Os ímãs permanentes de terras-raras tem um papel relevante na indústria de dispositivos eletromagnéticos, principalmente no que se refere à produção de motores para veículos híbridos e elétricos e geradores para turbinas eólicas. Com a recente restrição chinesa a exportação de terras-raras, os altos preços e a necessidade de substituição do Dy nesses ímãs, há um interesse mundial por alternativas a essas questões. A adição de elementos de liga em ímãs permanentes de terras raras tem como objetivo a melhora das propriedades magnéticas. O presente trabalho avalia a influência do Ti, V, Cr, Ni, Zr, Nb e Mo na microestrutura e nas propriedades magnéticas de ímãs sinterizados. Os ímãs foram preparados via metalurgia do pó, a partir de pós obtidos pelo processo de decrepitação por hidrogênio (HD). Na produção do ímã Pr16Fe66,9Co10,7B5,7Cu0,7, sem adição de elementos de liga, foi utilizada a mistura das ligas Pr20Fe73B5Cu2 (33% em peso) e Pr14Fe64Co16B6 (67% em peso). Para avaliar a influência das adições foi utilizada a liga Pr14Fe64Co16B6M0,1, onde M = Ti, V, Cr, Ni, Zr, Nb e Mo (67% em peso). As ligas utilizadas e os ímãs produzidos foram caracterizados por Microscopia Eletrônica de Varredura (MEV) e Difração de Raios-X (DRX), e as propriedades magnéticas foram obtidas por meio de Permeâmetro. O ímã com adição de Cr (iHc = 836 KA.m-1) apresentou coercividade intrínseca 11,8% superior ao ímã sem adição de elemento de liga (iHc = 748 KA.m-1). A maior remanência foi observada para o ímã com adição de Nb (Br = 1,04 T). Os ímãs com as adições de Ti, V e Zr apresentaram os maiores valores de produto de energia (BHmáx = 145, 145 e 144 KJ.m-3, respectivamente). Já o ímã com adição de Mo apresentou o maior fator de quadratura (FQ = 0,73) entre todas as amostras, 28% superior ao ímã sem adição de elementos de liga. / Rare earth permanent magnets perform an important role in the electromagnetic devices industry, particularly in the production of hybrid and electric vehicle engines and generators for wind turbines. With the recent Chinese restriction on the export of rare-earth elements, the increasing prices and the need to replace the Dy in the permanent magnets, there is a worldwide interest in alternatives to these issues. The addition of alloying elements on rare-earth permanent magnets is one of the methods used to improve the magnetic properties. This present work evaluates the influence of Ti, V, Cr, Ni, Zr, Nb and Mo as alloying elements on the microstructure and magnetic properties of sintered Pr-Fe-Co-B based permanent magnets. The permanent magnets were produced by the conventional powder metallurgy route using powder obtained by hydrogen-decrepitation (HD) method. In order to produce the magnet Pr16Fe66,9Co10,7B5,7Cu0,7 without alloying elements the mixture of alloys method was employed, mixing two compositions: Pr20Fe73B5Cu2 (33% w.t) and Pr14Fe64Co16B6 (67% w.t). With the purpose of evaluating the influence of the alloying elements, the Pr14Fe64Co16B6M0,1 (where M= Ti, V, Cr, Ni Zr, Nb or Mo) (67% w.t) alloy was employed. The characterization of the alloys and the magnets was carried out using scanning electron microscopy (SEM), X-ray diffraction (XRD) and the magnetic properties were measured using a permeameter. The magnet with Cr addition (iHc = 836 KA.m-1) presented intrinsic coercivity 11,8% higher in comparsion with the magnet without any addition (iHc = 748 KA.m-1). The highest remanence was observed for the magnet with Nb addition (Br = 1.04 T). The magnets with additions of Ti, V and Zr produced the highest energy products (BHmáx = 145, 145 and 144 KJ.m3 respectively). The magnet with Mo addition showed the highest squareness factor (SF = 0.73) among of all samples, 28% higher than the magnet without addition.

