Browsing by Author "Braceras, Iñigo"
Now showing 1 - 19 of 19
Results Per Page
Sort Options
Item Adhesion Enhancement on a Duplex DLC HiPIMS Positive Pulse Coating Performed by Active Screen Plasma Nitriding Pretreatment on 316L Stainless Steel Substrate(2022-11) Gómez, Iñigo; García, Jose Antonio; Santiago, Jose Antonio; Fernandez, Iván; Jose Fernandez, Palacio; Braceras, Iñigo; INGENIERÍA DE SUPERFICIESDiamond-like carbon (DLC) coatings have been the object of research interest due to properties such as excellent wear resistance, low coefficient of friction, high hardness, high elastic modulus, and biocompatibility. Despite this, DLC has poor adhesion properties, which makes it challenging to use in industrial applications. The application of DLC using the high-power pulse magnetron sputtering (HiPIMS) technique with positive pulses has been studied. Seeking greater DLC coating adherence, the application of a nitriding pretreatment prior to the DLC coating has been studied to improve its adhesion to AISI316L stainless steel soft metal substrates, employing active screen plasma nitriding (ASPN). The influence of the different pretreatment temperatures to reach the maximum levels of adhesion has been analyzed. Scratch methods have been employed to assess adhesion. The elemental composition, morphology, and roughness of the samples have been studied, as well as the behavior of resistance to wear and friction. The results show an improvement in DCL adhesion. Critical loads (LC3) increase at higher pretreatment temperatures, from 48 N for the DLC to 82 N for the ASPN + DLC. Pretreatment has also been shown to be effective in maintaining excellent dry wear resistance properties and a low coefficient of friction.Item Anti-soiling coatings for solar cell cover glass: Climate and surface properties influence(2018-10) Jesus, Magnum Augusto Moraes Lopes de; Timò, Gianluca; Agustín-Sáenz, Cecilia; Braceras, Iñigo; Cornelli, Marina; Ferreira, Angela de Mello; VALORIZACIÓN DE RESIDUOS; INGENIERÍA DE SUPERFICIESThe objective of this study has been twofold: i) to investigate different strategies for CPV module glass surface modification, in particular preparing hydrophilic and hydrophobic coatings in order to reduce the dust accumulation (soiling) on the module surface; ii) to perform a joint comparative soiling testing in Italy, Spain and Brazil in order to understand the limit and advantages of the proposed anti-soiling coatings in different climate condition. Two TiO2/SiO2 films with different titanium content have been synthesized and benchmarked against pure TiO2 in relation to transparency and hydrophilicity. Moreover, a hydrophobic antireflective material based on functionalized-SiO2 thin film was also investigated. All these coatings have been deposited over low iron float glass substrates by sol-gel dip-coating and electron-beam evaporation technique. TiO2/SiO2 and functionalized-SiO2 films showed higher transmittance in visible range than pure TiO2. TiO2/SiO2 films showed a persistent superhydrophilic character with water contact angles near to 0° while functionalized-SiO2 presented hydrophobic property. The joint comparative soiling tests showed the importance of setting anti-soiling strategies in region characterized by more dry climate: in Brazil, which during the soiling test was characterized by a long dry period, the anti-soiling coatings were effective in reducing the soiling deposition and in the removal of the contaminants by rainwater; in Spain and Italy, the more frequent rain precipitation made the soiling effect less relevant, however, the deposition of anti-soiling coating on the module cover glass allowed to fully recover the initial transmittance after rain washing. A chemical and mineral characterization of the soiling has been carried out revealing the dependence of the contaminants from the environment conditions (e.g. car traffic, presence of industries, amount of rain and local minerals in the ground).Item Corrosion preserving high density plasma treatment of precipitation hardening stainless steel(2018-12-15) Braceras, Iñigo; Ibáñez, Iñigo; Domínguez-Meister, Santiago; Urgebain, Aiala; Sánchez-García, Jose Angel; Larrañaga, Aitor; Garmendia, Iñaki; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIES; MATERIALES PARA CONDICIONES EXTREMASSpecialty alloys such as precipitation hardening stainless steels are routinely used in critical applications requiring high strength and corrosion resistance, e.g. in aeronautics, in ground transportation and the biomedical field. Nonetheless, their tribological properties remain