Arbetet behandlar utvecklingsprocessen för en insats till en ARCAM S12 Electron Beam Melting-maskin.   Behovet består i att dagens maskin kräver en full tank med tillverk-ningsmaterial för att kunna användas. Den överdrivna materialtillför-seln leder till att maskinen ej kan ses som lämplig för materialforskning, då nya material måste tillverkas i stora satser varav en stor del går som svinn. Målet med arbetet blev därför att utveckla en insats till maskinen, som skulle göra den gångbar att använda vid materialforskning, utan att permanent påverka ursprungsfunktionen.   Den utvecklade insatsen har som funktion att sänka materialanvänd-ningen i maskinen, och därigenom göra maskinen applicerbar för materialforskning. Detta genom att minska byggytan och skapa en mer sofistikerad materialmatning än originalutförandets. Materialmatningen är också modulär, på så sätt att mängden materialpulver som matas ut per cykel kan varieras med olika insatser.   Under arbetets gång behandlas alla processens steg, från målspecifikat-ionen till det slutgiltiga konstruktionsunderlaget. Projektet startade med en funktionsanalys och uppställande av en målspecifikation. Därefter startade konceptgenereringsprocessen med både kreativa och mer stringenta utvecklingsmetoder. Efter detta genomfördes konceptval med flera strukturerade konceptvalsmetoder. Det valda konceptet modellerades sedan i sin slutgiltiga form i SolidWorks. Via SolidWorks interna ritningssystem ritades även konstruktionsunderlag till insatts-modulen.   Projektets resultat är ett färdigt konstruktionsunderlag för en modul som passar i en ARCAM S12 EBM-maskin. Denna modul minskar byggvolymen till 110x110xbygghöjden i millimeter, och likriktar mängden material applicerat mellan lagerna. / This thesis work is focused on the product development of an insert module for an ARCAM S12 Electron Beam Melting machine The need for an insert module comes from the fact that the machine requires a full tank of building material to operate as intended. With concern to the large building volume the original machine cannot be seen as a viable alternative for materials research, because such research often uses expensive experimental materials. The goal for the module is therefore to lower the use of building material, and trough that make the machine viable for materials research without permanently affecting the original function. Another important function of the new module is the possibility to control and synchronize the amount of material dispensed between layers of the build.     During the length of the thesis, the entire development process of the module is discussed. From the target specification, to the finished blueprints.   The process started with the establishment of a target specification, followed by a phase of concept development containing both creative and stringent methods. After these concepts had been evaluated and culled through structured methods a final concept was selected. This concept was then modeled in Solid Works and technical drawings of the model was made for the blueprint.   The result of the thesis work is a finished blueprint for an insert module that fits an ARCAM S12 EBM machine. This module has lowered the build volume to 110x110xthe build height in millimeters, and has the possibility to synchronize the amount of material dispensed between layers. / <p>Betyg 190909</p>

Les procédés de fabrication additive sont aujourd'hui de plus en plus utilisés dans l'industrie. Parmi les différentes technologies existantes, les procédés additifs métalliques, et notamment les procédés en couches, sont les plus prometteurs pour la conception de produits mécaniques. Des travaux ont été menés sur la thématique de la conception de produits réalisés par ces moyens, il traitent principalement du choix du procédé le plus adapté, de l'optimisation de formes ou présentent des cas de reconception. Il n'existe cependant pas de démarche globale de conception de produits qui permettent de prendre en compte les spécificités des procédés additifs en couches, notamment leurs contraintes de fabrication.Lors de ce travail de thèse, les changements que ces procédés introduisent dans le domaine des possibles en conception de produits ont été montrés et illustrés par des pièces réalisées par EBM. De nouvelles opportunités s'offrent au concepteur, comme l'accès à l'ensemble du volume de fabrication, la facilité de réalisation de pièces complexes, la possibilité de réaliser des treillis tridimensionnels et la capacité de produire des mécanismes sans assemblage. Les contraintes de fabrication de ces procédés sont spécifiques. Les phénomènes thermiques lors de la fabrication ont une incidence sur la