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A Billard - One of the best experts on this subject based on the ideXlab platform.
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temperature dependence of the residual stresses and mechanical properties in tin crn nanolayered coatings processed by Cathodic Arc Deposition
Surface & Coatings Technology, 2014Co-Authors: F Lomello, Frederic Sanchette, Frederic Schuster, M Tabarant, Arab Pour M Yazdi, A BillardAbstract:Abstract Nanolayered TiN–CrN coatings were synthesized by Cathodic Arc Deposition (CAD) on M2 tool steel substrates. The aim of this study was to establish a double-correlation between the influence of the bilayer period and the Deposition temperature on the resulting mechanical–tribological properties. The superlattice hardening enhancement was observed in samples deposited at different temperatures — i.e. without additional heating, 300 °C and 400 °C. Nonetheless, the residual compressive stresses are believed to be the responsible for reducing the hardness enhancement when the Deposition temperature was increased. For instance, sample deposited without additional heating presented a hardness of 48.5 ± 1.3 GPa, while by increasing the processing temperature up to 400 °C it was reduced down to 31.2 ± 4.1 GPa due to the stress relaxation. Indeed, the sample deposited at low temperature which possesses the thinnest bilayer period (13 nm) exhibited better mechanical properties. On the contrary, the role of the interfaces introduced when the period is decreased seems to rule the wear resistance.
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Temperature dependence of the residual stresses and mechanical properties in TiN/CrN nanolayered coatings processed by Cathodic Arc Deposition
Surface & Coatings Technology, 2014Co-Authors: F Lomello, Frederic Sanchette, Frederic Schuster, M Tabarant, M. Arab Pour Yazdi, A BillardAbstract:Abstract Nanolayered TiN–CrN coatings were synthesized by Cathodic Arc Deposition (CAD) on M2 tool steel substrates. The aim of this study was to establish a double-correlation between the influence of the bilayer period and the Deposition temperature on the resulting mechanical–tribological properties. The superlattice hardening enhancement was observed in samples deposited at different temperatures — i.e. without additional heating, 300 °C and 400 °C. Nonetheless, the residual compressive stresses are believed to be the responsible for reducing the hardness enhancement when the Deposition temperature was increased. For instance, sample deposited without additional heating presented a hardness of 48.5 ± 1.3 GPa, while by increasing the processing temperature up to 400 °C it was reduced down to 31.2 ± 4.1 GPa due to the stress relaxation. Indeed, the sample deposited at low temperature which possesses the thinnest bilayer period (13 nm) exhibited better mechanical properties. On the contrary, the role of the interfaces introduced when the period is decreased seems to rule the wear resistance.
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influence of bias voltage on properties of alcrn coatings prepared by Cathodic Arc Deposition
Surface & Coatings Technology, 2013Co-Authors: F Lomello, Frederic Sanchette, Frederic Schuster, M Tabarant, A BillardAbstract:Abstract AlCrN coatings were prepared by vacuum Cathodic Arc Deposition. This low-temperature technique has been chosen due to its versatility, allowing the industrial up-scaling. In this study, the attention was focused on the correlation of the bias voltage with the resulting mechanical–tribological properties. For this purpose, the bias voltage was varied from 0 to − 150 V. Indeed, the variation of grain sizes from 24 to 16 nm as well as the residual stresses from − 0.68 to − 8.94 GPa lead to obtain different mechanical–tribological properties. In this context, the sample deposited at − 100 V exhibited an enhanced hardness (50 ± 2 GPa) and an acceptable wear resistance.
