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The technique of selective laser melting (SLM), developed in the late 20th century knows significant developments at present times. This technique, consisting of melting powder by successive layers, has the advantage of making extremely complex shapes, unachievable by traditional techniques. The use of different types of metal materials broadens its scope. The purpose of this work is the implementation of an Invar alloy by laser melting selective. Our main objective was to know the influence of each stage of heat treatment on microstructure and properties of Invar 36. Invar is an iron-nickel alloy with 36% Ni, which has the distinction of having a very low coefficient of thermal expansion in a wide temperature range around room temperature. This feature presents a major technological interest. After a brief explanation about the art on Invar, Invar effect and the SLM process, I will then present the pieces Invar manufactured by SLM for which a characterization of the microstructure was performed before and after heat treatment. The microstructural characterizations were performed with an optical microscope and scanning electron, and through Vickers hardness measurements and expansion. The results showed that the heat treatment does not significantly affect the microstructure and hardness of samples. The porosity rate decreases from the outside towards the inside of the building board and the thermal expansion coefficient of the alloys varies very little after heat treatment. In order to make a "preliminary validation and unoptimized" of the fabrication technique SLM Invar, a comparison is made between the parts produced by SLM and an extruded rod of Invar. An important discussion is then proposed on the influence of various parameters such as chemical composition, method of preparation and heat treatment on the properties and microstructure expansion.
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The present work explores the capability of fabbricating low-alloyed metal parts through the layer-by-layer Selective Laser Melting (SLM) technique. The alloy used was AISI S2, which is a carbide-free tool steel made of 0,49%wt of Carbon. Such kind of steels are not popular as for Additive Manufacturing process due to their unpromising welding properties. However, obtained results demonstrated the feasibility of printing fully dense, defects-free with good surface quality low-alloyed steels. A process map containing the optimum set of parameters for the realisation of the S2 metal parts will be presented. Indications for the use of the same process map in the situations of different process conditions or different manufactured steels will be provided as well. Later, the printed pieces were subject to microstructural investigation under their as-build and heat-treated conditions. The outcomes showed a epitaxial grain growth strongly influenced by the scan strategy. Moreover, the outermost top layer consisted of supersaturated martensite which was characterized in order to gain information about the prior microstructure which was present. Whereas the rest of the cross-sections of the as-built samples were found to have bands of tempered martensite at various degrees of tempering. The cause was related to the complex thermal history of the SLM process. In order to achieve all the results several unique techniques have been used such as reverse Differential Thermal Analysis, post-processing heat treatment and nanoindentation. The latters were used in less common ways to obtain a deeper knowledge of the microstructure of S2 metal parts printed through SLM technique, showing promising results.
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Three-dimensional printing is a futuristic technology capable of transforming the ways in which we make components and devices. It is almost certain that this technique will find its niche in the manufacturing sector in the very near future. In view of the growing importance of 3D printing, this book addresses key issues related to emerging science and technology in this area. Detailed and informative articles are presented in relation to a wide variety of materials, including those based on critical engineering metals such as aluminum, magnesium, titanium and composites. Advances in various techniques, such as electron beam melting and selective laser melting are discussed. Of key importance in the area of materials science is the end properties of the materials following processing. Accordingly, the articles presented critically discuss the effects of microstructural features such as porosity, forming defects and the heat treatment induced effects on the mechanical properties. Applications covered in these articles are targeted at the aerospace, automobile, defense and aerospace sectors. Overall, the information presented in this book is of significant importance for academic and industrial-based researchers who wish to inform themselves regarding this upcoming highly promising manufacturing technique.
composites --- laser metal deposition --- additive manufacturing --- titanium --- selective laser melting --- magnesium --- aluminum --- 3D printing --- electron beam melting
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3D printing is rapidly emerging as a key manufacturing technique that is capable of serving a wide spectrum of applications, ranging from engineering to biomedical sectors. Its ability to form both simple and intricate shapes through computer-controlled graphics enables it to create a niche in the manufacturing sector. Key challenges remain, and a great deal of research is required to develop 3D printing technology for all classes of materials including polymers, metals, ceramics, and composites. In view of the growing importance of 3D manufacturing worldwide, this Special Issue aims to seek original articles to further assist in the development of this promising technology from both scientific and technological perspectives. Targeted reviews, including mini-reviews, are also welcome, as they play a crucial role in educating students and young researchers.
