The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Zi-chen Li - One of the best experts on this subject based on the ideXlab platform.
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Experimental studies on grinding forces and force ratio of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Zi-chen Li, Y.-s. Xu, Jun HuAbstract:The whole machining process of Unsteady-State grinding was evaluated through the measurement of the grinding forces, namely tangential grinding force Ft and normal grinding force Fn. A number of accurate signals of the grinding forces were achieved by setting up a measurement system including a sensor, an amplifier, an oscilloscope and a personal computer. The tendency of the grinding forces reflected by the measurement system confirmed the existence of the cutting and micro-cutting action during the course of Unsteady-State grinding. Because the grinding force signals of Unsteady-State grinding are much weaker than those of steady-State grinding, a method of filtering was introduced. © Published by Elsevier Science B.V.link_to_subscribed_fulltex
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Theoretical generalization and research on the mechanism of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Zi-chen Li, Y.-s. Xu, Jun HuAbstract:In this paper, the concept of the Unsteady-State grinding technique is proposed and compared with the conventional grinding technique. Experimental work was performed to establish the existence of the Unsteady State in the process of ultra-precision grinding with a common abrasive wheel. From the results of the observation of the wheel topography, the whole grinding process in the Unsteady State was separated into three stages, namely cutting by grains peaks, micro-cutting by micro-edges of the broken grains, and rubbing without material removal. By utilizing the common abrasive wheel newly redressed to damage the finished surface of silicon nitride and comparing the finished surface with the damaged surface in aspects of their scanning electronic microscope (SEM) pattern and surface roughness, the existence of cutting and micro-cutting actions in the Unsteady-State grinding process was confirmed. © 2002 Elsevier Science B.V. All rights reserved.link_to_subscribed_fulltex
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Studies on the surface quality of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Y.-s. Xu, Jun Hu, Zi-chen LiAbstract:Ultra-precision grinding for advanced ceramics has been achieved by the Unsteady-State grinding technique. This paper deals mainly with observing and analyzing the surface quality of silicon nitride ground by a pink fused alumina wheel with different grinding parameters. To optimize the grinding parameters in the process of Unsteady-State grinding, experiments of X-ray diffraction, energy spectrum analysis, SEM observation and roughness measurement were performed. The results show that there do exist optimum grinding conditions such as grain size, coolant, and cutting depth, etc. Finally, the surface roughness Ra can be as good as 0.01 μm under optimum conditions. © 2002 Published Elsevier Science B.V.link_to_subscribed_fulltex
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Theoretical generalization and research on the mechanism of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2002Co-Authors: Zi-chen Li, Yunhua Xu, Jun HuAbstract:Abstract In this paper, the concept of the Unsteady-State grinding technique is proposed and compared with the conventional grinding technique. Experimental work was performed to establish the existence of the Unsteady State in the process of ultra-precision grinding with a common abrasive wheel. From the results of the observation of the wheel topography, the whole grinding process in the Unsteady State was separated into three stages, namely cutting by grains peaks, micro-cutting by micro-edges of the broken grains, and rubbing without material removal. By utilizing the common abrasive wheel newly redressed to damage the finished surface of silicon nitride and comparing the finished surface with the damaged surface in aspects of their scanning electronic microscope (SEM) pattern and surface roughness, the existence of cutting and micro-cutting actions in the Unsteady-State grinding process was confirmed.
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Experimental studies on grinding forces and force ratio of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2002Co-Authors: Zi-chen Li, Yunhua Xu, Jun HuAbstract:Abstract The whole machining process of Unsteady-State grinding was evaluated through the measurement of the grinding forces, namely tangential grinding force Ft and normal grinding force Fn. A number of accurate signals of the grinding forces were achieved by setting up a measurement system including a sensor, an amplifier, an oscilloscope and a personal computer. The tendency of the grinding forces reflected by the measurement system confirmed the existence of the cutting and micro-cutting action during the course of Unsteady-State grinding. Because the grinding force signals of Unsteady-State grinding are much weaker than those of steady-State grinding, a method of filtering was introduced.
Jun Hu - One of the best experts on this subject based on the ideXlab platform.