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nanostructured hard coatings deposited by Cathodic Arc Deposition from concepts to applications
Surface & Coatings Technology, 2011Co-Authors: F Sanchette, Cedric Ducros, Thomas Schmitt, P Steyer, A BillardAbstract:Abstract The vacuum Cathodic Arc Deposition (CAD) process is now widely used on an industrial scale to prepare protective hard coatings on cutting tools, metal molds, etc.… It has been recognized that high ionization levels of Cathodic Arc discharges and high ion energy can provide advantages such as enhanced adhesion required for mechanical applications involving high loads. CAD allows Deposition of a wide range of hard compounds as nitrides or carbonitrides. However, CAD is also often associated macrodroplet generation that degrades the surface roughness of coatings. The recent trend is to develop advanced nanostructured hard coatings in order to enhance properties as hardness, toughness, and oxidation resistance. This paper recalls the basic aspects of both CAD technology and nanostructured thin films synthesis. Deposition and characterization of both nanocomposite and nanolayered hard coatings are described. Mechanical behaviors of nitrides can be significantly enhanced by nanolayering. The first example deals with the development of hard nanolayered nitrides coatings for cutting tools protection. It is clearly shown in this example that TiN/AlTiN coatings perform better than CrN/AlTiN and TiN/CrN for the same periods and the best performance is reached for the thinnest periods. It is also shown, in a second example, how silicon addition in CrN can lead to enhancement of oxidation resistance associated with the nanocomposite structure. Thus, relationships are established between Deposition conditions, nanostructure and mechanical behaviors or oxidation resistance of the coatings. This short review recalls that CAD remains a powerful and industrial technology for nanostructured hard coatings Deposition.
Antoine Seyeux - One of the best experts on this subject based on the ideXlab platform.
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tantalum oxide nanocoatings prepared by atomic layer and filtered Cathodic Arc Deposition for corrosion protection of steel comparative surface and electrochemical analysis
Electrochimica Acta, 2013Co-Authors: Belen Diaz, Antoine Seyeux, Vincent Maurice, Emma Härkönen, Mikko Ritala, Sanna Tervakangas, Jukka Kolehmainen, Jolanta światowska, Philippe MarcusAbstract:Abstract A comparative study by Time-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i – E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of Deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized.
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Tantalum oxide nanocoatings prepared by atomic layer and filtered Cathodic Arc Deposition for corrosion protection of steel: Comparative surface and electrochemical analysis
Electrochimica Acta, 2013Co-Authors: Belen Diaz, Antoine Seyeux, Vincent Maurice, Emma Härkönen, Mikko Ritala, Jolanta Światowska, Sanna Tervakangas, Jukka Kolehmainen, Philippe MarcusAbstract:A comparative study by Tithe-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i-E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of Deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized. (C) 2012 Elsevier Ltd. All rights reserved.
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chromium and tantalum oxide nanocoatings prepared by filtered Cathodic Arc Deposition for corrosion protection of carbon steel
Surface & Coatings Technology, 2012Co-Authors: Marcin Pisarek, Belen Diaz, Antoine Seyeux, Vincent Maurice, Jolanta światowskaAbstract:Abstract Combined analysis by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS), polarization curves and Electrochemical Impedance Spectroscopy (EIS) of the relation between chemical Architecture of thin (10 and 50 nm) chromium and tantalum oxide coatings grown by filtered Cathodic Arc Deposition (FCAD) on carbon steel and their corrosion protection properties is reported. Pre-etching in the Deposition process allows reducing the substrate native oxide layer to traces of iron oxide. A carbidic interlayer is then formed by reaction between the first deposited metallic particles and the residual carbon surface contamination of the alloy. The bulk coatings mostly consist of Cr 2 O 3 or Ta 2 O 5 with no in-depth variation of the stoichiometry. Surface and bulk of the coatings are contaminated by hydroxyl and organic groups. The 50 nm coating has a relatively large porosity assigned to a columnar growth preventing good sealing at grain boundaries. The duplex structure (Ta/Ta–C) of the carbidic interlayer promotes a less defective growth of tantalum oxide than the single Cr–C interlayer for chromium oxide, thereby improving the sealing properties. The dielectric constants suggest poor insulating properties in line with a defective and porous nanostructure of the coatings. No dissolution was observed for both oxide nanocoatings in neutral 0.2 M NaCl. Penetration of the electrolyte and access to the interface with the carbon steel surface cause the dissolution of the Cr–C interlayer, but not that of the Ta/Ta–C interlayer, and a more rapid initiation of localized corrosion.
