[pt] O objetivo deste trabalho foi produzir, caracterizar e avaliar o comportamento mecânico de um compósito de matriz termoplástica (ABS) reforçado por fibras de carbono para uso futuro em manufatura aditiva. Misturas foram produzidas contendo diferentes quantidades (0 por cento, 5 por cento e 16,7 por cento) e comprimentos (3 mm e 6 mm) de fibras. Cada mistura foi processada através de uma extrusora dupla rosca para a produção de pellets. Os pellets de cada mistura (incluindo pellets de ABS puro) foram analisados para a caracterização do material processado. Posteriormente, corpos de prova foram extrusados para a determinação das propriedades mecânicas e análise da superfície de fratura. As técnicas utilizadas para a caracterização do material foram: espectroscopia no infravermelho (FTIR), análise termogravimétrica (TGA), reometria capilar e microscopia eletrônica de varredura (MEV). Para a avaliação do comportamento mecânico, os corpos de prova extrusados foram ensaiados para a determinação da resistência à tração, módulo de elasticidade e ductilidade. Em seguida, as superfícies de fratura dos corpos de prova foram analisadas no MEV. Foi verificada a possibilidade de degradação da matriz polimérica e formação de vazios durante o processamento inicial do material, que foram eliminados após a segunda extrusão. As fibras de carbono causaram aumento no módulo de elasticidade e diminuição da ductilidade do compósito, apesar de pouco influenciarem as propriedades reológicas. Além disto, pequenas variações na estabilidade térmica foram observadas. Ao final, em anexo, foi elaborado um panorama sobre a Manufatura Aditiva (MA) e a oportunidade de utilização de compósitos em técnicas de impressão 3D. / [en] The goal of this work was to produce, characterize and analyze the mechanical behavior of a carbon fiber reinforced thermoplastic composite with future applications in additive manufacturing. Mixtures were produced with varying carbon fiber content (0 per cent, 5 per cent, and 16,7 per cent) and initial length (3 mm and 6 mm). Each mixture was processed via a twin-screw extruder to produce pellets. Pellets from each mixture (including pure ABS) were analyzed to investigate the processed material properties. Afterwards, test specimens were extruded from each mixture s pellets for mechanical testing and fracture surface analysis. The following techniques were used for material characterization: Fourrier-Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), capillary rheology and Scanning Electron Microscopy (SEM). For the evaluation of mechanical properties, the extruded test specimens yield strength, Young s modulus and ductility were determined. Also, the fracture surfaces were observed using SEM. The effects of processing parameters and of the introduction of carbon fibers in the ABS polymer were determined. Results pointed out the possibility of degradation during initial processing and the formation of voids in the pellets structure, which were eliminated during the second extrusion. Results also showed an increase in modulus and a decrease in ductility of the composite, whereas rheological properties seemed largely unaffected. Additionally, small variations in thermal stability were observed with varying carbon fiber content and length. Finally, as an annex, a brief overview of Additive Manufacturing and the opportunities for using carbon fiber reinforced thermoplastics in 3D printing techniques is presented.

