The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Yi Zhu - One of the best experts on this subject based on the ideXlab platform.
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The influence of Iron Oxides on wheel–rail contact: A literature review
Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit, 2017Co-Authors: Yi ZhuAbstract:In contrast to other third-body layers – such as water, oil, sand, and leaves – Iron Oxides exert a constant influence on the friction and wear of wheel–rail contact. However, studies that focus on the influence of Iron Oxides have not been conducted systematically until the 21st century. This study is a comprehensive presentation of early and recent research works related to the influence of Iron Oxides on the wheel–rail contact. The characteristics of Iron Oxides in general and those between railway wheels and rails are discussed. A comparison of various laboratory tests and their relation to actual conditions is also presented. The authors find that the influence of various types of Iron Oxides on friction and adhesion differs. The thickness of the Iron oxide layer also affects the friction and wear. However, the results obtained from laboratory rigs differ from those obtained in field testing. Therefore, it is critical to formulate a standard procedure that produces Iron Oxides that are similar to tho...
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A study on Iron Oxides and surface roughness in dry and wet wheel−rail contacts
Wear, 2015Co-Authors: Yi Zhu, Wen Jian Wang, Xiao Ming Chen, Hangbo YangAbstract:Abstract In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel−rail adhesion and wear. Rolling−sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel−rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion. Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
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A study on Iron Oxides and surface roughness in dry and wet wheel-rail contacts
Wear, 2015Co-Authors: Yi Zhu, Yilin Zhu, Wen Jian Wang, Xindu Chen, Weizong Wang, Hang YangAbstract:In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel-rail adhesion and wear. Rolling-sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel-rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion.Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
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On the Iron Oxides between railway wheels and rails using laboratory tests
CM 2015 - 10th International Conference on Contact Mechanics of Wheel Rail Systems, 2015Co-Authors: Yi Zhu, W Wang, Ulf Olofsson, Xindu ChenAbstract:The contact between railway wheels and rails is influenced by various contaminants. Iron Oxides present on both wheel and rail surfaces which constantly affects the wheel?rail adhesion and wear. The paper summarizes some laboratory work investigating the Iron Oxides between the wheel and rai contact which were previous performed in the authors' group. A comparison of the contact conditions and application regarding the test rig (pin-on-disc and twin-disc) is also given. The influence of Iron Oxides on the coefficient of friction, adhesion coefficient and wear rate is presented and discussed. Results indicate Iron Oxides greatly influence the tribological behavior particularly under the wet condition. The author aims to highlight the importance of the Iron Oxides which may provide some hints to explain the difference between laboratory tests and field measurements. However, a quantitative study is needed based on controlled envIronmental conditions due to the complexity and fast transition of Iron Oxides.
Hang Yang - One of the best experts on this subject based on the ideXlab platform.
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A study on Iron Oxides and surface roughness in dry and wet wheel-rail contacts
Wear, 2015Co-Authors: Yi Zhu, Yilin Zhu, Wen Jian Wang, Xindu Chen, Weizong Wang, Hang YangAbstract:In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel-rail adhesion and wear. Rolling-sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel-rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion.Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
Wen Jian Wang - One of the best experts on this subject based on the ideXlab platform.
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A study on Iron Oxides and surface roughness in dry and wet wheel−rail contacts
Wear, 2015Co-Authors: Yi Zhu, Wen Jian Wang, Xiao Ming Chen, Hangbo YangAbstract:Abstract In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel−rail adhesion and wear. Rolling−sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel−rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion. Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
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A study on Iron Oxides and surface roughness in dry and wet wheel-rail contacts
Wear, 2015Co-Authors: Yi Zhu, Yilin Zhu, Wen Jian Wang, Xindu Chen, Weizong Wang, Hang YangAbstract:In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel-rail adhesion and wear. Rolling-sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel-rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion.Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
Xindu Chen - One of the best experts on this subject based on the ideXlab platform.
