Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 53) Show all publications
Zanella, C. & Lekka, M. (2019). A journey into mCBEEs training, the European training network on corrosion problems at micro- and nanoscale. Transactions of the Institute of Metal Finishing, 97(5), 227-229
Open this publication in new window or tab >>A journey into mCBEEs training, the European training network on corrosion problems at micro- and nanoscale
2019 (English)In: Transactions of the Institute of Metal Finishing, ISSN 0020-2967, E-ISSN 1745-9192, Vol. 97, no 5, p. 227-229Article in journal (Other academic) Published
Abstract [en]

Training and establishing networks for the future researchers in our field of surface engineering and metal finishing has been a key focus of EAST (European Academy for Surface Technology). Here the authors briefly describe the mCBEE training network, and how it operates. 

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
corrosion training, European training networks, Corrosion, Corrosion problems, Nano scale, Surface engineering, Surface technology, Training network, Metal finishing
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-46241 (URN)10.1080/00202967.2019.1644770 (DOI)000482972900001 ()2-s2.0-85071480823 (Scopus ID)PP JTH 2020 embargo 12;JTHMaterialIS (Local ID)PP JTH 2020 embargo 12;JTHMaterialIS (Archive number)PP JTH 2020 embargo 12;JTHMaterialIS (OAI)
Available from: 2019-09-18 Created: 2019-09-18 Last updated: 2020-01-22Bibliographically approved
Zhu, B., Seifeddine, S., Jarfors, A. E. .., Leisner, P. & Zanella, C. (2019). A study of anodising behaviour of Al-Si components produced by rheocasting. Paper presented at 15th International conference on semi-solid processing of alloys and composites, October 22nd to 24th, 2018, Shenzhen, China. Solid State Phenomena, 285, 39-44
Open this publication in new window or tab >>A study of anodising behaviour of Al-Si components produced by rheocasting
Show others...
2019 (English)In: Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779, Vol. 285, p. 39-44Article in journal (Refereed) Published
Abstract [en]

This paper aims to investigate the anodising behaviour of Al-Si components produced by rheocasting, to understand the effect of the surface liquid segregation (SLS) on the anodising response. The material investigated was EN AC 42000 Al-alloy with an addition of 150 ppm Sr. The component was rheocast and conventionally liquid cast for benchmarking. The RheoMetalTM process was used to prepare slurry and subsequently cast using a vertical pressure die casting machine. Prior to anodising, mechanical grinding was used as pre-treatment method for selected samples as comparison with components in the as-cast state. Anodising was performed on the components using a constant controlled voltage at 25 V, in 1 M H2SO4, at room temperature. The duration of anodising was varied from 30 mins to 120 mins to examine the relationship between oxide layer thickness and the anodising time. The oxide layer was investigated and characterised. The results demonstrated that the presence of the SLS layer, which was enriched with alloying elements, had a significant influence on the anodising behaviour of the cast component. The oxide layer thickness of the components produced by rheocasting and fully liquid casting was measured and compared. The relations between the oxide layer thickness and anodising time, as well as the casting methods are presented and discussed in this paper.

Place, publisher, year, edition, pages
Trans Tech Publications, 2019
Keywords
Anodising, Oxide Layer, Rheocasting
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-42630 (URN)10.4028/www.scientific.net/SSP.285.39 (DOI)2-s2.0-85059944290 (Scopus ID)
Conference
15th International conference on semi-solid processing of alloys and composites, October 22nd to 24th, 2018, Shenzhen, China
Available from: 2019-01-14 Created: 2019-01-14 Last updated: 2019-05-09Bibliographically approved
Gracco, A., Dandrea, M., Deflorian, F., Zanella, C., De Stefani, A., Bruno, G. & Stellini, E. (2019). Application of a molybdenum and tungsten disulfide coating to improve tribological properties of orthodontic archwires. Nanomaterials, 9(5), Article ID 753.
Open this publication in new window or tab >>Application of a molybdenum and tungsten disulfide coating to improve tribological properties of orthodontic archwires
Show others...
2019 (English)In: Nanomaterials, ISSN 2079-4991, Vol. 9, no 5, article id 753Article in journal (Refereed) Published
Abstract [en]