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Chromium and tantalum oxide nanocoatings prepared by filtered Cathodic Arc Deposition for corrosion protection of carbon steel
Surface and Coatings Technology, 2012Co-Authors: Belen Diaz, Marcin Pisarek, Antoine Seyeux, Vincent Maurice, Jolanta Światowska, Sandrine Zanna, Sanna Tervakangas, Jukka Kolehmainen, Philippe MarcusAbstract:Combined analysis by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS), polarization curves and Electrochemical Impedance Spectroscopy (EIS) of the relation between chemical Architecture of thin (10 and 50nm) chromium and tantalum oxide coatings grown by filtered Cathodic Arc Deposition (FCAD) on carbon steel and their corrosion protection properties is reported. Pre-etching in the Deposition process allows reducing the substrate native oxide layer to traces of iron oxide. A carbidic interlayer is then formed by reaction between the first deposited metallic particles and the residual carbon surface contamination of the alloy. The bulk coatings mostly consist of Cr2O3or Ta2O5with no in-depth variation of the stoichiometry. Surface and bulk of the coatings are contaminated by hydroxyl and organic groups. The 50nm coating has a relatively large porosity assigned to a columnar growth preventing good sealing at grain boundaries. The duplex structure (Ta/Ta-C) of the carbidic interlayer promotes a less defective growth of tantalum oxide than the single Cr-C interlayer for chromium oxide, thereby improving the sealing properties. The dielectric constants suggest poor insulating properties in line with a defective and porous nanostructure of the coatings. No dissolution was observed for both oxide nanocoatings in neutral 0.2M NaCl. Penetration of the electrolyte and access to the interface with the carbon steel surface cause the dissolution of the Cr-C interlayer, but not that of the Ta/Ta-C interlayer, and a more rapid initiation of localized corrosion. © 2012 Elsevier B.V.
Belen Diaz - One of the best experts on this subject based on the ideXlab platform.
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tantalum oxide nanocoatings prepared by atomic layer and filtered Cathodic Arc Deposition for corrosion protection of steel comparative surface and electrochemical analysis
Electrochimica Acta, 2013Co-Authors: Belen Diaz, Antoine Seyeux, Vincent Maurice, Emma Härkönen, Mikko Ritala, Sanna Tervakangas, Jukka Kolehmainen, Jolanta światowska, Philippe MarcusAbstract:Abstract A comparative study by Time-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i – E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of Deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized.
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Tantalum oxide nanocoatings prepared by atomic layer and filtered Cathodic Arc Deposition for corrosion protection of steel: Comparative surface and electrochemical analysis
Electrochimica Acta, 2013Co-Authors: Belen Diaz, Antoine Seyeux, Vincent Maurice, Emma Härkönen, Mikko Ritala, Jolanta Światowska, Sanna Tervakangas, Jukka Kolehmainen, Philippe MarcusAbstract:A comparative study by Tithe-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i-E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of Deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized. (C) 2012 Elsevier Ltd. All rights reserved.
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chromium and tantalum oxide nanocoatings prepared by filtered Cathodic Arc Deposition for corrosion protection of carbon steel
Surface & Coatings Technology, 2012Co-Authors: Marcin Pisarek, Belen Diaz, Antoine Seyeux, Vincent Maurice, Jolanta światowskaAbstract:Abstract Combined analysis by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS), polarization curves and Electrochemical Impedance Spectroscopy (EIS) of the relation between chemical Architecture of thin (10 and 50 nm) chromium and tantalum oxide coatings grown by filtered Cathodic Arc Deposition (FCAD) on carbon steel and their corrosion protection properties is reported. Pre-etching in the Deposition process allows reducing the substrate native oxide layer to traces of iron oxide. A carbidic interlayer is then formed by reaction between the first deposited metallic particles and the residual carbon surface contamination of the alloy. The bulk coatings mostly consist of Cr 2 O 3 or Ta 2 O 5 with no in-depth variation of the stoichiometry. Surface and bulk of the coatings are contaminated by hydroxyl and organic groups. The 50 nm coating has a relatively large porosity assigned to a columnar growth preventing good sealing at grain boundaries. The duplex structure (Ta/Ta–C) of the carbidic interlayer promotes a less defective growth of tantalum oxide than the single Cr–C interlayer for chromium oxide, thereby improving the sealing properties. The dielectric constants suggest poor insulating properties in line with a defective and porous nanostructure of the coatings. No dissolution was observed for both oxide nanocoatings in neutral 0.2 M NaCl. Penetration of the electrolyte and access to the interface with the carbon steel surface cause the dissolution of the Cr–C interlayer, but not that of the Ta/Ta–C interlayer, and a more rapid initiation of localized corrosion.
