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Toshifumi Mawatari - One of the best experts on this subject based on the ideXlab platform.
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EFFECTS OF Substrate Surface FINISH ON TRI- BOLOGICAL PERFORMANCE AND Surface TOPOGRA- PHY OF THERMALLY SPRAYED WC CERMET COATING
2016Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract: In this study, tribological characteris-tics and Surface topographies of thermally sprayed WC-Cr-Ni cermet coating were investi-gated experimentally under lubricated rolling with sliding contact conditions. Hi-HVOF sprayed WC cermet coatings were deposited onto the axi-ally ground, blasted and circumferentially ground roller specimens made of an induction hardened carbon steel. It was found that under a contact pressure 1.4 GPa, cermet coating showed a high durability and life of the coating was not influ-enced by the Substrate Surface finish. It was also found that coefficient of friction and Surface tem-perature were hardly affected by the Substrate Surface finish. On the other hand, after running, Surface topographical parameters such as skew-ness, kurtosis and Surface roughness were sig-nificantly influenced depending on the Substrate Surface finish. Namely, after the running-in proc-ess, the skewness in the case of circumferentially ground Substrate became much more negative than that in the case of axially ground or blasted Substrate. In addition, kurtosis and Surface roughness of the coated Surface were much more influenced in the case of circumferentially ground Substrate than that in the case of axially ground or blasted Substrate
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Tribological Properties of Thermally Sprayed WC Cermet Coating under Extreme Operating Conditions 13 TRIBOLOGICAL PROPERTIES OF THERMALLY SPRAYED WC CERMET COATING UNDER EXTREME OPERATING CONDITIONS
2015Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract: In this study, tribological properties of thermally sprayed WC-Cr-Ni cermet coating were investigated experimentally under lubricated rolling with sliding contact conditions. Hi-HVOF sprayed WC cermet coatings were deposited onto the axially ground, blasted and circumferentially ground roller specimens made of carburized hardened steel. Under extreme operating conditions such as contact pressure PH = 1.4 GPa, slip ratio s =- 28.0 % and mating Surface roughness Rmax = 6.0 µm, the effects of Substrate Surface finish on the tribological properties of the cermet coating were examined. It was found that cermet coating showed a long life and durability was not influenced by the Substrate Surface finish. It was also found that coefficient of friction, oil film formation, Surface temperature and oil film thickness were not much influenced by the Substrate Surface finish. On the other hand, Surface hardness, Surface roughness and coating material loss were significantly influenced depending on the Substrate Surface finish
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effects of Substrate Surface finish and Substrate material on durability of thermally sprayed wc cermet coating in rolling with sliding contact
Tribology International, 2006Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract In this study, using a two-roller testing machine, the authors examined the Surface durability of thermally sprayed WC-Cr-Ni cermet coating in lubricated rolling with sliding contact conditions. The coating was formed onto the axially ground, blasted and circumferentially ground roller specimens made of a thermally refined carbon steel or an induction hardened carbon steel by means of the high energy type flame spraying (Hi-HVOF) method. The WC cermet coated roller finished to a mirror-like condition was mated with the carburized steel roller without coating having a Surface roughness of Ry=3.0∼5.0 μm. In the experiments, a maximum Hertzian stress of P H =0.6 or 0.8 GPa was applied for the thermally refined carbon steel roller and P H =1.4 GPa was applied for the induction hardened carbon steel roller in line contact condition. As a result, it was found that in the case of induction hardened steel Substrate, the coated roller generally exhibits a long life without any serious damage and the Surface durability is hardly affected by the Substrate Surface finish, while in the case of thermally refined steel Substrate, the durability of coated roller is lowered and the life to flaking is very short particularly when the Substrate Surface is circumferentially ground and the mating Surface is rough. The Surface durability of coated roller was also compared with the durability of steel roller without coating. Finally, in order to discuss the durability of coated roller, the elastic-plastic behavior of the subSurface layer under repeated rolling with sliding contact was analyzed using a finite element method (FEM).