Coatings incorporating nanoparticles of molybdenum and tungsten disulfide (MoS2 and WS2)—known for their lubricating properties—are applied to orthodontic stainless steel wires to verify if there is an improvement in terms of tribological properties during the sliding of the wire along the bracket. To simulate in vitro sliding of the wire along the bracket and evaluate friction 0.019 × 0.025 inches orthodontic stainless steel (SS) wires were subjected to the application, by electrodeposition, of Ni, Ni + MoS2, and Ni + WS2 . The samples produced were analyzed with scanning electron microscopy and assessment of resistance to bending. Thirty-two test conditions have been analyzed, arising from the combination of four types of coatings (SS bare wires and strings with three types of coating), two types of self-ligating bracket (Damon Q, Ormco and In-Ovation R, GAC International), two bracket-wire angles (0◦ and 5◦), two environments (dry and wet). Analyses carried out on the samples show acceptable coatings incorporating MoS2 and WS2 and a resistance of coatings after a minimum bending. In “dry conditions” a statistically significant decrease in friction occurs for wires coated with MoS2 and WS2 if associated with the In-Ovation bracket. In “wet conditions” this decrease is observed only in isolated test conditions. Analysis of the wires after sliding tests show little wear of the applied coatings. Nanoparticles are acceptable and similar in their behavior. Improvements in terms of friction are obtained pairing coatings incorporating MoS2 and WS2 with the In-Ovation bracket in dry conditions. 

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
Friction, Inorganic nanoparticles, Stainless steel archwires
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-44854 (URN)10.3390/nano9050753 (DOI)000479007900095 ()31100885 (PubMedID)2-s2.0-85067098393 (Scopus ID)GOA JTH 2019;JTHMaterialIS (Local ID)GOA JTH 2019;JTHMaterialIS (Archive number)GOA JTH 2019;JTHMaterialIS (OAI)
Available from: 2019-06-24 Created: 2019-06-24 Last updated: 2019-08-15Bibliographically approved
Rosoiu, S., Pantazi, A., Petica, A., Cojocaru, A., Costovici, S., Zanella, C., . . . Enachescu, M. (2019). Comparative Study of Ni-Sn Alloys Electrodeposited from Choline Chloride-Based Ionic Liquids in Direct and Pulsed Current. Coatings, 9(12), Article ID 801.
Open this publication in new window or tab >>Comparative Study of Ni-Sn Alloys Electrodeposited from Choline Chloride-Based Ionic Liquids in Direct and Pulsed Current
Show others...
2019 (English)In: Coatings, ISSN 2079-6412, Vol. 9, no 12, article id 801Article in journal (Refereed) Published
Abstract [en]

This work presents, for the first time, the electrodeposition of Ni-Sn alloys in pulse current, from deep eutectic solvents (choline chloride: ethylene glycol eutectic mixture). Additionally, in this study, we report a comparison of the electrodeposition methods known as pulse and direct current. The elemental composition of the films, evaluated from EDX, remained almost constant independently on the electrodeposition parameters. The XRD data revealed the presence of the NiSn metastable phase, which has been confirmed by DSC analysis. This phase shows a nanocrystalline structure with crystallite sizes between 12 and 20 nm. The use of pulse current electrodeposition method has led to an improvement of alloys’ mechanical properties. Moreover, by controlling the electrodeposition parameters, we succeeded in tuning the mechanical properties of the coatings prepared through the PC method. We showed that the hardness parameters exhibited by the Ni-Sn alloys are strongly dependent on their crystallite sizes.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
electrodeposition, Ni-Sn coatings, deep eutectic solvent, direct current plating, pulse current plating, mechanical properties
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hj:diva-47486 (URN)10.3390/coatings9120801 (DOI)000506682800030 ()2-s2.0-85078027005 (Scopus ID)GOA JTH 2019;JTHMaterialIS (Local ID)GOA JTH 2019;JTHMaterialIS (Archive number)GOA JTH 2019;JTHMaterialIS (OAI)
Available from: 2020-01-22 Created: 2020-01-22 Last updated: 2020-02-13Bibliographically approved
Eslami, M., Deflorian, F. & Zanella, C. (2019). Electrochemical Behavior of Conventional and Rheo-High-Pressure Die Cast Low Silicon Aluminum Alloys in NaCl Solutions. Corrosion, 75(11), 1339-1353
Open this publication in new window or tab >>Electrochemical Behavior of Conventional and Rheo-High-Pressure Die Cast Low Silicon Aluminum Alloys in NaCl Solutions
2019 (English)In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 11, p. 1339-1353Article in journal (Refereed) Published
Abstract [en]

