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La micro-generación eléctrica es una alternativa usada en zonas de difícil acceso y que no están conectadas al sistema eléctrico nacional. Para resolver esta limitación, se utilizan diferentes tecnologías de aprovechamiento de las energías renovables, dentro de las que se destacan las turbinas tipo Pelton, las cuales se distinguen por requerir grandes saltos de agua y pequeños caudales. Para el desarrollo e implementación de esta tecnología de generación eléctrica, existen algunas metodologías de dimensionamiento entre las que se destacan: el uso de curvas paramétricas para el diseño del cangilón, dinámica de fluidos computacional para el diseño general de la turbina y del cangilón, y otras metodologías más tradicionales que utilizan métodos gráficos para el diseño del cangilón; todas éstas con algunas deficiencias que no permiten un desempeño óptimo bajo una condición específica de operación. En este trabajo se comparan tres metodologías tradicionales para el diseño del cangilón de las turbinas tipo Pelton (OLADE, Nechleba y Thake), esto con el fin de seleccionar la más adecuada para una condición especifica. Por lo tanto, se hace un análisis del comportamiento dinámico por medio de un análisis modal, y del comportamiento estático estructural en el software de elementos finitos ANSYS. De los resultados obtenidos, todos los cangilones cumplen con dos de los tres criterios de selección pre-establecidos, se destaca la metodología de Thake al tener los mejores resultados en la relación de resistencia - peso.

Metallic matrix composite materials (MMCs) reinforced with ceramic materials have been widely studied in the last decades due to their high mechanical properties. Different researches have investigated and reported the fabrication of lightweight metallic composites reinforced with micro and Nano-reinforcement to get an excellent strength-weight relation, which is attractive for structural applications in engineering. Several investigations tried to synthesize metallic composites reinforced with carbon nanotubes (CNTs) for structural and functional applications because of their exceptional mechanical, physics and chemical properties. This study employs a "sandwich" technique recently developed for metallic matrix composites fabrication with high mechanical specifications. Tribological behavior for possible use in extern implants of this metal matrix composites is also studied to obtain lightweight-reinforced metallic materials with high mechanical and tribological properties for user's comfortability, i. e, lighter materials than those most commonly used such as Aluminum and Titanium. The present study identifies the tribological behavior for Magnesium AZ31B composite material reinforced with carbon nanotubes in continuous and cyclic contact systems against non-reinforced metallic matrix to determine an average friction coefficient and the wear mechanisms over the metal matrix composite to metal interaction.

A variety of light alloys has been widely used from ancient to modern times. Aluminum is a light metal that is easy to melt, cast, and then process in a large variety of fabrication and forming processes. Being the lightest structural element, magnesium has become a premium choice in transportation industries. Most of these materials have been developed relying on many trial-and-error experiments, as well as the experience of researchers and companies. These alloys are needed for the development of new manufacturing routes even for the progress of improved alloys and nanocomposites. In the present age, computer-aided alloy design is, however, a useful tool to save time and cost necessary for the alloy development. This chapter presents a brief review of the manufacturing processes and some useful tools for the design of light alloys, which are the basis for the subsequent manufacturing process of nanocomposites.

Today, the manufacture of components with improved functionality and performance for industrial applications involves not only the selection of better and lighter materials but also the use of surface engineering to achieve superior resistance-to-weight ratio. For applications in aeronautical and aerospace sectors, friction, wear, temperature resistance, erosion, corrosion, adhesion, and surface finishing are some aspects of interest in research. The technique used for coating any substrate strictly depends on the type of material and the property that is required to improve. Nowadays, thermal spraying is a reliable and cost-efficient method to deposit thick coatings with a wide variety of feedstock materials and substrates. This chapter presents a review of the main thermal spray processes used to coat light alloys and shows experimental results of AlSiC and FeCrBSiNbW alloy coatings deposited on the 6061-T6 aluminum alloy. Splat formation and microstructure, including solid-liquid two-phase droplet impacting the coating deposition, are reviewed.

This chapter presents the production of light alloys (Ti-Mg) by severe plastic deformation. Alloys with different Mg content were synthesized by high-pressure torsion straining, technique that allows to obtain ultrafine-grained materials in both equilibrium and nonequilibrium, changing the chemical, thermodynamic, and mechanical properties of the materials. In the Ti-Mg system, the solid solubility of Mg in Ti is less than 2 at% and high-pressure torsion technique proved to be a useful way for the synthesis of Ti-Mg alloys supersaturated with Mg. Therefore, this severe plastic deformation technique is an effective route for the processing of light alloys and composites.

