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Andre Paulo Tschiptschi - One of the best experts on this subject based on the ideXlab platform.

  • effect of periodicity on hardness and scratch resistance of crn nbn nanoscale Multilayer Coating deposited by cathodic arc technique
    Wear, 2015
    Co-Authors: Juliano Avela Araujo, Gisela Marques Araujo, R M Souza, Andre Paulo Tschiptschi
    Abstract:

    Abstract Nano-scaled Multilayer CrN/NbN Coatings were produced in an industrial-size cathodic arc physical vapor deposition (PVD) chamber, with three cathodes in alternate positions (Cr/Nb/Cr). Four Multilayer NbN/CrN Coatings were produced with different periodicities (20 nm, 10 nm, 7.5 nm and 4 nm) with total thickness from 25 to 30 μm in all cases. The Coatings were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM), which provided the lattice parameter in each of the constituent layers and structural analysis of the Multilayers, respectively. The Multilayer Coating system is composed of CrN and NbN with similar structures, but with a lattice mismatch, which varies the fraction of the region with lattice strain depending on the periodicity. For the thicker individual layers, the adjustment of lattice parameter at the interfaces does not represent a predominant fraction of the entire structure, i.e. separate peaks of NbN and CrN can be distinguished in the XRD analysis. In the presence of low periodicity (lower than 10 nm), the lattice of each constituent may be coherently strained and just one intermediate lattice (d-spacing) is detected for the NbN/CrN Multilayer. Mechanical and tribological characterization was conducted by microhardness measurements using a 500 mN load (Instrumented indentation) and scratch tests using a conical diamond indenter with a 0.1 mm tip radius. From high to low periodicity, the Multilayer NbN/CrN Coatings showed increasing hardness, decreasing coefficient of friction and increasing resistance to cohesive failure, possibly due to a strong (200) texture for the Coatings with 10 nm periodicity or less, indicating a potential better performance of the lower periodicity Multilayer Coating systems in service.

  • structural and mechanical characterization of duplex Multilayer Coatings deposited onto h13 tool steel
    Journal of materials research and technology, 2012
    Co-Authors: Abel Andre Cândido Recco, Andre Paulo Tschiptschi
    Abstract:

    Quenched and tempered H13 tool steel was plasma nitrided and Physical Vapour Deposition (PVD) coated in a hybrid reactor aiming to obtain a TiN/TiC Multilayer Coating deposited on a plasma nitrided substrate, with a more gentle transition of elastic-plastic properties between the outermost layer of the Coating and the substrate. Duplex treatment (plasma nitriding and PVD Coating) was carried out in a hybrid reactor. Plasma nitriding preceded the DC triode magnetron sputtering PVD process, conducted inside the same chamber, using CH 4 and N 2 as reactive gases. Multilayer TiN/TiC Coatings deposited on a nitrided H13 substrate were obtained. The Multilayer Coating was composed by a first Ti interlayer to grant adhesion, followed by a second 18.4 at% C TiC layer with a cF8 NaCl type unit cell, then a 41.9 at% N TiN layer and finally an outermost 32.3 at% C TiC layer with the same cF8 NaCl type unit cell. The Multilayer Coating showed a gentle transition of elastic-plastic properties assessed by the H/E * and the H 3 /E *2 ratios and the elastic recovery as a function of the distance from the surface of the specimen. The adhesion of the Multilayered Coating to the substrate was greater in the case of the duplex coated specimen as compared to the non duplex treated H13 steel.

Zhufang Yang - One of the best experts on this subject based on the ideXlab platform.

  • performance and damage mechanism of tin zrn nano Multilayer Coatings based on different erosion angles
    Applied Surface Science, 2020
    Co-Authors: Jiao Chen, Zhaolu Zhang, Guanjun Yang, Zhihao Fang, Zhufang Yang
    Abstract:

    Abstract Nano-Multilayer Coating is an effective method for improving the sand erosion resistance of a material employed in any industrial field. However, very few studies have addressed this subject of research, especially in the aspects of the multi-angles erosion performance and the corresponding mechanism. In this study, a TiN/ZrN nano-Multilayer Coating was prepared on the Ti6Al4V substrate by employing physical vapor deposition; the nano-layer thickness of the alternating structure of this Coating was less than 200 nm. The mechanical and erosion properties of TiN/ZrN were examined, accompanied by varying the erosion angles from 15° to 90°. The 3D surface topographies of the eroded surface were characterized by using a white-light interfering profilometer. The Coating damage was examined by cross-sectioning the samples using the focused ion beam (FIB) method. The experiment shows that the maximum erosion rate occurs at 90°, which is approximately 3.1, 2.8 and 1.2 times larger than 15°, 45°, and 75° erosion angles, respectively. The diameter, depth and density of the erosion pit increases with a rise in the erosion angle. The erosion mechanism of the TiN/ZrN nano-Multilayer Coatings is governed by lateral cracks and the tensile stress of the Coating itself at 15° and 45°; further, it is influenced by the longitudinal cracks at 75° and 90°. Lateral cracks in the erosion damage of Coating are primarily Mode Ⅱ cracks. The average crack density in the effective FIB trenches reveals that the cracks are more probable to occur at high angles (75° and 90°); this further explains the results of a higher erosion rate at a high erosion angle.

