FRCU - GIS: Grupo de Ingeniería de Superficies - Artículos
Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/812
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Item Tribological behaviour of a multilayer CrN/DLC coating obtained using PVD-MS(2022-08) Delfín, Francisco Andrés.; Brühl, Sonia PatriciaDiamond-like Carbon (DLC) coatings are used as protective layers for steel components due to their hardness, chemical inertia and interesting tribological properties. Reducing wear and friction coefficient is of great importance for industries today in order to increase energy efficiency and reduce harmful emissions to the environment. In this paper, a multilayer CrN/DLC coating is analysed. It was deposited using a commercial Plasma Enhanced Magnetron Sputtering over nitrided and not nitrided mild-alloy steel AISI 4140, produced for the first time in Argentina, at the firm Coating.Tech by Flubetech-Tantal. The base of the coating is an anchor layer made of CrN and the top layer is a chromium-dopped hydrogenated amorphous carbon (a-C:H:Cr), which provides excellent tribological properties. Wear tests were carried out in a Pin-on-Disk apparatus, using an Al2O3 ball as counterpart, with Hertzian contact stress from 1370 up to 1460 MPa. The friction coefficient was μ~0.1, which is 80% less than the untreated steel and the wear volume loss was reduced eight times. The adhesion was evaluated by means of Scratch Test, where major improvement was noticed in the samples which were nitrided as pre-treatment, increasing critical load from 25 N up to 65 N.Item Near superhydrophobic carbon nanotube coatings obtained via electrophoretic deposition on low-alloy steels(2021-01-20) Alderete Gómez, Bruno Martín; Suárez Vallejo, Sebastián; Mac Lucas, Timothy; Espin, Douglas; Mücklich, Frank; Brühl, Sonia PatriciaSucker rods are a key element in certain oil-extraction processes as they link the motor group on the surface with the pumps located downhole. During the transport from the production site toward the extraction well, these components are prone to corrosion. A hydrophobic carbon nanotube (CNT) coating, deposited via electrophoretic deposition (EPD), is proposed as a protective layer, shielding the rods from harsh environmental conditions. Three different coating systems are considered and thoroughly characterized (depending on the additive that is used to deposit the CNT), namely, magnesium nitrate hexahydrate (Mg– Nit), triethylamine (TEA), and a duplex coating (DD). The latter presents an approach which combine s the advantages of each additive, mechanical stability from Mg–Nit and strong hydrophobicity from TEA (near superhydrophobic). The former coatings are further processed to overcome their individual shortcomings,resulting in an increase in the coating’s stability for TEA coating, as well astransforming the hydrophilic Mg–Nit surface into a hydrophobic surface.Item Contact fatigue behavior of α-Al PROOF 2 O -Ti(C,N) CVD coated WC-Co under dry and wet conditions(2020-11-07) Sosa, D.A.; Collado Ciprés, Verónica; García, José Luis; Dalibón Bähler, Eugenia Laura; Escalada, Lisandro; Roa, Joan Josep; Soldera, Flavio; Brühl, Sonia Patricia; Llanes, L.; Simison, SilviaThe response to cycling contact fatigue load of a WC-6%Co carbide coated with a Ti(C,N)/α-Al2O3 CVD multilayer was investigated in dry and wet conditions. Imprints in dry conditions were characterized by small thin cracksformingacircumferenceatthemaximumradiioftheimprint.Thedamagedcoatingwastotallypresentin thefinalimprintofthedrytest.Wetindentationsshowcaseanareaintheimprintwherethe α-Al2O3 layerhas beenremovedthroughoutaringbutwaskeptatthecenteroftheindentation,suggestingthatthecoatingdamageundercyclingcontactloadinwetconditionsisdominatedbyα-Al2O3degradation,associatedwithafretting effectortangentialloadsacceleratingthefatigue-corrosionofthealuminalayer.Item Tribological and corrosion Behavior of Duplex Coated AISI 316L using plasma based ion implantation and deposItion(2020) Vaca, Laura Silvia; Quintana, Juan Pablo; Vega, Daniel; Márquez, Adriana Beatriz; Brühl, Sonia PatriciaThe implementation of a duplex process, which combines plasma nitriding with hard coatings obtained by cathodic arc, on stainless steel substrates has faced adhesion problems that affected the wear and corrosion behavior of the treated surfaces. One variation of the cathodic arc process, which could improve the adhesion, is its combination with plasma ion implantation. This work presents results of the wear and corrosion behavior of duplex TiTiN bilayer coatings obtained by cathodic arc deposition combined with ion implantation (PBII&D) on plasma nitrided AISI 316L stainless steel In order to compare the application of PBII&D in duplex processes against conventional cathodic arc deposition, other two types of samples were obtained; one group of samples was coated using the same experimental device with the substrate at floating potential and the other one with a commercial PVD system. The coatings were characterized by SEM, XRD, and nanoindentation. The adhesion was evaluated by the Scratch Test and Rockwell C indentation. The wear resistance was analyzed by the pin-on-disk test and the corrosion behavior was evaluated by means of anodic polarization tests in NaCl solution, as well as by the Salt pray Fog Test. The PBII&D bilayer coatings showed better adhesion while the commercial PVD TiN coatings presented the smallest wear volume loss, but the delamination inside and around the track evidenced adhesion problems. Corrosion resistance was improved in all coatings benchmarked against nitride substrates, but PBII&D processes offered better protection.Item Soft and thick DLC deposited on AISI 316L stainless steel with nitriding as pre-treatment tested in severe wear conditions(2020) Dalibón Bähler, Eugenia Laura; Moreira, Ramiro Damián; Heim, Daniel; Forsich, Christian; Brühl, Sonia PatriciaThick and soft DLC coatings were deposited over stainless steel to improve their surface properties, protecting them from wear in different conditions. When a protective film is thick, it can be considered as selfsustaining in terms of loadcarrying capacity during wear situations even if the substrate is soft or hard. Thin and hard DLC coatings are well known for having high hardness and low friction coefficient; however they have adhesion problems when deposited on soft steels and many of their wear properties also depend on adhesion. For this reason, a previous plasma nitriding process may be convenient. In this work, the fretting and erosion wear behaviour of DLC soft coatings deposited on nitrided and nonnitrided austenitic stainless steel was evaluated using high loads and long tests both simulating severe conditions wear. The aim is to analyse under which conditions the film thickness is not enough to withstand wear damage when deposited onto soft steels. The results showed that in the fretting tests, the duplex sample presented better resistance than the only coated sample in all tested conditions, except for the minimum load, 12 N. In slurry erosion tests, the mass loss was similar in both samples until nine hours, when the influence of the nitrided layer became noticeable as a hard layer since the coating partially removed.