poor, while the application of surface treatments results in loss of corrosion resistance. Therefore, typically a not fully satisfactory compromise must be adopted. In the present work, the improvement of tribological features, without loss of corrosion resistance, of the 1.4545 (15-5PH) steel has been explored with the use of high density plasmas. The work has focused on long cylindrical geometries, close to those of real applications. The microstructure and composition of the treated surfaces were studied and the corresponding corrosion resistance stablished. The characteristics of the high density plasmas as well as the sample disposition were key factors in the outcomes, which ranged from fully corroded to corrosion resistant surfaces. Results also showed in certain cases the high density plasmas causing surface cracks followed by local corrosion. Additionally tribological studies demonstrated improvement in wear resistance, and electrical contact resistance (ECR) was found to be a good indicator of the wear phenomena occurring along the tests. An equivalent electric circuit is proposed. Actually ECR could be a useful and simple way of monitoring the surface status and assist in assuring safe and dependable operational lives of the components. In conclusion, treatment conditions of cylindrical 1.4545 (15-5PH) have been defined, which provide with an improved tribological performance, preserving corrosion resistance, with ECR a useful performance monitoring parameter.Item Decrease of Staphylococcal adhesion on surgical stainless steel after Si ion implantation(2014-08-15) Braceras, Iñigo; Pacha-Olivenza, Miguel A.; Calzado-Martín, Alicia; Multigner, Marta; Vera, Carolina; Broncano, Luis Labajos; Gallardo-Moreno, Amparo M.; González-Carrasco, José Luis; Vilaboa, Nuria; González-Martín, M. Luisa; INGENIERÍA DE SUPERFICIES; Biomateriales316LVM austenitic stainless steel is often the material of choice on temporal musculoskeletal implants and surgical tools as it combines good mechanical properties and acceptable corrosion resistance to the physiologic media, being additionally relatively inexpensive. This study has aimed at improving the resistance to bacterial colonization of this surgical stainless steel, without compromising its biocompatibility and resistance. To achieve this aim, the effect of Si ion implantation on 316LVM has been studied. First, the effect of the ion implantation parameters (50 keV; fluence: 2.5-5 × 10 16 ions/cm 2 ; angle of incidence: 45-90°) has been assessed in terms of depth profiling of chemical composition by XPS and nano-topography evaluation by AFM. The in vitro biocompatibility of the alloy has been evaluated with human mesenchymal stem cells. Finally, bacterial adhesion of Staphylococcus epidermidis and Staphylococcus aureus on these surfaces has been assessed. Reduction of bacterial adhesion on Si implanted 316LVM is dependent on the implantation conditions as well as the features of the bacterial strains, offering a promising implantable biomaterial in terms of biocompatibility, mechanical properties and resistance to bacterial colonization. The effects of surface composition and nano-topography on bacterial adhesion, directly related to ion implantation conditions, are also discussed.Item Electro-tribological properties of diamond like carbon coatings(2019-06-07) Braceras, Iñigo; Ibáñez, Iñigo; Dominguez-Meister, Santiago; Velasco, Xabier; Brizuela, Marta; Garmendia, Iñaki; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESDiamond like carbon (DLC) coatings typically present good self-lubricating tribological properties that could be of interest in sliding dielectric contacts in multiple electrical applications. In this work electro-tribological studies have been performed on several DLC coatings against aluminum in different humidity conditions, in which the coefficients of friction (CoFs) and electrical contact resistance (ECR) were continuously monitored. Results show that CoF and ECR data can be linked to the properties of the coatings (thickness, finishing, microstructure, residual stresses, and wettability) and the degradation modes of their tribological and electrical properties. Therefore, electro-tribological data can provide valuable information about the performance of dielectric coatings, the reasons behind it, and assist in the development of the coatings. ECR also shows potential for on-line monitoring of coated parts in operation.Item Histomorphometric study of ion implantation and diamond-like carbon as dental implant surface treatments in beagle dogs(2007-03) De Maeztu, Miguel