Dewan Muhammad Nuruzzaman - One of the best experts on this subject based on the ideXlab platform.
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EFFECTS OF Substrate Surface FINISH ON TRI- BOLOGICAL PERFORMANCE AND Surface TOPOGRA- PHY OF THERMALLY SPRAYED WC CERMET COATING
2016Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract: In this study, tribological characteris-tics and Surface topographies of thermally sprayed WC-Cr-Ni cermet coating were investi-gated experimentally under lubricated rolling with sliding contact conditions. Hi-HVOF sprayed WC cermet coatings were deposited onto the axi-ally ground, blasted and circumferentially ground roller specimens made of an induction hardened carbon steel. It was found that under a contact pressure 1.4 GPa, cermet coating showed a high durability and life of the coating was not influ-enced by the Substrate Surface finish. It was also found that coefficient of friction and Surface tem-perature were hardly affected by the Substrate Surface finish. On the other hand, after running, Surface topographical parameters such as skew-ness, kurtosis and Surface roughness were sig-nificantly influenced depending on the Substrate Surface finish. Namely, after the running-in proc-ess, the skewness in the case of circumferentially ground Substrate became much more negative than that in the case of axially ground or blasted Substrate. In addition, kurtosis and Surface roughness of the coated Surface were much more influenced in the case of circumferentially ground Substrate than that in the case of axially ground or blasted Substrate
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Tribological Properties of Thermally Sprayed WC Cermet Coating under Extreme Operating Conditions 13 TRIBOLOGICAL PROPERTIES OF THERMALLY SPRAYED WC CERMET COATING UNDER EXTREME OPERATING CONDITIONS
2015Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract: In this study, tribological properties of thermally sprayed WC-Cr-Ni cermet coating were investigated experimentally under lubricated rolling with sliding contact conditions. Hi-HVOF sprayed WC cermet coatings were deposited onto the axially ground, blasted and circumferentially ground roller specimens made of carburized hardened steel. Under extreme operating conditions such as contact pressure PH = 1.4 GPa, slip ratio s =- 28.0 % and mating Surface roughness Rmax = 6.0 µm, the effects of Substrate Surface finish on the tribological properties of the cermet coating were examined. It was found that cermet coating showed a long life and durability was not influenced by the Substrate Surface finish. It was also found that coefficient of friction, oil film formation, Surface temperature and oil film thickness were not much influenced by the Substrate Surface finish. On the other hand, Surface hardness, Surface roughness and coating material loss were significantly influenced depending on the Substrate Surface finish
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effects of Substrate Surface finish and Substrate material on durability of thermally sprayed wc cermet coating in rolling with sliding contact
Tribology International, 2006Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract In this study, using a two-roller testing machine, the authors examined the Surface durability of thermally sprayed WC-Cr-Ni cermet coating in lubricated rolling with sliding contact conditions. The coating was formed onto the axially ground, blasted and circumferentially ground roller specimens made of a thermally refined carbon steel or an induction hardened carbon steel by means of the high energy type flame spraying (Hi-HVOF) method. The WC cermet coated roller finished to a mirror-like condition was mated with the carburized steel roller without coating having a Surface roughness of Ry=3.0∼5.0 μm. In the experiments, a maximum Hertzian stress of P H =0.6 or 0.8 GPa was applied for the thermally refined carbon steel roller and P H =1.4 GPa was applied for the induction hardened carbon steel roller in line contact condition. As a result, it was found that in the case of induction hardened steel Substrate, the coated roller generally exhibits a long life without any serious damage and the Surface durability is hardly affected by the Substrate Surface finish, while in the case of thermally refined steel Substrate, the durability of coated roller is lowered and the life to flaking is very short particularly when the Substrate Surface is circumferentially ground and the mating Surface is rough. The Surface durability of coated roller was also compared with the durability of steel roller without coating. Finally, in order to discuss the durability of coated roller, the elastic-plastic behavior of the subSurface layer under repeated rolling with sliding contact was analyzed using a finite element method (FEM).