Grâce à la fabrication additive, il est aujourd'hui possible de fabriquer de nouvelles géométries. Les perspectives offertes par les moyens de fabrications conventionnelles et additives sont très différentes. Des propositions de design très contraintes peuvent devenir beaucoup plus libres avec la fabrication additive. Cette liberté qu'elle offre fait émerger une multitude de possibilités. Dans ce manuscrit, nous nous sommes focalisés sur un type particulier de structures (les octetruss) ainsi que sur les moyens de fabrication EBM (Electron Beam Melting) de la société ARCAM. Les travaux présentés dans cette thèse ont été réalisés au sein des laboratoires G-SCOP et SIMAP ainsi qu'en partenariat avec l'entreprise POLY-SHAPE. Ce manuscrit est articulé autour de trois principaux points.Il s'agit tout d'abord de faire émerger des structures treillis lors du processus de conception. Pour cela, deux approches existantes sont détaillées. La première met en œuvre l'optimisation topologique et la seconde s'appuie sur le concept de matériau équivalent. Ensuite deux méthodologies permettent de faire émerger des zones dans lesquelles l'intégration de structures treillis est adaptée. La première consiste à réaliser les différentes zones en s'appuyant sur un champ de contraintes issu d'un calcul Eléments Finis, la seconde se base sur un résultat d'optimisation topologique pour établir les différentes zones. Cette seconde méthodologie est appliquée à un cas d'étude industriel.Ensuite nous étudions comment remplir les différentes zones avec des structures treillis adaptées en nous focalisant tout d'abord sur leur génération. Un accent particulier est porté sur l'intersection des différents barreaux par la mise en place de sphères. Une méthodologie permettant de générer des arrondis est également proposée. Une étude est menée sur l'ensemble des paramètres et informations à considérer pour intégrer une structure treillis à une zone donnée. Cette étude conduit à une proposition de méthodologie qui est appliquée à un cas d'étude industriel.Enfin, les aspects liés à la fabrication sont pris en compte. Pour cela, nous considérons différentes limites du moyen de fabrication EBM pour des structures treillis comme les dimensions maximales réalisables ou les problématiques thermiques. Une étude consistant à prédire la dépoudrabilité des pièces est réalisée. Enfin, des essais mécaniques sont effectués. Nos résultats sont comparés à ceux obtenus dans d'autres travaux. L'impact des arrondis sur le comportement mécanique d'une pièce est discuté. / Thanks to additive manufacturing, it is now possible to manufacture new geometric shapes. The prospects offered by the methods of conventional and additive manufacturing are very different. Highly constrained design proposals can become much freer with additive manufacturing. The freedom it offers brings forward a multitude of possibilities. In this manuscript, we focused on a particular type of structures (the octetruss) as well as the use of EBM (Electron Beam Melting) of ARCAM as a means of manufacturing. The work presented in this thesis was carried out in the laboratories G-SCOP and SIMAP as well as in partnership with the company POLY-SHAPE. This manuscript focuses on three main points.The first of which is the action of emergence of lattice structures during the design process. For this, two existing approaches are detailed. The first uses topological optimization and the second is based on the concept of equivalent material. Following these, there are two methodologies used to identify areas in which the integration of lattice structures is possible and appropriate. The first consists of creating the different zones by relying on a stress field resulting from a finite element calculation, the second establishes the different zones using a topological optimization result. This second methodology is applied to an industrial case study.Secondly, we study how to fill the different areas with appropriate lattice structures by focusing first on their generation. Particular emphasis is placed on the intersection of the various bars by the establishment of spheres. A methodology for generating rounded-shape is also proposed. A study is carried out on all the parameters and information in order to integrate a lattice structure to a given area. This study leads to a proposed methodology that is applied to an industrial case study.Finally, aspects related to manufacturing are taken into account. For this, we consider different limits of the EBM manufacturing and what they mean for lattice structures; such as maximum achievable dimensions or thermal problems. A study to predict powder removal in order to extract the fabricated structure is performed. Mechanical tests are carried out. Our results are compared to those obtained in other works. The impact of curve on the mechanical behavior of a product is discussed.