Os ímãs permanentes de terras-raras tem um papel relevante na indústria de dispositivos eletromagnéticos, principalmente no que se refere à produção de motores para veículos híbridos e elétricos e geradores para turbinas eólicas. Com a recente restrição chinesa a exportação de terras-raras, os altos preços e a necessidade de substituição do Dy nesses ímãs, há um interesse mundial por alternativas a essas questões. A adição de elementos de liga em ímãs permanentes de terras raras tem como objetivo a melhora das propriedades magnéticas. O presente trabalho avalia a influência do Ti, V, Cr, Ni, Zr, Nb e Mo na microestrutura e nas propriedades magnéticas de ímãs sinterizados. Os ímãs foram preparados via metalurgia do pó, a partir de pós obtidos pelo processo de decrepitação por hidrogênio (HD). Na produção do ímã Pr16Fe66,9Co10,7B5,7Cu0,7, sem adição de elementos de liga, foi utilizada a mistura das ligas Pr20Fe73B5Cu2 (33% em peso) e Pr14Fe64Co16B6 (67% em peso). Para avaliar a influência das adições foi utilizada a liga Pr14Fe64Co16B6M0,1, onde M = Ti, V, Cr, Ni, Zr, Nb e Mo (67% em peso). As ligas utilizadas e os ímãs produzidos foram caracterizados por Microscopia Eletrônica de Varredura (MEV) e Difração de Raios-X (DRX), e as propriedades magnéticas foram obtidas por meio de Permeâmetro. O ímã com adição de Cr (iHc = 836 KA.m-1) apresentou coercividade intrínseca 11,8% superior ao ímã sem adição de elemento de liga (iHc = 748 KA.m-1). A maior remanência foi observada para o ímã com adição de Nb (Br = 1,04 T). Os ímãs com as adições de Ti, V e Zr apresentaram os maiores valores de produto de energia (BHmáx = 145, 145 e 144 KJ.m-3, respectivamente). Já o ímã com adição de Mo apresentou o maior fator de quadratura (FQ = 0,73) entre todas as amostras, 28% superior ao ímã sem adição de elementos de liga. / Rare earth permanent magnets perform an important role in the electromagnetic devices industry, particularly in the production of hybrid and electric vehicle engines and generators for wind turbines. With the recent Chinese restriction on the export of rare-earth elements, the increasing prices and the need to replace the Dy in the permanent magnets, there is a worldwide interest in alternatives to these issues. The addition of alloying elements on rare-earth permanent magnets is one of the methods used to improve the magnetic properties. This present work evaluates the influence of Ti, V, Cr, Ni, Zr, Nb and Mo as alloying elements on the microstructure and magnetic properties of sintered Pr-Fe-Co-B based permanent magnets. The permanent magnets were produced by the conventional powder metallurgy route using powder obtained by hydrogen-decrepitation (HD) method. In order to produce the magnet Pr16Fe66,9Co10,7B5,7Cu0,7 without alloying elements the mixture of alloys method was employed, mixing two compositions: Pr20Fe73B5Cu2 (33% w.t) and Pr14Fe64Co16B6 (67% w.t). With the purpose of evaluating the influence of the alloying elements, the Pr14Fe64Co16B6M0,1 (where M= Ti, V, Cr, Ni Zr, Nb or Mo) (67% w.t) alloy was employed. The characterization of the alloys and the magnets was carried out using scanning electron microscopy (SEM), X-ray diffraction (XRD) and the magnetic properties were measured using a permeameter. The magnet with Cr addition (iHc = 836 KA.m-1) presented intrinsic coercivity 11,8% higher in comparsion with the magnet without any addition (iHc = 748 KA.m-1). The highest remanence was observed for the magnet with Nb addition (Br = 1.04 T). The magnets with additions of Ti, V and Zr produced the highest energy products (BHmáx = 145, 145 and 144 KJ.m3 respectively). The magnet with Mo addition showed the highest squareness factor (SF = 0.73) among of all samples, 28% higher than the magnet without addition.