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Chromium and tantalum oxide nanocoatings prepared by filtered Cathodic Arc Deposition for corrosion protection of carbon steel
Surface and Coatings Technology, 2012Co-Authors: Belen Diaz, Marcin Pisarek, Antoine Seyeux, Vincent Maurice, Jolanta Światowska, Sandrine Zanna, Sanna Tervakangas, Jukka Kolehmainen, Philippe MarcusAbstract:Combined analysis by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS), polarization curves and Electrochemical Impedance Spectroscopy (EIS) of the relation between chemical Architecture of thin (10 and 50nm) chromium and tantalum oxide coatings grown by filtered Cathodic Arc Deposition (FCAD) on carbon steel and their corrosion protection properties is reported. Pre-etching in the Deposition process allows reducing the substrate native oxide layer to traces of iron oxide. A carbidic interlayer is then formed by reaction between the first deposited metallic particles and the residual carbon surface contamination of the alloy. The bulk coatings mostly consist of Cr2O3or Ta2O5with no in-depth variation of the stoichiometry. Surface and bulk of the coatings are contaminated by hydroxyl and organic groups. The 50nm coating has a relatively large porosity assigned to a columnar growth preventing good sealing at grain boundaries. The duplex structure (Ta/Ta-C) of the carbidic interlayer promotes a less defective growth of tantalum oxide than the single Cr-C interlayer for chromium oxide, thereby improving the sealing properties. The dielectric constants suggest poor insulating properties in line with a defective and porous nanostructure of the coatings. No dissolution was observed for both oxide nanocoatings in neutral 0.2M NaCl. Penetration of the electrolyte and access to the interface with the carbon steel surface cause the dissolution of the Cr-C interlayer, but not that of the Ta/Ta-C interlayer, and a more rapid initiation of localized corrosion. © 2012 Elsevier B.V.
Dayung Wang - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of nano-composite Ti–Si–N hard coating by filtered Cathodic Arc Deposition
Surface & Coatings Technology, 2008Co-Authors: Chi-lung Chang, Wei-yu Ho, Jun-han Chen, Pi-chuen Tsai, Dayung WangAbstract:Abstract Nano-composite Ti–Si–N films were deposited on tungsten carbide substrates by a filtered Cathodic Arc Deposition system using TiSi-alloy as Arc sources. The influences of bias voltages on the microstructure, mechanical and corrosion properties of the films were investigated. Field emission scanning electron microscope, atomic force microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, high-resolution electron probe microanalyzer, polarization and immersion tests were employed to identify microstructures and properties of Ti–Si–N films. Both magnetic 90°-filter duct Arc source and substrate bias voltage have important effects on the surface roughness, microstructure and corrosion properties of Ti–Si–N coatings. The results showed that both the increase of Si content and decrease of grain size resulted from the increase of substrate bias voltage. The microhardness of the coatings was enhanced by increasing substrate bias voltage. The corrosion resistance of coatings tested in 1 N H 2 SO 4 solution confirmed that Ti–Si–N coatings with a magnetic 90°-filter duct Arc source were better than Ti–Si–N coatings without a magnetic 90°-filter duct Arc source due to the effect of reducing microparticles. On the other hand, the corrosion resistance is also increased with reducing surface roughness of Ti–Si–N films, which can be controlled by substrate bias voltage in Deposition process.
