https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 12 Jun 2026 11:44:24 GMT 2026-06-12T11:44:24Z http://hdl.handle.net/10985/9657 Tribological response of AA 2024-T3 aluminium alloy coated with a DLC duplex coating STAIA, Mariana; PUCHI-CABRERA, Eli-Saul; IOST, Alain; ZAIRI, Amel; BELAYER, S.; VAN GORP, Adrien Considerable improvement in the tribological response was achieved during sliding wear tests against alumina ball, when AA 2024-T3-aluminium alloy substrate was coated with DLC/NiP duplex coating. Quantitative EPMA analysis carried out on the coated sample cross-section coupled with nanoindentation techniques allowed the identification of the coated system architecture as composed of 4 main layers, with distinct mechanical properties, on top of the aluminium substrate: DLC (a:C-H chromium dopped layer and graded layer of CrC), a newly formed graded layer of CNiPCr, product of the interdifusion during PVD processing, and the NiP coating. The change in the elastic modulus with penetration depth was described by means of an original approach that was developed for its specific application to multilayer coatings. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9657 2015-01-01T00:00:00Z STAIA, Mariana PUCHI-CABRERA, Eli-Saul IOST, Alain ZAIRI, Amel BELAYER, S. VAN GORP, Adrien Considerable improvement in the tribological response was achieved during sliding wear tests against alumina ball, when AA 2024-T3-aluminium alloy substrate was coated with DLC/NiP duplex coating. Quantitative EPMA analysis carried out on the coated sample cross-section coupled with nanoindentation techniques allowed the identification of the coated system architecture as composed of 4 main layers, with distinct mechanical properties, on top of the aluminium substrate: DLC (a:C-H chromium dopped layer and graded layer of CrC), a newly formed graded layer of CNiPCr, product of the interdifusion during PVD processing, and the NiP coating. The change in the elastic modulus with penetration depth was described by means of an original approach that was developed for its specific application to multilayer coatings. http://hdl.handle.net/10985/9674 Sliding Wear Response of Nanostructured YSZ Suspension Plasma-Sprayed Coating KOSSMAN, Stephania; CHICOT, Didier; DECOOPMAN, Xavier; IOST, Alain; VAN GORP, Adrien; MEILLOT, E.; PUCHI-CABRERA, Eli-Saul; SANTANA, Y.Y.; STAIA, Mariana Nanostructured yttria-stabilized zirconia coatings for applications in high-temperature environments can be deposited by suspension plasma spraying (SPS) techniques. The present research has been conducted in order to study the sliding wear response of a SPS ZrO2–8% mol. Y2O3 coating (75 lm in thickness) deposited onto a Haynes 230 substrate, using pin-on-disc tests. Some of the coated samples were subsequently heat-treated for 1 h at 300 and 600 !C. Samples characterization prior and after the wear tests was carried out by SEM, EDS, XRD and optical profilometry techniques. Instrumented indentation was employed to determine elastic modulus and hardness. The results have shown that the as-sprayed and heat-treated samples experienced severe wear (10213 m3/Nm) and the worst wear performance corresponded to the sample heat treated at 600 !C. Such a behavior could be related to both the structural changes that took place during heat treatment and the nature and level of the residual stresses in the coatings. In general, the morphologies of the wear tracks observed by SEM have shown a smoothing of the surface, brittle fracture, smearing and grain pull-out. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/9674 2014-01-01T00:00:00Z KOSSMAN, Stephania CHICOT, Didier DECOOPMAN, Xavier IOST, Alain VAN GORP, Adrien MEILLOT, E. PUCHI-CABRERA, Eli-Saul SANTANA, Y.Y. STAIA, Mariana Nanostructured yttria-stabilized zirconia coatings for applications in high-temperature environments can be deposited by suspension plasma spraying (SPS) techniques. The present research has been conducted in order to study the sliding wear response of a SPS ZrO2–8% mol. Y2O3 coating (75 lm in thickness) deposited onto a Haynes 230 substrate, using pin-on-disc tests. Some of the coated samples were subsequently heat-treated for 1 h at 300 and 600 !C. Samples characterization prior and after the wear tests was carried out