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effect of Substrate Surface finish on durability of thermally sprayed wc cermet coating under rolling sliding contact
Japanese journal of tribology, 2005Co-Authors: Akira Nakajima, Dewan Muhammad Nuruzzaman, Toshifumi Mawarari, Mitsugu YoshidaAbstract:Using a two-roller testing machine, we have examined the Surface durability of thermally sprayed WC-Cr-Ni cermet coating in lubricated rolling/sliding contact conditions. In the present investigation, the coating of 60 to 210 μm in thickness was formed onto the blasted, axially ground, and circumferentially ground roller specimens made of a thermally refined carbon steel or an induction-hardened carbon steel by high-energy flame spraying (Hi-HVOF). The coated roller finished to a mirrorlike condition was mated with the carburized steel roller without coating, and a maximum Hertzian stress of P H = 1.0 to 1.4 GPa was applied in line contact. In the thermally refined steel Substrate roller, the coating on the circumferentially ground Substrate generally showed a lower durability compared with that on the axially ground Substrate or blasted Substrate, and this difference appeared more distinctly as the coating thickness decreased. On the other hand, the induction-hardened steel Substrate roller showed a higher durability, and the effect of Substrate Surface finish was hardly recognized. The effect of Substrate Surface finish on the durability of thermally sprayed coating was also examined by the elastic-plastic analysis of the subSurface layer.
Rui Huang - One of the best experts on this subject based on the ideXlab platform.
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effects of mismatch strain and Substrate Surface corrugation on morphology of supported monolayer graphene
Journal of Applied Physics, 2010Co-Authors: Zachary H Aitken, Rui HuangAbstract:Graphene monolayers supported on oxide Substrates have been demonstrated with superior charge mobility and thermal transport for potential device applications. Morphological corrugation can strongly influence the transport properties of the supported graphene. In this paper, we theoretically analyze the morphological stability of a graphene monolayer on an oxide Substrate, subject to van der Waals interactions and in-plane mismatch strains. First, we define the equilibrium separation and the interfacial adhesion energy as the two key parameters that characterize the van der Waals interaction between a flat monolayer and a flat Substrate Surface. By a perturbation analysis, a critical compressive mismatch strain is predicted, beyond which the graphene monolayer undergoes strain-induced instability, forming corrugations with increasing amplitude and decreasing wavelength on a perfectly flat Surface. When the Substrate Surface is not perfectly flat, the morphology of graphene depends on both the amplitude an...
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effects of mismatch strain and Substrate Surface corrugation on morphology of supported monolayer graphene
arXiv: Mesoscale and Nanoscale Physics, 2010Co-Authors: Zachary H Aitken, Rui HuangAbstract:Graphene monolayers supported on oxide Substrates have been demonstrated with superior charge mobility and thermal transport for potential device applications. Morphological corrugation can strongly influence the transport properties of the supported graphene. In this paper, we theoretically analyze the morphological stability of a graphene monolayer on an oxide Substrate, subject to van der Waals interactions and in-plane mismatch strains. First, we define the equilibrium separation and the interfacial adhesion energy as the two key parameters that characterize the van der Waals interaction between a flat monolayer and a flat Substrate Surface. By a perturbation analysis, a critical compressive mismatch strain is predicted, beyond which the graphene monolayer undergoes strain-induced instability, forming corrugations with increasing amplitude and decreasing wavelength on a perfectly flat Surface. When the Substrate Surface is not perfectly flat, the morphology of graphene depends on both the amplitude and the wavelength of the Surface corrugation. A transition from conformal (corrugated) to non-conformal (flat) morphology is predicted. The effects of Substrate Surface corrugation on the equilibrium mean thickness of the supported graphene and the interfacial adhesion energy are analyzed. Furthermore, by considering both the Substrate Surface corrugation and the mismatch strain, it is found that, while a tensile mismatch strain reduces the corrugation amplitude of graphene, a corrugated Substrate Surface promotes strain-induced instability under a compressive strain. These theoretical results suggest possible means to control the morphology of graphene monolayer on oxide Substrates by Surface patterning and strain engineering.