I detta   projekt har en studie av krympning vid additiv tillverkning i materialet   Ti6Al4V gjorts, detta för att analysera hur utskrifter i olika storlekar och   riktningar påverkas. Arbetet har genomförts av två studenter vid   Mittuniversitetet i Östersund och görs på uppdrag av universitetets   forskningssida. I projektet har förstudier gjorts för att lägga en grund för   arbetet. Under förstudierna hittades information om att krympningen kunde   minskas med hjälp av att använda stödmaterial i utskrifterna. Design för de   detaljer som ska skrivas ut har valts ut med hjälp av tidigare forskning där   trappor varit rekommenderat för att lätt kunna avgöra vad som händer i olika   delar av en utskrift. Även detaljer för mätning av vassa kanter och   avrundningar skrevs ut för att kunna kontrollera dessa om tid blev över men   dessa mättes aldrig då fokus under hela detta arbetet legat på trapporna.   Trapporna skrevs ut i tre olika storlekar. De skrevs ut både med och utan   stöd och i både liggande och stående led i en EBM-maskin, Arcam S12. När de   blivit utskrivna mättes de med hjälp av mikroskopet “Dino-Light edge Digital   Microscope”. Informationen som kommit fram ur dessa mätningar har sedan lagts   in i ett Excel dokument där tabeller och grafer tagits fram för att göra det   lätt att uppfatta tendenser. De utmärkande tendenser som upptäcktes var att   en större krympning alltid inträffade vid det första och tredje steget i en   utskrift. Detta inträffade oavsett vilken storlek av trappor som   kontrollerades och kunde undvikas med hjälp av att använda stödmaterial. I   modellerna med stödmaterial kunde inte speciella tendenser synas och den   krympning som syns i dessa mätningar kan bero på fel från den mänskliga   faktorn vid mätningen. Trenderna är tydliga i de detaljer som skrivits ut   utan stödmaterial. Detta fenomen kan bero på att materialet i skrivplattan   som finns i skrivaren inte är detsamma som Ti6Al4V, vilket kan ha en inverkan   på det utskrivna materialet i de lagren som är närmast skrivplattan. Krymp i   detaljerna beror också på att pulvret i skrivaren blir mindre då det smälter   vilket gör att varje lager inte får förväntad/ önskad tjocklek. Detta är ett   problem som följer med genom hela utskriften oavsett om stödmaterial används   eller ej. Arbetet som gjorts anses lyckat. / This project is a about studying and anylazing shrinkage during the   use of a EBM-machine in the material Ti6A14V. The study is done to anaylze   how prints of diffrent size and printing direction are affected by the   shrinkage. The project is done by two students at Mid Sweden University in   Östersund and the project is requested by the research department of the   university. Research has been made before the start of the project to give   the students a solid understanding in the matter. During the research for   information it was found that the shrink could be minimized by using   supportmaterial in the print. The design for the parts that was going to be   printed have been chosen through earlier studies of the matter where stairs   was recommended to easy be able to see what goes on in the different parts of   a print. Some details was also created so that measurements considering sharp   edges and round details could be checked for deformations if there was enough   time. Those were never measured since all the time of this project was   focused around the stairs. The stairs were printed in three different sizes.   They were also printed with and without supportmaterial and both standing up   and lying down in the printer EBM Arcam S12. When the parts had been printed   they were measured with a microscope called “Dino-Light edge Digital   Microscope”. The information gotten from these measurements were put into a   Microsoft Excel document where tables and graphs were created to make it easy   to spot the tendencies of the prints. The tendencies that were noticeable was   that the first and third step of every print had more shrink than the others.   This occurred no matter the size the stairs were but did not occur in the   parts printed with supportmaterial. No tendencies were noticed in the prints   with supportmaterial and the shrinkage that was noted in these prints might   also be because of the human factor. The trends are clearly visible in the   parts printed without supportmaterial. This might be because of the different   material in the printing plate that is stainless steel instead of Ti6Al4V.   This might cause problem for the layers that are printed closest to the   plate. The reason for shrinking in the details is also because of the fact   that the powder that is being printed gets melted and therefor shrinks. This   results in a thicker layer of powder everytime the powder is applied to the   printing surface. This is a problem that goes on throughout the whole print   no matter if supportmaterial is used or not. The work completed is considered to be well done. / <p>Betyg: 180809</p>

abstract: Material extrusion based rapid prototyping systems have been used to produceprototypes for several years. They have been quite important in the additive manufacturing field, and have gained popularity in research, development and manufacturing in a wide field of applications. There has been a lot of interest in using these technologies to produce end use parts, and Fused Deposition Modeling (FDM) has gained traction in leading the transition of rapid prototyping technologies to rapid manufacturing. But parts built with the FDM process exhibit property anisotropy. Many studies have been conducted into process optimization, material properties and even post processing of parts, but were unable to solve the strength anisotropy issue. To address this, an optical heating system has been proposed to achieve localized heating of the pre- deposition surface prior to material deposition over the heated region. This occurs in situ within the build process, and aims to increase the interface temperature to above glass transition (Tg), to trigger an increase in polymer chain diffusion, and in extension, increase the strength of the part. An increase in flexural strength by 95% at the layer interface has been observed when the optical heating method was implemented, thereby improving property isotropy of the FDM part. This approach can be designed to perform real time control of inter-filament and interlayer temperatures across the build volume of a part, and can be tuned to achieve required mechanical properties. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016