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Experimental studies on grinding forces and force ratio of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Zi-chen Li, Y.-s. Xu, Jun HuAbstract:The whole machining process of Unsteady-State grinding was evaluated through the measurement of the grinding forces, namely tangential grinding force Ft and normal grinding force Fn. A number of accurate signals of the grinding forces were achieved by setting up a measurement system including a sensor, an amplifier, an oscilloscope and a personal computer. The tendency of the grinding forces reflected by the measurement system confirmed the existence of the cutting and micro-cutting action during the course of Unsteady-State grinding. Because the grinding force signals of Unsteady-State grinding are much weaker than those of steady-State grinding, a method of filtering was introduced. © Published by Elsevier Science B.V.link_to_subscribed_fulltex
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Theoretical generalization and research on the mechanism of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Zi-chen Li, Y.-s. Xu, Jun HuAbstract:In this paper, the concept of the Unsteady-State grinding technique is proposed and compared with the conventional grinding technique. Experimental work was performed to establish the existence of the Unsteady State in the process of ultra-precision grinding with a common abrasive wheel. From the results of the observation of the wheel topography, the whole grinding process in the Unsteady State was separated into three stages, namely cutting by grains peaks, micro-cutting by micro-edges of the broken grains, and rubbing without material removal. By utilizing the common abrasive wheel newly redressed to damage the finished surface of silicon nitride and comparing the finished surface with the damaged surface in aspects of their scanning electronic microscope (SEM) pattern and surface roughness, the existence of cutting and micro-cutting actions in the Unsteady-State grinding process was confirmed. © 2002 Elsevier Science B.V. All rights reserved.link_to_subscribed_fulltex
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Studies on the surface quality of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Y.-s. Xu, Jun Hu, Zi-chen LiAbstract:Ultra-precision grinding for advanced ceramics has been achieved by the Unsteady-State grinding technique. This paper deals mainly with observing and analyzing the surface quality of silicon nitride ground by a pink fused alumina wheel with different grinding parameters. To optimize the grinding parameters in the process of Unsteady-State grinding, experiments of X-ray diffraction, energy spectrum analysis, SEM observation and roughness measurement were performed. The results show that there do exist optimum grinding conditions such as grain size, coolant, and cutting depth, etc. Finally, the surface roughness Ra can be as good as 0.01 μm under optimum conditions. © 2002 Published Elsevier Science B.V.link_to_subscribed_fulltex
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Theoretical generalization and research on the mechanism of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2002Co-Authors: Zi-chen Li, Yunhua Xu, Jun HuAbstract:Abstract In this paper, the concept of the Unsteady-State grinding technique is proposed and compared with the conventional grinding technique. Experimental work was performed to establish the existence of the Unsteady State in the process of ultra-precision grinding with a common abrasive wheel. From the results of the observation of the wheel topography, the whole grinding process in the Unsteady State was separated into three stages, namely cutting by grains peaks, micro-cutting by micro-edges of the broken grains, and rubbing without material removal. By utilizing the common abrasive wheel newly redressed to damage the finished surface of silicon nitride and comparing the finished surface with the damaged surface in aspects of their scanning electronic microscope (SEM) pattern and surface roughness, the existence of cutting and micro-cutting actions in the Unsteady-State grinding process was confirmed.
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Experimental studies on grinding forces and force ratio of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2002Co-Authors: Zi-chen Li, Yunhua Xu, Jun HuAbstract:Abstract The whole machining process of Unsteady-State grinding was evaluated through the measurement of the grinding forces, namely tangential grinding force Ft and normal grinding force Fn. A number of accurate signals of the grinding forces were achieved by setting up a measurement system including a sensor, an amplifier, an oscilloscope and a personal computer. The tendency of the grinding forces reflected by the measurement system confirmed the existence of the cutting and micro-cutting action during the course of Unsteady-State grinding. Because the grinding force signals of Unsteady-State grinding are much weaker than those of steady-State grinding, a method of filtering was introduced.
Marcus Grunewald - One of the best experts on this subject based on the ideXlab platform.
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Unsteady State operation of trickle bed reactors
Chemical Engineering Science, 2004Co-Authors: Rudiger Lange, Markus Schubert, Wulf Dietrich, Marcus GrunewaldAbstract:An experimental and theoretical study of forced Unsteady-State operation of trickle-bed reactors in comparison to the steady-State operation is the subject of this paper. It is well known that changes in the control variables influence the regime and the performance of trickle-bed reactors. In this study as one example for a forced periodic operation of a trickle-bed reactor an Unsteady-State technique was used in which the catalyst bed is contacted periodically with different liquid flow rates. The Unsteady-State operation was considered as square-waves cycling liquid flow rate at the reactor inlet. The hydrogenation of alpha-methylstyrene to cumene: C 6 H 5 (CH 3 ) = CH 2(L) + H 2(G) → C 6 H 5 CH(CH 3 ) 2(L) over a Palladium-catalyst (0.7% Pd/γ-Al 2 O 3 ) was selected as a model reaction. The experimental results of the alpha-methylstyrene hydrogenation in a laboratory-scale trickle-bed reactor showed, that the reactor performance can be significantly improved by feed liquid flow modulation. The simulation studies demonstrate that the liquid flow variation has a strong influence on the liquid hold-up oscillation and on the catalyst wetting efficiency. Consequently the time average alpha-methylstyrene conversion will be increased, because the mass transfer resistance between the phases (gas-liquid, gas-solid and liquid-solid) affect the overall reaction rate and consequently the conversion will be improved.
Y.-s. Xu - One of the best experts on this subject based on the ideXlab platform.