The electrochemical behavior of a low silicon aluminum alloy cast by the conventional and rheo-high-pressure die cast processes is evaluated using polarization test and electrochemical impedance spectroscopy in 0.01 M, 0.05 M, 0.1 M, and 0.6 M sodium chloride solutions. Compared to the conventional high-pressure die cast process, rheocasting introduces some alterations in the microstructure including the presence of aluminum grains with different sizes, formed at different solidification stages. According to the results of the anodic polarization test, conventional cast and rheocast samples show similar breakdown potentials. However, the rheocast samples present enhanced oxygen reduction kinetics compared to the conventional cast sample. Based on scanning electron microscopy examinations, localized microgalvanic corrosion is the main corrosion mechanism for both alloys and it initiates at the interface of aluminum with iron-rich intermetallic particles which are located inside the eutectic regions. The corrosion further develops into the eutectic area. Although the rate of the cathodic reaction can be influenced by the semisolid microstructure, according to the results of anodic polarization and electrochemical impedance spectroscopy tests, the corrosion behavior is not meaningfully affected by the casting process.

Place, publisher, year, edition, pages
NACE International, 2019
Keywords
aluminum-silicon alloy, intermetallic particles, micro-galvanic corrosion, rheocasting, semisolid casting
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-46913 (URN)10.5006/3254 (DOI)000493898700009 ()PP JTH 2019 embargo 03;JTHMaterialIS (Local ID)PP JTH 2019 embargo 03;JTHMaterialIS (Archive number)PP JTH 2019 embargo 03;JTHMaterialIS (OAI)
Available from: 2019-11-27 Created: 2019-11-27 Last updated: 2020-01-20Bibliographically approved
Eslami, M., Deflorian, F. & Zanella, C. (2019). Electrochemical performance of polypyrrole coatings electrodeposited on rheocast aluminum-silicon components. Progress in organic coatings, 137, Article ID 105307.
Open this publication in new window or tab >>Electrochemical performance of polypyrrole coatings electrodeposited on rheocast aluminum-silicon components
2019 (English)In: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 137, article id 105307Article in journal (Refereed) Published
Abstract [en]

Electropolymerization of polypyrrole coatings in the presence and absence of sodium nitrate was applied on rheo-cast Al-4.5% Si alloy and pure aluminum. The results showed that the eutectic silicon phase and intermetallic particles in the alloy's microstructure increase the electrodeposition rate in comparison to the pure aluminum substrate. The electrochemical and microstructural studies show that the polypyrrole coatings are able to protect the surface due to the barrier properties and the passivation protection provided by the reduction of the conductive polymer. The coating electrodeposited from sodium nitrate-containing electrolyte presented improved protection for longer immersion time. Localized formation of a thick oxide layer as a result of the drastic galvanic coupling at the polypyrrole/aluminum interface leads to blister formation and failure of the coating. It was revealed that the coating could be deposited into the porosities produced by the casting related defects, but in most cases, this affects the corrosion protection leading to imminent failure.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Al-Si alloy, Casting defect, Corrosion protection, Galvanic coupling, Polypyrrole, Aluminum coatings, Aluminum corrosion, Corrosion resistant coatings, Electrodeposition, Electrodes, Electrolytes, Electropolymerization, Galvanic corrosion, Nitrates, Polypyrroles, Silicon alloys, Sodium nitrate, Barrier properties, Conductive Polymer, Electrochemical performance, Inter-metallic particle, Polypyrrole coatings, Aluminum alloys
National Category
Corrosion Engineering
Identifiers
urn:nbn:se:hj:diva-46215 (URN)10.1016/j.porgcoat.2019.105307 (DOI)000500944400007 ()2-s2.0-85072036968 (Scopus ID)PP JTH 2019 embargo 24;JTHMaterialIS (Local ID)PP JTH 2019 embargo 24;JTHMaterialIS (Archive number)PP JTH 2019 embargo 24;JTHMaterialIS (OAI)
Available from: 2019-09-17 Created: 2019-09-17 Last updated: 2020-01-20Bibliographically approved
Pinate, S., Leisner, P. & Zanella, C. (2019). Electrocodeposition of nano-SiC particles by pulse-reverse under an adapted waveform. Journal of the Electrochemical Society, 166(15), D804-D809
Open this publication in new window or tab >>Electrocodeposition of nano-SiC particles by pulse-reverse under an adapted waveform
2019 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 166, no 15, p. D804-D809Article in journal (Refereed) Published
Abstract [en]