Orientador: Ruis Camargo Tokimatsu / Resumo: Na área da ortopedia a busca por novos avanços tecnológicos tem sido muito pouco e as pessoas que necessitam de dispositivos como órteses acabam sofrendo mais devido ao alto custo dos aparelhos ortopédicos. A maioria da população que possui patologias sofre por não ter renda suficiente para adquirir esses dispositivos e acabam agravando essas patologias. Este estudo busca inovar e propor a utilização de novas tecnologias para desenvolver órteses a essa população de baixa renda. Uma tecnologia de custo baixo e que possa ser implementada na rede pública. Através das análises feitas pelos profissionais da área como ortopedistas e terapeutas nas imagens bidimensionais dos exames do paciente consultados, com a utilização de aparelhos com a técnica de Engenharia Reversa será possível digitalizar o membro afetado ou posicioná-los de forma adequada para que seja tirado o molde da órtese personalizada. Esses aparelhos permitem utilizar dados de exames já feitos como Ultrassom, Ressonância Magnética, Tomografia ou Raio X e convertê-los em modelos tridimensionais. O objetivo deste projeto é utilizar essas técnicas de Engenharia Reversa para digitalizar o membro que necessite de auxílio e confeccionar as órteses com a tecnologia de Manufatura Aditiva, uma tecnologia que vem se desenvolvendo rapidamente nesses últimos anos e permitindo fabricar diretamente qualquer peça ou objeto através de um arquivo tridimensional modelado. Nos dias atuais, a Manufatura Aditiva tem sido utilizada em div... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Accompagner l’intégration de la fabrication additive dans les grands groupes donneurs d’ordres devient crucial pour les sous-traitants. L’enseignement actuel des procédés et des règles de conception, limité à une vision techno-centrée, ne suffit pas pour projeter ses futures applications dans diverses industries telles que l’aéronautique, l’énergie, le médical, etc... D’un côté, les travaux sur la fabrication additive et les observations de terrain indiquent que les connaissances sur ses procédés, les matériaux et leur mise en œuvre sont régulièrement enrichies. D’un autre côté, les travaux de recherche en créativité montrent qu’il est possible de stimuler la capacité créative des individus pour les guider dans la génération d’idées et de concepts créatifs. Cette thèse explore alors un rapprochement possible entre créativité et fabrication additive, dans la perspective de proposer une méthode de créativité et des outils d’applications spécifiques au paradigme additif. Cette liaison vise à mettre en évidence des moyens de stimuler la créativité, dans le contexte spécifique de la fabrication additive. Cette approche a permis de faire émerger le rôle prépondérant des objets intermédiaires qui articulent les interactions entre plusieurs dimensions de la capacité créative : les motivations, les émotions, l’exploration des connaissances, l’alternance individu/collectif et l’organisation spatiale. Elle a aussi fait émerger le besoin de redéfinir les rôles de ces objets intermédiaires au regard de la fabrication additive. En ce sens, deux dispositifs opérationnels de stimulation, basés sur la manipulation d’objets tangibles, ont été conçus puis testés dans des contextes industriels. Les résultats expérimentaux montrent que l’exploration des connaissances matérialisées par ces dispositifs favorise la génération d’idées créatives qui peuvent ouvrir à de futures applications de la fabrication additive. Finalement, une méthode de Créativité par et pour la fabrication additive est proposée. Elle permet d’enrichir à la fois les pratiques méthodologiques des sciences de la conception et les pratiques opérationnelles sur deux terrains : celui de l’industrie de la fabrication additive et celui de l’innovation. / Emphasizing the integration of Additive Manufacturing (AM) into big industrial companies becomes crucial for subcontractors. Teaching additive processes and design rules is a techno-centric vision. It is not sufficient to project future applications of additive manufacturing in various industries such as aeronautics, energy, medical, etc. On one hand, the state of the art and field observations show that AM knowledge is steadily increasing. On the other hand, the state of the art about creativity shows that individuals creative capacity can be stimulated to guide them to the generation of creative ideas and concepts. This thesis then explores a possible linking between AM and creativity in order to propose a methodology and its application tools to stimulate creativity, in the specific context of additive manufacturing. This approach allowed us to bring out the major role of intermediate objects which articulate the interactions between several dimensions of the creative capacity: motivations, emotions, knowledge exploration, individual/collective work phases and spatial organization. It also highlighted the need for a new definition of intermediate objects’ roles regarding additive manufacturing. In this sense, we designed two operational devices, based on sensory manipulation of tangible objects, and tested them in real industrial contexts. Our experimental results show that the exploration of the knowledge embodied in these devices emphasizes the generation of creative ideas opening to potential applications of additive manufacturing. Finally, a model of Creativity Through Additive Manufacturing (CTAM) has been proposed. It enables us to contribute both to the methodological practices of design science and operational practices in two fields: the additive manufacturing industry and the field of innovation.