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Theoretical generalization and research on the mechanism of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Zi-chen Li, Y.-s. Xu, Jun HuAbstract:In this paper, the concept of the Unsteady-State grinding technique is proposed and compared with the conventional grinding technique. Experimental work was performed to establish the existence of the Unsteady State in the process of ultra-precision grinding with a common abrasive wheel. From the results of the observation of the wheel topography, the whole grinding process in the Unsteady State was separated into three stages, namely cutting by grains peaks, micro-cutting by micro-edges of the broken grains, and rubbing without material removal. By utilizing the common abrasive wheel newly redressed to damage the finished surface of silicon nitride and comparing the finished surface with the damaged surface in aspects of their scanning electronic microscope (SEM) pattern and surface roughness, the existence of cutting and micro-cutting actions in the Unsteady-State grinding process was confirmed. © 2002 Elsevier Science B.V. All rights reserved.link_to_subscribed_fulltex
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Experimental studies on grinding forces and force ratio of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Zi-chen Li, Y.-s. Xu, Jun HuAbstract:The whole machining process of Unsteady-State grinding was evaluated through the measurement of the grinding forces, namely tangential grinding force Ft and normal grinding force Fn. A number of accurate signals of the grinding forces were achieved by setting up a measurement system including a sensor, an amplifier, an oscilloscope and a personal computer. The tendency of the grinding forces reflected by the measurement system confirmed the existence of the cutting and micro-cutting action during the course of Unsteady-State grinding. Because the grinding force signals of Unsteady-State grinding are much weaker than those of steady-State grinding, a method of filtering was introduced. © Published by Elsevier Science B.V.link_to_subscribed_fulltex
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Studies on the surface quality of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2020Co-Authors: Y.-s. Xu, Jun Hu, Zi-chen LiAbstract:Ultra-precision grinding for advanced ceramics has been achieved by the Unsteady-State grinding technique. This paper deals mainly with observing and analyzing the surface quality of silicon nitride ground by a pink fused alumina wheel with different grinding parameters. To optimize the grinding parameters in the process of Unsteady-State grinding, experiments of X-ray diffraction, energy spectrum analysis, SEM observation and roughness measurement were performed. The results show that there do exist optimum grinding conditions such as grain size, coolant, and cutting depth, etc. Finally, the surface roughness Ra can be as good as 0.01 μm under optimum conditions. © 2002 Published Elsevier Science B.V.link_to_subscribed_fulltex
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Studies on the surface quality of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2002Co-Authors: Y.-s. Xu, B. Lin, Jun Hu, Zi-chen LiAbstract:Ultra-precision grinding for advanced ceramics has been achieved by the Unsteady-State grinding technique. This paper deals mainly with observing and analyzing the surface quality of silicon nitride ground by a pink fused alumina wheel with different grinding parameters. To optimize the grinding parameters in the process of Unsteady-State grinding, experiments of X-ray diffraction, energy spectrum analysis, SEM observation and roughness measurement were performed. The results show that there do exist optimum grinding conditions such as grain size, coolant, and cutting depth, etc. Finally, the surface roughness Ra can be as good as 0.01 μm under optimum conditions. © 2002 Published Elsevier Science B.V.
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Theoretical generalization and research on the mechanism of the Unsteady-State grinding technique
Journal of Materials Processing Technology, 2002Co-Authors: B. Lin, Zi-chen Li, Y.-s. Xu, Jun HuAbstract:In this paper, the concept of the Unsteady-State grinding technique is proposed and compared with the conventional grinding technique. Experimental work was performed to establish the existence of the Unsteady State in the process of ultra-precision grinding with a common abrasive wheel. From the results of the observation of the wheel topography, the whole grinding process in the Unsteady State was separated into three stages, namely cutting by grains peaks, micro-cutting by micro-edges of the broken grains, and rubbing without material removal. By utilizing the common abrasive wheel newly redressed to damage the finished surface of silicon nitride and comparing the finished surface with the damaged surface in aspects of their scanning electronic microscope (SEM) pattern and surface roughness, the existence of cutting and micro-cutting actions in the Unsteady-State grinding process was confirmed. © 2002 Elsevier Science B.V. All rights reserved.
Jingyun Tian - One of the best experts on this subject based on the ideXlab platform.
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Unsteady-State temperature field and sensitivity analysis of gear transmission
Tribology International, 2017Co-Authors: Wei Li, Jingyun TianAbstract:This paper investigated three-dimensional analysis of Unsteady-State temperature field and temperature sensitivity analysis of gear transmission, for which frictional heat caused surface temperature rise which reduced their bearing capacity and scuffing resistance. Unsteady-State temperature field of gear surface was analyzed, results providing continuous temperature distribution of any meshing moment and at any position on gear surface. Thermal sensitivity comparison considering different operating conditions and gear geometric parameters was given out. Flash temperature influenced by dynamic load was also provided. The thermal experiment validated the correctness of the model and analysis results. The numerical analysis and calculation results combined with experimental results offered evidence to improve gear scoring and scuffing capacity.