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Characteristics of chromium-doped titanium oxide coatings synthesized by Cathodic Arc Deposition
Thin Solid Films, 2008Co-Authors: Wei-yu Ho, Mu-hsuan Chan, Chi-lung Chang, Dayung WangAbstract:Abstract Cr-doped titanium oxide (Cr/TiO2) thin films were deposited on stainless steel and glass substrates by using the Cathodic Arc Deposition technique. The characteristics of undoped and Cr-doped TiO2 thin films were compared by using several analytical approaches. The undoped TiO2 film as an as-deposited coating had an anatase structure, while the Cr/TiO2 film had an amorphous structure, as revealed by X-ray diffraction. After 3 h of heat treatment at 450 °C, the undoped and Cr-doped titanium oxide films became mixed anatase and rutile phases. The microstructure observed under a scanning electron microscope of the Cr-doped TiO2 film was more compact than that of the undoped film. UV–VIS spectroscopy indicated that chromium doping shifted the absorption edge of the titanium oxide film from the UV region to the visible region. Chromium doping extends the optical absorption range to the visible region and reduces the optical band gap of as-deposited films from 3.2 to 2.2 eV. The drop in the water contact angle from 28° to zero following visible light irradiation implies that the Cr/TiO2 thin film becomes a better photocatalytic material because of better hydrophilic property.
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high temperature oxidation resistance of cralsin coatings synthesized by a Cathodic Arc Deposition process
Journal of Alloys and Compounds, 2008Co-Authors: Yinyu Chang, Dayung Wang, Chi-pang Chang, Sheng-min Yang, Weite WuAbstract:Abstract The high-temperature oxidation behavior of the CrN and Cr–Al–Si–N coatings was studied. These coatings were deposited on silicon substrates by using a Cathodic-Arc Deposition system with lateral rotating Arc cathodes. Chromium and Al 88 Si 12 cathodes were used for the Deposition of Cr–Al–Si–N coatings. The deposited Cr 0.38 Al 0.56 Si 0.06 N exhibited higher hardness of 41 ± 2 GPa and higher H 3 /E *2 ratio of 0.468 GPa than CrN due to the introduction of Al and Si to form a nanocrystalline structure. For the high-temperature oxidation test, the coated samples were annealed at 800 °C in air for 2 h. The Cr 0.38 Al 0.56 Si 0.06 N possessed much lower oxidation rate as measured by the oxide layer of the coatings. The addition of Al and Si in the coating may inhibit the formation of Cr 2 N phase and grain coarsening as found in the deposited CrN coating. In addition, the coexisting Al 2 O 3 and SiO 2 near the surface retarded the diffusion of oxygen into the Cr 0.38 Al 0.56 Si 0.06 N. The deposited Cr 0.38 Al 0.56 Si 0.06 N showed an oxidation behavior superior to the CrN. The high-temperature oxidation resistance of the CrN coatings can be improved by the formation of nanocomposite Cr–Al–Si–N.
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High temperature oxidation resistance of CrAlSiN coatings synthesized by a Cathodic Arc Deposition process
Journal of Alloys and Compounds, 2008Co-Authors: Yinyu Chang, Dayung Wang, Chi-pang Chang, Sheng-min Yang, Weite WuAbstract:The high-temperature oxidation behavior of the CrN and Cr-Al-Si-N coatings was studied. These coatings were deposited on silicon substrates by using a Cathodic-Arc Deposition system with lateral rotating Arc cathodes. Chromium and Al88Si12 cathodes were used for the Deposition of Cr-Al-Si-N coatings. The deposited Cr0.38Al0.56Si0.06N exhibited higher hardness of 41 +/- 2 GPa and higher H-3/E*(2) ratio of 0.468 GPa than CrN due to the introduction of Al and Si to form a nanocrystalline structure. For the high-temperature oxidation test, the coated samples were annealed at 800 degrees C in air for 2 h. The Cr0.38Al0.56Si0.06N possessed much lower oxidation rate as measured by the oxide layer of the coatings. The addition of Al and Si in the coating may inhibit the formation of Cr2N phase and grain coarsening as found in the deposited CrN coating. In addition, the coexisting Al2O3 and SiO2 near the surface retarded the diffusion of oxygen into the Cr0.38Al0.56Si0.06N. The deposited Cr0.38Al0.56Si0.06N showed an oxidation behavior superior to the CrN. The high-temperature oxidation resistance of the CrN coatings can be improved by the formation of nanocomposite Cr-Al-Si-N. (C) 2007 Elsevier B.V. All rights reserved
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structural and mechanical properties of altin crn coatings synthesized by a Cathodic Arc Deposition process
Surface & Coatings Technology, 2006Co-Authors: Yinyu Chang, Shunjan Yang, Dayung WangAbstract:Abstract Monolayered AlTiN and Multilayered AlTiN/CrN coatings were synthesized by a Cathodic-Arc Deposition process, using TiAl (with 50/50 and 33/67 at.%) and Cr elemental cathodes. The atomic ratio of Al/(Ti + Al) in the AlTiN coatings was reduced to 0.44 and 0.61, respectively, compared with the corresponding Ti 50 Al 50 and Ti 33 Al 67 cathode materials. The multilayered AlTiN/CrN films showed smaller crystallite size, larger lattice strain, higher hardness, higher residual stress, and better adhesion strength as well than the monolayered AlTi films. The multilayered Al 0.35 Ti 0.22 N 0.43 /CrN coating exhibited the highest hardness of about 38 GPa and the highest H 3 / E * 2 ratio value of 0.188 GPa, indicating the best resistance to plastic deformation, among all the coatings studied.
