Electron Beam Powder Bed Fusion manufacturing of components is an additive manufacturing process that is complex and has widespread advantages for aerospace and many industrial processes. It reduces costs and has a larger powder particle size requirement. This gives the benefit of a higher mass deposition rate and thus faster production time compared to Laser-Powder Bed Fusion process. Powder bed manufacturing processes often lead to columnar grain structure formation along the build direction, resulting in components that have anisotropic physical and mechanical properties. This is a major problem that limits the applications of this technique. In order to promote equiaxed grains, as well as refine the columnar morphology and eliminate anisotropic properties, the roles of process conditions and presence of inoculants or heterogeneous nucleating sites are considered. In this study, the addition of titanium nitride inoculants is used to promote columnar to equiaxed grain transition in ferritic stainless steel with the use of melting strategies and variable process parameters. It has been found that the thermal gradient (G) to solidification rate (R) ratio (G/R ratio) controls grain morphology and texture: a low G/R ratio has been shown to promote the formation of equiaxed grains. The process conditions for this transition were investigated. The samples were analyzed after printing single line tracks in the Freemelt One machine, and thereafter studied with the aid of optical microscopy to ascertain the combination of machine parameters that results in a successful transition from columnar grains to equiaxed. The study concluded that there was an increase in the fraction of equiaxed grains under these conditions; a low thermal gradient, high scanning velocity and low area energy. Ultimately, further investigation will be needed to establish the exact process parameters that will promote the transition from columnar to equiaxed grains in ferritic stainless steel. The findings from this study can be used by future researchers to create solidification maps for this steel grade and assist industry to tailor specific textures in ferritic stainless steel to achieved desired microstructures and mechanical properties. / Electron  Beam  Powder  Bed  Fusion  (E-PBF)  tillverkning  av  komponenter  är en  additiv tillverkningsprocess  som  är  komplex  och  har  omfattande fördelar  för  flyg  och  många industriella processer. Det minskar kostnaderna och har ett större krav på pulverpartikelstorlek. Detta ger fördelen av en högre massavsättningshastighet och därmed snabbare produktionstid jämfört med Laser-Powder Bed Fusion-processen. Tillverkningsprocesser för pulverbädd leder ofta  till  att en kolumnformig  kornstruktur  bildas  längs  byggriktningen, vilket resulterar  i komponenter  som  har  anisotropa  fysikaliska  och mekaniska egenskaper.  Detta  är  ett  stort problem som begränsar tillämpningarna av denna teknik. För att främja likaxliga korn, samt förfina den kolumnära morfologin och eliminera anisotropa egenskaper, övervägs rollerna för processbetingelser och närvaron av ympmedel eller heterogena kärnbildningsställen. I denna studie  används  tillsatsen  av  inokulanter  av  titannitrid  för  att  främja  kolumnär  till  likaxlig kornövergång  i  ferritiskt rostfritt  stål  med  användning  av  smältstrategier  och  variabla processparametrar.  Det  har  visat  sig  att  förhållandet  mellan  termisk gradient  (G)  och stelningshastighet   (R)   (G/R-förhållande)   styr   kornmorfologi   och   textur:   ett   lågt   G/R- förhållande har visat sig främja bildningen av likaxliga korn. Processförhållandena för denna övergång undersöktes. Proverna analyserades efter att ha skrivit ut spår med en rad i Freemelt One-maskinen  och  studerades  därefter  med  hjälp  av  optisk mikroskopi  för  att  fastställa kombinationen   av   maskinparametrar   som   resulterar   i   en   framgångsrik   övergång   från kolumnära  korn till  likaxliga.  Studien  drog  slutsatsen  att  det  fanns  en  ökning  av andelen likaxliga korn under dessa förhållanden; en låg termisk gradient, hög avsökningshastighet och låg areaenergi. I slutändan kommer ytterligare undersökningar att behövas för att fastställa de exakta processparametrarna som kommer att främja övergången från kolumnära till likaxliga korn i ferritiskt rostfritt stål. Resultaten från denna studie kan användas av framtida forskare för att skapa stelningskartor för denna stålkvalitet och hjälpa industrin att skräddarsy specifika texturer i ferritiskt rostfritt stål för att uppnå önskade mikrostrukturer och mekaniska egenskaper.

Laser powder bed fusion is a type of metal-based additive manufacturing method that can be customized for a given material through modification of process parameters, resulting in changes to the overall quality and mechanical properties of the as-built component. Optimal mechanical properties are typically achieved by performing experimental builds of fully dense components with multiple parameter sets and comparing the resulting mechanical properties. Additionally, AM allows geometric freedom that can be utilized to produce structures tailored for energy absorption, such as cellular structures or lattice structures. There is limited previous work of scaling effects on mechanical properties of cellular structures. The first part of this work aims to determine process parameters that result in the best overall mechanical properties of L-PBF manufactured maraging 300 steel. This work then uses the optimal parameters to produce cellular structures scaled both uniformly and selectively to perform mechanical and physical analysis on their response.