fabricabilité et la qualité des pièces. La phase de retrait de poudre impose quant à elle des contraintes d'accessibilités. Pour prendre en compte cette évolution, il est nécessaire de concevoir spécifiquement les pièces pour la fabrication additive.Le procédé EBM est au centre du travail réalisé. Il s'agit d'un moyen de fabrication additive en couches, par fusion, à l'aide faisceau d'électrons. Les phénomènes thermiques, qui peuvent causer déformations et mauvaise intégrité de la matière, l'opération de dépoudrage et la problématique de la qualité des pièces fabriquées par EBM ont fait l'objet de caractérisations expérimentales. La durée de fabrication et le coût de revient technique des pièces réalisées par EBM ont également été étudiés, afin d'établir la relation entre durée, coût et géométrie des pièces.Pour de prendre en compte les contraintes explicitées auparavant, et pour bénéficier des importantes libertés que ce procédé offre aux concepteurs, une démarche de conception a été proposée. Cette démarche consiste à générer une ou plusieurs géométries initiales, soit directement par le concepteur, soit par l'utilisation d'outils d'optimisation topologique, à partir de données extraites du cahier des charges. Une fois le balançage de la pièce choisi (en prenant en compte les contraintes de fabrication, le tolérancement de la pièce et la productivité de la fabrication), la pièce est modélisée en incluant un jeu de paramètres pour effectuer une optimisation paramétrique. Cette optimisation permet de dimensionner la pièce, tout en prenant en compte les contraintes de fabrication. A l'issue de cette phase d'optimisation, la géométrie finale est obtenue en prenant en compte les exigences des opérations de parachèvement éventuelles et en définissant les supports, s'ils sont nécessaires. Cette démarche a été illustrée par la reconception de deux pièces mécaniques qui répondent aux exigences de leur cahier des charges fonctionnel, sont fabricables à l'aide du procédé EBM et offrent des gains de masse importants.Enfin, un chapitre particulier est consacré aux perspectives mises en évidence (et ayant parfois fait l'objet de travaux préliminaires) à l'occasion de ce travail de thèse. / Nowadays, the use of Additive Manufacturing processes keeps growing in the industry. Among the numerous kinds of AM processes, metallic additive manufacturing processes, and metallic Additive Layer Manufacturing in particular, are the most interesting from a mechanical designer point of view. Several research studies have been conducted on the topic of Design For Additive Manufacturing, mostly discussing the choice of AM processes or presenting the redesign of parts. There is no specific design methodology for ALM processes that takes their specificities into account.During this PhD thesis, the changes that ALM processes bring to the design space were investigated. The designer has the opportunity to easily manufacture thin parts, complex parts, lattice structures or mechanisms that don't need any assembly. These processes also have specific manufacturing constraints compared to conventional processes. The heat dissipation is the most important factor since it can cause distortions and porosities. Powder removal, surface and geometrical quality also need to be considered during design. A specific design for additive manufacturing methodology is necessary to take these changes into account.This work focuses on the Electron Beam Manufacturing process. Experiments were conducted and analyzed to assess the manufacturability regarding the thermal phenomena (during melting), the powder removal and the quality of the parts produced by EBM. The impact of the part geometry on manufacturing duration and manufacturing cost was also established.In order to use allow designers to use these pieces of information, we suggested a designing methodology. From the requirements of the parts, one or several parts are generated by the designer or by using topological optimization tools. The orientation of the part inside the manufacturing space is set before designing a refined parametric geometry. This parametric geometry is optimized in order to meet the user requirements as well as the EBM requirements. The last step is the modification of the geometry to comply with the finishing operations (machining allowances for example) and the placement of supports, if needed. This methodology was illustrated with the redesign of two example parts and showed important mass savings from the parts (while meeting user and process requirements).The prospects discovered and highlighted during this work, some of which were preliminary investigated, are presented in a specific chapter.

