ELINER AFFONSO FERREIRA
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Artigo IPEN-doc 23028 Heat treatment and microstructural studies of LaNi-Type battery electrode alloys2017 - FERREIRA, E.A.; BARBOSA, L.P.; FARIA, R.N.The effects of annealing on the microstructures and electrochemical characteristics of a La0.7Mg0.3Al0.3Mn0.4Co0.5Ni3.8 hydrogen storage alloy have been studied. The heat treatment by vacuum annealing was carried out at 700 oC, 800 oC, 900 oC and 1000 oC. The microstructure and phase composition of the alloy have been investigated using inductively coupled plasma - atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD). The battery anode was prepared using a mixture of the pulverized alloy with carbon black and polytetrafluoroethylene as a binder.Artigo IPEN-doc 20829 Effect of Sn substitution for Co on microstructure and electrochemical performance of ABsub(5) type Lasub(0.7)Mgsub(0.3)Mnsub(0.4)Cosub(0.5)-sub(x)Snsub(3.8)(x=0-0.5) alloys2015 - CASINI, JULIO C.S.; GUO, ZAIPING; LIU, HUA K.; FERREIRA, ELINER A.; FARIA, RUBENS N.; TAKIISHI, HIDETOSHI: The effects of substitution of Sn for Co on the microstructure, hydrogen storage and electrochemical discharge capacity of La0.7Mg0.3Al0.3Mn0.4Co0.5−xSnxNi3.8 (x=0, 0.1, 0.2, 0.3 and 0.5) alloys were investigated using X-ray diffraction (XRD), pressure composition isotherm (PCT) and electrochemical discharge cycle. XRD, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) tests showed that all of alloys are mainly composed of LaNi5 and MgNi2 phases, but when increasing the content of Sn in alloys, the LaNiSn phase appears and microstructure is refined. The PCT showed that increasing substitution of Sn for Co results in decrease of the maximum hydrogen storage capacity from 1.48% (x=0) to 0.85% (x=0.5). The electrochemical tests indicated that the maximum discharge capacity decreases from 337.1 mA·h/g (x=0) to 239.8 mA·h/g (x=0.5); however, the discharge capacity retention at the 100th cycle increases from 70.2% (x=0) to 78.0% (x=0.5).Artigo IPEN-doc 18816 Microstructure and electrochemical properties of a LaMgAlMnCoNi based alloy for Ni/MH batteries2012 - FERREIRA, E.A.; SERRA, J.M.; CASINI, J.C.S.; TAKIISHI, H.; FARIA, R.N.Artigo IPEN-doc 14030 Microstructure and microanalysis studies of some lanthanum-magnesium based hydrogen storage alloys2008 - ZARPELON, L.M.C.; FERREIRA, E.A.; TAKIISHI, H.; FARIA, R.N.Artigo IPEN-doc 14467 Microstructure and magnetic properties of PrFeCoBnB sintered magnets produced from HD and HDDR powders2008 - FERREIRA, E.A.; SILVA, S.C.; PERIGO, E.A.; FARIA, R.N.; TAKIISHI, H.Sintered magnets have been produced with powder obtained using the hydrogenation, disproportionation, desorption and recombination process (HDDR). The new processing procedure for the production of the sintered magnets has been adopted in an attempt to reduce the milling time. Commercial cast ingot alloys based on the compositions Pr14Fe75.9Co4B6Nb0.1 and Pr20.5FebalB5Cu2.0 have been employed in this investigation. The HDDR powder was used to produce sintered magnets using a mixture of these alloys, in very distinct proportions. Only a small amount (20 wt. %) of the copper-containing alloy has been added as a sintering aid. Standard hydrogen decrepitation (HD) magnets have also been included in this work for a comparison. The effect of a reduced milling time on the magnetic properties of the HDDR sintered magnets has been investigated. Sintering temperature and time of were kept constant for all magnets (1050ºC for 60 minutes). The microstructures of the permanent magnets have been investigated by scanning electron microscopy and energy dispersive X-ray analysis.Artigo IPEN-doc 16321 The effect of the processing temperature on the microstructures of Pr-Fe-Co-Nb HDDR magnets2008 - SILVA, S.C.; FERREIRA, E.A.; FARIA, R.N.; TAKIISHI, H.Pr14FebalCoxB6Nb0.1 magnets have been produced using the hidrogenation disproportionation desorption recombination (HDDR) process. The effect of the Co content (x= 0, 4, 8, 10, 12, 16) and the reaction temperature (800-900 ºC) on the microstructure and magnetic properties of the HDDR material have been investigated. The processing temperature (desorption/recombination) affected the microstructure and magnetic properties of the bonded magnets. The alloy with low cobalt content (4 at.%) required the highest reaction temperature (880°C) to yield anisotropic bonded magnets. The optimum temperature for alloys with 8 at.% Co and 10 at.% Co were 840°C and 820°C, respectively. Alloys with high cobalt content (12 at.% and 16 at.%) were processed at 840°C. Each alloy required an optimum reaction temperature and exhibited a particular microstructure according to the composition. Pr14Fe80B6Nb0.1 magnets have been processed for comparison.Artigo IPEN-doc 16541 Hydrogenation and discharge capacity of a Lasub(0.7)Mgsub(0.3)Alsub(0.3)Mnsub(0.4)Cosub(0.5)Nisub(3.8) alloy for nickel-metal hydride batteries2010 - CASINI, JULIO C.S.; ZARPELON, LIA M.C.; FERREIRA, ELINER A.; TAKIISHI, HIDETOSHI; FARIA JUNIOR, RUBENS N. deArtigo IPEN-doc 16545 The effect of high charging rates activation on the specific discharge capacity and efficiency of a negative electrode based on a LaMgAlMnCoNi alloy2010 - FERREIRA, E.A.; ZARPELON, L.M.C.; CASINI, J.C.S.; TAKIISHI, H.; FARIA, R.N.