A.; Braceras, Iñigo; Alava, J. Iñaki; Sánchez-Garcés, M. Angeles; Gay-Escoda, Cosme; INGENIERÍA DE SUPERFICIESPurpose: Improvements in the bone-implant interface can provide clinical benefits, such as increasing the amount of bone in contact with the implant and shortening the time required to achieve sufficient bone appositioning to allow early prosthetic loading. The present study describes the results obtained with 2 new surface treatments: (a) CO ion implantation; and (b) diamond-like carbon (DLC) coating. Materials and Methods: Each group (ion implantation, DLC, and the control group, turned titanium) consisted of 12 samples. Beagle dogs subjected to previous partial edentulation were used. Dual histologic evaluation was made of percentage bone-implant contact (% BIC) of all samples based on conventional histomorphometric analysis and environmental scanning electron microscopy (ESEM). Results: The results obtained after 3 and 6 months of dental implant placement showed greater and faster bone integration in the CO ion implantation group (61% and 62% BIC, respectively) compared with the DLC group (47% and 50%); the data corresponding to the ion implanted samples were statistically significant compared with the control group (33% and 49% BIC after 3 and 6 months, respectively). Conclusions: The results showed improved % BIC for implants with ion-implanted surfaces in comparison to DLC coating and machined controls. Furthermore, bone integration appeared to be accelerated in the ion implantation group, since high % BIC values were recorded in the early stages after in vivo implantation.Item Ion implantation as surface treatment for Osseointegration: From the lab to the clinic(2010) Braceras, Iñigo; Alava, Iñaki; Muñoz, Roberto; De Maeztu, Miguel Angel; INGENIERÍA DE SUPERFICIESA key process in a successful treatment of patients with a great variety of musculoskeletal implants requires a fast, reliable and consistent osseointegration. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Different surface modification techniques to improve osseointegration have been proposed and tested to date, but most focus on microscale features, and few control surface modifications at nanoscale. On the other hand, ion implantation modifies the outermost surface properties in relation to the nanotopography, chemical and physical characteristics at nanoscale. The meta-stable surface that results from the treatment, affects the adsorption of bio-molecules in the very first stages of the implant placement, and thus the signaling pathway that promotes the differentiation and apposition of osteoblast cells. This study aimed at assessing the performance, in terms of osseointegration levels and speed, of ion implanted titanium made implants. The study included several in vitro and in vivo tests. The latter, comprised different insertion periods and both experimental and commercial implants as comparative surfaces. The final stage of the study included clinical trials in human patients. In each and every case, bone integration improvement of tested materials/implants was achieved for the CO ion implanted samples. Furthermore, contact osteogenesis was observed in the ion implanted samples, unlike the Ti control samples, where only distance osteogenesis occurred, being this potentially one of the reasons for their faster healing and osseointegration process. Finally, the use of ion implantation as a surface modification tool that allows for evaluating the effects of nanotopography and composition changes independently is presented.Item Ion implantation induced nanotopography on titanium and bone cell adhesion(2014-08-15) Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; De Maeztu, Miguel Ángel; INGENIERÍA DE SUPERFICIES; BiomaterialesPermanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40-80 keV), fluence (1-2 e17 ion/cm 2 ) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted surfaces, without surface chemistry modification, are in the same range and that such modifications, in certain conditions, do have a statistically significant effect on bone tissue forming cell adhesion.Item Mikrobioak eta gainazalak: arazoa eta konponbidea?