Akira Nakajima - One of the best experts on this subject based on the ideXlab platform.
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EFFECTS OF Substrate Surface FINISH ON TRI- BOLOGICAL PERFORMANCE AND Surface TOPOGRA- PHY OF THERMALLY SPRAYED WC CERMET COATING
2016Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract: In this study, tribological characteris-tics and Surface topographies of thermally sprayed WC-Cr-Ni cermet coating were investi-gated experimentally under lubricated rolling with sliding contact conditions. Hi-HVOF sprayed WC cermet coatings were deposited onto the axi-ally ground, blasted and circumferentially ground roller specimens made of an induction hardened carbon steel. It was found that under a contact pressure 1.4 GPa, cermet coating showed a high durability and life of the coating was not influ-enced by the Substrate Surface finish. It was also found that coefficient of friction and Surface tem-perature were hardly affected by the Substrate Surface finish. On the other hand, after running, Surface topographical parameters such as skew-ness, kurtosis and Surface roughness were sig-nificantly influenced depending on the Substrate Surface finish. Namely, after the running-in proc-ess, the skewness in the case of circumferentially ground Substrate became much more negative than that in the case of axially ground or blasted Substrate. In addition, kurtosis and Surface roughness of the coated Surface were much more influenced in the case of circumferentially ground Substrate than that in the case of axially ground or blasted Substrate
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Tribological Properties of Thermally Sprayed WC Cermet Coating under Extreme Operating Conditions 13 TRIBOLOGICAL PROPERTIES OF THERMALLY SPRAYED WC CERMET COATING UNDER EXTREME OPERATING CONDITIONS
2015Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract: In this study, tribological properties of thermally sprayed WC-Cr-Ni cermet coating were investigated experimentally under lubricated rolling with sliding contact conditions. Hi-HVOF sprayed WC cermet coatings were deposited onto the axially ground, blasted and circumferentially ground roller specimens made of carburized hardened steel. Under extreme operating conditions such as contact pressure PH = 1.4 GPa, slip ratio s =- 28.0 % and mating Surface roughness Rmax = 6.0 µm, the effects of Substrate Surface finish on the tribological properties of the cermet coating were examined. It was found that cermet coating showed a long life and durability was not influenced by the Substrate Surface finish. It was also found that coefficient of friction, oil film formation, Surface temperature and oil film thickness were not much influenced by the Substrate Surface finish. On the other hand, Surface hardness, Surface roughness and coating material loss were significantly influenced depending on the Substrate Surface finish
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effects of Substrate Surface finish and Substrate material on durability of thermally sprayed wc cermet coating in rolling with sliding contact
Tribology International, 2006Co-Authors: Dewan Muhammad Nuruzzaman, Akira Nakajima, Toshifumi MawatariAbstract:Abstract In this study, using a two-roller testing machine, the authors examined the Surface durability of thermally sprayed WC-Cr-Ni cermet coating in lubricated rolling with sliding contact conditions. The coating was formed onto the axially ground, blasted and circumferentially ground roller specimens made of a thermally refined carbon steel or an induction hardened carbon steel by means of the high energy type flame spraying (Hi-HVOF) method. The WC cermet coated roller finished to a mirror-like condition was mated with the carburized steel roller without coating having a Surface roughness of Ry=3.0∼5.0 μm. In the experiments, a maximum Hertzian stress of P H =0.6 or 0.8 GPa was applied for the thermally refined carbon steel roller and P H =1.4 GPa was applied for the induction hardened carbon steel roller in line contact condition. As a result, it was found that in the case of induction hardened steel Substrate, the coated roller generally exhibits a long life without any serious damage and the Surface durability is hardly affected by the Substrate Surface finish, while in the case of thermally refined steel Substrate, the durability of coated roller is lowered and the life to flaking is very short particularly when the Substrate Surface is circumferentially ground and the mating Surface is rough. The Surface durability of coated roller was also compared with the durability of steel roller without coating. Finally, in order to discuss the durability of coated roller, the elastic-plastic behavior of the subSurface layer under repeated rolling with sliding contact was analyzed using a finite element method (FEM).