This work has explored the potential of using pulse reverse (PR) plating for increasing the deposited fraction of SiC nanoparticles. Two PR waveforms were selected, a short pulse (500 Hz) waveform and a newly modified and adapted pulsed sequence that equals the plating thickness to the particles’ diameter (50 nm) for the on-time and half-diameter during the anodic time. The pulse waveforms were designed with 4 and 10 A⋅dm−2 as the average current density and cathodic peak current density, respectively. Direct current (DC) deposits at the same values were also produced as reference. In all cases, the codeposition of nano-SiC particles influenced the microstructure. The electroplating under DC 10 A⋅dm−2 showed the strongest grain refinement and increased the content of the particles (up to 2% vol.) PR using high-frequency achieved a similar codeposition. The maximum particle incorporation was achieved by the proposed adapted pulse waveform, doubling the SiC content produced by other set-ups (up to 4% vol.); increasing the microhardness of the deposits to 400 HV, despite no grain refinement compared to the pure metal. From these results, it was observed a relationship between the influence of the plating method on the microstructure, the particle content, and the material's hardness.

Place, publisher, year, edition, pages
Electrochemical Society, 2019
Keywords
Electrodeposition, Composite coating, Electroplating, Pulse reverse current
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-46770 (URN)10.1149/2.0441915jes (DOI)000494282300003 ()2-s2.0-85076115008 (Scopus ID)PP JTH 2019 (Local ID)PP JTH 2019 (Archive number)PP JTH 2019 (OAI)
Note

Included in licentiate thesis in manuscript form with the title: "Codeposition of nano-SiC particles by pulse-reverse electroplating".

Available from: 2019-11-04 Created: 2019-11-04 Last updated: 2019-12-18Bibliographically approved
Eslami, M., Speranza, G., Fedel, M., Andersson, N.-E., Deflorian, F., Omanovic, S. & Zanella, C. (2019). Electropolymerization and possible corrosion protection effect of polypyrrole coatings on AA1050 (UNS A91050) in NaCl solutions. Corrosion, 75(7), 745-755
Open this publication in new window or tab >>Electropolymerization and possible corrosion protection effect of polypyrrole coatings on AA1050 (UNS A91050) in NaCl solutions
Show others...
2019 (English)In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 7, p. 745-755Article in journal (Refereed) Published
Abstract [en]

Effect of solution chemistry on the electropolymerization and the electrochemical properties of polypyrrole coatings on aluminum is studied by means of electrochemical techniques, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy. It is shown that the protection effect of the coating in long-term exposures and when exposed to more concentrated NaCl solutions depends on the chemistry of electropolymerization electrolyte. The results show that nitrate anions passivate the aluminum substrate during the electropolymerization process. The resulting coating is less prone to blistering in a NaCl solution and probably due to its higher electrochemical activity presents a higher anodic protection effect. The galvanic interaction of polypyrrole coating with aluminum in a NaCl solution is directly observed using focused ion beam-assisted SEM.

Place, publisher, year, edition, pages
National Association of Corrosion Engineers International, 2019
Keywords
Aluminum, Conductive polymer, Corrosion protection, Galvanic interaction, Passivation, Polypyrrole, Aluminum coatings, Aluminum corrosion, Anodic protection, Electrolytes, Electropolymerization, Galvanic corrosion, Ion beams, Polypyrroles, Scanning electron microscopy, Sodium chloride, X ray photoelectron spectroscopy, Aluminum substrate, Electrochemical activities, Electrochemical techniques, Long term exposure, Polypyrrole coatings, Solution chemistry, Corrosion resistant coatings
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-45537 (URN)10.5006/3124 (DOI)000474438600005 ()2-s2.0-85069675948 (Scopus ID)HOA JTH 2019;JTHMaterialIS (Local ID)HOA JTH 2019;JTHMaterialIS (Archive number)HOA JTH 2019;JTHMaterialIS (OAI)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-13Bibliographically approved
Zhu, B. & Zanella, C. (2019). Hardness and corrosion behaviour of anodised Al-Si produced by rheocasting. Materials & design, 173, Article ID 107764.
Open this publication in new window or tab >>Hardness and corrosion behaviour of anodised Al-Si produced by rheocasting
2019 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 173, article id 107764Article in journal (Refereed) Published
Abstract [en]

