Person: Arrabal Durán, Raúl
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First Name
Raúl
Last Name
Arrabal Durán
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ciencia de los Materiales e Ingeniería Metalúrgica
Identifiers
55 results
Search Results
Now showing 1 - 10 of 55
Item Combination of Electron Beam Surface Structuring and Plasma Electrolytic Oxidation for Advanced Surface Modification of Ti6Al4V Alloy(Coatings, 2022) Mora-Sanchez, Hugo; Pixner, Florian; Buzolin, Ricardo; Mohedano Sánchez, Marta; Arrabal Durán, Raúl; Warchomicka, Fernando; Matykina, EndzheThe objective of this work is to study for the first time the combination of electron beam (EB) surface structuring and plasma electrolytic oxidation (PEO) with the aim of providing a multiscale topography and bioactive surface to the Ti6Al4V alloy for biomedical applications. Ca and P-containing coatings were produced via 45 s PEO treatments over multi-scale EB surface topographies. The coatings morphology and composition were characterized by a means of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The effect on the previous EB topography was evaluated by means of a 3D optical profilometry and electrochemical response via potentiodynamic polarization tests. In general, the PEO process, morphology, composition and growth rate of the coatings were almost identical, irrespective of the topography treated. Minimal local differences were found in terms of morphology, and the growth rate were related to specific topographical features. Nevertheless, all the PEO-coated substrates presented essentially the same corrosion resistance. Electrochemical tests revealed a localized crevice corrosion susceptibility of all the bare EB topographies, which was successfully prevented after the PEO treatment.Item AlSiC thermal spray coatings for corrosion protection of Mg–Al alloys in humid and saline environments(Surface and Coatings Technology, 2010) Arrabal Durán, Raúl; Pardo Gutiérrez Del Cid, Ángel; Merino Casals, María Concepción; Mohedano Sánchez, Marta; Casajús, P.; Merino, S.The corrosion behaviour of thermal spray Al/SiC coatings deposited on AZ31, AZ80 and AZ91D Mg–Al–Zn alloys was evaluated in neutral salt fog (ASTM B 117) and high relative humidity (98% RH, 50 °C) environments. The findings revealed porous as-sprayed coatings with paths providing access of the corrosive media to the magnesium substrates. This resulted in galvanic corrosion at the substrate/coating interfaces and formation of magnesium corrosion products, which eventually led to coating spalling in the case of salt fog tests after protracted times of exposure. The application of a cold-pressing post-treatment improved the corrosion performance of the coatings. Thus, in high humidity atmosphere, corrosion signs were only visible at the Al/SiC interfaces in the outermost surface of the coatings and, in salt fog environment, the galvanic corrosion of the substrates was delayed.Item Hybrid PEO/sol-gel coatings loaded with Ce for corrosion protection of AA2024-T3(Progress in Organic Coatings, 2023) Del Olmo Martínez, Rubén; López, E.; Matykina, Endzhe; Tiringer, U.; Mol, J.M.C.; Mohedano Sánchez, Marta; Arrabal Durán, RaúlPlasma electrolytic oxidation (PEO) has been targeted as an eco-friendly alternative technology to conventional chromic acid anodizing (CAA) for corrosion protection of aluminium alloys in the aircraft industry. However, conventional PEO technology implies high energy consumption. Flash-PEO coatings (≤10 μm) produced in short treatment times (≤ 5 min) constitute a feasible way to overcome this limitation. Nevertheless, the long-term corrosion resistance is compromised, thus requiring novel sealing post-treatments. The present work studies the effect of stand-alone hybrid sol-gel (HSG) and Ce-doped hybrid sol-gel (HSGCe) coatings as a sealing post-treatment to evaluate the long-term corrosion resistance of Flash-PEO coatings on aluminium alloy (AA) 2024-T3. The characterization of the PEO, HSG, and HSG-Ce coatings was performed by scanning electron microscopy, X-ray diffraction, water contact angle, dry adhesion tests (ISO 2409), optical profilometry and Fourier transform infrared spectroscopy. The corrosion behaviour was assessed by electrochemical impedance spectroscopy up to 21 days (3.5 wt% NaCl). Active corrosion protection was assessed by immersion tests of artificially scratched coatings. Present findings reveal that low-energy-cost Flash-PEO coatings were successfully formed on AA2024-T3 alloy. Both HSG and HSG-Ce coatings were homogeneously formed on Flash PEO coating. Regarding the corrosion resistance, HSG-Ce showed significant scratch