inconel 718 Produced by Selective Laser Melting written by Daniel James Brown and published by . This book was released on 2017 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of additive manufacturing (AM) in the past decade has brought along with it a number of new opportunities and challenges when it comes to how parts are manufactured. While this development represents an increase in the capabilities and performance of the AM parts, much work and research still needs to be done in order to ascertain how to avoid the limitations that plague AM such as low dimensional accuracy, high surface roughness, and large tensile residual stress. Ongoing efforts to improve part quality through process optimization of parameters such as scan speed and laser power, post heat treatment, or machining, are currently being pursued to mitigate these limitations, and it is likely that the fabrication of a functional part lies within the use of all of these efforts. Little study has been done to characterize surface integrity of an as-SLM part followed by milling (e.g., hybrid SLM-milling). In this paper, surface integrity including surface roughness, microstructure, and microhardness have been characterized for the IN718 samples processed by the hybrid process. It has been found that surface integrity can be significantly improved by the hybrid SLM-milling route. To investigate the machinability of the deposited materials, energy consumption was collected and analyzed in terms of specific energy between dry and flood milling of as-SLM IN718, dry-milling of conventional IN718, and flood-milling of conventional IN718. Energy consumption was the lowest for both flood milling cases compared to the dry milling case, and the lowest for both as-SLM cases in comparison to the conventionally produced cases.
Download or read book Predictive Quality Modelling of Polymer and Metal Parts Fabricated by Laser based Manufacturing Processes written by Hamed Sohrabpoor and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser processing techniques are widely used in industrial applications for their repeatability and reliability. However, the optimization of a laser process for a specific application is challenging and require detailed experimental investigations to determine the input processing conditions and parameter values that deliver high repeatability and reliability. The objective of this doctoral work was therefore to develop prediction models for laser-based processing techniques to understand the laser processing parameter relationship with the output properties and to forecast events not observed experimentally. The important techniques of Selective Laser Sintering (SLS), Laser Surface Texturing (LST),and Selective Laser Melting (SLM) were selected for development of the predictive models. For SLS of glass filled polyamide parts, an Adaptive Neuro-Fuzzy Inference system using Simulated Annealing method (ANFIS-SA) and Grey Relational Analysis (GRA) were utilised to determine processing parameters (laser power and scan speed, spacing and length) delivering best mechanical properties (tensile strength and elongation). ANFIS-SA system outperformed the GRA in finding optimal solutions for the SLS process applied for glass fiber reinforced part production. For LST study, Artificial Intelligence (AI) models were developed to predict the properties (diameter increase, insertion force and pullout force) of laser processed stainless steel 316 samples used for interference fit. Artificial Neural Network (ANN) and ANFIS were used to predict the characteristics of laser surface texturing. The models based on feedforward neural network (FFNN) were used to examine the effect of the laser process parameters for surface texturing on 316L cylindrical pins. This study demonstrated that ANFIS prediction was 48% more accurate compared to that provided by the FFNN model. Stainless steel 316L cylindrical pins with defined surface structures for interference fit application were manufactured by the Selective Laser Melting Additive Manufacturing technique. The fabricated pins were assessed for resulting bond strength within interference fit joints. The effects of texture profile on the insertion and removal forces were investigated using Box-Behnken design of Response Surface Methodology (RSM) and results are presented and discussed. ANalysis Of VAriance (ANOVA) was used to check the adequacy of the developed empirical relationships. Two quadratic models were generated. One for correlation between profile geometry and insertion force and second for relating the profile geometry to removal force. The models were validated using experimental results and demonstrated good agreement with less than 10% error.
