The Experts below are selected from a list of 7368 Experts worldwide ranked by ideXlab platform
Fei Zhou - One of the best experts on this subject based on the ideXlab platform.
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microstructure and water Lubricated Friction and wear properties of crn c coatings with different carbon contents
Applied Surface Science, 2013Co-Authors: Qianzhi Wang, Fei Zhou, Xiangdong Ding, Zhifeng Zhou, Chundong Wang, Wenjun Zhang, Shuittong LeeAbstract:Abstract The CrN(C) coatings with different carbon contents were deposited using unbalanced magnetron sputtering via adjusting the carbon target current, and their microstructure and mechanical properties were characterized using Raman spectrum, X-ray photoelectron spectroscopy and nano-indenter, respectively. The water-Lubricated tribological properties of the CrN(C) coatings against Si 3 N 4 balls were investigated using the ball-on-disk tribometer. The results showed that the C content in the CrN(C) coatings increased gradually, and the peak intensity correlated to Cr 7 C 3 crystal phase became stronger when the carbon target current increased. When the carbon target current was 1 A, the hardness of the CrN(C) coatings increased to 22.5 GPa due to formation of Cr 7 C 3 phase and amorphous CN x , and a little amorphous carbon had positive effect on tribological properties of the CrN(C) coatings in water lubrication. On the other hand, CrN(C) coatings deposited at 2–4 A exhibited a lower hardness and deteriorated tribological properties, due to the presence of a major amount of Cr 2 O 3 particles in the films.
Saiko Aoki - One of the best experts on this subject based on the ideXlab platform.
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In-Liquid Lateral Force Microscopy of Micropatterned Surfaces in a Fatty Acid Solution under Boundary Lubrication
Scientific Reports, 2019Co-Authors: Masaki Tsuchiko, Saiko AokiAbstract:This study aims to investigate the influence of surface morphology on boundary-Lubricated Friction in a stearic acid solution. The surface morphology was controlled by fabricating submicrometer line-and-space patterns on Si(100) surface via photolithography. The boundary-Lubricated Friction on the patterns was measured by in-liquid lateral force microscopy for both transverse and longitudinal ridges, with respect to the sliding direction; the highest Friction was observed on longitudinal ridges and grooves, which is in agreement with the tendency observed in our previous Friction studies on steel surfaces. To further investigate this phenomenon, some additional patterns having different submicrometer morphologies were prepared and their Friction characteristics were investigated. On the patterns not allowing the fluid to flow along the grooves, the Frictional forces were equivalent for transverse and longitudinal grooves and ridges. Therefore, the high Friction observed on the longitudinal ridges was caused by flowing out of fluid along the grooves, and it was possible to conclude that the fluidity around the submicrometer ridges and grooves influences the Friction-reducing effect of stearic acid in boundary lubrication regime.
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influence of lubricant additive and surface texture on the sliding Friction characteristics of steel under varying speeds ranging from ultralow to moderate
Tribology Transactions, 2005Co-Authors: Masabumi Masuko, Saiko Aoki, Akihito SuzukiAbstract:A newly developed tribometer that undergoes significant changes in sliding speed, ranging from ultralow (5 μm/s) to moderate (17 cm/s), was used to study the Lubricated Friction characteristic of steel. In this study, the Friction characteristics of stearic acid-formulated oil were studied to clarify the effects of surface roughness or surface roughness texture on Friction. Several kinds of specimens having isotropic and anisotropic surface roughness with different textures were used. For an isotropic surface, a rougher surface resulted in low Friction under low-speed conditions. The same surface produced high Friction under high-speed conditions, where macroscopic hydrodynamic action was predominant. Remarkably less Friction was observed in the transverse than in the longitudinal direction when the specimen had anisotropic roughness. This difference was particularly notable under ultra-low-speed conditions. Two other parameters of skewness and kurtosis of roughness distributions show that low Friction wa...
Michael R. Lovell - One of the best experts on this subject based on the ideXlab platform.