(2022-07) Braceras, Iñigo; Imaz, Naroa; INGENIERÍA DE SUPERFICIESCOVID-19a dela medio, eguneroko albiste bihurtu zaizkigu gaixotasun infekziosoak. Dena den, gaixotasun horiekiko kezka aurretikoa da, mikrobioak antibiotikoekiko erresistentzia garatzen ari baitira etengabe. Hori dela eta, etorkizunerako beste estrategia batzuk ikertzen ari dira. Horien artean, jakinekoa da gainazalek garrantzi handia dutela hainbat mikrobioren hedapenean . Beraz, mikrobioei aurre egiteko gainazal aproposak bagenitu inguru desberdinetarako, arazoa mugatzeko bidean geundeke. Helburu horrekin, Tecnaliak eta Cidetec Surface Engineeringek arlo horretan teknologia ezberdinak ikertzen eta ahalbide berriak garatzen dihardute.Item Nitriding of titanium by hollow cathode assisted active screen plasma and its electro-tribological properties(2021-04-15) Domínguez-Meister, Santiago; Ibáñez, Iñigo; Dianova, Anastasia; Brizuela, Marta; Braceras, Iñigo; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESTitanium presents good corrosion resistance, a high strength-to-weight ratio, but poor tribological properties. However, these can be enhanced by nitriding processes. Hollow cathode assisted active screen plasma has proved to be an effective and fast nitriding technique. In this work, the effect of process parameters (hollow cathode induced temperature and plasma intensity, electrical bias…) on the resulting surface microstructure (XRD, SEM/EDS), finishing and hardness of titanium (TiGr4) have been studied. Additionally, the electro-tribological properties have been evaluated on a ball on cylinder reciprocating configuration. The results show that hollow cathode assisted active screen plasma nitriding of titanium can produce titanium nitride surfaces with thicknesses far exceeding those typical in PVD coatings. Moreover, higher plasma processing intensities can generate same layer thicknesses at lower temperatures, minimizing the deleterious effect on grain size growth. Finally, monitoring of the electrical contact resistance can provide valuable information concerning the evolution of the status of the surfaces.Item On the Electro-Tribological Properties and Degradation Resistance of Silver-Aluminum Coatings(2018-11-15) Braceras, Iñigo; Ibáñez, Iñigo; Taher, Mamoun; Mao, Fang; del Barrio, Andrés; Saenz De Urturi, Saioa; Berastegui, Pedro; Andersson, Anna M.; Jansson, Ulf; INGENIERÍA DE SUPERFICIES; MATERIALES PARA CONDICIONES EXTREMASContact materials in sliding electrical applications must possess low electrical contact resistance, low friction and wear coefficients, and high degradation resistance to the surrounding media. Silver coatings are commonly used in such applications despite their shortcomings. This work has focused on the study of alternative silver-aluminum coatings deposited by PVD. The main findings include the strong dependence of the tribological performance on the concentration of Al and hence the phases present in the coatings. Besides, the wear mechanism was found to be affected by the working media, either on air or insulating oil. Results have shown that for full HCP phase coatings (Ag67Al33), wear rates are lowest, with no adhesive wear and good surface sulphidation resistance, though with some proclivity to oxidation, coupled with a moderate increase in the electrical contact resistance.Item Plasma nitriding of the inner surface of stainless steel tubes(2018-12-15) Braceras, Iñigo; Ibáñez, Iñigo; Dominguez-Meister, Santiago; Sánchez-García, Jose Angel; Brizuela, Marta; Larrañaga, Aitor; Garmendia, Iñaki; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESStainless steels, especially the austenitic grades, present a good corrosion resistance but poor mechanical properties. Nitriding can increase the surface hardness but typically at the expense of corrosion resistance. Besides, nitriding of inner surfaces is not straight forward, as control of the plasma there is challenging. This work has focused on the development of active screen plasma nitriding processes of inner geometries of the widely used AISI 316L austenitic stainless steel, with preservation of the corrosion resistance. The structure and composition of the nitrided surfaces were studied and corrosion resistance of the inner surfaces assessed. As a result of the study, a relation has been established between plasma treatment parameters, geometrical features and the corrosion resistance. Additionally, electro-tribological studies have been performed. It has been observed that wear resistance improved and that ECR (Electrical Contact Resistance) is a good indicator of the wear phenomena occurring along the test and potentially could be a useful and simple monitoring tool of the status of the surface and assist in defining safe and dependable operational lives. As part of the study, an equivalent electric circuit is proposed. In conclusion, treatment conditions for AISI316L inner tube surfaces have been defined, with corrosion resistance preservation and improved tribological performance, while