While tribology involves the study of friction, wear, and lubrication of interacting surfaces, the tribosurfaces are the pair of surfaces in sliding contact with a fluid (or particulate) media between them. The ubiquitous nature of tribology is evident from the usage of its principles in all aspects of life, such as the friction promoting behavior of shoes on slippery water-lubricated walkways and tires on roadways to the wear of fingernails during filing or engine walls during operations. These tribosurface interfaces, due to the small length scales, are difficult to model for contact mechanics, fluid mechanics and particle dynamics, be it via theory, experiments or computations. Also, there is no simple constitutive law for a tribosurface with a particulate media. Thus, when trying to model such a tribosurface, there is a need to calibrate the particulate media against one or more property characterizing experiments. Such a calibrated media, which is the “virtual avatar” of the real particulate media, can then be used to provide predictions about its behavior in engineering applications. This thesis proposes and attempts to validate an approach that leverages experiments and modeling, which comprises of physics-based modeling and machine learning enabled surrogate modeling, to study particulate media in two key particle matrix industries: metal powder-bed additive manufacturing (in Part II), and energy resource rock drilling (in Part III). The physics-based modeling framework developed in this thesis is called the Particle-Surface Tribology Analysis Code (P-STAC) and has the physics of particle dynamics, fluid mechanics and particle-fluid-structure interaction. The Computational Particle Dynamics (CPD) is solved by using the industry standard Discrete Element Method (DEM) and the Computational Fluid Dynamics (CFD) is solved by using finite difference discretization scheme based on Chorin's projection method and staggered grids. Particle-structure interactions are accounted for by using a state-of-the art Particle Tessellated Surface Interaction Scheme and the fluid-structure interaction is accounted for by using the Immersed Boundary Method (IBM). Surrogate modeling is carried out using back propagation neural network. The tribosurface interactions encountered during the spreading step of the powder-bed additive manufacturing (AM) process which involve a sliding spreader (rolling and sliding for a roller) and particulate media consisting of metal AM powder, have been studied in Part II. To understand the constitutive behavior of metal AM powders, detailed rheometry experiments have been conducted in Chapter 5. CPD module of P-STAC is used to simulate the rheometry of an industry grade AM powder (100-250microns Ti-6Al-4V), to determine a calibrated virtual avatar of the real AM powder (Chapter 6). This monodispersed virtual avatar is used to perform virtual spreading on smooth and rough substrates in Chapter 7. The effect of polydispersity in DEM modeling is studied in Chapter 8. A polydispersed virtual avatar of the aforementioned AM powder has been observed to provide better validation against single layer spreading experiments than the monodispersed virtual avatar. This experimentally validated polydispersed virtual avatar has been used to perform a battery of spreading simulations covering the range of spreader speeds. Then a machine learning enabled surrogate model, using back propagation neural network, has been trained to study the spreading results generated by P-STAC and provide much more data by performing regression. This surrogate model is used to generate spreading process maps linking the 3D printer inputs of spreader speeds to spread layer properties of roughness and porosity. Such maps (Chapters 7 and 8) can be used by a 3D-printer technician to determine the spreader speed setting which corresponds to the desired spread layer properties and has the maximum spread throughout. The tribosurface interactions encountered during the drilling of energy resource rocks which involve a rotary and impacting contact of the drill bit with the rock formation in the presence of drilling fluids have been studied in Part III. This problem involves sliding surfaces with fluid (drilling mud) and particulate media (intact and