The anodised layer of Al-Si alloys produced by rheocasting was studied and compared to anodised traditional liquid casting in this paper. The anodising was performed in 1.0 M H2SO4 solution at room temperature on the as-cast substrates, and anodising voltage and time were optimised as process parameters. This study focuses on understanding the effect of the surface liquid segregation (SLS) layer by rheocasting on the hardness and corrosion protection of the oxide layer. The hardness depends on the anodising parameters and varies along the oxide thickness. The corrosion protection given by the oxide layer was evaluated by electrochemical impedance spectroscopy (EIS) in 3 wt-% NaCl solution, and the results revealed that the longitudinal macrosegregation influences the corrosion protection, with the near-to-vent region showing lower corrosion protection due to a higher eutectic fraction. A comparison between liquid and rheocast samples indicated that the presence of SLS layer by the transverse macrosegregation does not have a significant impact on the corrosion resistance of the oxide layer. Moreover, it was found that an increase of the oxide layer thickness by longer anodising time or higher applied voltage decreases both the hardness and corrosion resistance of the oxide layer.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Rheocasting, Anodising, Al oxide layer, Corrosion protection, Surface layer segregation
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-43433 (URN)10.1016/j.matdes.2019.107764 (DOI)000465533900004 ()2-s2.0-85063813035 (Scopus ID)GOA JTH 2019 (Local ID)GOA JTH 2019 (Archive number)GOA JTH 2019 (OAI)
Funder
Knowledge Foundation, 20100280; 20170066
Available from: 2019-04-08 Created: 2019-04-08 Last updated: 2019-06-03Bibliographically approved
Sainis, S. & Zanella, C. (2019). Influence of size and distribution of intermetallic particles in Al-Si cast alloys on the cerium conversion coating deposition. In: Electrochem 2019, Glasgow: Abstracts book. Paper presented at Electrochem 2019 Annual Meeting, 26-28 August, Glasgow, United Kingdom (pp. 99-99).
Open this publication in new window or tab >>Influence of size and distribution of intermetallic particles in Al-Si cast alloys on the cerium conversion coating deposition
2019 (English)In: Electrochem 2019, Glasgow: Abstracts book, 2019, p. 99-99Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Aluminium alloys are susceptible to corrosion due to microgalvanic coupling of the Al matrix and intermetallic particles (IMP). Among different protection strategies, conversion coatings can be selectively deposited on more noble sites. Cerium conversion coatings (CeCC) have been proven to inhibit the cathodic reaction by preferentially depositing on the cathodic IMP. Their spontaneous deposition achieved by immersion of aluminium substrate in Ce-ion containing baths is a consequence of the localised pH increase because of oxygen reduction reaction at local cathodic sites of the microstructure. The influence of bath process parameters (like cerium salt type, cerium ion concentration, pH etc.) have been widely investigated primarily on AA2024 and AA7075, but the more general role of microstructure remains to be clearly understood. Due to the localised nature of deposition reactions, the microstrucutre, in the sense of chemical composition, size and distribution of the second phase or IMP play a crucial role in the deposition behaviour. This research investigates the role of IMP size and distribution in the microstructure, i.e. how far or close they are spaced from each other, on the deposition of CeCC. Two model cast Al-7wt.% Si alloys are selected with 2wt.% Cu and 1wt.% Fe respectively. Different IM distribution in the microstructure is achieved by implementing slow and fast cooling rates for solidification of these hypoeutectic Al-Si alloys. CeCC coatings are spontaneously deposited by immersion in cerium chloride salt solutions. Bare metal and CeCC deposited microstructure is characterized with optical microscopy, scanning electron microscopy and energy dispersive x-ray spectroscopy.

National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-47182 (URN)
Conference
Electrochem 2019 Annual Meeting, 26-28 August, Glasgow, United Kingdom
Available from: 2019-12-20 Created: 2019-12-20 Last updated: 2019-12-20Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-2924-137X

Search in DiVA

Show all publications