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effect of Substrate Surface finish on durability of thermally sprayed wc cermet coating under rolling sliding contact
Japanese journal of tribology, 2005Co-Authors: Akira Nakajima, Dewan Muhammad Nuruzzaman, Toshifumi Mawarari, Mitsugu YoshidaAbstract:Using a two-roller testing machine, we have examined the Surface durability of thermally sprayed WC-Cr-Ni cermet coating in lubricated rolling/sliding contact conditions. In the present investigation, the coating of 60 to 210 μm in thickness was formed onto the blasted, axially ground, and circumferentially ground roller specimens made of a thermally refined carbon steel or an induction-hardened carbon steel by high-energy flame spraying (Hi-HVOF). The coated roller finished to a mirrorlike condition was mated with the carburized steel roller without coating, and a maximum Hertzian stress of P H = 1.0 to 1.4 GPa was applied in line contact. In the thermally refined steel Substrate roller, the coating on the circumferentially ground Substrate generally showed a lower durability compared with that on the axially ground Substrate or blasted Substrate, and this difference appeared more distinctly as the coating thickness decreased. On the other hand, the induction-hardened steel Substrate roller showed a higher durability, and the effect of Substrate Surface finish was hardly recognized. The effect of Substrate Surface finish on the durability of thermally sprayed coating was also examined by the elastic-plastic analysis of the subSurface layer.
Eduardo Julio - One of the best experts on this subject based on the ideXlab platform.
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correlation between concrete to concrete bond strength and the roughness of the Substrate Surface
Construction and Building Materials, 2007Co-Authors: Pedro Santos, Eduardo Julio, Vi Tor D SilvaAbstract:Abstract Previous studies proved that the bond strength between two concrete layers is highly influenced by the roughness of the Substrate Surface. In this paper, the authors describe a subsequent study, conducted to investigate the possibility of quantifying the roughness of the Substrate Surface and correlate this with the corresponding interface bond strength. Specimens with the Substrate Surface prepared with different roughening techniques were considered. The roughness profile of the Substrate Surface was obtained with digital image processing. Several roughness parameters were assessed based on this profile and were correlated with the corresponding bond strength, both in shear and in tension, measured with slant shear and pull-off tests, respectively.
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concrete to concrete bond strength influence of an epoxy based bonding agent on a roughened Substrate Surface
Magazine of Concrete Research, 2005Co-Authors: Eduardo Julio, Fernando A Branco, Vitor SilvaAbstract:An experimental study was performed to evaluate the bond strength between two concrete layers, using different techniques for increasing the roughness of the Substrate Surface and a commercial epoxy-based bonding agent. A total of 40 slant shear half specimens and 40 pull-off half specimens first had the Substrate Surface prepared by wire-brushing, sand-blasting, chipping with a light jackhammer, or were left as-cast against steel formwork. Three months later, the bonding agent was applied and the new concrete was added. Pull-off tests and slant shear tests were performed to evaluate the bond strength in tension and in shear. Analysis of the results indicates that the application of an epoxy-based bonding agent does not improve the bond strength since the adopted method for Surface preparation adequately increases its roughness.
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concrete to concrete bond strength influence of the roughness of the Substrate Surface
Construction and Building Materials, 2004Co-Authors: Eduardo Julio, Fernando A Branco, Vitor SilvaAbstract:Abstract An experimental study was performed to evaluate the bond strength between two concrete layers, for different techniques for increasing the roughness of the Substrate Surface. In a total of 25 slant shear specimens and 25 pull-off specimens the Substrate Surface was prepared by wire-brushing; sand-blasting; chipping with a light jackhammer; or were left as-cast against steel formwork. Three months later, the new concrete was added. Pull-off tests were performed to evaluate the bond strength in tension. Slant shear tests were conducted to quantify the bond strength in shear. Analysis of results indicated that: the highest value of bond strength was achieved with sand-blasting; pull-off tests are adequate to estimate the bond strength in situ; and pre-wetting the Substrate Surface does not seem to influence the bond strength.