ECR monitoring has been found insightful and informative of the evolution of the later.Item "Plasma-click" based strategy for obtaining antibacterial surfaces on implants(2013-04) Braceras, Iñigo; Oyarbide, Joseba; Azpiroz, Patxi; Briz, Nerea; Ipiñazar, Enrique; Álvarez, Noelia; Atorrasagasti, Garbiñe; Fratila, Raluca M.; Aizpurua, Jesus M.; INGENIERÍA DE SUPERFICIES; TECNOLOGÍAS DE HIDRÓGENO; SG; VALORIZACIÓN DE RESIDUOS; BiomaterialesBiomaterials with surface antibacterial properties are promising components for medical implants that might provide an alternative to conventional systemic antibiotic treatments. Herein is reported a general method, based on plasma polymerization techniques, to promote the formation of "clickable surfaces" which can be conjugated with chemically modified antibiotics (e.g., azido-vancomycin) under very mild conditions. The procedure is comprised of three operations: (i) surface alkylcarboxylation with acrylic acid/CO 2 plasma, (ii) alkyne functionalization by condensation with propargylamine, and (iii) in situ Cu(I)-catalyzed alkyne-azide conjugation with azidovancomycin. The antibacterial activity of the resulting functionalized surfaces has been assessed against Staphylococcus epidermidis.Item Surface modification by plasma-based processes(World Scientific Publishing Co., 2009-01-01) De Las Heras, Evangelina; Ybarra, Gabriel; Braceras, Iñigo; Corengia, Pablo; INGENIERÍA DE SUPERFICIES; GENERALIn this chapter, the use of plasma processes technology in the biomedical field is presented. The introduction focuses on plasmas and the associated techniques employed to modify surfaces of a wide variety of materials. The versatility of plasma-based treatments allows the design of special function-oriented surfaces for medical devices, which are presented next. An overview of the plasma-based thin films and surface treatments is included for a number of applications ranging from the improvement of mechanical properties and the modification of the surface chemistry of materials to regulate the interaction with living tissues, diagnostics, and drug delivery.Item Synthesis and characterization of plasma-polymerized HMDSO films using an ion gun inverse magnetron source(2007) García-Luis, Alberto; Corengia, Pablo; González-Santamaría, Daniel; Brizuela, Marta; Braceras, Iñigo; Briz, Nerea; Azpiroz, Patxi; Bellido-González, Victor; Powell, Sarah; TECNOLOGÍAS DE HIDRÓGENO; GENERAL; INGENIERÍA DE SUPERFICIES; SGPlasma-polymerized hexamethyldisiloxane (PPHMDSO) films have been deposited using an ion gun inverse magnetron source at low pressure with Ar/O2/N2/HMDSO plasmas. Deposition rates and structures of the highly cross-linked PPHMDSO layers have been determined. Surface mechanical properties were studied using the nanoindentation technique, and wettability was measured by contact angle method and modifications induced on optical properties were studied at different wavelengths. Results showed remarkable differences in hardness and contact angles of distilled water depending on the plasma conditions. In addition, plasma parameters also had a very significant effect on the background fluorescence.Item TiN-Ag as an antimicrobial and wear resistant coating(2021-12) Braceras, Iñigo; Brizuela, Marta; Álvarez, Noelia; Martínez Van Geeteruyen, Miguel; Azkona, Ibon; INGENIERÍA DE SUPERFICIES; BiomaterialesNosocomial infections are a major clinical concern, posing great risks for patients and rising costs for health services providers. This work aims at developing a hard, wear resistant coating, whose antimicrobial properties shall prevent the transmission of infections. TiN coatings deposited by Physical Vapour Deposition, PVD, with different Ag contents have been studied, especially in relation to the hardness and adhesion, their microstructure and morphology. The antimicrobial activity of the surfaces has been assessed against Staphylococcus epidermidis at different time frames, one of the most troublesome source of infections in trauma and orthopaedic surgeries. The electro-tribology properties of different silver contest have been studied. Finally, the coatings have been deposited on surgical acetabular reamers and wear resistance tests have been carried out against synthetic composite bone (simulating cortical and cancellous bone). Results have shown a good coating adhesion on stainless steel (both quantitatively in the scratch tests and qualitatively in the tests against synthetic composite bone), while the hardness decreased with higher Ag percentages. Furthermore, coatings exhibited antimicrobial activity against