by SEM, EDS, XRD and optical profilometry techniques. Instrumented indentation was employed to determine elastic modulus and hardness. The results have shown that the as-sprayed and heat-treated samples experienced severe wear (10213 m3/Nm) and the worst wear performance corresponded to the sample heat treated at 600 !C. Such a behavior could be related to both the structural changes that took place during heat treatment and the nature and level of the residual stresses in the coatings. In general, the morphologies of the wear tracks observed by SEM have shown a smoothing of the surface, brittle fracture, smearing and grain pull-out. http://hdl.handle.net/10985/11954 Sliding wear resistance of thermal sprayed wc-12co coatings reinforced with carbon nanotubes SANTANA, Y.Y.; GUTIÉRREZ, M.V.; STAIA, Mariana; LA BARBERA-SOSA, J.G.; PUCHI-CABRERA, Eli-Saul; IOST, Alain; CHICOT, Didier Thermal sprayed coatings based on WC-Co are widely used for providing wear resistance to engineering components. The High Velocity Oxygen Fuel (HVOF) thermal spraying technique is one of the most commonly employed for depositing wear resistant coatings on steel substrates and constitutes one of the coating processes that have been technically validated for the replacement of electrolytic hard chrome (EHC) coatings, especially for extreme operating conditions. The present work aims at studying the tribological behavior, under sliding wear conditions, of a coating based on WC-12Co, with and without the reinforcement of carbon nanotubes (CNTs). The coating has been deposited by HVOF thermal spraying on a SAE 1045 substrate steel. Wear tests were carried out under the ball-on-disk configuration, at a constant sliding velocity of ∼ 0.2 m.s-1 and an applied load of 10 N, employing WC-6Co balls as static counterparts. The results for the CNTs reinforced coating have shown a decrease of ∼ 58% and 86% in the values of the average friction coefficient and wear rate, respectively, as compared with the conventional coatings. The observed wear mechanism was mainly of an abrasive type. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/11954 2017-01-01T00:00:00Z SANTANA, Y.Y. GUTIÉRREZ, M.V. STAIA, Mariana LA BARBERA-SOSA, J.G. PUCHI-CABRERA, Eli-Saul IOST, Alain CHICOT, Didier Thermal sprayed coatings based on WC-Co are widely used for providing wear resistance to engineering components. The High Velocity Oxygen Fuel (HVOF) thermal spraying technique is one of the most commonly employed for depositing wear resistant coatings on steel substrates and constitutes one of the coating processes that have been technically validated for the replacement of electrolytic hard chrome (EHC) coatings, especially for extreme operating conditions. The present work aims at studying the tribological behavior, under sliding wear conditions, of a coating based on WC-12Co, with and without the reinforcement of carbon nanotubes (CNTs). The coating has been deposited by HVOF thermal spraying on a SAE 1045 substrate steel. Wear tests were carried out under the ball-on-disk configuration, at a constant sliding velocity of ∼ 0.2 m.s-1 and an applied load of 10 N, employing WC-6Co balls as static counterparts. The results for the CNTs reinforced coating have shown a decrease of ∼ 58% and 86% in the values of the average friction coefficient and wear rate, respectively, as compared with the conventional coatings. The observed wear mechanism was mainly of an abrasive type. http://hdl.handle.net/10985/11760 Surface Modification Technologies STAIA, Mariana; TROCELIS, A; ZAIRI, Amel; SUAREZ, M; PUCHI-CABRERA, Eli-Saul; IOST, Alain; MONTAGNE, Alex The present work has been conducted in order to assess the mechanical and tribological performance of a ZrN coating deposited onto a H13 steel substrate by means of a closed field unbalanced magnetron-sputtering ion-plating (CFUMSIP) process. The hardness and elastic modulus of the coated system have been determined by means of nanoindentation techniques. Dry and wet sliding wear tests, employing a tribometer under a ball-on-disc configuration, were carried out making use of an alumina ball as counterpart, with an applied normal load of 2 N at a constant speed of 5 cm/s. For the wet wear tests, a 3.5 wt% NaCl solution was used. The resulting wear scars were analyzed by means of both SEM and optical profilometry techniques. It has been determined that, during testing under the corrosive solution, the coating experiences a severe abrasive wear mechanism, due to the combined action of the alumina ball, the hard “debris” and the phenomenon of crevice corrosion. On the other hand, it has also been shown that the coated system is able to increase the wear resistance of the substrate by more than one order of magnitude, if the wear tests are carried out in air under the same conditions. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/11760 2016-01-01T00:00:00Z STAIA, Mariana TROCELIS, A ZAIRI, Amel SUAREZ, M PUCHI-CABRERA, Eli-Saul IOST, Alain MONTAGNE, Alex The present work has been conducted in order to assess the mechanical and tribological performance of a ZrN coating deposited onto a H13 steel substrate by means of a closed field unbalanced magnetron-sputtering ion-plating (CFUMSIP) process. The hardness and elastic modulus of the coated system have been determined by means of nanoindentation techniques. Dry and wet sliding wear tests, employing a tribometer under a ball-on-disc configuration, were carried out making use of an alumina ball as counterpart, with an applied normal load of 2 N at a constant speed of 5 cm/s. For the wet wear tests, a 3.5 wt% NaCl solution was used. The resulting wear scars were analyzed by means of both SEM and optical profilometry techniques. It has been determined that, during testing under the corrosive solution, the coating experiences a severe abrasive wear mechanism, due to the combined action of the alumina ball, the hard “debris” and the phenomenon of crevice corrosion. On the other hand, it has also been shown that the coated system is able to increase the wear resistance of the substrate by more than one order of magnitude, if the wear tests are carried out in air under the same conditions. http://hdl.handle.net/10985/11956 Recubrimientos nanoestructurados de circonia estabilzada con itria (ysz) depositados mediante técnicas de termorrociado por plasma en suspensión STAIA, Mariana; KOSSMAN, Stephania; CONTREPAS, V; CHICOT, Didier; IOST, Alain; VAN GORP, Adrien Las propiedades de los recubrimientos a base de circonia estabilizada con ytria (YSZ) les confieren un excelente desempeño como barreras térmicas (TBC). En el presente trabajo, recubrimientos de 8YSZ fueron depositados sobre Haynes 230 mediante el proceso de termorrociado por plasma por suspensión (SPS) con el fin de servir de enlace (subcapa) entre el sustrato y un recubrimiento más grueso de YSZ, depositado por termorrociado por plasma atmosférico (APS). Se estudió el efecto del espesor de la subcapa depositada por SPS y la influencia de los tratamientos térmicos posteriores (TT) a 300°C y 600°C sobre su desempeño tribológico a temperatura ambiente (Tamb) y 650°C, respectivamente. Durante los ensayos de desgaste deslizante con una carga de 2 N contra alúmina, se determinó que la reducción del espesor del recubrimiento de 75 μm a 25 μm incrementa la resistencia al desgaste aproximadamente 5 veces. Asimismo, para el espesor de 25 μm el TT a la temperatura de 600°C disminuye 6 veces su resistencia al desgaste con respecto a la condición original del recubrimiento. Similarmente, cuando el ensayo se realizó a 650°C, el comportamiento tribológico desmejoró significativamente. Los resultados han sido relacionados con los cambios morfológicos que tienen lugar durante el calentamiento. Sun, 01 Jan 2017 00:00:00 GMT http://hdl.handle.net/10985/11956 2017-01-01T00:00:00Z STAIA, Mariana KOSSMAN, Stephania CONTREPAS, V CHICOT, Didier IOST, Alain VAN GORP, Adrien Las propiedades de los recubrimientos a base de circonia estabilizada con ytria (YSZ) les confieren un excelente desempeño como barreras térmicas (TBC). En el presente trabajo, recubrimientos de 8YSZ fueron depositados sobre Haynes 230 mediante el proceso de termorrociado por plasma por suspensión (SPS) con el fin de servir de enlace (subcapa) entre el sustrato y un recubrimiento más grueso de YSZ, depositado por termorrociado por plasma atmosférico (APS). Se estudió el efecto del espesor de la subcapa depositada por SPS y la influencia de los tratamientos térmicos posteriores (TT) a 300°C y 600°C sobre su desempeño tribológico a temperatura ambiente (Tamb) y 650°C, respectivamente. Durante los ensayos de desgaste deslizante con una carga de 2 N contra alúmina, se determinó que la reducción del espesor del recubrimiento de 75 μm a 25 μm incrementa la resistencia al desgaste aproximadamente 5 veces. Asimismo, para el espesor de 25 μm el TT a la temperatura de 600°C disminuye 6 veces su resistencia al desgaste con respecto a la condición original del recubrimiento. Similarmente, cuando el ensayo se realizó a 650°C, el comportamiento tribológico desmejoró significativamente. Los resultados han sido relacionados con los cambios morfológicos que tienen lugar durante el calentamiento. http://hdl.handle.net/10985/10825 Increase of the load carrying capacity of aluminium 2024-T3 by means of a NiP-CRC-DLC coating STAIA, Mariana; PUCHI-CABRERA, Eli-Saul; SANTANA, Y.Y.; LA BARBERA-SOSA, J.G.; IOST, Alain; CHICOT, Didier; PEREZ DELGADO, Yeczain; DE BAETS, Patrick The present investigation has been conducted in order to evaluate the tribological behavior of an AA2024-T3 aluminum alloy, coated with a NiP-CrC-DLC coating. The effect of NiP as intermediate layer was evaluated by carrying out calculations using ELASTICA © in order to determine its adequate thickness needed to avoid the plastic deformation of the substrate, ensuring then the integrity of the coating. To evaluate the efficiency of these calculations, a number of dry sliding wear tests were performed employing a ball-on-disk configuration, where alumina balls of 6 mm in diameter were used as counterpart. The sliding wear tests were carried out up to a sliding distance of 800 m, with a normal load of 5 N, a linear speed of 5 cm/s and a contact radius of 3 mm. The wear tracks were analyzed by means of scanning electron microscopy (SEM) techniques coupled with energy dispersive spectroscopy (EDS). The wear volume was determined by means of optical profilometry. The results indicate that, under the present testing conditions, the NiP-CrC-DLC coating exhibits a satisfactory behavior from the mechanical stability point of view when the thickness of the NiP layer is higher than 60 µm, since no surface failures were observed at the end of the tests. For the coated system, the magnitude of the friction coefficient was found to be of approximately 0.1 and that of the wear rate was of about 2.31 ± 0.09 x 10-16 m3/N.m. On the contrary, for the uncoated substrate, the friction coefficient was of approximately 0.5 and the wear rate of 5.46 x 10-13 m3/N.m, that is to say, 3 orders of magnitude greater than that determined for the coated system. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/10825 2013-01-01T00:00:00Z STAIA, Mariana PUCHI-CABRERA, Eli-Saul SANTANA, Y.Y. LA BARBERA-SOSA, J.G. IOST, Alain CHICOT, Didier PEREZ DELGADO, Yeczain DE BAETS, Patrick The present investigation has been conducted in order to evaluate the tribological behavior of an AA2024-T3 aluminum alloy, coated with a NiP-CrC-DLC coating. The effect of NiP as intermediate layer was evaluated by carrying out calculations using ELASTICA © in order to determine its adequate thickness needed to avoid the plastic deformation of the substrate, ensuring then the integrity of the coating. To evaluate the efficiency of these calculations, a number of dry sliding wear tests were performed employing a ball-on-disk configuration, where alumina balls of 6 mm in diameter were used as counterpart. The sliding wear tests were carried out up to a sliding distance of 800 m, with a normal load of 5 N, a linear speed of 5 cm/s and a contact radius of 3 mm. The wear tracks were analyzed by means of scanning electron microscopy (SEM) techniques coupled with energy dispersive spectroscopy (EDS). The wear volume was determined by means of optical profilometry. The results indicate that, under the present testing conditions, the NiP-CrC-DLC coating exhibits a satisfactory behavior from the mechanical stability point of view when the thickness of the NiP layer is higher than 60 µm, since no surface failures were observed at the end of the tests. For the coated system, the magnitude of the friction coefficient was found to be of approximately 0.1 and that of the wear rate was of about 2.31 ± 0.09 x 10-16 m3/N.m. On the contrary, for the uncoated substrate, the friction coefficient was of approximately 