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analysis of the contribution of adhesion and hysteresis to shoe floor Lubricated Friction in the boundary lubrication regime
Tribology Letters, 2012Co-Authors: Caitlin T Strobel, Pradeep L. Menezes, Michael R. Lovell, Kurt E. BeschornerAbstract:Slip and fall accidents cause frequent occupational injuries. Despite recent evidence that boundary lubrication is relevant to slipping, few studies have examined the mechanisms that contribute to shoe–floor Friction in this lubrication regime. This study aims to identify the contributions of adhesion and hysteresis to Friction in boundary lubrication. Three shoe materials (40 Shore A hardness polyurethane, 60 Shore A hardness rubber, and 70 Shore A hardness rubber), two floor materials (vinyl and marble), and six lubricants (water, 1.5 % detergent, 25 % glycerol–75 % water, 50 % glycerol–50 % water, 75 % glycerol–25 % water, and canola oil) were tested at a single sliding speed (0.01 m s−1). Dry adhesion and hysteresis were quantified for each of the shoe–floor combinations and Lubricated adhesion was quantified for all shoe–floor-fluid combinations. The contribution of adhesion and hysteresis to shoe–floor-lubricant Friction was affected by both the shoe and floor material due to differences in hardness and roughness. Lubricated adhesion was complex and multifactorial with contributions from the shoe, fluid, shoe–floor interaction, floor-lubricant interaction, and shoe-lubricant interactions. A simple regression model including two fluid coefficients and the dry adhesion Friction force was able to predict 49 % of the Lubricated adhesion Friction variability.
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Analysis of the Contribution of Adhesion and Ploughing to Shoe-Floor Lubricated Friction in the Boundary Lubrication Regime
ASME STLE 2011 Joint Tribology Conference, 2011Co-Authors: Caitlin Moore, Pradeep L. Menezes, Kurt E. Beschorner, Michael R. LovellAbstract:Slip and fall accidents cause frequent occupational injuries. Despite recent evidence that boundary lubrication is relevant to slipping, few studies have examined the mechanisms that contribute to shoe–floor Friction in this lubrication regime. This study aims to identify the contributions of adhesion and hysteresis to Friction in boundary lubrication. Three shoe materials (40 Shore A hardness polyurethane, 60 Shore A hardness rubber, and 70 Shore A hardness rubber), two floor materials (vinyl and marble), and six lubricants (water, 1.5 % detergent, 25 % glycerol–75 % water, 50 % glycerol–50 % water, 75 % glycerol–25 % water, and canola oil) were tested at a single sliding speed (0.01 m s−1). Dry adhesion and hysteresis were quantified for each of the shoe–floor combinations and Lubricated adhesion was quantified for all shoe–floor-fluid combinations. The contribution of adhesion and hysteresis to shoe–floor-lubricant Friction was affected by both the shoe and floor material due to differences in hardness and roughness. Lubricated adhesion was complex and multifactorial with contributions from the shoe, fluid, shoe–floor interaction, floor-lubricant interaction, and shoe-lubricant interactions. A simple regression model including two fluid coefficients and the dry adhesion Friction force was able to predict 49 % of the Lubricated adhesion Friction variability.
Kurt E. Beschorner - One of the best experts on this subject based on the ideXlab platform.