Les véhicules électriques (VE) ou les véhicules électriques hybrides (VEH) offrent de nombreux avantages par rapport aux véhicules à moteur à combustion interne classiques. Selon les tendances récentes, la demande en VE(H) efficaces devrait augmenter considérablement. Pour une gamme haute puissance, la technologie des moteurs à aimants permanents a été le choix privilégié dans les véhicules électriques hybrides. La demande croissante de moteurs à haut rendement est en corrélation directe avec la demande d'aimants puissants (NdFeB ou SmCo) utilisant des terres rares. La disponibilité et la production des terres rares sont très critiques particulièrement pour les terres rares lourdes. L'objectif de cette thèse de doctorat est donc de concevoir un moteur Halbach à rotor extérieur pour une application VE(H) avec recyclage et réutilisation faciles des aimants. En outre, le projet vise à étudier et à proposer la fabrication d'un aimant Halbach utilisé dans les moteurs de forte puissance pour application VE.Tout d'abord, la fabrication d'un aimant Halbach utilisant un aimant NdFeB fritté avec et sans liant a été étudiée. L'étude montre que la fabrication d'une configuration de Halbach à l'aide d'un aimant collé est beaucoup plus facile et plus rentable que la fabrication d'un aimant fritté. La caractérisation d'un aimant NdFeB lié utilisé pour fabriquer un aimant Halbach a également été réalisée. Diverses voies de recyclage des aimants frittés et liés ont été analysées; on peut en déduire que les aimants collés sont beaucoup plus faciles à recycler, de manière rentable et respectueuse de l'environnement. La thèse propose également un moyen de recyclage pour l'aimant collé utilisé dans le moteur.Deuxièmement, un moteur à aimant Halbach collé a été conçu en modélisation éléments finis 2D et 3D. Pour obtenir un moteur très efficace et compact, on a utilisé un bobinage à pas fractionnaire. Les propriétés de l'aimant Halbach ont été calculées à l'aide du modèle éléments finis et comparées au modèle analytique. Les résultats obtenus par les deux approches étaient similaires. De plus, l'impact des combinaisons nombre d’encoches-pôles sur les pertes moteur et le couple a été étudié, en particulier les pertes Joule (compte tenu de toutes les contraintes de conception). Différentes stratégies pour utiliser des aimants recyclés à faible rémanence sont également présentées. L'utilisation d'un aimant recyclé avec une augmentation de la longueur axiale du moteur pourrait être le meilleur choix compte tenu de différents facteurs, notamment la fabrication de l'aimant Halbach. Sur la base de différentes études paramétriques, une conception du moteur a été proposée et un prototype a été construit. Il a été montré qu'un aimant Halbach de grande puissance pouvait être construit de manière économique avec un aimant NdFeB collé. La densité de flux d'entrefer du rotor, mesurée sur le prototype, est en étroite concordance avec les valeurs calculées.De plus, la méthodologie WIRE (Weighted Index of Recycling and Energy) a été présentée pour comparer différentes conceptions de moteurs en fonction de leur performance et de leur recyclabilité. La méthode développée produit deux indices basés sur-Facilité de recyclage du moteur en ce qui concerne le matériau, le montage et le démontage des aimants.-Impact d'un aimant recyclé sur la consommation d'énergie d'un moteur pendant sa durée de vie.En utilisant ces deux indices, on peut facilement analyser les avantages et les inconvénients des différentes conceptions sur la base de la recyclabilité et de l'efficacité énergétique. La conception proposée a été évaluée à l'aide cette méthode et on montre que le moteur est facile à monter et à démonter. De plus, l’assemblage moteur (sans colle) permet une extraction facile des aimants et une réutilisation directe. L'indice énergétique évalué du moteur montre l'impact de l'utilisation d'un aimant recyclé et sa viabilité pour les applications VE dans différents scénarios / Electric vehicles (EVs) or Hybrid electric vehicles (HEVs) offer many advantages over the conventional IC engine vehicles. According to recent trends, the demand for efficient (H)EVs is expected to grow significantly. For a high-power range, permanent magnet based motor technology has been the preferred choice for motors deployed in (H)EVs. Growing demand of highly efficient motors is in direct correlation to the demand of strong magnets (NdFeB or SmCo), which uses rare earth elements (REE). The availability and supply of REEs specially heavy REEs is very