8 documents found, page 1 of 1
Effect of different acidic media on the corrosion behaviour of hardmetals with ...
Pereira, P.; Rocha, A. M. Ferro; Sacramento, J.; Oliveira, F. J.; Malheiros, L. F.; Senos, A. M. R.; Bastos, AlexandreHighly corrosive agents, such as saltwater, hydrogen sulphide, hydrofluoric or hydrochloric acids, are frequently found in oil and gas exploration. The high costs associated with the premature replacement of equipment damaged by corrosion and the consequent production losses justify the search for more resistant materials. In this work, the corrosion behaviour of cemented carbides with different Ni-based binder...
Layered double hydroxides for corrosion-related applications: main developments...
Tedim, João; Galvão, Tiago L. P.; Yasakau, Kiryl; Bastos, Alexandre; Gomes, José R. B.; Ferreira, Mario G. S.This work describes the main advances carried out in the field of corrosion protection using layered double hydroxides (LDH), both as additive/pigmentbased systems in organic coatings and as conversion films/pre-treatments. In the context of the research topic “Celebrating 20 years of CICECO”, the main works reported herein are based on SECOP’s group (CICECO) main advances over the years. More specifically, thi...
Corrosion resistance of WC hardmetals with different Co and Ni-based binders
Pereira, P.; Rocha, A.M. Ferro; Sacramento, J.; Oliveira, F. J.; Senos, A. M. R.; Malheiros, L. F.; Bastos, AlexandreIn this work, industrially relevant WC composites with alternative binders (Ni, CoNi, NiCr, CoCr, CoNiCr and NiCrMo) were produced and their corrosion resistance in 0.5 M NaCl was compared to conventional WC-Co system. The main objective is to develop hardmetals with higher corrosion resistance to extend the lifetime of tools and equipment, reducing the demand for new parts and maintenance, thus decreasing the ...
Atomic layer deposition of nanometric alumina for corrosion protection of heter...
Oliveira, Marco P.; Silva, Ricardo M.; Yasakau, Kiryl A.; Bastos, Alexandre; Kallip, Silvar; Zheludkevich, Mikhail L.; Silva, Rui F.Nanometric layers of Al2O3 were applied by atomic layer deposition (ALD) on 2024-T3 aluminium alloy. The ALD layers suppressed the corrosion of the alloy as confirmed by Scanning Kelvin Probe Force Microscopy (SKPFM), polarization curves and Electrochemical Impedance Spectroscopy (EIS). The protection provided by the ALD layers weakened with the time of immersion and this was attributed to the incorporation of ...
On Demand Release of Cerium from an Alginate/Cerium Complex for Corrosion Prote...
da Silva, Bruno; Bastos, Alexandre; Tedim, João; Ferreira, Mário; Marino, Cláudia; Riegel-Vidotti, IzabelAlginate (ALG) is a natural polymer used in a wide range of applications. Cerium is a sustainable corrosion inhibitor for many metal substrates. In this study, ALG/Ce3+ hydrogel microparticles are presented as an innovative cerium(III) reservoir system for the smart release of cerium ions. The active corrosion inhibition capacity of the ALG/Ce3+ complex was investigated. Tests using ALG/Ce3+ macrogels (beads) a...
Molybdenum oxide thin films grown on flexible ITO-coated PET substrates
Marciel, Alice; Graça, Manuel; Bastos, Alexandre; Pereira, Luiz; Suresh Kumar, Jakka; Borges, Joel; Vaz, F.; Peres, Marco; Magalhães, SergioMolybdenum oxide thin films were deposited on stiff and flexible substrates by reactive DC magnetron sputtering. Two sets of samples were prepared. The first with different O<sub>2</sub>/Ar flow rate ratios and the second, fixing the oxygen content, with different time of deposition. As the O<sub>2</sub>/Ar flow rate ratio varies from 0 up to 0.56, a threshold was found, ranging from crystalline to amorphous na...
Ni-Fe layered double hydroxides for oxygen evolution Reaction: Impact of Ni/Fe ...
Wilhelm, Manon; Bastos, Alexandre; Neves, Cristina; Martins, Roberto; Tedim, JoãoThe Oxygen Evolution Reaction (OER), half-reaction of the water-splitting process for hydrogen production, suffers from sluggish kinetics. NiFe materials appeared as interesting catalytic materials for this reaction in alkaline electrolyzers and have been studied, particularly in the form of NiFe Layered Double Hydroxides (LDH). However, the impact of the specificity of the atomic arrangement in the LDH and of ...
Anonim superchampions: Bozo D’água rafting team and the characterization of adv...
Bandeira, Marília Martins; Bastos, Alexandre; Amaral, Sílvia Cristina FrancoThis paper´s objective was to analyse the characterization of adventure sports though the analysis of the practice conditions of the Brazilian rafting team called Bozo D´água, a counterexample regarding the literature review. Part of an ethnography, it is focused on ten in depth interviews and field observation. The results indicate that, on the contrary of the adventure practice described as leisure participat...