S.epidermidis, limited silver release, a remarkable wear resistance (vs. uncoated surgical acetabular reamers), while the electrical contact resistance provided valuable information about the evolution of friction and the status of the coating. Therefore TiN-Ag coatings present promising features for reducing the risk of infections, monitoring and extending cutting edge life and quality, and thus limiting damage to living tissues, e.g. necrosis.Item Tribological and electric contact resistance properties of pulsed plasma duplex treatments on a low alloy steel(2023-02-15) Murua, Joseba; Ibañez, Iñigo; Dianova, Anastasia; Domínguez-Meister, Santiago; Larrañaga, Oihane; Larrañaga, Aitor; Braceras, Iñigo; INGENIERÍA DE SUPERFICIESLow friction low cost tribology systems involve most often use of lubricants, which must be periodically refurbished and often present environmental issues. Furthermore, use of liquid lubricants is a non-starter in many critical applications. In this work, the performance of single process duplex tribo-conditioning treatments is explored. The treatments are based on pulsed low-pressure plasma treatments, where nitriding processes are complemented with the deposition of carbonaceous solid lubricating top layers. The duplex treatments are carried out sequentially in the same chamber. The study comprised, among others, exploring the use of different residual gas mixes and pulse frequencies. Roughened blasted 42CrMo4 low alloy steel (AISI 4140 equivalent) was used as substrate. Resulting surface properties were studied with nano-indentation, profilometry and contact angle measurements. Besides, tribological studies were carried out against 100Cr6 steel at different humidities. The evolution of the coefficient of friction and the electrical contact resistance (ECR) was assessed for each test, as well as the wear rates. Results showed tribological outcomes heavily dependent of ambient conditions, and ECR of the wear track surface condition, i.e. the amount of remaining coated surfaces. The use of pulsed plasmas generated comparatively softer, smoother and more hydrophobic surfaces.Item Use of smartphones as optical metrology tools for surface wear detection(2021-03) Diamanti, Eleftheria; Iriarte, Eneko; Oblak, Eva; Dominguez-Meister, Santiago; Ibañez, Iñigo; Braceras, Iñigo; Berger, Andreas; Tecnalia Research & Innovation; INGENIERÍA DE SUPERFICIESProper wear level information and early wear detection are crucial goals in many engineering applications and industrial components in order to improve efficiency and reduce production, maintenance, or replacements costs. Furthermore, this should ideally be achieved with a user-friendly, low-cost, and easy to implement methodology for wear level monitoring and detection. In this work, we present the design of a new approach to accomplish early wear detection that is implemented by means of a stand-alone smartphone device and application providing real-time online metrology. The online monitoring is done by means of optical measurements and image processing based on the advanced smartphone vision system technology currently available in commercial devices. The developed mobile App works in continuous mode without interrupting the wear process. Specifically, it traces surface changes and monitors the progression of wear enabling just-in-time warning alarms for “significant wear” and “critical wear” detection. We demonstrate that critical wear of a surface prior to fatal rupture can be detected, which is the main objective in many industrial applications.Item Wear behaviour of UHMWPE against DC-pulsed plasma nitrided and duplex treated AISI 316L used in hip joint replacements(2009) Perez, Ezequiel; Pazos, Leonardo; De Heras, Evangelina Las; Parodi, Belén; Corengia, Pablo; Braceras, Iñigo; GENERAL; INGENIERÍA DE SUPERFICIESWear behaviour of the artificial joint replacements plays a critical role in implant failure. The UHMWPE-AISI 316L tribological system, widely used on joint prostheses, was studied. Two surface modifications were applied to the stainless steel counterface: DC-pulsed plasma nitriding and duplex (DC-pulsed plasma nitriding + TiN coating by cathodic-arc evaporation) treatments. An Amsler Disc Machine Type A-135 was used as an approximation to real loading conditions. Worn surfaces, weight loss curves and wear debris were analysed. The results show that the nitriding and duplex treatments improve the wear resistance of the tribological system. Different types of damages were observed on the UHMWPE worn surfaces depending on the surface treatment of the stainless steel.