critical. Therefore, the aim of this doctoral thesis is to design an outer rotor Halbach motor for a (H)EV application with easy recycling and reuse of the magnet. Further, the project aims to investigate and propose the manufacturing of a Halbach magnet used in a high power motor EV applications.Firstly, the manufacturing of Halbach magnet using a sintered and a bonded NdFeB magnet was investigated. The study shows that the manufacturing of Halbach array using a bonded magnet is much easier and more cost effective than the sintered magnet. The characterisation of a bonded NdFeB magnet used for manufacturing a Halbach magnet was also performed. Various recycling routes for both sintered and bonded magnets were analysed and it can be inferred that bonded magnets are much easier to recycle in a cost effective and environment friendly manner. The thesis also proposes the recycling route for the bonded magnet used in the motor.Secondly, a motor with bonded Halbach magnet was designed using 2D and 3D FEM. To achieve a highly efficient and compact motor, fractional slot tooth coil winding was used. The properties of Halbach magnet was calculated using FEM model and benchmarked against the analytical model. The results obtained from the two approaches were in close agreement. Further, the impact of slot pole combinations on motor losses and the subsequent torque were investigated, specifically eddy loss (considering all the design constraints). Different strategies to use recycled magnet with lower remanence is also presented. It is shown that using a recycled magnet with increased axial length of the motor could be the best choice considering different factors, specially manufacturing of the Halbach magnet. Based on different parametric studies a design of the motor was proposed and prototype was built. It was demonstrated that a high power Halbach magnet could be built economically using a bonded NdFeB magnet. The airgap flux density of the rotor, measured on the prototype is in close agreement with the calculated values.Additionally, WIRE (Weighted Index of Recycling and Energy) methodology was presented to benchmark different motor designs on the basis of performance and recy- clability. The method developed produces two indices based on:• Ease of motor recyclability considering material, assembly and disassembly of magnets.• Impact of a recycled magnet on the energy consumption of a motor during its operational lifetime.Using both the above indices, one can easily analyse the pros and cons of different motor designs on the basis of recyclability and energy efficiency. The proposed motor design was evaluated using the developed method and it is shown that the motor is easy to assemble and disassemble. In addition, the motor assembly (glue free) enables easy magnet extraction and direct reuse. The evaluated energy index of the motor shows the impact of using a recycled magnet and its viability for EV applications in different scenarios.

<p>Critical materials are crucial to the wide deployment of clean energy technologies and advanced technology such as electric vehicles (EVs), smartphones, high-efficiency lighting, and wind turbines. Particularly, rare earth elements (REEs) and lithium are key elements for clean energy and EVs. However, higher REEs and lithium demand for clean energy transformation, extreme supply reliance on certain area exports, and severe environmental issues during mining and processing cause uncertainty for future clean energy and transportation development. Our study aims to develop dynamic LCA with scenario analysis to simulate the future possible sustainability pathways for critical materials for stakeholders and apply life cycle assessment (LCA) to evaluate the latest REEs and lithium extraction and recycling technologies. Dynamic LCA (DLCA) integrates the temporal datasets to predict the future environmental impact of a product. The databases are mainly from Ecoinvent and Critical Materials Life Cycle Assessment Tool (CMLCAT). Python package Brightway2 and Temporalis are used to simulate the DLCA.