protection during 21 days of immersion in 3.5 wt% NaCl. The results suggest that, while the release of Si and Ce from the coating provided corrosion protection, NO3−release promoted localized corrosion phenomena in the scribe. This was associated with the preferential pitting corrosion phenomena at the Cu-rich intermetallic compounds instead of forming a thick and stableNO3−-rich passive layer.Item Degradation Rate Control Issues of PEO-Coated Wrought Mg0.5Zn0.2Ca Alloy(Coatings, 2024) Moreno, Lara; Mohedano Sánchez, Marta; Arrabal Durán, Raúl; Matykina, EndzheBioactive plasma electrolytic oxidation (PEO) coatings were developed on a wrought Mg0.5Zn0.2Ca alloy using a transparent electrolyte for easy maintenance and waste disposal, compared to a conventional suspension-based solution. Treatment times of 300, 600, and 900 s were evaluated for their effects on coating morphology, composition, and corrosion resistance. A short-time electrochemical impedance spectroscopy (EIS) screening was utilized to identify coatings with optimal corrosion protection. To assess the degradation rate and corrosion mechanisms, hydrogen evolution was monitored under pH-controlled quasi-in vivo conditions over extended immersion periods. Coating thickness increased by only 3% from 300 to 900 s of treatment (13 and 18 µm, respectively), with pore bands formed near the barrier layer at 900 s. The short-term EIS screening revealed that the coatings produced at 600 and 900 s were less protective and consistent than those at 300 s due to the presence of pore bands, which increased permeability. Hydrogen evolution measurements during 5 days of immersion at pH 7.4 indicated a tenfold higher degradation rate of the PEO-coated alloy compared to the bare substrate. Therefore, none of the PEO coatings provided effective corrosion protection after 24 h of immersion, which is attributed to crack formation at the PEO/corrosion products interface. This highlights the importance of crevices in the corrosion of Mg-Zn-Ca alloys. The presence of ZnO exacerbates the corrosion of magnesium in crevice areas.Item Corrosion of magnesium-aluminum alloys with Al-11Si/SiC thermal spray composite coatings in chloride solution(Journal of Thermal Spray Technology, 2011) Arrabal Durán, Raúl; Pardo Gutiérrez Del Cid, Ángel; Merino Casals, María Concepción; Mohedano Sánchez, Marta; Casajus, P.; Matykina, EndzheDepositions of Al-11Si coatings reinforced with 5, 15, and 30 vol.% SiC particles (SiCp) were performed onto AZ31, AZ80, and AZ91D magnesium alloys. The influence of substrate composition and SiCp proportion on the anti-corrosion properties of composite coatings was evaluated using DC and AC electrochemical measurements in 3.5 wt.% NaCl solution at 22 °C. The as-sprayed coatings were permeable to the saline solution, and galvanic corrosion occurred at the substrate/coating interface after immersion in the saline solution for a few hours. The addition of SiCp yielded coatings with higher porosity and less effectiveness against corrosion. The application of a cold-pressing post-treatment produced denser coatings with reduced surface roughness, improved hardness, and superior corrosion resistance. However, galvanic corrosion was observed after several days of immersion because of penetration of the 3.5 wt.% NaCl solution through the remaining pores in the coatings.Item Influence of sealing post-treatments on the corrosion resistance of PEO coated AZ91 magnesium alloy(Applied Surface Science, 2018) B. Mingo; Arrabal Durán, Raúl; Mohedano Sánchez, Marta; Y. Llamazares; Matykina, Endzhe; A. Yerokhin; Pardo Gutiérrez Del Cid, ÁngelThe effect of three different post-treatments carried out on Plasma Electrolytic Oxidation (PEO) coated magnesium alloys are evaluated in terms of characterisation and corrosion resistance. Special interest is given to the role of a common additive (NaF) to the coating properties. The post–treatments are based on immersion sealing processes in aqueous solutions of inorganic salts (cerium and stannate based salts) and alcoholic solution of an organic acid (octodecylphosphate acid, ODP). Sealing mechanisms for each post-treatment are proposed. Cerium and stannate sealings are based on filling of the pores with the products of dissolution/precipitation reactions, while the ODP acid sealing is based on the formation of a thin layer of ODP over the coating through specific interactions between the polar part of the organic acid and the coating surface. All coatings are evaluated by salt fog test and analysed by electrochemical impedance spectroscopy. All sealings show a slight increase in the corrosion resistance of the coatings formed in the NaF-free electrolyte, but their positive influence is boosted in case of the coatings obtained in the NaF-containing electrolyte. This is related to the chemical and morphological changes at the coating surface induced by the presence of NaF in the electrolyte.- Project number: 72