Aujourd’hui, la fabrication additive de pièces métalliques par le procédé EBM (fusion sélective par faisceau d’électrons) concerne essentiellement les alliages de titane et les alliages cobalt-chrome. Une forte demande du secteur aéronautique pousse à étudier la possibilité d'étendre les champs d’application de ce nouveau procédé d'élaboration à d'autres matériaux à haute valeur ajoutée, notamment les superalliages base Nickel.Après la caractérisation des poudres et la description des particularités du procédé EBM (mise en œuvre, paramètres, thermique…), ce travail s'est attaché à développer une méthodologie permettant de structurer l’utilisation d’un nouveau matériau par EBM. Cette méthodologie a dans un premier temps été validée sur un superalliage base Nickel soudable: l'inconel 625.La mise en œuvre d’un superalliage non-soudable a révélé une problématique de fissuration à chaud. Une partie du travail de thèse a été consacrée à la compréhension de l'origine de la fissuration à partir de caractérisations microstructurales multi-échelles. L'étude de la genèse des microstructures et des défauts hérités de la fabrication a permis de proposer des règles de fabrication afin de limiter, et même d'éviter complètement la fissuration. Une adaptation des paramètres opératoires et des stratégies de fusion lors du procédé EBM est utilisée pour générer des microstructures présentant des structures de grains différentes allant de structures équiaxes jusqu'à la fabrication de monocristaux en passant par des structures colonnaires de différentes tailles.Le couplage entre un modèle de solidification prédisant la transition colonnaire-équiaxe et des simulations éléments finis permettant de quantifier les gradients thermiques et les vitesses de solidification a permis d’établir des liens entre les paramètres procédé et les microstructures résultantes. / Over the last decade, new processing routes based on additive manufacturing (AM) have emerged. Among the AM processes, Electron Beam Melting (EBM) was mainly dedicated to the fabrication of components made of titanium or chromium-cobalt alloys. Aeronautic industry has been a driving force to investigate the possibility to extend the EBM process to other materials and in particular to Ni-based superalloys.The first objective of this work was to develop a methodology to rationalize the use of a new material in the EBM machine. This can be achieved by studying the main characteristics of the EBM process: powder requirements, melting parameters and strategies, thermal aspects.... The methodology was first validated on a weldable Ni-based superalloy: the Inconel 625 grade.The methodology was then extended to the fabrication of a non-weldable Ni-based superalloy, i.e. a grade containing a large fraction of the γ' strengthening phase. Processing such non-weldable superalloys by EBM usually induced cracks in the fabricated components. The microstructures were characterized in order to identify the mechanism at the origin of the cracks. Understanding the mechanism responsible for the development of cracks has allowed to propose new melting strategies limiting or completely avoiding the formation of cracks.Adjusting melting parameters and strategies turns out to be an efficient way for tailoring the grain structure. Equiaxed grains, columnar grains with different sizes as well as single crystals can thus be generated with suitable process parameters.Finally, coupling a solidification model predicting the equiaxed/columnar transition and finite element calculations quantifying the magnitude of the thermal gradient and solidification velocity allowed to establish some links between microstructures and EBM melting parameters.