n/a --- microstructure --- reversed austenite --- corrosion behavior --- advanced X-ray computed tomography (XCT) --- additive manufacturing --- forming defects --- single strut --- wear properties --- thermodynamic behavior --- laser deposition welding --- titanium alloys --- SLM structure performance --- porosity --- formation mechanism --- magnesium --- part redesign --- forming morphology --- microhardness --- bonding quality --- electron beam melting --- mechanical properties --- frame structure reconstruction --- aging behaviour --- aluminum matrix composites --- Selective Laser Melting (SLM) --- maraging steel --- tailored blanks --- selective laser melting --- selective laser melting (SLM) --- 3D printing --- Ti6Al4V
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The thesis aims at determining suitable selective laser melting process parameters enabling high productivity and sufficient part quality, for two materials: the aluminium alloy AlSi10Mg and the stainless steel SS316L. To do that, the concept of productivity is first defined. On that basis, a strategy to optimize it is determined. It consists of finding adequate exposure parameters (power, scanning speed, hatch spacing, contour powers and contour scanning speeds) leading to a high relative density and low surface roughness, when the layer thickness is set to 0.1 mm (AlSi10Mg) and 0.08 mm (SS316L). Experiments consisting of printing small cubes with different sets of parameters are conducted. Selecting test series parameters is reasoned using an index, which provides an estimation of the lack of fusion porosity that should be expected given a combination of power, scanning speed, hatch spacing and layer thickness. Relative density is measured through Archimede’s method and micrography. AlSi10Mg and SS316L samples associated to a high index show lack-of-fusion pores. Besides, AlSi10Mg samples manufactured with low scanning speeds are subjected to spherical porosity, due to hydrogen bubbles that had time to grow in the melt pool before being trapped by solidification, most likely. SS316L samples present keyhole pores at high-energy-density regimes and porosity due to Plateau-Rayleigh instability at high-power-and-scanning-speed regimes. Regarding surface quality, AlSi10Mg samples show a lower roughness when linear energy density is increased using two pre-contours, whereas SS316L samples present a better surface quality with one post-contour. Best surface roughness obtained after sandblasting is 6 μm for AlSi10Mg and 7 μm for SS316L. Based on the conclusions of the experiments, a model is built to delimit windows of parameters leading to a sufficiently high density. Optimal sets regarding productivity are selected inside the windows. Predicted build rates are 16.5 mm3/s and 9.6 mm3/s for AlSi10Mg and SS316L, respectively. They increase current volume build rates by 58% and 159%, respectively.
Selective laser melting --- AlSi10Mg --- 316L --- Highly productive --- Experiments --- Density --- Surface roughness --- Layer thickness --- Parameters --- Power --- Scanning speed --- Hatch spacing --- Ingénierie, informatique & technologie > Ingénierie mécanique --- Ingénierie, informatique & technologie > Science des matériaux & ingénierie
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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.
n/a --- geometrical dimensioning and tolerancing (GD and T) --- Ti–6Al–4V --- microstructure --- compression testing --- analytical melt pool calculation --- stainless steel --- build orientation --- surface roughness --- process variability --- Tukey’s test --- additive manufacturing --- phase change --- AlSi10Mg --- analysis of variance --- SLM --- repeatability and reproducibility --- inter-repeatability --- distortion analysis --- laser powder bed fusion --- porosity --- dimensional quality analysis --- cylindrical symmetry --- metrology --- mechanical properties --- HIP --- fatigue strength --- process capability --- hatch angle --- line heat source --- selective laser melting --- selective laser melting (SLM) --- intra-repeatability --- Ti-6Al-4V --- Tukey's test
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This special issue provides a current snapshot of recent advances and ongoing challenges in the development of titanium alloys for biomedical implants and devices. Titanium offers significant advantages over other materials including higher strength and better biocompatibility. This issue highlights current trends and recent developments, including the uptake of additive manufacturing (3D printing), and approaches to improve processing and performance of titanium alloys for medical applications.
