Materials Science Forum Vols. 727-728

Abstract: The coordination of lanthanide íons with organic ligands has provided good luminescent properties and allows its application in molecular light converter devices, which motivates the scientific interest of seeking coordination of these íons with organic ligands that potentiate the luminescence and associate biological properties of the complexes formed. From this perspective the complex was synthesized Eu (III) with mesoionic 2(4-chlorophenyl)-3-methyl (methoxyphenyl)-1,3-thiazole-5-thiolate (MS-1) and bipy, with the aim of its possible application in the areas of photoluminescence and drug. Analyses were performed using TG, DSC, XRD and IR. The complex obtained after reaction of the lanthanide salt and organic ligands showed five stages of decomposition and different fusion of the isolated ligands.

Abstract: This paper proposes to assess the efficiency of ZnAl₂O₄ obtained by combustion reaction on the process of esterification and transesterification of soybean oil to biodiesel production. In the synthesis it was used three heating conditions: spiral resistance, muffle furnace, and microwave oven. In order to investigate the influence of the heating source on the structure, morphology, and on the catalytic activity, the samples were characterized by XRD, FTIR, granulometric analysis, TGA, carbon content, TEM, and gas chromatography. The results showed that it was possible to obtain the ZnAl₂O₄ cubic phase with traces of ZnO. The ZnAl₂O₄ monophasic was just obtained by the synthesis carried out in the microwave oven and in the electrical resistance. All the samples showed a typical morphology of dense agglomerates and low carbon content. The samples also presented low catalytic activity in the esterification and transesterification process under the adopted conditions.

Abstract: Many engineering specifications, manufacturing procedures, inspection and quality control have begun to require that the residual stress of a particular component be evaluated. This is becoming as commonplace as the demands on the mechanical properties. In the country there are few research laboratories qualified to perform these tests and also found a worrying lack of skilled labor. Studying the formation and distribution of residual stress fields will improve the operational criteria of wheel safety, among other gains. It is known that these residual stress fields could be added to the effects of system load (tare weight plus occupation of vehicle traction, braking and torque combined). The results obtained used drilling method and rosette type strain gages, are convergent with similarity to those obtained using FEA simulation over critical region for global and superficial in principal stresses mode. The relevance of the present study and research on residual stresses meets safety improvements in cars wheel industry.

Abstract: The new engine developments are providing engine mechanical and thermal loads increase on the components. Besides the unfavorable wear conditions, the components should provide similar or improved performance compared with current baselines. For piston rings, the performance is given by the ring capacity of sealing and scrapping. These performances can be measured in an engine using the results of lube oil consumption and blow-by. The main intention of this work is to provide support for new piston rings developments by laser hardening parameters optimization, reducing the wear degradation. Hence, the aim of this work was to evaluate the influence of laser hardening on contact surface from the second ring and verify the microstructure modification and rings shape distortion due to heat input. The results indicate that the laser parameters can be tailored in order to achieve adequate macrostructures and micro constituents distribution. The ring ovality was inside to acceptable levels.