  • erosion resistance and damage mechanism of tin zrn nanoscale Multilayer Coating
    THE Coatings, 2019
    Co-Authors: Jiao Chen, Mingrui Geng, Zhufang Yang, Yan Chai
    Abstract:

    Ceramic Coating is an effective method for improving the erosion resistance of a material, particularly for titanium alloys. In this study, a TiN/ZrN (ceramic/ceramic) nanoscale Multilayer Coating is designed and prepared on the Ti6Al4V titanium alloy surface by the physical vapor deposition (PVD) process. The cross-sectional microstructure and phase composition are measured using SEM and XRD, respectively. The hardness, elastic modulus, and adhesion of the Coating are measured by the nano-indentation and scratch method. The erosion test is conducted at a 45° angle with 100 m/s velocity using self-developed erosion equipment. The erosion resistance mechanisms of both the substrate and the Coating are revealed more intuitively through a single sand particle impact test. The results show that the erosion resistance rate of the Coating is 15.5 times higher than that of the titanium alloy substrate. The damage mechanisms of material removal of the Coating include crack deflection, crack branching, and succeeding interaction between them when suffering an impacting load. These cracks are started from the droplets and the stress concentrations on the Coating surface during the preparation of Coating. They are the primary reasons for the decrease in the erosion resistance of the Coating. This research is important for the optimization of the erosion-resistant Coating structure.

  • Erosion Resistance and Damage Mechanism of TiN/ZrN Nanoscale Multilayer Coating
    MDPI AG, 2019
    Co-Authors: Jiao Che, Mingrui Geng, Zhufang Yang, Ya Chai
    Abstract:

    Ceramic Coating is an effective method for improving the erosion resistance of a material, particularly for titanium alloys. In this study, a TiN/ZrN (ceramic/ceramic) nanoscale Multilayer Coating is designed and prepared on the Ti6Al4V titanium alloy surface by the physical vapor deposition (PVD) process. The cross-sectional microstructure and phase composition are measured using SEM and XRD, respectively. The hardness, elastic modulus, and adhesion of the Coating are measured by the nano-indentation and scratch method. The erosion test is conducted at a 45° angle with 100 m/s velocity using self-developed erosion equipment. The erosion resistance mechanisms of both the substrate and the Coating are revealed more intuitively through a single sand particle impact test. The results show that the erosion resistance rate of the Coating is 15.5 times higher than that of the titanium alloy substrate. The damage mechanisms of material removal of the Coating include crack deflection, crack branching, and succeeding interaction between them when suffering an impacting load. These cracks are started from the droplets and the stress concentrations on the Coating surface during the preparation of Coating. They are the primary reasons for the decrease in the erosion resistance of the Coating. This research is important for the optimization of the erosion-resistant Coating structure

Liping Wang - One of the best experts on this subject based on the ideXlab platform.

  • prolonged anti bacterial action by sluggish release of ag from tisin ag Multilayer Coating
    Journal of Alloys and Compounds, 2019
    Co-Authors: Yebiao Zhu, Minpeng Dong, Keke Chang, Liping Wang
    Abstract:

    Abstract Biofouling of materials has caused significant loss to marine engineering and protective Coatings have served as a solution. In this work, the TiSiN/Ag Multilayer Coatings synthesized by ion plating were investigated. Discontinuous Ag layers in the Coating was prepared to keep excellent mechanical properties of the Coating. In microcosmic, it was observed that Ag ions released from the Coating by ‘micro-channel’ and expressed anti-bacterial activity in seawater environment. The released rate is found to be determined by the microstructure of the Coating. In order to prolong the service life of the Coating, it is expected that the Ag ions release concentration can approach the minimal inhibitory concentration (MIC). In this work, the TiSiN/Ag Multilayer Coating can release Ag ions at a pretty low concentration and maintain its excellent biocidal activity. This work has provided a new thought to synthesize a long-lasting anti-bacterial and superhard Coating.

  • effect of multi interfacial structure on fracture resistance of composite tisin ag tisin Multilayer Coating
    Thin Solid Films, 2018
    Co-Authors: Temitope Olugbade, Chaoqun Dang, Jinlong Li, Liping Wang
    Abstract:

    Abstract A composite TiSiN/Ag/TiSiN Multilayer Coating was deposited on a Ti6Al4V substrate by multi-arc ion plating system. The Coating had a special structure with a TiN buffer layer, TiSiN/Ag Multilayers that possess alternating TiSiN (45 nm) and Ag (12 nm) layers, and TiSiN Coating interlayers of 120 nm thickness for a total thickness of 1.7 μm. The TiSiN layers had a nanocrystalline/amorphous microstructure of nc-TiN, nc-Ag and amorphous Si3N4, with amorphous Si3N4 present around nanocrystal TiN and Ag boundaries, and Ag layers consisting of ductile nanocrystal silver. We have shown that this design of the composite TiSiN/Ag/TiSiN Multilayer Coating can effectively hinder crack propagation and increase fracture resistance of the Coating.