drilled rock particles). Again, like the AM powder, the particulate media, viz. the rock formation being drilled into, does not have a simple and a well-defined constitutive law. An index test detailed in ASTM D 5731 can be used as a characterization test while trying to model a rock using bonded particle DEM. A model to generate weak concrete-like virtual rock which can be considered to be a mathematical representation of a sandstone has been introduced in Chapter 10. Benchtop drilling experiments have been carried out on two sandstones (Castlegate sandstone from the energy rich state of Texas and Crab Orchard sandstone from Tennessee) in Chapter 11. Virtual drilling has been carried out on the aforementioned weak concrete-like virtual rock. The rate of penetration (RoP) of the drill bit has been found to be directly proportional to the weight on bit (WoB). The drilling in dry conditions resulted in a higher RoP than the one which involved the use of water as the drilling fluid. P-SATC with the bonded DEM and CFD modules was able to predict both these findings but only qualitatively (Chapter 11)

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2018-05-24T13:45:49Z No. of bitstreams: 1 PDF - Inácio Costa Neto.pdf: 37706583 bytes, checksum: 2e6b9e65c5857fc8eda45146b4f4d0bb (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2018-06-05T11:34:00Z (GMT) No. of bitstreams: 1 PDF - Inácio Costa Neto.pdf: 37706583 bytes, checksum: 2e6b9e65c5857fc8eda45146b4f4d0bb (MD5) / Made available in DSpace on 2018-06-05T11:34:00Z (GMT). No. of bitstreams: 1 PDF - Inácio Costa Neto.pdf: 37706583 bytes, checksum: 2e6b9e65c5857fc8eda45146b4f4d0bb (MD5) Previous issue date: 2017-04-17 / This work seeks to perform a mapping of the production process for Good Manufacturing Practices in Additive Manufacturing in the Laboratory of Three Dimensional Technologies of the Nucleus of Technology for Health of the State University of Paraíba based on chapter five of RDC 16/13, in order to Possible future preparation of a manual of good manufacturing practices of this laboratory. This is a theoretical work in order to guarantee methodologies to extract the maximum quality of the process in question, aiming to provide guarantees of reliability, reproducibility and predictability of the biomodels produced, through standards, manuals, methods and resolutions when manufacturing medical products Such as surgical guides, temporary or permanent prostheses and orthoses. This work is justified on the assumption that biomodels are already being manufactured, but that they do not follow the necessary method in order to optimize the manufacturing process, thus spending too much time and financial resources. With this, it was possible to guarantee that the process is carried out following a layout for the laboratory that will facilitate the manufacture of the biomodel, and the creation of a flow chart proper to good manufacturing practices, allowing each agent to have its own function. / Este trabalho busca realizar um mapeamento do processo de produção para as Boas Práticas de Fabricação em Manufatura Aditiva no Laboratório de Tecnologias Tridimensionais do Núcleo de Tecnologia para Saúde da Universidade Estadual da Paraíba baseando-se no capítulo cinco da RDC 16/13, a fim de possibilitar a futura elaboração de um manual de boas práticas de fabricação deste laboratório. Trata-se e um trabalho teórico a afim de garantir metodologias que permitam extrair a máxima qualidade do processo em questão, objetivando proporcionar garantias de fidedignidade, reprodutibilidade e previsibilidade dos biomodelos produzidos, por meio de normas, manuais, métodos e resoluções ao fabricar produtos médicos específicos como guias cirúrgicos, próteses provisórias ou permanentes e órteses. Justifica -se esse trabalho a partir do pressuposto que já existem biomodelos sendo fabricados, mas que não seguem o método necessário a fim de avalizar a fabricação de maneira otimizada, gastando assim tempo e recursos financeiros em demasia. Com isso, foi possível garantir que o processo seja realizado seguindo um layout para o laboratório que facilitará a manufatura do biomodelo, e a criação de um fluxograma próprio para as boas práticas de fabricação, permitindo que cada agente tenha sua própria função.