0.5 and the wear rate of 5.46 x 10-13 m3/N.m, that is to say, 3 orders of magnitude greater than that determined for the coated system. http://hdl.handle.net/10985/11967 Mechanical characterization of a prototype a-C:Cr,Si and its tribological behavior at high temperature STAIA, Mariana; DUBAR, Laurent; DUBAR, Mirentxu; PUCHI-CABRERA, Eli-Saul; IOST, Alain; DE BAETS, Patrick; DUBOIS, André The results of the mechanical and tribological characterization of a prototype a-C:Cr, Si sputtered coating are presented. The hardness and the elastic modulus of the coated system have been determined by means of nanoindentation taking into account the actual architecture of the bi-layer coating. Both mechanical properties were recorded continuously versus the indentation depth, h, up to approximately 2000 nm, at a constant indentation rate and maximum applied loads of 700 mN. The results were analyzed by means of the Oliver and Pharr method and modeled on the basis of novel approach proposed recently by some of the authors. Wear tests were conducted at 25 °C, 400 °C and 450 °C against alumina, employing a contact pressure of 540 MPa. Characterization of the worn surfaces by SEM and elemental X-ray mapping has also been carried out. A wear rate as low as 1.2×10−18 m3/N m was determined for the coating tested at 25 °C, which is approximately one order of magnitude and three times less than those found from the tests performed at 400 °C and 450 °C, respectively. It has been determined that the a-C:Cr,Si coating exhibits a very good wear resistance even at temperatures up to 450 °C, as consequence of the Si and Cr oxides formed due to the oxidation process. Also, it has found that at this temperature, a continuous oxide film is formed, which reduces the wear rate of the coated system in comparison to that determined at 400 °C. However, the volume increase due to the oxidation process at 450 °C and the elimination of CO2, Ar and H2O vapors, induces a severe surface cracking of the coating. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/11967 2016-01-01T00:00:00Z STAIA, Mariana DUBAR, Laurent DUBAR, Mirentxu PUCHI-CABRERA, Eli-Saul IOST, Alain DE BAETS, Patrick DUBOIS, André The results of the mechanical and tribological characterization of a prototype a-C:Cr, Si sputtered coating are presented. The hardness and the elastic modulus of the coated system have been determined by means of nanoindentation taking into account the actual architecture of the bi-layer coating. Both mechanical properties were recorded continuously versus the indentation depth, h, up to approximately 2000 nm, at a constant indentation rate and maximum applied loads of 700 mN. The results were analyzed by means of the Oliver and Pharr method and modeled on the basis of novel approach proposed recently by some of the authors. Wear tests were conducted at 25 °C, 400 °C and 450 °C against alumina, employing a contact pressure of 540 MPa. Characterization of the worn surfaces by SEM and elemental X-ray mapping has also been carried out. A wear rate as low as 1.2×10−18 m3/N m was determined for the coating tested at 25 °C, which is approximately one order of magnitude and three times less than those found from the tests performed at 400 °C and 450 °C, respectively. It has been determined that the a-C:Cr,Si coating exhibits a very good wear resistance even at temperatures up to 450 °C, as consequence of the Si and Cr oxides formed due to the oxidation process. Also, it has found that at this temperature, a continuous oxide film is formed, which reduces the wear rate of the coated system in comparison to that determined at 400 °C. However, the volume increase due to the oxidation process at 450 °C and the elimination of CO2, Ar and H2O vapors, induces a severe surface cracking of the coating. http://hdl.handle.net/10985/9668 Scratch evaluation on a high performance polymer RODRIGUEZ, Vanessa; SUKUMARAN, Jacob; PEREZ DELGADO, Yeczain; STAIA, Mariana; IOST, Alain; DE BAETS, Patrick The scratching process is a well know concept and is usually defined as a kind of surface abrasion, where plastic deformation is promoted by relative friction between soft phase and a hard intender. It is necessary to reduce material loss to minimum or even to reach zero to have an efficient and effective