</p> <p>The study of DLCA on the REEs industry reveals the future predictive REEs environmental impact trend, providing a clear policy strategy to reach sustainability goals for stakeholders. The results show that shifting REEs resources from China to Australia and increasing the recycling rate are key factors in reducing environmental impact in the future. Considering the degradation of rare earths ore and storage depletion in China, such as the decreased production of heavy REEs from Ion adsorption clay in southern China, exploration, and inclusion of potential REEs production projects will be the possible sustainable way in the following decade. </p> <p>LCA of RE recovery from room temperature ionic liquid (RTIL) electrochemical process helps us explore the benefits of recycling RE from the e-waste. Although RTIL contributes a higher impact on ozone depletion and global warming, close-loop recycling RTIL could reduce substantial environmental impact. Lithium recovery from geothermal brine provides the great source for fulfilling the domestic demand of the U.S. Compared to the conventional Li compounds production, this method is efficient and has 25-41% lower global warming potential. The government, researchers, and industry could benefit from this study for exploring advantage and drawback strategies for the future environmental footprint of NdFeB magnet production and identifying environmental hotspots of the latest recycling and extraction process of REEs and lithium.</p>

The aim of this master thesis is to design and analyse a FSCW PMaSynRM (Permanent Magnet assisted Synchronous Reluctance Motor) for industrial applications. The design process includes analytical calculations (initial design and PM amount minimization) and nite element method (FEM) based design optimization. An overcompensated design is proved to be advantageous for a 10-pole reluctance motor. A comparative analysis with other rotor topologies was made, where motor performance, temperature e ects and production costs are taken into account. Detailed curves which describe eciency, power factor and current with respect to ambient temperature are studied for the proposed motor designs at di erent working points. The demagnetization risk is also taken into account and the safe working temperature ranges have been dened for all the considered motors. The results show that the initial motor design with 10 poles/12 slots PMaSynRM with NdFeB magnets has poor performance in terms of eciency and power factor, with huge amount of PM inserted. This is mainly due to the lack of reluctance torque for this relatively higher number of poles solution. Moreover, it has been found in literature and conrmed in this investigation that this negative e ect for the 10-pole motor is amplied due to the presence of the concentrated winding. Indeed, it is shown by simulations that the motor performance is improved by employing 8 poles/12 slots PMaSynRM conguration with a relatively lower NdFeB magnet amount, thanks to the improved rotor anisotropy. The 10 poles/12 slots interior permanent magnet (IPM) and surface mounted permanent magnet (SMPM) topologies present higher performance due to the e ective utilization of PM, mainly or completely producing the torque. Hence, IPM and SMPM do not su er the lack of anisotropy. / Syftet med detta examensarbete ar att utforma och analysera en FSCW PMaSynRM (Permanent Magnet assisted Synchronous Reluctance Motor) for industriella applikationer. Designprocessen omfattar analytiska berakningar (ursprungliga konstruktion och PM belopp minimering) och nita elementmetoden (FEM) baserad design optimering. En overkompenserad design visat sig vara fordelaktigt for en 10-polig reluktansmotor. En jamforande analys med andra rotor topologier gjordes, dar motor prestanda, temperature ekter och produktionskostnader beaktas. Detaljerade kurvor som beskriver e ektivitet, e ektfaktor och strom med avseende pa omgivningstemperatur studeras for de foreslagna motorn for vid olika arbetspunkter. Den avmagnetisering risken ocksa beaktas och sakerhetstemperaturomraden har denierats for alla ansag motorerna. Resultaten visar att den initiala motordesign med 10-polig/12 spar PMaSynRM med NdFeB magneter har daliga e ektivitet och e ektfaktor, med enorma mangder PM insatt. Detta ar framst pa grund av bristen pa reluktansvridmomentet for denna relativt hogre poltal losning. Dessutom har man funnit i litteraturen och bekraftat i denna unders okning att denna negativa e ekt for 10-polig motorn forstarks pa grund av narvaron av den koncentrerade lindningen. Faktum ar att det framgar av simuleringar att motorprestanda forbattras med en 8-polig/12 spar PMaSynRM konguration med en relativt lagre NdFeB magnet belopp, tack vare den forbattrade rotor anisotropi. Den 10-polig/12 spar interior permanentmagnet (IPM) och ytmonterade permanent magnet (SMPM) topologier presentera hogre prestanda tack vare ett e ektivt utnyttjande av PM och deras produktion vridmoment, huvudsakligen eller helt anfortrotts PM effekten.