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Maintenance of oil and gas pipelines presenting corrosion damage can be done following conventional routes as cutting and substitution of the damage parts or double sleeve welded method. Recently, the use of composite materials for repair of damaged pipelines is increasing due to the advantages presented by this process like the ease application and the possibility of performing the repair without interrupting the use of the line. As the pipe operates under hydrostatic pressure, it is important to make a stress analysis in order to know the stresses transferred to the composite material repair. In the present work, a microstructural and mechanical characterization of two composite materials used in pipe repair is made. One of the composites is made of continuous fiber glass and the other of a fiber glass fabric, both with polymeric matrix. The first was pulltruded and the second was processed by hand lay up.

Characterization of aluminum alloy obtained of recycled material is the objective of this study. A aluminum alloy was used to determine the mechanics characteristics and microstructure analyze and their correlation. Specimens were produced to the failure and strength test. Optical and scanning electron microscopy were used the microstructure. In the aluminum alloy was found some porosity that is response for the fragile comportment. The results of the experience were valid when compared with others aluminum alloys in the same fabrication process. In the conclusion of this study perceive that the aluminum alloy have fragile characteristic in function of the heterogeneous composition in associate with the porosity in function of the material that was used to produce the specimen. Perhaps other method of fabrication would can reduce the porosity and increase the mechanics properties de porosities.

The use of composites as engineering materials have gained more space in various sectors of human activity. For these materials enable a good synergy between the various components that constitute it, resulting in a range of properties inherent to the material more convenient than the individual components. The strengthening of these composite materials, plant fibers have advantages compared to synthetic fibers because they are abundant, are biodegradable by biological processes, renewable and recyclable. In this paper, polyester matrix composites reinforced by short bamboo fibers arranged randomly were produced, using the lowest possible level of technological processes in production stages. The matrix used was polyester terephthalic pre-accelerated with cobalt naphthenate and cured at room temperature peroxide, methyl ethyl ketone (MEK) in proportion to the resin of 0,33% by volume. The bamboo fibers used were extracted from the campus - Belém of Federal University of Pará.

The curauá fiber, a bromeliad (Ananas erectifolius LB Smith), is considered large in the Amazon region, its mechanical properties of high strength, low density - capable of giving lightness to the final product - and potential for recycling, is listed for replace the fiberglass used as reinforcement to the plastic in the manufacture of parts with reduced features and detailed, produced by injection molding process, such as cars panel buttons, knobs and hinges. The materials used for manufacturing the polymer composites were curauá fibers acquired commercially from Belém in nature form, and a matrix of polyester resin terephthalic unsaturated and pre-accelerated chosen from one of the proportions of 0.33% (v / v), 1.66% (v / v), 3.33% (v / v) and 5% (v / v) which was initially studied. In the manufacture of the composite resin was used in combination with curauá fibers with lengths of 10 mm and a mass fraction of 3.87%, 4.87% and 5.87%.