A ce jour, la fabrication additive est développée avec plusieurs procédés qui sont capables de fabriquer les pièces en plastique ou en métallique. De plus, la FA a des avantages qui sont des limites pour la technologie traditionnelle. Par exemple, grâce à la liberté de la forme de la pièce, il n’y pas besoin des outillages spécifiques. Mais la FA a aussi des inconvénients, par exemple, la qualité de surface de la pièce, normalement faible, le cout, de la fabrication, notamment à cause de l’investissement pour la machine de fabrication et aussi la matière première. Il y a beaucoup de différences entre la FA et les technologies traditionnelles. Nous considérons donc qu’il est nécessaire d’avoir un nouveau processus de conception pour la fabrication additive On étudie une méthode de conception pour la fabrication additive qui nous permet de fabriquer une pièce ou un mécanisme de manière optimale.Notre travail de thèse est appuyé sur les deux questions de recherche :• Quel modèle pour le processus de conception d’une pièce par fabrication additive ?o Comment tirer les profits de l’avantage de la FA, par exemple, la liberté de la forme ?o Comment intégrer des caractéristiques du procédé de FA dans le processus de conception ?• Quelle est l’influence de la représentation intermédiaire dans le processus de conception pour la fabrication additive ?o Les types de représentations intermédiaires avec la FAo Le choix du type de représentation intermédiaire pour évaluer le produit dans un moment spécifique du processus de conception pour la FA.En première temps, nous avons développé une modèle de processus qui permet de prise en compte la caractéristique des procédés, ainsi de tirer les profits de l’avantage de fabrication additive.En deuxième temps, nous avons déterminé une méthode de choix qui nous permet de choisir entre les types de représentations intermédiaire pour évaluer le produit dans un processus de conception pour la FA. Cette méthode est basé sur Case Based Reasoning. / To date, additive manufacturing is being developed with several processes that are capable of manufacturing plastic or metal parts. In addition, the FA has advantages that are limitations for traditional technology. For example, thanks to the freedom of the shape of the part, there is no need for specific tools. But the FA also has disadvantages, for example, the surface quality of the part, normally low, cost, manufacturing, especially because of investment for the manufacturing machine and also the raw material. There are many differences between AF and traditional technologies. We therefore consider it necessary to have a new design process for additive manufacture. A design method for additive manufacturing is being studied which allows us to manufacture a part or mechanism in an optimal way.Our thesis work is based on the two research questions:• Which model for the design process of a part by additive manufacturing?O How to draw the benefits of the FA advantage, for example, freedom of form?O How to integrate AF process characteristics into the design process?• What is the influence of intermediate representation in the design process for additive manufacturing?O Types of intermediate representations with FAO The choice of intermediate representation type to evaluate the product at a specific time in the design process for the FA.In the first phase, we have developed a process model that takes into account the characteristic of the processes, thus taking advantage of the additive manufacturing advantage.As a second step, we determined a method of choice that allows us to choose between the types of intermediate representations to evaluate the product in a design process for FA. This method is based on Case Based Reasoning.

Syftet med detta projekt var att undersöka möjligheterna att externt mata in pulver i en PBF-maskin (en EBM-maskin, Electron Beam Melting), för att öka maskinens effektivitet. Huvudmålet med projektet var att designa ett sätt att leverera pulver till byggkammaren från en extern källa. Metoden som användes var produktutveckling från lektioner på universitetet, litteratur och några faser uppfanns specifikt för att hjälpa till med utvecklingen. Metoden delades upp i olika faser som hjälpte till att hålla en jämn takt under hela projektet. Vissa tester gjordes för att pröva om den nuvarande utrustningen kunde användas i konceptet. Resultaten visar att extern pulvermatning för EBM-maskiner har en öppning på marknaden, vilket innebär att inget företag har upptäckt ett sätt att externt mata pulver. Ytterligare resultat visade nuvarande brister och positiva delar av det nuvarande matningssystemet, men ännu viktigare vilka områden som kan förbättras och saker att tänka på när man utvecklar det nya konceptet. Testerna på ventilen visade att den kan ta "fullt" vakuum när den är ren, men mer utveckling måste göras för att välja den perfekta ventilen. Testet av tunnan visade att tunnan kunde stå emot visst vakuum och tätningen kunde förbli intakt. Men det behövs mer utveckling av tunnan för att få det att fungera. En målspecifikation gjordes och några koncept utvecklades. Efter det togs ett beslut om vilket koncept som gick framåt, det var det blå konceptet. Sedan gjordes några skisser och design i CAD för att visualisera hur konceptet såg ut. Syftet med projektet uppnåddes och huvudmålet uppfylldes. Ytterligare arbete och utveckling krävs för att göra detta koncept redo