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analysis of the contribution of adhesion and hysteresis to shoe floor Lubricated Friction in the boundary lubrication regime
Tribology Letters, 2012Co-Authors: Caitlin T Strobel, Pradeep L. Menezes, Michael R. Lovell, Kurt E. BeschornerAbstract:Slip and fall accidents cause frequent occupational injuries. Despite recent evidence that boundary lubrication is relevant to slipping, few studies have examined the mechanisms that contribute to shoe–floor Friction in this lubrication regime. This study aims to identify the contributions of adhesion and hysteresis to Friction in boundary lubrication. Three shoe materials (40 Shore A hardness polyurethane, 60 Shore A hardness rubber, and 70 Shore A hardness rubber), two floor materials (vinyl and marble), and six lubricants (water, 1.5 % detergent, 25 % glycerol–75 % water, 50 % glycerol–50 % water, 75 % glycerol–25 % water, and canola oil) were tested at a single sliding speed (0.01 m s−1). Dry adhesion and hysteresis were quantified for each of the shoe–floor combinations and Lubricated adhesion was quantified for all shoe–floor-fluid combinations. The contribution of adhesion and hysteresis to shoe–floor-lubricant Friction was affected by both the shoe and floor material due to differences in hardness and roughness. Lubricated adhesion was complex and multifactorial with contributions from the shoe, fluid, shoe–floor interaction, floor-lubricant interaction, and shoe-lubricant interactions. A simple regression model including two fluid coefficients and the dry adhesion Friction force was able to predict 49 % of the Lubricated adhesion Friction variability.
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Analysis of the Contribution of Adhesion and Ploughing to Shoe-Floor Lubricated Friction in the Boundary Lubrication Regime
ASME STLE 2011 Joint Tribology Conference, 2011Co-Authors: Caitlin Moore, Pradeep L. Menezes, Kurt E. Beschorner, Michael R. LovellAbstract:Slip and fall accidents cause frequent occupational injuries. Despite recent evidence that boundary lubrication is relevant to slipping, few studies have examined the mechanisms that contribute to shoe–floor Friction in this lubrication regime. This study aims to identify the contributions of adhesion and hysteresis to Friction in boundary lubrication. Three shoe materials (40 Shore A hardness polyurethane, 60 Shore A hardness rubber, and 70 Shore A hardness rubber), two floor materials (vinyl and marble), and six lubricants (water, 1.5 % detergent, 25 % glycerol–75 % water, 50 % glycerol–50 % water, 75 % glycerol–25 % water, and canola oil) were tested at a single sliding speed (0.01 m s−1). Dry adhesion and hysteresis were quantified for each of the shoe–floor combinations and Lubricated adhesion was quantified for all shoe–floor-fluid combinations. The contribution of adhesion and hysteresis to shoe–floor-lubricant Friction was affected by both the shoe and floor material due to differences in hardness and roughness. Lubricated adhesion was complex and multifactorial with contributions from the shoe, fluid, shoe–floor interaction, floor-lubricant interaction, and shoe-lubricant interactions. A simple regression model including two fluid coefficients and the dry adhesion Friction force was able to predict 49 % of the Lubricated adhesion Friction variability.
Shuittong Lee - One of the best experts on this subject based on the ideXlab platform.
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microstructure and water Lubricated Friction and wear properties of crn c coatings with different carbon contents
Applied Surface Science, 2013Co-Authors: Qianzhi Wang, Fei Zhou, Xiangdong Ding, Zhifeng Zhou, Chundong Wang, Wenjun Zhang, Shuittong LeeAbstract:Abstract The CrN(C) coatings with different carbon contents were deposited using unbalanced magnetron sputtering via adjusting the carbon target current, and their microstructure and mechanical properties were characterized using Raman spectrum, X-ray photoelectron spectroscopy and nano-indenter, respectively. The water-Lubricated tribological properties of the CrN(C) coatings against Si 3 N 4 balls were investigated using the ball-on-disk tribometer. The results showed that the C content in the CrN(C) coatings increased gradually, and the peak intensity correlated to Cr 7 C 3 crystal phase became stronger when the carbon target current increased. When the carbon target current was 1 A, the hardness of the CrN(C) coatings increased to 22.5 GPa due to formation of Cr 7 C 3 phase and amorphous CN x , and a little amorphous carbon had positive effect on tribological properties of the CrN(C) coatings in water lubrication. On the other hand, CrN(C) coatings deposited at 2–4 A exhibited a lower hardness and deteriorated tribological properties, due to the presence of a major amount of Cr 2 O 3 particles in the films.
