Examinando por Autor "Otero, Enrique"

Mostrando 1 - 5 de 5

An energetic approach to the wear behaviour of plasma-sprayed alumina-13% titania coatings
(Elsevier, 2010) Rico, Álvaro; Garrido, Miguel Ángel; Otero, Enrique; Rodríguez, Jesús
Corrosion behavior of 316L stainless steel coatings on ZE41 magnesium alloy in chloride environments
(Elsevier, 2019-11-25) García-Rodríguez, Sonia; Torres, Belén; Pulido-González, Nuria; Otero, Enrique; Rams, Joaquín
The corrosion behavior of the ZE41 magnesium alloy with a HVOF 316L stainless steel coating was electrochemically evaluated in 3.5 wt% NaCl solution and by salt spray testing. Electrochemical Impedance Spectroscopy (EIS) allowed determining the resistance of the coatings deposited, the growth of compact corrosion products on the ZE41 Mg alloy and the failure of the non-optimized coatings. The best coating resisted the chloride attack for long times in immersion and in salt spray environments, and it drastically reduced galvanic couple formation. Its behavior is associated with its reduced porosity and its higher compactness and mechanical stability.
Corrosion behavior of mechanically alloyed A6005 aluminum alloy composite reinforced with TiB2 nanoparticles
(Wiley-V C H Verlag Gmbh, 2020) Abu‐Warda, Najib; López, María Dolores; Escalera‐Rodríguez, María Dolores; Otero, Enrique; Utrilla, María Victoria
Corrosion susceptibility of the A6005 alloy reinforced with n‐TiB2 was studied through electrochemical tests. The mechanical alloying (MA) technique was used as the processing route and a posterior hot extrusion was employed to consolidate the powders. Bulk samples were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and microhardness tests. The combination of both MA processing and 5 wt% n‐TiB2 addition in the aluminum matrix produced 61% increase of microhardness. Electrochemical tests were performed in 3.5 wt% NaCl solution to assess the effect of MA processing and TiB2 presence on corrosion behavior. The corrosion resistance of the samples processed by MA increased slightly compared with the base A6005 alloy. The amorphous Al2O3 phase formed during MA processing was the cause of this increase, providing continuity to the passive layer. Furthermore, the addition of TiB2 on the sample processed by MA did not significantly affect corrosion resistance. Polarization tests confirmed that the reinforced sample had similar icorr to that of the unreinforced alloy, and cyclic polarization tests revealed that pit nucleation sites were localized in the interface between Al2O3 and the aluminum matrix.
High Temperature Oxidation Behaviour of Nanostructured Alumina-Titania APS Coatings
(Springer, 2010) Rico, Álvaro; Rodríguez, Jesús; Otero, Enrique
Precipitation Hardening and Corrosion Behavior of Friction Stir Welded A6005‑TiB2 Nanocomposite
(Springer, 2020-03-25) Abu‑Warda, Najib; González, Belén; Otero, Enrique; Escalera- Rodríguez, María Dolores; Cruz, S; Rey, P.; Verdera, D.; Utrilla, María Victoria
Precipitation hardening and corrosion behavior of a friction stir welding (FSW) based on the aluminum alloy A6005 reinforced with TiB2 nanoparticles have been studied. Mechanical alloying (MA) and hot extrusion techniques have been employed as processing route followed by FSW. Samples characterization has been performed by DSC and TEM, and precipitation strengthening of the bulk samples and the FSW joint has been evaluated by micro-hardness tests after T6 thermal treatment. TEM characterization revealed the presence of Mg–Si hardening phases, mainly of β′ phase, and dispersoids of α-Al(FeMnCr)Si into the aluminum matrix. The results revealed that samples subjected to MA had less susceptibility to T6 thermal treatment and that the presence of nano-TiB2 reinforcement accelerates aging time. In addition, electrochemical tests based on polarization tests have been performed in 3.5% NaCl solution to assess the effect of FSW process on corrosion behavior. The FSW joint had worse corrosion behavior since the passive Al2O3 film was not generated on the weld zone. SEM–EDS analysis revealed that pits nucleated mainly in sites with a higher presence of Fe contaminant which acts cathodically with respect to the aluminum matrix, producing galvanic corrosion.