In the present study, poly (ethylene terephthalate)-based composites were produced and characterized. These composites were composed by poly (ethylene terephthalate) (PET) reinforced with geopolymer concrete waste (GCW). Both untreated (U-GCW) and treated with oleic acid (OA) geopolymer concrete waste (T-GCW) were used in the production of the composites. The PET/GCW ratios used for either treated or untreated GCW bodies were 80/20 (wt%), 60/40 (wt%) and 50/50 (wt%). Chemical compositions were assessed by X-ray fluorescence spectroscopy (XRF), crystallinity by differential scanning calorimetry (DSC), thermal stability by thermogravimetry (TGA), microstructure by field emission gun scanning electron microscopy (FEG-SEM) with energy dispersive X-ray spectroscopy (EDS), and mechanical properties were assessed by compression tests. Fourier transform infrared spectroscopy (FT-IR) was used to check the efficiency of the treatment with OA, as well as the interaction between PET and GCW. The T-GCW PET composites showed better thermal, physical, and mechanical properties, for non-structural applications, when compared to U-GCW.

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This work studies the microstructural characteristics and mechanical properties for different aluminium alloys (1100, 3104 and 8011) hot rolled sheets that were subjected to a solution heat treatment with distinct soaking times, in order to promote microstructural and mechanical changes on these alloys with solute fractions slightly above the maximum solubility limit. Scanning Electronic Microscopy (SEM) / Energy Dispersive Spectroscopy X-Ray (EDS), X-Ray Diffraction (XRD) and Hardness Tests were employed to observe the microstructural / compositional and mechanical evaluation. For the 1100 and 8011 alloys the more suitable soaking time occur between 1 and 2 hours, and for the 3104 alloy occurs between 2 and 3 hours.

The 304L austenitic stainless steel is susceptible to mechanically induced martensitic transformation from slightly above room temperature down to cryogenic temperatures. In this work, austenitic 304L steel produced by two different thermomechanical processes, hot rolling (HR) and cold rolling and annealing (CR/A), were subjected to martensitic transformation by rolling and by tensile tests at 298 K and 155 K and the volume fraction of martensite was determined by X-ray diffraction and ferritescope measurements. The results showed that the martensitic transformation was complete for CR/A samples rolled at 155 K and that the volume fraction of martensite was larger in CR/A samples than in HR samples in all cases.

Resumo O material em estudo consistiu em um aço inoxidável austenítico 201LN, na forma de chapa com aproximadamente 5,00 mm de espessura na condição laminada a quente. As etapas de processamento adotadas neste estudo consistiram em laminação a temperatura ambiente e pré-resfriamento em salmoura, com o objetivo de avaliar a formação de martensita e evolução da resistência mecânica do material. As técnicas de caracterização utilizadas foram macro Dureza Rockwell C (HRC), Ferritoscopia e Difração de Raios-X (DRX). Os resultados preliminares mostraram que tanto a fração volumétrica de martensita formada, como a dureza, foram maiores nas amostras submetidas a maiores percentuais de redução e préresfriamento em salmoura. Palavras-chave: Aço Inoxidável Austenítico; Laminação a frio; Martensita; Efeito TRIP.