History of engineering & technology --- selective laser melting --- gradient structure --- porous biomaterial --- Ti6Al4V --- mechanical properties --- osteoblast --- biomechanics --- dental implant(s) --- in vitro --- systematic reviews --- evidence-based medicine --- atrophic maxilla --- titanium hybrid-plates --- finite element analysis --- biomechanical analysis --- single-point incremental forming --- AHP --- cranioplasty plates --- decision-making --- titanium alloys --- medical devices --- machining --- titanium --- temperature --- strain --- grain refinement --- ultrafine --- nanocrystalline --- mechanical characterization --- press-fit --- primary stability --- Ti-6Al-4V --- additive manufacturing --- selective laser melting (SLM) --- electron beam melting (EBM) --- direct metal deposition (DMD) --- wire and arc additive manufacturing (WAAM) --- diffraction line profile analysis --- extended convolution multiple whole profile (eCMWP) --- implanted electrodes --- electrical stimulation --- corrosion --- mandibular reconstruction --- scaffolds --- reconstruction plate --- 3D printing --- titanium alloy --- Titanium alloys --- Ti-6Al-4V-ELI --- fatigue --- laser cutting --- post-processing --- α’-martensite --- HAZ --- barrel grinding --- notch --- fracture --- selective laser melting --- gradient structure --- porous biomaterial --- Ti6Al4V --- mechanical properties --- osteoblast --- biomechanics --- dental implant(s) --- in vitro --- systematic reviews --- evidence-based medicine --- atrophic maxilla --- titanium hybrid-plates --- finite element analysis --- biomechanical analysis --- single-point incremental forming --- AHP --- cranioplasty plates --- decision-making --- titanium alloys --- medical devices --- machining --- titanium --- temperature --- strain --- grain refinement --- ultrafine --- nanocrystalline --- mechanical characterization --- press-fit --- primary stability --- Ti-6Al-4V --- additive manufacturing --- selective laser melting (SLM) --- electron beam melting (EBM) --- direct metal deposition (DMD) --- wire and arc additive manufacturing (WAAM) --- diffraction line profile analysis --- extended convolution multiple whole profile (eCMWP) --- implanted electrodes --- electrical stimulation --- corrosion --- mandibular reconstruction --- scaffolds --- reconstruction plate --- 3D printing --- titanium alloy --- Titanium alloys --- Ti-6Al-4V-ELI --- fatigue --- laser cutting --- post-processing --- α’-martensite --- HAZ --- barrel grinding --- notch --- fracture
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Additive manufacturing (AM), more commonly known as 3D printing, has grown trememdously in recent years. It has shown its potential uses in the medical, automotive, aerospace, and spare part sectors. Personal manufacturing, complex and optimized parts, short series manufacturing, and local on-demand manufacturing are just some of its current benefits. The development of new materials and equipment has opened up new application possibilities, and equipment is quicker and cheaper to use when utilizing the new materials launched by vendors and material developers. AM has become more critical for the industry but also for academics. Since AM offers more design freedom than any other manufacturing process, it provides designers with the challenge of designing better and more efficient products.
Technology: general issues --- History of engineering & technology --- additive manufacturing --- modular design --- design-for-manufacturability --- design optimization --- part consolidation --- product re-design --- topology optimization --- design for additive manufacturing --- 3D printing --- aerospace --- full-life cycle manufacturing flow --- airfoil --- carbon fiber tubes --- telescoping spars --- chevrons --- porous scaffold design --- tetrahedral implicit surface modeling --- triply periodic minimal surface --- selective laser melting (SLM) --- Ti6Al4V --- structure-property relationship --- microstructure --- Hall-Petch relationship --- additive manufacturing --- modular design --- design-for-manufacturability --- design optimization --- part consolidation --- product re-design --- topology optimization --- design for additive manufacturing --- 3D printing --- aerospace --- full-life cycle manufacturing flow --- airfoil --- carbon fiber tubes --- telescoping spars --- chevrons --- porous scaffold design --- tetrahedral implicit surface modeling --- triply periodic minimal surface --- selective laser melting (SLM) --- Ti6Al4V --- structure-property relationship --- microstructure --- Hall-Petch relationship
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This book is an exciting collection of research articles that offer a unique view into the fast developing field of metal additive manufacturing, providing insights into this advanced manufacturing technology. The articles span recent advances in metal AM technologies, and their application to a wide range of metals, exploring how the processing parameters offer unique material properties. This book encapsulates the state of the art in this rapidly evolving field of technology and will be a valuable resource for researchers in the field, from Ph.D. students to professors, and through to industrial end users.
