This research is a systematic study exploring a new fabrication methodology for long-fiber-reinforced metal matrix composites (MMCs) using a novel additive manufacturing technology. The research is devoted to the manufacture of long-fiber-reinforced MMC structures using the Ultrasonic Consolidation (UC) process. The main objectives of this research are to investigate the bond formation mechanisms and fiber embedment mechanisms during UC, and further to study the effects of processing parameters on bond formation and fiber embedment, and the resultant macroscopic mechanical properties of UC-made MMC structures. From a fundamental research point of view, bond formation mechanisms and fiber embedment mechanisms have been clarified by the current research based on various experimental observations. It has been found that atomic bonding across nascent metal is the dominant bond formation mechanism during the UC process, whereas the embedded fiber are mechanically entrapped within matrix materials due to significant plastic deformation of the matrix material during embedment. From a manufacturing process point of view, the effects of processing parameters on bond formation and fiber embedment during the UC process have been studied and optimum levels of parameters have been identified for manufacture of MMC structures. An energy-based model has been developed as a first step toward analytically understanding the effects of processing parameters on the quality of ultrasonically consolidated structures. From a material applications point of view, the mechanical properties of ultrasonically consolidated structures with and without the presence of fibers have been characterized. The effects on mechanical properties of UC-made structures due to the presence of embedded fibers have been discussed.

There is a wide range of applications for 3D printing technology with an additive manufacturing such as aerospace, automotive, marine and oil/gas, medical, consumer, electronics, building construction, and many others. There have been many pros and cons for 3D additive manufacturing. Even though 3D printing technology has many advantages: freedom to design and innovate without penalties, rapid iteration through design permutations, excellence mass customization, elimination of tolling, green manufacturing, minimal material wastes, energy efficiency, an enablement of personalized manufacturing. 3D additive manufacturing still has many disadvantages: unexpected pre- and post-processing requirement, high-end manufacturing, low speed for mass production, high thermal residual stress, and poor surface finish and dimensional accuracy, and many others. Especially, the issues for 3D additive manufacturing are on high cost for process and equipment for high-end manufacturing, low speed for mass production, high thermal residual stress, and poor surface finish and dimensional accuracy. In particular, it is relatively challenging to produce casting products with lattice or honeycomb shapes having sophisticated geometries. In spite of the scalable potential of periodic cellular metals to structural applications, the manufacturing methods of I∙AM Casting have been not actively explored nor fully understood. A few qualitative studies of I∙AM Casting has been reported. Recently, a sand casting of cellular structures was attempted, resulting in casting porosity and the sharp corners in the lattice structure of the cellular structural molds, a sharpness which prevent fluid-flow and causes undesired solidification, resulting in misrun casting defects. Research on the indirect AM methods has not been aggressively conducted due to the highly complex and multidisciplinary problems across the process – continuum modeling (thermal stress, flow, heat transfer, and water diffusion) with multiple materials (polymer, metals, and ceramic) for multiphase simulations – solid, liquid, and gas. As an initial step to fully understand the processing of I∙AM Casting, a quantitative study on I∙AM Casting is conducted in this work.

Orientador: Marizilda dos Santos Menezes / Resumo: A fabricação digital se tornou uma realidade para a produção em diversos setores da indústria nos últimos anos. Com seu uso desenvolvido e consolidado em alguns setores como a medicina, a arquitetura e a robótica, ela ainda é pouco explorada na moda apresentando um grande potencial para construção de superfícies que possam ser vestidas. O uso da fabricação digital implica na concepção tridimensional da superfície vestível o que traz ao Design de Moda desafios a serem superados no que diz respeito ao custo, ao uso dos materiais, à distribuição de produtos e, principalmente, às formas de criação e construção. Sendo assim, esta pesquisa se propõe a investigar o desenvolvimento de superfícies tridimensionais mediante os processos de manufatura aditiva sob a ótica do Design de Superfícies. Analisa-se a viabilidade do uso destes métodos para a construção de superfícies vestíveis e são propostas estratégias para a utilização, de maneira a contribuir com o conhecimento teórico acerca do Design de Superfícies no que tange a tridimensionalidade e ao uso das tecnologias de fabricação digital. Para tal, inicia-se o trabalho com uma revisão bibliográfica sobre o Design de Superfícies, a fabricação de superfícies vestíveis ao longo da história e sobre a manufatura aditiva, em seguida, parte-se para a análise dos projetos realizados por designers envolvendo as superfícies tridimensionais e a fabricação digital, para então proceder com experimentações. Propõe-se a construção por meio de módu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Digital manufacturing has become a reality for production in various industry sectors in recent years. With its use developed and consolidated in some sectors such as medicine, architecture and robotics, it is still poorly explored in fashion presenting a great potential for construction of wearable surfaces. The use of digital fabrication implies the three-dimensional design of the wearable surface which brings to Fashion Design challenges to be overcome with regard to cost, the use of materials, the distribution of products and especially the forms of creation and construction. Thus, this research aims to investigate the development of three-dimensional surfaces through additive manufacturing processes from the perspective of Surface Design. The feasibility of using these methods for the construction of wearable surfaces is analyzed and strategies for their use are proposed, in order to contribute to the theoretical knowledge about surface design in terms of three-dimensionality and the use of digital manufacturing technologies. To this end, the work begins with a literature review on Surface Design, the manufacture of wearable surfaces throughout history and on digital fabrication, then starts with the analysis of designs carried out by designers involving surfaces. dimensions and digital fabrication, and then proceed with experimentation. Modular construction is proposed as the main strategy for the construction of wearable surfaces through additive manufacturing. / Doutor