för prototypframställning och produktion. / The purpose of this project was to investigate the possibilities to externally feed powder into a PBF-machine (a EBM-machine, Electron Beam Melting) to increase the effectiveness of the machine. The main goal of the project was to design a way to deliver powder to the building-chamber from an external source. The method used was product development learnt from lessons at the university, literature and some phases were specifically invented to help with development. The method was split up into different phases that helped keep a steady pace during the whole project. Some tests were made to try if the current equipment could be used in the concept. The results show that external powder feed for EBM machines have an opening in the market, meaning that no company has jet discovered a way to externally feed powder. Further results showed the current flaws and positive parts of the current feeding system, but more importantly what areas that could be improved and things to consider when devel-oping the new concept. The tests on the valve showed that it can take “full” vacuum when clean, but more research must be done to choose the perfect valve. The barrel test showed that the barrel could withstand some vacuum and the sealing could remain intact. But more research on the barrel is needed. A target specification was made and some con-cepts were developed. After that a decision was made which concept was moving forward, it was the blue concept. Then some sketches and designs in CAD was made to visualize how the concept looked like. The purpose of the project was achieved and the main goal was met. Further work and development are needed to make this concept ready for prototyping and production. / <p>Betygsdatum 2023-06-28</p>

Additive tillverkning (AM) är en tillverkningsteknik som har använts i stor utsträckning i industrier de senaste åren. Electron beam melting (EBM) är en innovativ teknik för tillverkning inom ortopediska implantat- och flygindustrin för att EBM erbjuder hög produktivitet och lägre kostnad per del. Jämfört med traditionella tillverkningsmetoder kan EBM tillverka delar med betydande mekaniska egenskaper, men det finns några vanliga brister som hindrar EBMs förmåga att bli en vanligare bearbetningsmetod vid tillverkning. I detta arbete, som tar an formen av en State of the Art Rapport, introduceras EBM-metoden på teknisk nivå och jämförs med andra AM-metoder och konventionella tillverkningsmetoder. / Additive manufacturing (AM) is a manufacturing technology that has been widely used in industries in recent years. Electron beam melting (EBM) is an innovative technology for manufacturing of the orthopedic implant and aerospace industry because EBM offers high productivity and lower cost per part. Compared to traditional manufacturing methods, EBM can produce parts with significant mechanical properties, but there is some common shortcoming that prevent EBM's ability to become a more common processing method in manufacturing. This work, which takes the form of a State of the Art Report, introduces the EBM method at the technical level and compares with other AM methods and conventional manufacturing methods.

Fibromyalgia syndrome (FMS) is a chronic pain condition with significant societal and personal burdens of illness. Chronic opioid therapy in the treatment of chronic nonmalignant pain has increased drastically over the past decade. This is a worrisome trend in general, but specifically, given the pathophysiologic characteristics seen in fibromyalgia syndrome patients, the use of this class of medication deserves special scrutiny. Although the theoretical case against this therapy choice is strong, little empirical evidence exists. In order to supplement this literature, retrospective analysis methods are utilized to examine the association of state-, provider-, and patient level characteristics with the prevalence of chronic opioid use in this disease state. Data gathered through this analysis is then used to develop a propensity index for the identification of an appropriate control group for fibromyalgia patients, a task that has proven difficult in the literature to date. Using propensity stratification and matching techniques analysis of the impact of fibromyalgia, chronic opioid use, and the interaction of these two variables are undertaken. Several key findings and updates to the understanding of chronic opioid use and fibromyalgia syndrome are reported. Wide geographic variation in chronic opioid utilization between states is seen. The role of diagnosing provider type in the rate of chronic opioid prescribing is significant and can be aggregated at various levels. Demographic characteristics, comorbid conditions, and concurrent medication use are all important associates of chronic opioid use in fibromyalgia syndrome. Additionally, chronic opioid use in fibromyalgia patients, independent of propensity to receive that therapy choice is a significant correlate with healthcare costs. A diagnosis of fibromyalgia is a statistically significant source of healthcare costs, though the clinical significance of its impact when compared to a closely matched control group is minimized. Despite the minimization of the role of this diagnosis the impact of the interaction of chronic opioid use with fibromyalgia, despite control for myriad regressors, is significant both statistically and clinically.