Technology: general issues --- additive manufacturing --- laser powder bed fusion --- A357.0 --- mechanical performance --- Laser powder bed fusion --- selective laser melting --- SKD61 tool steel --- nanoindentation --- strain-rate sensitivity --- nonhorizontal suspension structure --- boundary remelting --- surface roughness --- forming accuracy --- Ti–6Al–4V alloy --- metallurgical quality --- mechanical properties --- aluminum alloys --- high-temperature deformation --- microstructure --- selective laser melting (SLM) --- Ti alloy --- high temperature tensile --- erosion --- wear --- construction --- WAAM --- welding --- steel --- ESPI --- design --- powder bed fusion (PBF) --- Ti-6Al-4V --- phase transformation --- tensile --- 90W-7Ni-3Fe --- densification --- properties --- hyper-duplex stainless steel --- mechanical property --- corrosion resistance --- Alsi10Mg --- stress relieve --- Inconel 718 --- embrittlement --- titanium --- drilling --- chip geometry --- cutting forces --- hole quality --- DED --- laser --- thermal conductivity --- thermal diffusivity --- thermal modeling --- hot stamping --- AISI H13 --- plasma transferred arc --- processing conditions --- Hastelloy C-22 --- wire and arc additive manufacturing --- low-carbon high-strength steel --- anisotropy --- additive manufacturing --- laser powder bed fusion --- A357.0 --- mechanical performance --- Laser powder bed fusion --- selective laser melting --- SKD61 tool steel --- nanoindentation --- strain-rate sensitivity --- nonhorizontal suspension structure --- boundary remelting --- surface roughness --- forming accuracy --- Ti–6Al–4V alloy --- metallurgical quality --- mechanical properties --- aluminum alloys --- high-temperature deformation --- microstructure --- selective laser melting (SLM) --- Ti alloy --- high temperature tensile --- erosion --- wear --- construction --- WAAM --- welding --- steel --- ESPI --- design --- powder bed fusion (PBF) --- Ti-6Al-4V --- phase transformation --- tensile --- 90W-7Ni-3Fe --- densification --- properties --- hyper-duplex stainless steel --- mechanical property --- corrosion resistance --- Alsi10Mg --- stress relieve --- Inconel 718 --- embrittlement --- titanium --- drilling --- chip geometry --- cutting forces --- hole quality --- DED --- laser --- thermal conductivity --- thermal diffusivity --- thermal modeling --- hot stamping --- AISI H13 --- plasma transferred arc --- processing conditions --- Hastelloy C-22 --- wire and arc additive manufacturing --- low-carbon high-strength steel --- anisotropy
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In recent years, the industry has started to use parts printed by powder-based laser additive manufacturing (LAM) when precision and good mechanical properties are required. Applications can be found in the aerospace, automotive, and medical sectors. However, the powder materials available are often inadequate for contemporary processing tasks, and often generate process instabilities as well as porosities and defects in the resulting parts. This Special Issue, “New Frontiers in Materials Design for Laser Additive Manufacturing”, focuses on advances in material design and the development of laser additive manufacturing. Of particular interest are original papers dealing with metal and polymer powders for laser powder bed fusion or directed energy deposition. In this Special Issue, we are especially interested in answering the following questions: How can laser process parameters and material properties be adapted to the LAM process via the matrix modification (e.g., alloying, doping, compounding) of powders? How can powder properties like flowability, wetting, porosity, or (heterogeneous) nucleation be adapted to the LAM process via the surface modification of powders? How may calorimetry, high-speed videography, pyrometry, and online spectroscopy, as well as modeling, contribute to understanding dynamics of melting and recrystallization, in addition to the lateral distribution of the thermal process window?
Technology: general issues --- Chemical engineering --- powder bed fusion --- magnesium --- process development --- additive manufacturing --- PBF-LB/M --- tool steel (1.2709) --- nanocomposite --- microstructure --- mechanical properties --- laser powder bed fusion --- selective laser melting --- oxide dispersion strengthened steel --- phase-field model --- finite element simulation --- nanoparticle interaction --- pure copper --- short wavelength laser system --- green laser --- eddy-current method --- electrical conductivity --- polyamide 12 --- nanocomposites --- nanoparticles --- dispersion --- LB-PBF --- additively manufactured parts --- aluminum alloys --- intermetallics --- thermal exposure --- n/a --- aluminium alloys --- hot cracking --- rapid solidification --- differential fast scanning calorimetry --- undercooling --- grain size --- crack density
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