Orientadora: Profª. Drª. Maria Elizete Kunkel / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Engenharia Biomédica, 2017. / A reconstrução auricular está presente desde 600 a.C. na forma de implante de retalhos de pele. Nos últimos anos, tem ocorrido cada vez mais pesquisas sobre o desenvolvimento de próteses que visam substituir um órgão do paciente sem a necessidade de realização de cirurgias. Novas tecnologias, como processos de aquisição da anatomia e manufatura aditiva, têm sido investigadas como alternativa para a produção de próteses auriculares com uma melhor relação custo/qualidade quando comparada com o processo manual. Nesta pesquisa foi desenvolvida uma metodologia para investigar o uso de quatro métodos de aquisição da estrutura externa do pavilhão auricular de uma voluntária (fotogrametria, escaneamento 3D, reconstrução 3D de imagens de tomografia computadorizada e modelagem 3D parametrizada) para a produção de moldes de prótese auricular por manufatura aditiva (técnica de deposição de material fundido). As próteses auriculares de silicone produzidas com esta metodologia apresentaram um excelente resultado estético com menos 3% de erro dimensional. Além disso, análises mecânicas (ensaios de resistência à tração e dureza) do silicone utilizado revelaram que as próteses produzidas apresentam ótima resistência mecânica que não é alterada pelo processo de pigmentação. Ensaios com pele suína mostraram que, dos quatro adesivos analisados, três apresentaram força de adesão satisfatória. Os resultados demonstram a viabilidade de uma metodologia acessível para a produção de próteses de orelhas utilizando softwares livres, tecnologias e suprimentos disponíveis no mercado brasileiro. / The auricular reconstruction is present since 600 BC through skin flaps implants. In the current years, prostheses have been developed to replace the patient's organ without the use of surgeries. Recently, new technologies, such as anatomical acquisition and additive manufacturing techniques are being applied in the production of auricular prostheses, aiming at obtaining a product with better cost/quality relation when compared to the manual manufacturing process. In this research, a methodology was developed to investigate the use of four methods to acquire the external structure of a volunteer's ear (photogrammetry, 3D scanning, 3D reconstruction of computed tomography images and parameterized 3D modeling) for the production of auricular prosthesis molds by additive manufacture (melt deposition technique). The silicone ear prosthesis produced with the presented methodology shows an excellent esthetic result with only 3% dimensional error. In addition, mechanical analysis (tensile strength and hardness tests) of the used silicone showed that the produced prostheses has excellent mechanical resistance that is not altered by the pigmentation process. Tests with swine skin showed that, of the four analyzed adhesives , three had satisfactory adhesion strength. The results demonstrate the feasibility of an accessible methodology for the production of ear prostheses using free softwares, technologies and supplies available in the Brazilian market.

Les composites à matrice titane (CMTi) sont des matériaux attractifs pour des applications aéronautiques, en raison de leurs performances mécaniques à haute température et de leur faible densité. La difficulté d’usiner ce type de matériaux rend les procédés de fabrication additive intéressants pour la fabrication de pièces complexes en trois dimensions. Cette étude porte sur l'élaboration de composites à matrice titane par le procédé de fabrication additive par fusion laser de poudre projetée. Dans un premier temps, différents types de poudres- renfort et de préparations de poudre ont été utilisés pour faciliter la mise en œuvre du procédé additif, dans le but d’obtenir des microstructures homogènes. Dans un second temps, l’étude s’est concentrée sur le mélange Ti-6Al-4V / B4C formant des renforts TiB et TiC par voie in-situ dans une matrice de Ti-6Al-4V. Les mécanismes de formation des microstructures obtenues ont pu être expliqués puis une étude des propriétés mécaniques (dureté, module d’Young et comportement sous une sollicitation en traction à chaud et à l’ambiante) a été réalisée afin d’évaluer l’effet du renforcement sur les propriétés mécaniques du matériau. Parmi les résultats importants ce cette étude, la présence de taux de carbone élevés en solution solide dans la matrice de titane a été évoqué comme étant le facteur prédominant dans l'augmentation des propriétés mécaniques avec le taux de B4C. / Titanium matrix composites are attractive materials for aeronautical applications, mainly because of their superior mechanical resistance at elevated temperature, combined with a low density. The critical machinability of such composites makes additive manufacturing processes particularly adapted for building complex 3D shapes. This study has been focused on the Direct Metal Deposition (DMD) of Metal matrix composites. In a first step, various powders and powder blends have been carried out in order to facilitate the DMD process and to obtain homogeneous microstructures. Following this, Ti-6Al-4V / B4C powder blends, allowing to obtain TiB + TiC particles distributed in the Ti matrix were more specifically considered. Metallurgical mechanisms involved in the formation of microstructures were identified prior to an investigation on mechanical properties at ambient and elevated temperature for various DMD process conditions and particle concentrations. Among the most interesting results of this study, the influence of a high carbon content solubilized in the Ti-matrix was considered as a dominant factor to explain the evolution of mechanical properties with increased amounts of reinforcements.