  • microstructures and properties of zr crn Multilayer Coatings fabricated by multi arc ion plating
    Tribology International, 2017
    Co-Authors: Xiaoyan Guan, Yongxin Wang, Guangan Zhang, Xin Jiang, Liping Wang, Qunji Xue
    Abstract:

    Zr/CrN Multilayer Coatings with different modulation ratios were fabricated by multi-arc ion plating. By virtue of X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM), the influences of modulation ratios on Coatings microstructures were investigated. The corrosion and wear behaviors of Coatings in seawater solutions were evaluated. Results showed that the textures and properties of Zr/CrN Multilayer Coatings depended on the modulation ratios. The hardness, corrosion resistances and tribological performances of Zr/CrN Multilayer Coatings increased as the increase of individual CrN layers thickness. Multilayer Coating with thick CrN layer exhibited superior anti-corrosion and tribological performances. The high charge transfer resistance maybe contribute to the better corrosion resistances, while the wear mechanisms were identified as oxidation wear.

Lichun Chen - One of the best experts on this subject based on the ideXlab platform.

  • improvement of lithium ion battery performance by two layered slot die Coating operation
    Energy technology, 2017
    Co-Authors: Lichun Chen
    Abstract:

    The cathode and anode electrodes in lithium-ion batteries typically contain a significant proportion of particles and binders. During the electrode drying process, the high temperature will lead to the so-called "binder migration" phenomenon. Uneven particle/binder distribution can cause poor adhesion between Coating and substrate, disruption of conductive paths and decrease in electrode performance. In this study, a two-layered cathode was designed using separate compositions of slurry ingredients in each layer, as produced by means of a simultaneous Multilayer Coating method. The two-layered cathode with the top layer containing less binder than the bottom layer was found to yield a better particle/binder distribution in the final structure under high temperature drying. The battery made with the two-layered cathode appeared to give a better overall performance.

Marc Schneider - One of the best experts on this subject based on the ideXlab platform.

  • Multilayer Coating of gold nanoparticles with drug polymer coadsorbates
    Langmuir, 2010
    Co-Authors: Nico Reum, Tobias Klein, Rolf W. Hartmann, Claus-michael Lehr, Claudia Finkstraube, Marc Schneider
    Abstract:

    The aim of our present study was the development of a drug Multilayer-based carrier system for delivery of water-insoluble drugs. As drug, we applied the anticancer drug 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin, mTHPP, which is a model photosensitizer for photodynamic therapy. Gold nanoparticles (AuNP) with a diameter of 14.5 ± 0.9 nm were prepared and used as template for the layer-by-layer approach. The drug and the negatively charged polyelectrolyte (PE) poly(styrene sulfonate) sodium salt (PSS) were complexed with a new developed method using freeze−drying. The complexation efficiency was determined to be ∼11−12 monomers PSS per mTHPP molecule by CHNS analysis and UV/vis measurement. Molecular docking simulations revealed π−π interactions and H-bonding to be the responsible mechanisms. A drug Multilayer system based on the layer-by-layer (LbL) technique utilized the water-soluble complex as anionic layer material and poly(allylamine hydrochloride) (PAH) as cationic layer. The modified AuNP were c...

  • Multilayer Coating of gold nanoparticles with drug-polymer coadsorbates
    Langmuir, 2010
    Co-Authors: Nico Reum, Claudia Fink-straube, Tobias Klein, Rolf W. Hartmann, Claus-michael Lehr, Marc Schneider
    Abstract:

    The aim of our present study was the development of a drug Multilayer-based carrier system for delivery of water-insoluble drugs. As drug, we applied the anticancer drug 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin, mTHPP, which is a model photosensitizer for photodynamic therapy. Gold nanoparticles (AuNP) with a diameter of 14.5 ± 0.9 nm were prepared and used as template for the layer-by-layer approach. The drug and the negatively charged polyelectrolyte (PE) poly(styrene sulfonate) sodium salt (PSS) were complexed with a new developed method using freeze-drying. The complexation efficiency was determined to be ∼11-12 monomers PSS per mTHPP molecule by CHNS analysis and UV/vis measurement. Molecular docking simulations revealed π-π interactions and H-bonding to be the responsible mechanisms. A drug Multilayer system based on the layer-by-layer (LbL) technique utilized the water-soluble complex as anionic layer material and poly(allylamine hydrochloride) (PAH) as cationic layer. The modified AuNP were characterized by different physicochemical techniques such as UV/vis, ζ-potential, ICP-OES, and TEM. To the best of our knowledge, we could demonstrate for the first time the adsorption of three drug layers to a nanoparticulate system. Furthermore, the adaptation of the LbL-technique resulted in drastically increased drug deposition efficiency (factor of 100). Furthermore, we developed a new and comfortable way to solubilize water-insoluble drugs in water.