Item Implementación de una nueva práctica de Laboratorio: "Fusión y electroafino del cobre con una orientación a la economía circular"(2023) Muñoz Sánchez, Jesús Ángel; Castro Ruiz, Laura; González González, Felisa; Arrabal Durán, Raúl; Matykina, Endzhe; Mohedano Sánchez, Marta; Pillado Ríos, Borja; Moreno Turiégano, Lara; López Martínez, Esther; Mateo Gómez, Gerardo; Abarca García, Isabel Item Permanganate loaded Ca-Al-LDH coating for active corrosion protection of 2024-T3 alloy(Corrosion Science, 2022) Olmo Martínez, Rubén del; Mohedano Sánchez, Marta; Matykina, Endzhe; Arrabal Durán, RaúlCa-Al-Layered Double Hydroxide (Ca-Al-LDH) coating was explored on 2024-T3 aluminium alloy by in situ growth methodology following a 1 h treatment at atmospheric pressure. Mn-based species were successfully incorporated into the Ca-Al-LDH structure by a low-temperature post-treatment (Ca-Al-LDH-Mn). Both LDH coatings disclosed a flaky-like morphology and low thickness (~0.6 µm). Ca-Al-LDH-Mn coating showed optimal paint adhesion and the highest long-term corrosion resistance in 3.5 wt% NaCl solution. Evaluation of scribed LDH specimens by SEM/EDS techniques up to 7 days of immersion in 3.5 wt% NaCl solution revealed that the presence of Mn species in the Ca-Al-LDH-Mn provided active corrosion protection.Item Biological Performance of Duplex PEO + CNT/PCL Coating on AZ31B Mg Alloy for Orthopedic and Dental Applications(Journal of Functional Biomaterials, 2023) Daavari, Morteza; Atapour, Masoud; Mohedano Sánchez, Marta; Matykina, Endzhe; Arrabal Durán, RaúlTo regulate the degradation rate and improve the surface biocompatibility of the AZ31B magnesium alloy, three different coating systems were produced via plasma electrolytic oxidation (PEO): simple PEO, PEO incorporating multi-walled carbon nanotubes (PEO + CNT), and a duplex coating that included a polycaprolactone top layer (PEO + CNT/PCL). Surfaces were characterized by chemical content, roughness, topography, and wettability. Biological properties analysis included cell metabolism and adhesion. PEO ± CNT resulted in an augmented surface roughness compared with the base material (BM), while PCL deposition produced the smoothest surface. All surfaces had a contact angle below 90°. The exposure of gFib-TERT and bmMSC to culture media collected after 3 or 24 h did not affect their metabolism. A decrease in metabolic activity of 9% and 14% for bmMSC and of 14% and 29% for gFib-TERT was observed after 3 and 7 days, respectively. All cells died after 7 days of exposure to BM and after 15 days of exposure to coated surfaces. Saos-2 and gFib-TERT adhered poorly to BM, in contrast to bmMSC. All cells on PEO anchored into the pores with filopodia, exhibited tiny adhesion protrusions on PEO + CNT, and presented a web-like spreading with lamellipodia on PEO + CNT/PCL. The smooth and homogenous surface of the duplex PEO + CNT/PCL coating decreased magnesium corrosion and led to better biological functionality.Item Corrosion behaviour of AZ magnesium alloys with Al and Al–11Si thermal spray coatings(Corrosion. The Journal of Science & Engineering, 2011) Pardo Gutiérrez Del Cid, Ángel; Merino Casals, María Concepción; Arrabal Durán, Raúl; Casajús, P.; Mohedano Sánchez, Marta; Feliú Jr., S.; Merino, S.The corrosion behaviour of AZ31, AZ80 and AZ91D Mg–Al–Zn alloys coated with Al and Al–11Si thermal spray was evaluated in 3.5 wt.% NaCl solution at 22 ºC by gravimetric and electrochemical impedance spectroscopy (EIS) measurements. The corrosion products were examined by scanning electron microscopy (SEM), energy dispersive X–ray analysis (EDX) and low–angle X–ray diffraction (XRD). The as–sprayed Al and Al–11Si coatings were porous and galvanic corrosion of magnesium substrates was observed at the substrate/coating interfaces. The application of a cold–pressing post–treatment smoothed and densified the coatings, improved the contact between coating and substrate and substantially increased the corrosion resistance. Cold–pressed Al coatings were an effective barrier against corrosion and revealed the same corrosion performance regardless of the composition of the magnesium substrate. However, cold–pressed Al–11Si coatings were permeable to the chloride–containing solution and galvanic corrosion of magnesium substrates was observed after a few days of immersion in 3.5 wt.% NaCl solution.