O presente trabalho teve como objetivo verificar a influência dos parâmetros tecnológicos do processo de secagem por aspersão sobre as características do produto obtido a partir de extrato seco de Maytenus ilicifolia. Para tanto, foi realizado um estudo exploratório, utilizado um desenho experimental fatorial, analisando quatro parâmetros: a concentração de dióxido de silício coloidal (10 e 30 %), o tempo de dispersão em meio líquido das matérias-primas (0,5 e 4 horas), a temperatura de entrada do ar de secagem na torre de aspersão (150 e 180 ºC), e a velocidade de rotação do disco aspersor (9.500 e 11.000 rpm). O teor de umidade residual, a morfologia, a distribuição granulométrica e o fluxo dos pós obtidos, assim como o rendimento do processo e a concentração do marcador catequina foram considerados como respostas ao desenho fatorial. O aumento da temperatura de entrada conduziu a produtos com umidade reduzida e a maior eficiência do processo. A concentração do dióxido de silício coloidal afetou principalmente as propriedades de fluxo e o teor de catequina nos pós produzidos. A maior velocidade de rotação influenciou de modo positivo somente sobre o rendimento do processo. / The present study aimed to evaluate the influence of technological parameters related to the spray drying process over the product obtained from a Maytenus ilicifolia spray dried extract. Therefore, an exploratory study was carried out using an experimental factorial design assessing four parameters: colloidal silicon dioxide concentration (10 – 30 %), dispersion time of the feed material (0.5 – 4 h), air inlet temperature in the spray dryer (150 – 180 ºC), and atomizer speed (9,500 – 11,000 rpm). According to an experimental factorial design four parameters were assessed: colloidal silicon dioxide concentration (10 – 30 %), mixing time (0.5 – 4 h), inlet temperature (150 – 180 ºC), and atomizer speed (9,500 – 11,000 rpm). Moisture content, morphology, particle size, flow, process yield and catechin concentration were considered as responses of the factorial design. Increasing inlet temperature led to dried products with reduced moisture content and higher process yield. Aerosil content mainly affected flow properties and catechin content in the powders. Atomizer speed at high level only enhanced process yield.

O presente trabalho teve como objetivo verificar a influência dos parâmetros tecnológicos do processo de secagem por aspersão sobre as características do produto obtido a partir de extrato seco de Maytenus ilicifolia. Para tanto, foi realizado um estudo exploratório, utilizado um desenho experimental fatorial, analisando quatro parâmetros: a concentração de dióxido de silício coloidal (10 e 30 %), o tempo de dispersão em meio líquido das matérias-primas (0,5 e 4 horas), a temperatura de entrada do ar de secagem na torre de aspersão (150 e 180 ºC), e a velocidade de rotação do disco aspersor (9.500 e 11.000 rpm). O teor de umidade residual, a morfologia, a distribuição granulométrica e o fluxo dos pós obtidos, assim como o rendimento do processo e a concentração do marcador catequina foram considerados como respostas ao desenho fatorial. O aumento da temperatura de entrada conduziu a produtos com umidade reduzida e a maior eficiência do processo. A concentração do dióxido de silício coloidal afetou principalmente as propriedades de fluxo e o teor de catequina nos pós produzidos. A maior velocidade de rotação influenciou de modo positivo somente sobre o rendimento do processo. / The present study aimed to evaluate the influence of technological parameters related to the spray drying process over the product obtained from a Maytenus ilicifolia spray dried extract. Therefore, an exploratory study was carried out using an experimental factorial design assessing four parameters: colloidal silicon dioxide concentration (10 – 30 %), dispersion time of the feed material (0.5 – 4 h), air inlet temperature in the spray dryer (150 – 180 ºC), and atomizer speed (9,500 – 11,000 rpm). According to an experimental factorial design four parameters were assessed: colloidal silicon dioxide concentration (10 – 30 %), mixing time (0.5 – 4 h), inlet temperature (150 – 180 ºC), and atomizer speed (9,500 – 11,000 rpm). Moisture content, morphology, particle size, flow, process yield and catechin concentration were considered as responses of the factorial design. Increasing inlet temperature led to dried products with reduced moisture content and higher process yield. Aerosil content mainly affected flow properties and catechin content in the powders. Atomizer speed at high level only enhanced process yield.

