Materials Research

http://www.scielo.br/scielo.php?script=sci_issues&pid=1516-1439&lng=pt&nrm=iso

List of Papers (Total 148)

Comparative study between the electrochemical behavior of TiN, TiCxNy and CrN hard coatings by using microscopy and electrochemical techniques

Hard thin TiN, TiCxNy and CrN films deposited by Physical Vapor Deposition (PVD) techniques onto steel substrates were immersed in an aggressive environment and evaluated by Atomic Force Microscopy (AFM) and Electrochemical Impedance Spectroscopy (EIS). The mechanical and electrochemical behavior, as well as the microstructure of TiCxNy depended directly on the contents of carbon...

Microstructure of undercooled Pb-Sn alloys

Melt undercooling opens new solidification pathways for non-equilibrium phases and non-conventional microstructures. Several techniques, including the fluxing technique, have been developed in order to reduce nucleation sites and to produce high undercoolings for metals and alloys. In this work the fluxing technique was applied to Pb-25wt%Sn (hypoeutectic), Pb-61.9wt%Sn (eutectic...

Electrodeposition of polypyrrole films on aluminum surfaces from a p-toluene sulfonic acid medium

Electrodeposition of polypyrrole films on aluminum from aqueous solutions containing p-toluene sulfonic acid and pyrrole was performed by cyclic voltammetry and galvanostatic technique. The influence of applied current density on the morphology of the films was studied by Scanning Electron Microscopy. The films displayed a cauliflower-like structure consisting of micro-spherical...

The Effects of ZnO2 nanoparticles on strength assessments and water permeability of concrete in different curing media

In this study, the effect of limewater on strength assessments and percentage of water absorption of concrete incorporating ZnO2 nanoparticles has been investigated. Portland cement was partially replaced by ZnO2 nanoparticles with the average particle size of 15 nm and the specimens were cured in water and saturated limewater for specific ages. The results indicate that ZnO2...

Porous stainless steel for biomedical applications

Porous 316L austenitic stainless steel was synthesized by powder metallurgy with relative density of 0.50 and 0.30 using 15 and 30 wt. (%) respectively of ammonium carbonate and ammonium bicarbonate as foaming agents. The powders were mixed in a planetary ball mill at 60 rpm for 10 minutes. The samples were uniaxially pressed at 287 MPa and subsequently vacuum heat treated in two...