Philippe Marcus - One of the best experts on this subject based on the ideXlab platform.
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tantalum oxide nanocoatings prepared by atomic layer and filtered Cathodic Arc Deposition for corrosion protection of steel comparative surface and electrochemical analysis
Electrochimica Acta, 2013Co-Authors: Belen Diaz, Antoine Seyeux, Vincent Maurice, Emma Härkönen, Mikko Ritala, Sanna Tervakangas, Jukka Kolehmainen, Jolanta światowska, Philippe MarcusAbstract:Abstract A comparative study by Time-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i – E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of Deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized.
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Tantalum oxide nanocoatings prepared by atomic layer and filtered Cathodic Arc Deposition for corrosion protection of steel: Comparative surface and electrochemical analysis
Electrochimica Acta, 2013Co-Authors: Belen Diaz, Antoine Seyeux, Vincent Maurice, Emma Härkönen, Mikko Ritala, Jolanta Światowska, Sanna Tervakangas, Jukka Kolehmainen, Philippe MarcusAbstract:A comparative study by Tithe-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i-E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50 nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of Deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2 M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized. (C) 2012 Elsevier Ltd. All rights reserved.
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Chromium and tantalum oxide nanocoatings prepared by filtered Cathodic Arc Deposition for corrosion protection of carbon steel
Surface and Coatings Technology, 2012Co-Authors: Belen Diaz, Marcin Pisarek, Antoine Seyeux, Vincent Maurice, Jolanta Światowska, Sandrine Zanna, Sanna Tervakangas, Jukka Kolehmainen, Philippe MarcusAbstract:Combined analysis by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS), polarization curves and Electrochemical Impedance Spectroscopy (EIS) of the relation between chemical Architecture of thin (10 and 50nm) chromium and tantalum oxide coatings grown by filtered Cathodic Arc Deposition (FCAD) on carbon steel and their corrosion protection properties is reported. Pre-etching in the Deposition process allows reducing the substrate native oxide layer to traces of iron oxide. A carbidic interlayer is then formed by reaction between the first deposited metallic particles and the residual carbon surface contamination of the alloy. The bulk coatings mostly consist of Cr2O3or Ta2O5with no in-depth variation of the stoichiometry. Surface and bulk of the coatings are contaminated by hydroxyl and organic groups. The 50nm coating has a relatively large porosity assigned to a columnar growth preventing good sealing at grain boundaries. The duplex structure (Ta/Ta-C) of the carbidic interlayer promotes a less defective growth of tantalum oxide than the single Cr-C interlayer for chromium oxide, thereby improving the sealing properties. The dielectric constants suggest poor insulating properties in line with a defective and porous nanostructure of the coatings. No dissolution was observed for both oxide nanocoatings in neutral 0.2M NaCl. Penetration of the electrolyte and access to the interface with the carbon steel surface cause the dissolution of the Cr-C interlayer, but not that of the Ta/Ta-C interlayer, and a more rapid initiation of localized corrosion. © 2012 Elsevier B.V.