O presente trabalho teve como objetivo verificar a influência dos parâmetros tecnológicos do processo de secagem por aspersão sobre as características do produto obtido a partir de extrato seco de Maytenus ilicifolia. Para tanto, foi realizado um estudo exploratório, utilizado um desenho experimental fatorial, analisando quatro parâmetros: a concentração de dióxido de silício coloidal (10 e 30 %), o tempo de dispersão em meio líquido das matérias-primas (0,5 e 4 horas), a temperatura de entrada do ar de secagem na torre de aspersão (150 e 180 ºC), e a velocidade de rotação do disco aspersor (9.500 e 11.000 rpm). O teor de umidade residual, a morfologia, a distribuição granulométrica e o fluxo dos pós obtidos, assim como o rendimento do processo e a concentração do marcador catequina foram considerados como respostas ao desenho fatorial. O aumento da temperatura de entrada conduziu a produtos com umidade reduzida e a maior eficiência do processo. A concentração do dióxido de silício coloidal afetou principalmente as propriedades de fluxo e o teor de catequina nos pós produzidos. A maior velocidade de rotação influenciou de modo positivo somente sobre o rendimento do processo. / The present study aimed to evaluate the influence of technological parameters related to the spray drying process over the product obtained from a Maytenus ilicifolia spray dried extract. Therefore, an exploratory study was carried out using an experimental factorial design assessing four parameters: colloidal silicon dioxide concentration (10 – 30 %), dispersion time of the feed material (0.5 – 4 h), air inlet temperature in the spray dryer (150 – 180 ºC), and atomizer speed (9,500 – 11,000 rpm). According to an experimental factorial design four parameters were assessed: colloidal silicon dioxide concentration (10 – 30 %), mixing time (0.5 – 4 h), inlet temperature (150 – 180 ºC), and atomizer speed (9,500 – 11,000 rpm). Moisture content, morphology, particle size, flow, process yield and catechin concentration were considered as responses of the factorial design. Increasing inlet temperature led to dried products with reduced moisture content and higher process yield. Aerosil content mainly affected flow properties and catechin content in the powders. Atomizer speed at high level only enhanced process yield.

<p>Kroz istraživanja je postavljen i razvijen kompleksan model sistema<br />identifikacije procesnih parametara štampe na osnovama<br />savremenih programskih sistema i alata koji omogućuju značajno<br />ubrzanje procesa dolaska do rešenja čime su se unapredili grafički<br />proizvodni procesi i procesi sticanja i proširivanja znanja. Model<br />je baziran na integrativnim modulima koga čine, sistem<br />identifikacije procesnih parametara štampe na osnovi sistema<br />zasnovanih na algoritamskoj programskoj strukturi, sistem<br />identifikacije procesnih parametara štampe na osnovi sistema<br />zasnovanih na principima gradnje ekspernih sistema i sistem<br />identifikacije procesnih parametara štampe na osnovi sistema<br />zasnovanih na učenju na daljinu.</p> / <p>The complex model of the printing processing parameter identification<br />system is set and developed through research on the basis of modern<br />software systems and tools that enable you to significantly speed up the<br />process reaching solutions which have improved graphics production<br />processes and the processes of acquiring and expanding knowledge. The<br />model is based on the integration modules, which consist the printing<br />processing parameter identification system based on algorithmic structure,<br />the printing processing parameter identification system based on the<br />construction principles of expert systems and the printing processing<br />parameter identification system based on distance learning principles.</p>