This chapter presents a review of some industrial applications of light alloys and composites. While aluminum alloys and their composites play an important role in the development of aeronautical, aerospace, defense, and automotive industries owing to their improved mechanical properties and low weights, other lightweight materials such as Ti and Mg are being also successfully applied in these industrial sectors. The high-performance characteristics of a modern aeronautic industry are a direct consequence of the high-performance light materials, composites, and their manufacturing. The selection of the alloy type, with characteristics that will depend on the expected application, is a very important aspect from the point of view of its industrial implementation. A case study of the manufacture of thermal spray coatings, based on the use of light alloys with high potential for industrial-scale production, is here presented.

The metal matrix composites (MMCs) have been used in several applications where high specific resistance and temperature are required for some uses in the aerospace and aeronautic industry. In general, these composites are manufactured using as reinforcing material particles or some fibers like glass, ceramic and carbon fibers. Recently a new manufacturing process for the production of MMCs reinforced with carbon nanotubes, known as sandwich technique has been proposed. This technique produces materials comprised of a metallic matrix and banded structured-layers of multiwall carbon nanotubes (MWCNTs). However, among other issues, the matrix-reinforcement interface and the reinforcement dispersion degree are still open questions. The present study has been aimed on the reinforcement of magnesium sheets with MWCNTs by the sandwich technique. Field emission scanning electron microscopy was used to demonstrate that the method is capable of producing a good dispersion of the MWCNTs with no evidence of damage. The mechanical properties were measured by tensile and nanoindentation tests; yield and ultimate strengths, elastic modulus and hardness were increased with respect to the unreinforced material.

In this study, Equal-Channel Angular Sheet Drawing- ECASD with a die set at 135° was used to produce plastic deformation onto an aluminum alloy AA-1100-O and a magnesium alloy AZ31-O samples, expecting a decreasing the grain size in order to increase the plasticity of these alloys under certain specific working conditions. In this study, the microstructural and mechanical properties changed due to this process were analyzed by optical microscopy and mechanical testing like micro-hardness and tension test. ECASD produces work hardening with no significant dimensional changes into the flat specimens with small changes in the microstructural characteristics. The ECASD process also produces important microstructural changes close to the surface of the investigated samples therefore its hardness is strongly modified in this region. This is due to the high contact stresses and friction developed with the die during the ECASD process. RESUMEN En este estudio, se usó la técnica de extrusión de láminas de una aleación de aluminio AA-1100-O y una aleación de magnesio AZ31-O por medio de un dado de cizalladura con un ángulo de 135 ° (ECASD, por sus siglas en inglés) para producir la deformación plástica en las aleaciones, que permita obtener microestructuras con tamaños de grano pequeños para aumentar su plasticidad en situaciones específicas de trabajo. En este estudio, se evaluó el cambio en las propiedades microestructurales y mecánicas por medio de microscopía óptica y ensayos mecánicos como microdureza y ensayos de tensión. La técnica de deformación plástica severa ECASD produce cambios en las propiedades mecánicas, sin cambios significativos en la masa de las muestras con pequeños cambios en las características micro-estructurales en el núcleo del material. Sin embargo, el proceso ECASD produce importantes cambios microestructurales cerca de la superficie de los materiales investigados, por tanto, la dureza está fuertemente modificada en esta región. Esto es debido a las altas tensiones de contacto y fricción desarrolladas con la matriz durante el proceso de ECASD.

In recent years, due to their high specific mechanical properties, the polymer matrix composites have been widely used. In particular, carbon nanotubes (CNTs) have been used as reinforcement due to its exceptional mechanical and electrical properties. In this work the mechanical behavior of polyvinyl alcohol (PVA) reinforced with different percentages of mechanically oriented CNTs was studied. The composite material was made starting with a solution of PVA+ distilled water, and then the CNTs were added to the solution and dispersed by magnetic stirring and ultrasonic agitation. During this step, a surfactant was added to help with the CNTs dispersion. This mixture was poured into a container and dried using a heat source to accelerate its polymerization and curing. The layers obtained were subjected to mechanical stretching at controlled temperature to align the CNTs in the loading direction. The mechanical properties were measured by tensile testing and nanoindentation. The results show a large increase in modulus and hardness compared with non-reinforced polymeric material, it was also found a significant increase in the tensile strength. The composite with the best properties was subjected to thermal stabilization by ethanol, obtaining an increase in the degradation temperature of about 100°C approximately, although in this case the mechanical stiffness and hardness were decreased compared to unstabilized material, the usefulness of this material is enhanced.