This thesis was conducted to better understand how consumers in Sweden are affectedin the evaluation stage of the EBM model in the context of social media advertisingexposure within the fashion industry and further to identify what factors are importantfor consumers when evaluating different options and see what type of advertisementthat is preferred. The thesis was conducted using a qualitative approach and datacollection consisted of conducting 25 in-depth semi-structured interviews withconsumers representing different parts of Sweden and 2 expert interviews to betterunderstand the retailer's perspective. The authors found that social media advertisinginfluences consumers decision-making and that it can affect the consumer evaluationstage however mainly through the information search stage. The authors further foundthat sponsored advertisements are the preferred type, and that advertising can createboth negative and positive relationships. The authors could see that social mediaadvertising exposure affected consumers and made them willing to try new brands outbut often choose brands that they previously had a relationship with. The author'simplication of consumers' receptiveness towards social media advertising togetherwith their habits of taking their final decision on retailers or brands websites showhow marketers focus need to be on click through and targeting consumers makingtheir final decisions there. The thesis provides useful knowledge in consumerbehaviour and implications for how brands and retailers within the fashion industryshould focus their marketing efforts.

No description available.

Additive Manufacturing (AM) as a method is on the rise and allow for a high freedom to create unique shapes without being limited by conventional machining methods. The Electron Beam Melting method, developed by Arcam AB in Mölndal, Sweden, use Powder Bed Fusion together with an electron beam and at an elevated temperature (+1000ºC) to lower stress due to thermal gradients. The purpose of this paper is to study the influence of Scan Length during Electron Beam Melting of Alloy 718 in regards to the appearance of shrinkage, porosity, primary carbide precipitation (mainly NbC), primary dendrite width and hardness. Samples built had the dimensions of 10x15xVar mm3 (Height x Depth x Width) with widths ranging from 10 mm in steps of 5 mm up to a maximum of 90 mm. The parameters were set as a single entry within the build project and as such each layer was melted as a single unit. A Light-Optical Microscope (LOM) and a Scanning Electron Microscope (SEM) was used to obtain images for manual counting to calculate the fraction of porosity and NbC-precipitates as well as the columnar grain width. The space between lines of interdendritical precipitation of NbC was used to determine the dendrite arm widths and a series of Hardness Vickers (500g for 15s) indents was performed. An Energy-Dispersive X-Ray Spectroscope (EDS) was used to help identify precipitates and phases. Columnar grain width and the spacing between vertical bands of interdendritical NbC was measured according to ASTM112-13 while porosity and hardness was measured according to ASTM562-11. Both of these only looked at the XZ-plane instead of all three planes. The columnar grain width was measured in the 10 mm, 40 mm and 90 mm samples at a distance of 4 mm from the top and with a slight spread over the sample width according to ASTM112-13 but using only one plane for counting. No significant change to columnar width was found. Primary dendrite arm width was measured on the 10 mm, 40 mm and 90 mm samples at about 5 mm from the top. An average for all samples was found to be 7.82 μm ± 2.89. No significant trend could be found with increased sample width. A total average porosity of 0.33% ± 0.16 was found. Variations between samples were less than the standard deviation. Even though the variations were not high enough to be significant, no obvious trend could be seen in regards to sample width, position on the base plate or heat transfer through the build. The presence of NbC was investigated in all samples with a total average of 0.36% ± 0.23 with variations between sample lengths being within the standard deviation. An insignificant trend could be seen between the smaller samples together with the wider samples having a higher degree of NbC compared to the middle samples. No significant trend could be seen in NbC based on row. Across all samples, the mean hardness was found to be 406.75 HV0.5 ± 16.53. No significant trend could be seen with increased sample width. Based on sample rows no significant trend could be seen.