Engenharia de Materiais
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/17
Navegar
3 resultados
Resultados da Pesquisa
- Effect of Mo substitution by W on the passive characteristics and mechanical properties of AISI 316L austenitic stainless steel(2019) Terra B.C.M.; Magnabosco R.© 2019 NACE International.This work studied the influence on pitting corrosion resistance and mechanical behavior of the partial or total substitution of Mo by W in AISI 316L austenitic stainless steel. Alloys that contain 0%, 25%, 50%, 75%, or 100% of Mo substitution by W in atomic content were produced and analyzed. Microstructural analysis showed that W does not cause any difference in the size, distribution, and composition of inclusions. However, the grain sizes are slightly reduced in samples with W. Tensile tests did not show any difference in their mechanical properties. Cyclic polarization results do not show any difference between the samples with and without W in 3.5% NaCl at room temperature. However, the sample with 50% W and 50% Mo showed the highest critical pitting temperature in 1 M NaCl solution after potentiostatic polarization at 180 mVAg/AgCl, 40±4°C. This result shows a synergic effect of Mo and W for pitting corrosion resistance of austenitic stainless steel.
- Investigation on the effect of a compatibilizer on the fatigue behavior of PP/coir fiber composites(2011) Bettini S.H.P.; Antunes M.C.; Magnabosco R.The mechanical behavior of polypropylene (PP) and 30 wt% coir fiber reinforced PP composites, with and without compatibilizer, were assessed through monotonic (tensile and bending) and cyclic (fatigue) tests. Fatigue load controlled tests were conducted under tension loads at a frequency of 6 Hz. The fracture mechanism was accompanied by surface fracture analyses using both optical microscopy and scanning electron microscopy. The compatibilizer used was the PP grafted with maleic anhydride. The compatibilized composites exhibited longer fatigue life times. It was also concluded that the presence of coir fibers changed the preferential fatigue mechanism, because the fracture mechanism in PP was mainly caused by heat generated by viscous effects during solicitation (thermal fatigue), whereas in the compatibilized and noncompatibilized PP/coir composites the predominant fracture mechanism was mechanical fatigue. However, thermal fatigue was also observed in the composites, especially in the noncompatibilized ones. © POLYM. ENG. SCI., 2011. Copyright © 2011 Society of Plastics Engineers.
- Fatigue life of coir fiber reinforced PP composites: Effect of compatibilizer and coir fiber contents(2013) Antunes M.C.; Moraes D.V.O.; Magnabosco R.; Bonse B.C.; Bettini S.H.P.The fatigue behavior of polypropylene/coir fiber composites was investigated. Composites were prepared according to an experimental statistical design, in which the independent variables coir fiber and compatibilizer content were varied. The compatibilizer used was maleic anhydride grafted polypropylene (PP-g-MA). Compatibilizer free composites were also prepared. Composites were prepared in a corotating twin-screw extruder and the mechanical behavior of polypropylene/coir fiber composites were assessed through monotonic (tensile) and cyclic (fatigue) tests. Fatigue load controlled tests were conducted under tension-tension loads at a frequency of 6 Hz. The fracture mechanism was accompanied by surface fracture analyses using scanning electron microscopy (SEM). The results indicated the need for using compatibilizer in the composites; however, increase in compatibilizer content did not affect composite fatigue lifetime. Coir content was the variable with the strongest effect on composite properties; increasing this variable caused significant increase in fatigue life. © 2013 Society of Plastics Engineers.