Dans la Fabrication Additive (FA), les objets en trois dimensions sont créés couche par couche en joignant chaque couche à la précédente. Pour les pièces métalliques, il existe trois méthodes principales : le lit de poudre, le dépôt de poudre et le dépôt de fil. Ce dernier utilise de manière optimale le matériau contrairement aux autres procédés, ce qui le rend très intéressant industriellement. En effet, avec la poudre, le rapport entre la poudre utilisée et la poudre fondue n’est pas égal à un, en opposition à l’utilisation de fil. Afin de garantir la bonne fusion du métal, plusieurs méthodes existent déjà, notamment l’utilisation de lasers ou d’arcs électriques. Ce manuscrit présente une nouvelle approche de dépôt de fil utilisant l’énergie inductive pour les applications de fabrication additive (WIAM). Cette approche ne fait pas appel à un stockage du matériau fondu. Au lieu de cela, la pointe d’un fil métallique est fondue par un système de chauffage par induction. L’énergie inductive est également utilisée pour obtenir un gradient thermique optimal entre l’extrémité du fil et le substrat ou la couche précédente. Les travaux de thèse concernent le développement de cette approche par un modèle numérique et sa validation expérimentale. Il est montré que le système de chauffage par induction est capable de faire fondre la pointe du fil et de chauffer le substrat pour créer un dépôt approprié. La microstructure après dépôt de fabrication additive pour un matériau en acier inoxydable a été étudiée. Ces résultats ont été comparés avec la méthode WAM. On montre que le système de chauffage par induction donne une microstructure à très faible porosité et une microstructure sans changement soudain de composition. Ces résultats préliminaires indiquent que la fabrication additive par fil métallique avec induction (WIAM) est susceptible de constituer un processus approprié pour la FA, mais qu’elle doit encore être développée. / In Additive Manufacturing (AM), three dimensionalobjects are built layer by layer by joining each layer to the previous one. For metal parts, there are three main methods: powder bed, powder depositionand wire deposition. This latter makes optimal use of the material in contrast to other processes, which makes it very interesting industrially. Indeed, with powder,the ratio between powder used and powder meltedis not equal to one, in opposition of the use of wire. In order to ensure the proper melting of the metal, several methods already exist, including the use of lasers or electric arc. This manuscript presents a novel approach of wire deposition using inductive energy for additive manufacturing applications (WIAM). This approach does not make use of a storage of the molten material. Instead, the tip of a metal wire is melted by an induction heating system. Inductive energy is also used to obtain an optimal thermal gradient between the tip of the wire and the substrate or previous layer. Thesis work concerns the development of this approach by a numerical model, and its experimental validation. It shows that the induction heating system is able to melt the tip of the wire and heat the substrate to create suitable deposition. The microstructure of additive manufacturing stainless steel has been studied. These results have been compared with WAM method. It is shown that the induction heating system gives a microstructure with very low porosities and a microstructure without a sudden change of composition. These preliminary results indicate that Wire Induction Additive Manufacturing (WIAM) is likely to a suitable process for AM but it still needs to be developed.

The surface quality is identified by surface roughness parameters. The average surface roughness (Ra) is used in this study, as it is the most commonly used roughness parameter in the industry. A particular curved cavity of a forging die is selected for the experimental study. Different milling methods are tested. The comparison studies are conducted between 3-axes and 5-axes milling, linear and circular tool path strategies and down and up milling. According to the experimental study, appropriate method is determined for the milling of a particular curved cavity of a forging die. The experimental analysis based on design of experiments (DOE) has been employed by considering cutting speed, feed per tooth and stepover parameters. Multiple linear regression technique is used by which a mathematical formula has been developed to predict the Ra values for milling parameters. The results of the mathematical formula are controlled by conducting test experiments and good correlations are observed between the results of the formula and the results of test experiments.

Biomass and biomass-derived waste are important renewable energy sources which plays a vital role in greenhouse gas reduction from fossil fuel.  Biomass can be degraded in a process known as anaerobic digestion (AD) to produce biogas. Biogas is a mixture of methane and carbon dioxide which is utilized as a renewable source of energy. This project was based on the investigation of AD process in Nordvästra Skånes Renhållnings AB (NSR) a biogas facility in Helsingborg Sweden. A lab simulation of NSR digesters was conducted to evaluate the effects of swine manure on AD using two continuously stirred tank reactors (CSTR) R1 (control) and R2 with a working volume of 4L for 21 weeks. The study was divided into 4 periods and the investigation was carried out by increasing the organic loading rate (OLR) step wise from 2.5 to 3.6 gVSL-1day-1. To assess the effects of swine manure, the performance and stability of the reactors were monitored by collecting data from process parameters. These process parameters included biogas production, pH, volatile fatty acids, methane yield, methane content and organic solids (total and volatile solids). Increase in OLR resulted in increase biogas production in both reactors, however R2 with additional swine manure (15%) produced more biogas than R1. Methane yield was fairly stable during the experiment and had a similar trend in both reactors, but however R2 had a slightly higher average yield (730±60 mLCH4 gVS-1) than R1 (690±60 mLCH4 gVS-1) during the entire experiment. Increase OLR resulted in increase VFA in period 2; R2 with additional swine manure had a lower peak VFA concentration of 25 mM as compared to 33mM in R1.  The characteristics of NSR substrate mix and swine manure provided a good buffering system (stable pH), and reactors were still running stably at 3.6 gVSL-1day-1. Furthermore swine manure was investigated to contain macro-nutrients and trace metals which might have enhanced the AD process in R2 containing more Co, Zn, Ni and Mo than R1. Since this investigation was a simulation, the waste mix used at NSR contained 7% swine manure, this made it difficult to give clearer conclusions about the effects of co-digestion of swine manure on the biogas process since the control (R1) had 7% swine manure. Keywords: Anaerobic digestion, co-digestion, swine manure, substrate mix, organic loading rate, biogas production, methane yield, VFA, process parameters, CSTR.

The work deals with the analysis of the influence of process parameters, material factor and tools power effect to compliance with the limit shape tolerances of specified parts of bending tubes by method of wrapping. Their evaluation using statistics and the resulting recommendations for process optimization.