Research & Reviews: Journal of Material Sciences
MenuISSN:2321-6212
ISSN:2321-6212
E A Brocchi, Eliana P Marin and I G Solorzano
Pontifical Catholic University of Rio de Janeiro, Brazil
Posters & Accepted Abstracts: Res. Rev. J Mat. Sci
Metals alloys are of great technological interest which may even increase if they are nanostructured. Also, it can be found in the literature, same proposed chemical synthesis methodologies obtain different kind of materials with nanocrystal particles content. Then, the main objective of this work was to obtain a CuNiCo alloy, by an alternative procedure capable of generating nanostructured grains, followed by its preliminary characterization. It has been done by dividing the process into two steps the first one is the thermal decomposition of a nitrate solution [Cu(NO3)2, Ni(NO3)2 and Co(NO3)3] aiming to obtain a homogeneous co-formed metal oxide. In the second step, these oxides are heated up to a desired temperature and kept in a reductive flow of hydrogen, leaving the CuNiCo alloy as final product. The applied reduction temperatures were 300�°C and 900�°C. The materials obtained after each step were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray detector (EDS). As result of the first step, it was found that oxygen, Cu, Ni and Co were, as desired, homogeneously distributed, as shown in the SEM elemental mapping (Figure-1). The after reduction obtained material present different shape and particle size, depending on the applied reducing temperatures (Figure-2). The more circular and greater size observed at 900�°C confirms an increased sintering occurrence at higher temperature and the EDS results indicate the expected composition for Co, Ni and Cu (Figure-3). The initial results given by transmission electron microscopy (TEM) have shown the presence of particles with spherical morphology and a homogeneous distribution of the elements, which are sharing the same crystal structure. Also, it was noted the presence of particles smaller than 100 nm in the CuNiCo alloy, as show in Figure-4 (bright and dark fields).
E A Brochii completed Metallurgical Engineer (1975) and Master in Materials Engineering (1977) from Pontifical Catholic University of Rio de Janeiro (PUC-Rio). Doctorate (PhD) in Extractive Metallurgy from Imperial College of Science and Technology, London (1983). Since this year he has been at the Department of Chemical and Materials Engineering of PUC-Rio teaching and doing research focusing on the recovery of metals from mineral concentrates, and residues as well as synthesis, normaly including a thermodynamic/kinetics studies related to pyrometallurgy routes such as general types of roasting (ex: chlorination) and hydrogen reduction.
E-mail: eabrocchi@gmail.com