ME - Artigos em revistas internacionais
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Browsing ME - Artigos em revistas internacionais by Subject "Aluminium alloys"
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- ELV recycling steps up a gear: development of improved sorting technologies for the non-ferrous fraction of auto-shreddersPublication . Nogueira, Carlos; Pedrosa, Fátima; Margarido, F.; Santos, R. Novais; Durão, F.; Guimarães, C.Although the number of end of life vehicles (ELVs) needing recycling is growing, due to processing limitations aluminium recycling rates are being hindered. A European-funded project - ShredderSort - aims to contribute to new solutions to the aluminium recycling industry. More than 10 million tons of automotive waste from end of life vehicles (ELV) are generated yearly in the EU and the values are continuously increasing. ELV wastes are managed by the auto-shredder plants which process ELVs through a series of mechanical and physical operations in order to separate the materials into different streams: ferrous, non-ferrous, heavy non-metal and fluff. Ferrous materials, constituting more than 60wt% (percentage by weight), are sent to steel-making plants, while the non-ferrous (NF) fraction, rich in aluminium and representing slightly less than 10wt%, is processed to separate some alloys.
- Exploring Marine Biomineralization on the Al-Mg Alloy as a Natural Process for In Situ LDH Growth to Improve Corrosion ResistancePublication . Marques, Maria João; Mercier, Dimitri; Seyeux, Antoine; Zanna, Sandrine; Tenailleau, Christophe; Duployer, Benjamin; Jeannin, Marc; Marcus, Philippe; Basséguy; BASSEGUY, RegineABSTRACT: This study provides a detailed characterization of the AA5083 aluminum alloy, surface, and interface over 6 months of immersion in seawater, employing techniques such as SEM/EDX, GIXRD, mu-Raman and XPS. The purpose was to evaluate the evolution of the biomineralization process that occurs on the Al-Mg alloy. By investigating the specific conditions that favor the in situ growth of layered double hydroxide (LDH) during seawater immersion as a result of biomineralization, this research provides insights into marine biomineralization, highlighting its potential as an innovative and sustainable strategy for corrosion protection.
- Influence of natural seawater variables on the corrosion behaviour of aluminium-magnesium alloyPublication . Marques, Maria João; Benedetti, A.; Castelli, F.; Delucchi, Marina; Faimali, Marco; Delsante, S.; Valenza, F.; Garaventa, F.; Pavanello, G.; Basseguy, RegineABSTRACT: Corrosion is an important issue for alloys in natural seawater, where microorganisms can accelerate or mitigate corrosion. Al-Mg alloys are used for marine activities and various associated technologies. Here, the behaviour of AA5083 alloy was investigated in natural seawater with marine exposure lasting up to 50 days and detailing the first 8 days in two experimental series.Experimental work was carried out, including semi-field tests in natural seawater (biotic conditions) compared with abiotic conditions. The open circuit potential (OCP) measurements, during the immersion time, exhibited significantly different behaviours: an OCP downward displacement occurred under abiotic conditions, while, in biotic conditions OCP remained generally stable since the beginning of the immersion, revealing an inhibiting effect of the biological activity on the Al-Mg corrosion. This was accompanied by different surface modifications under biotic conditions: surface and cross-section characterization, performed by scanning electron microscopy with energy dispersive X-ray spectroscopy, showed less corrosion developed on the surface after 8-day immersion and formation of a protective layer during 50-day immersion.The present study shows that marine biological activity positively influences the Al alloy corrosion process, with surface modifications resulting in a protective effect counteracting the aggressiveness of chloride ions.
- Interactions between marine microorganisms and metal: the start point of a new bioinspired solution for corrosion protectionPublication . Marques, Maria João; Jaume, Julien; Diderot, Anthony; Délia, Marie-Line; Basseguy, RegineABSTRACT: Among the strategies currently used to protect metallic materials from corrosion, and thus increase their durability, conversion treatments and coatings can be considered as the most efficient and cost-effective alternatives. However, these techniques must comply with increasingly stringent regulations such as REACH. On another note, in the field of interactions between microorganisms and conductive material, it has been shown that microorganisms can not only accelerate corrosion in some cases (biocorrosion or MIC) but also inhibit it in others, thus protecting the underlying material (MIC Inhibition). In this context, the MICOATEC ANR project is based on the observation that interactions between an aluminium alloy (AA5083) and microorganisms in the marine environment lead to the formation of a protective layer against corrosion. The MICOATEC project aims to develop, via a biomimetic strategy, a new type of process for producing anti-corrosion coatings. The main goal is therefore to translate the natural biotic process into an abiotic technological process for corrosion protection, without replicating the biofilm itself or incorporating active biocompounds into the coating matrix.
- The positive impact of biomineralization for marine corrosion protection of AA5083 alloyPublication . Marques, Maria João; Jaume, Julien; Mercier, Dimitri; Seyeux, Antoine; Zanna, Sandrine; Basseguy, Regine; Marcus, PhilippeABSTRACT: This paper investigates, using surface characterisation techniques (SEM, XPS and ToF-SIMS), the impact of marine biological activity on AA5083 corrosion behaviour during seawater immersion. Different solar exposure (light vs. dark) results in distinct marine fouling development, influencing surface modifications. On the dark side, an Al/Mg oxide/hydroxide layer forms, allowing Cl - penetration. Pitting attack is observed after immersion. For the light side, a dual layer structure forms, with a hydrated Mg rich outer layer, showing barrier effect to Cl - penetration. No localized corrosion occurs. A comparison with abiotic conditions demonstrates the corrosion inhibiting effect of marine biological activity on AA5083.