functionality of the materials. Polymers being highly sensitive to wear and scratch damage, their various modes of deformation such as, tearing, cracking, delamination, abrasive and adhesive vary with a narrow range of contact variables like applied normal load, sliding velocity, interfacial lubrication and testing temperature. This is particularly important when these materials are used to improve the tribological performance by adding various types of fillers such as, carbon fibers, graphite,PTFE, TiO2, and ZnS are added. The polymers with nanocomposites have the advantages over micro- composites from the viewpoint of wear and scratch damage, the underlying mechanism of damage in the single asperity mode is still unclear. The goal of this study is to experimentally evaluate the deformation modes and the friction processes involved during the scratching of polymer reinforced with nanocomposites. The scratches were produced on the semicrystalline polyetheretherketone (PEEK) surface using a Rockwell C diamond indenter was pressed onto the flat surface of each sample, until a complete loadindentation depth-curve was achieved. These scratched surfaces were assessed with optical microscope and scanning electron microscope (SEM) for prevailing deformation mechanism and the geometry of damage. The authors wish to thank the participating communities, the Laboratory of Mechanics surfaces and materials processing, University Lille for the access and 84 usage of its research facility. Present research is financially sponsored by Found for Scientific Research of the Flemish Community (FWO) and the Ghent University Research Board. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/9668 2013-01-01T00:00:00Z RODRIGUEZ, Vanessa SUKUMARAN, Jacob PEREZ DELGADO, Yeczain STAIA, Mariana IOST, Alain DE BAETS, Patrick The scratching process is a well know concept and is usually defined as a kind of surface abrasion, where plastic deformation is promoted by relative friction between soft phase and a hard intender. It is necessary to reduce material loss to minimum or even to reach zero to have an efficient and effective functionality of the materials. Polymers being highly sensitive to wear and scratch damage, their various modes of deformation such as, tearing, cracking, delamination, abrasive and adhesive vary with a narrow range of contact variables like applied normal load, sliding velocity, interfacial lubrication and testing temperature. This is particularly important when these materials are used to improve the tribological performance by adding various types of fillers such as, carbon fibers, graphite,PTFE, TiO2, and ZnS are added. The polymers with nanocomposites have the advantages over micro- composites from the viewpoint of wear and scratch damage, the underlying mechanism of damage in the single asperity mode is still unclear. The goal of this study is to experimentally evaluate the deformation modes and the friction processes involved during the scratching of polymer reinforced with nanocomposites. The scratches were produced on the semicrystalline polyetheretherketone (PEEK) surface using a Rockwell C diamond indenter was pressed onto the flat surface of each sample, until a complete loadindentation depth-curve was achieved. These scratched surfaces were assessed with optical microscope and scanning electron microscope (SEM) for prevailing deformation mechanism and the geometry of damage. http://hdl.handle.net/10985/11955 Mechanical characterization of coated systems involving multilayer films PUCHI-CABRERA, Eli-Saul; STAIA, Mariana; GUÉRIN, J.D.; IOST, Alain; DUBAR, Laurent The computation of the elastic contact stresses and particularly the detemination of the change in the von Mises stress from the surface of a coated system, when it is subjected to spherical indentation, constitutes an important aspect of the tribological performance assessment of such system. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/11955 2016-01-01T00:00:00Z PUCHI-CABRERA, Eli-Saul STAIA, Mariana GUÉRIN, J.D. IOST, Alain DUBAR, Laurent The computation of the elastic contact stresses and particularly the detemination of the change in the von Mises stress from the surface of a coated system, when it is subjected to spherical indentation, constitutes an important aspect of the tribological performance assessment of such system. http://hdl.handle.net/10985/9659 Modeling the composite hardness of multilayer coated systems PUCHI-CABRERA, Eli-Saul; STAIA, Mariana; IOST, Alain The change in the composite hardness with penetration depth derived from nanoindentation tests conducted on coated systems, which involve the deposition of multilayer coatings, in general exhibits a complex shape, as a consequence of the sequential contribution of each coating layer to the composite hardness during indentation loading. In spite that there are a number of models, which have been proposed for describing the change of the composite hardness with penetration depth for monolayer coatings, as well as for determining the coating and substrate hardness, very few research works have addressed the problem of describing this kind of data for multilayer coatings. In the present communication, a rational approach is proposed for extending two models widely used for the analysis of monolayer coatings, in order to describe the composite hardness data of multilayer coatings, as well as for determining the hardness of each individual layer and that of the substrate. Thus, a modified form of the models earlier advanced by Korsunsky et al. and Puchi-Cabrera, as well as their computational instrumentation, are proposed. The extension of both models to deal with multilayer coatings is conducted on the basis of the model developed by Iost et al., in order to adapt the Jönsson–Hogmark model to the analysis of indentation data of multilayer coatings. Such a methodology provides a means of computing the volume fraction of each individual layer in the coating, which contributes to the composite hardness. According to the results obtained, this scheme seems to be general enough to be applicable to different hardness models other than the Jönsson–Hogmark model. The proposed modified models are validated employing nanoindentation results obtained from a 2024-T6 aluminum alloy coated with a diamond-like carbon film, employing electroless NiP as intermediate layer. The advantages and disadvantages of the different models employed in the analysis are thoroughly discussed. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9659 2015-01-01T00:00:00Z PUCHI-CABRERA, Eli-Saul STAIA, Mariana IOST, Alain The change in the composite hardness with penetration depth derived from nanoindentation tests conducted on coated systems, which involve the deposition of multilayer coatings, in general exhibits a complex shape, as a consequence of the sequential contribution of each coating layer to the composite hardness during indentation loading. In spite that there are a number of models, which have been proposed for describing the change of the composite hardness with penetration depth for monolayer coatings, as well as for determining the coating and substrate hardness, very few research works have addressed the problem of describing this kind of data for multilayer coatings. In the present communication, a rational approach is proposed for extending two models widely used for the analysis of monolayer coatings, in order to describe the composite hardness data of multilayer coatings, as well as for determining the hardness of each individual layer and that of the substrate. Thus, a modified form of the models earlier advanced by Korsunsky et al. and Puchi-Cabrera, as well as their computational instrumentation, are proposed. The extension of both models to deal with multilayer coatings is conducted on the basis of the model developed by Iost et al., in order to adapt the Jönsson–Hogmark model to the analysis of indentation data of multilayer coatings. Such a methodology provides a means of computing the volume fraction of each individual layer in the coating, which contributes to the composite hardness. According to the results obtained, this scheme seems to be general enough to be applicable to different hardness models other than the Jönsson–Hogmark model. The proposed modified models are validated employing nanoindentation results obtained from a 2024-T6 aluminum alloy coated with a diamond-like carbon film, employing electroless NiP as intermediate layer. The advantages and disadvantages of the different models employed in the analysis are thoroughly discussed.