ABSTRACT The structure is a component that plays an extremely important role in the equipment’s performance, it must withstand efforts without compromising the function, receive and transfer heat, dampen vibrations and position the elements, as well as promote ergonomics and aesthetics. In lightweight and precision equipment’s the raw material used must also allow thin walls, rigid, resistant and low density. The objective of the present work is the development of a synthetic granite composite for manufacturing of equipment’s structures. For this, an abundant Brazilian granite, a high strength epoxy resin and segmented carbon fibers were selected as materials. Test specimens, with maximized packing with granite gravel less than 2.0 mm were fabricated and tested for tensile strength, compression, flexural, damping, hardness, dilatometry, thermal conductivity and density. The maximized composition supported flexural stresses above 42 MPa, without fiber reinforcement and 51 MPa with carbon fiber reinforcement. The damping coefficient was about 7 times higher than cast iron, coefficient of thermal expansion of 1.4E-05 m/m.K, thermal conductivity coefficient of 1.2 W/m.K and density of 2.1 g/cm3. The developed composite showed potential for refining structures, with ease of molding of thin-walled elements, use of inserts, re-machining, providing economical manufacture of single parts, and is still able to perform the function with high damping coefficient and low weight.

This study presents an innovative and original biomaterial designed to substitute for articular cartilage and mimic its mechanical behavior, including elastic cushioning and the characteristics of fiber-reinforced gel. The material was composed of polyurethane and bioglass microfiber 45S5. It was designed to present a tribological surface to the cartilage of the tibial plateau, and to convert over a functional gradient to an osteointegrable region for self-anchorage to the subchondral bone. The biomaterial samples showed no toxicity and promoted cell spreading. Subsequent in vivo studies in rabbits demonstrated the formation of a rigid structure similar to bone trabeculae in the distal region of the tribological surface of the implant. The tribological surface of the proximal region showed a fibrocartilaginous tissue with highly vascularized chondrocytes, thus validating the proposed concept for the design of the implant incorporating a functional gradient and auto-stability.

Many methods have been developed to test and evaluate the mechanical properties of the biopolymer from castor oil employed in implants and osteo-repositions, among other things. Most of the methods are performed under quasi-static and cyclic loads (creep and relaxation tests) and under high strain rate, uniaxial compression conditions. This paper presents and discusses the development and applicability of a simple load-application apparatus, devised to reduce shear and barrelling effects on specimens and allow for conventional strain around 45%. Besides contributing valuable information on the mechanical behavior of the castor oil polyurethane, the results of this research point to multiple biomedical applications for this material.

Cerâmicas avançadas para aplicações estruturais estão presentes em componentes de engenharia submetidos a solicitações complexas. Tal combinação única de propriedades torna essas cerâmicas solução sem paralelo para seleção de materiais em casos especiais. Uma seleção de materiais não pode contudo ser feita independentemente da escolha de processos de fabricação, forma e custo. A determinação de uma metodologia para a avaliação do grau de confiança dos componentes cerâmicos sinterizados é tão importante quanto as técnicas de seleção e de processamento. Este trabalho apresenta as tendências recentes na aplicação de cerâmicas estruturais avançadas, na conformação a frio por prensagem isostática e moldagem por processos de injeção, a elaboração de uma metologia para avaliação de desempenho e escolha de processos de corformação relacionados com propriedades mecânicas, microestrutura e desgaste por atrito sem lubrificante.

Advanced ceramics for structural applications are present in engineering parts subjected to complex solicitations. Such unique combination of properties makes these ceramics the unique solution for material selection in special cases. However a material selection cannot be made independently of the choice of manufacturing processes, shape and cost. The determination of a methodology for the evaluation of the sintered ceramic parts reliability is as important as the selection and processing techniques. This work presents the recent trends in the structural advanced ceramics application, the cold forming isostatic pressing and injection processes molding, the elaboration of a methodology for the performance evaluation and choice of forming processes related with the mechanical properties, microstructure and unlubricated sliding wear.