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A study on Iron Oxides and surface roughness in dry and wet wheel-rail contacts
Wear, 2015Co-Authors: Yi Zhu, Yilin Zhu, Wen Jian Wang, Xindu Chen, Weizong Wang, Hang YangAbstract:In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel-rail adhesion and wear. Rolling-sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel-rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion.Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
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On the Iron Oxides between railway wheels and rails using laboratory tests
CM 2015 - 10th International Conference on Contact Mechanics of Wheel Rail Systems, 2015Co-Authors: Yi Zhu, W Wang, Ulf Olofsson, Xindu ChenAbstract:The contact between railway wheels and rails is influenced by various contaminants. Iron Oxides present on both wheel and rail surfaces which constantly affects the wheel?rail adhesion and wear. The paper summarizes some laboratory work investigating the Iron Oxides between the wheel and rai contact which were previous performed in the authors' group. A comparison of the contact conditions and application regarding the test rig (pin-on-disc and twin-disc) is also given. The influence of Iron Oxides on the coefficient of friction, adhesion coefficient and wear rate is presented and discussed. Results indicate Iron Oxides greatly influence the tribological behavior particularly under the wet condition. The author aims to highlight the importance of the Iron Oxides which may provide some hints to explain the difference between laboratory tests and field measurements. However, a quantitative study is needed based on controlled envIronmental conditions due to the complexity and fast transition of Iron Oxides.
Yilin Zhu - One of the best experts on this subject based on the ideXlab platform.
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A study on Iron Oxides and surface roughness in dry and wet wheel-rail contacts
Wear, 2015Co-Authors: Yi Zhu, Yilin Zhu, Wen Jian Wang, Xindu Chen, Weizong Wang, Hang YangAbstract:In addition to contaminants such as dirt, precipitation and leaves, Iron Oxides are constantly present on railway wheel and rail surfaces. Iron Oxides potentially influences adhesion and wear between wheels and rails, which in turn affect railway operation, safety and maintenance. Surface roughness also has a large impact on wheel-rail adhesion and wear. Rolling-sliding tests were conducted on a typical rail and wheel steel combination using a disk-on-disk machine to study the influence of Iron Oxides and surface roughness on the wheel-rail adhesion and wear. The Iron Oxides were created in a climate-controlled chamber, and two levels of roughness were investigated under both dry and wet conditions. Worn surfaces were examined using scanning electron microscopy, energy dispersive spectrometry and X-ray diffractometer. An extra set of tests was also performed to study the influence of surface roughness on the removal of the oxide layers and to investigate its role in recovering adhesion.Results indicate that the surface roughness after testing tends towards a saturation level in dry contacts under the given contact condition. The low adhesion problem is unlikely to occur under dry conditions, while thick Oxides on rough surfaces result in extremely high adhesion and wear. Under wet conditions, thin Oxides help to protect contacting surfaces, producing negligible wear and a smooth surface. Either increasing surface roughness or having thick Oxides increases wear. A rough surface is efficient in removing the thin oxide layer in order to recover adhesion under the wet conditions.
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Friction Between Wheel and Rail: A Pin-On-Disc Study of EnvIronmental Conditions and Iron Oxides
Tribology Letters, 2013Co-Authors: Yilin Zhu, Ulf Olofsson, Hua ChenAbstract:The coefficient of friction between railway wheels and rails is crucial to railway operation and maintenance. Since the wheel–rail system is an open system, envIronmental conditions, such as humidity and temperature, affect the friction coefficient. Pin-on-disc testing was conducted to study the influence of envIronmental conditions and Iron Oxides on the coefficient of friction between the wheel and rail. The Iron Oxides were pre-created in a climate chamber. The surfaces of the tested samples were analysed using X-ray diffraction, scanning electron/focused ion beam microscopy, and Raman spectroscopy. Results indicate that the coefficient of friction decreases with increasing relative humidity (RH) up to a saturation level. Above this level, the coefficient of friction remains low and stable even when the RH increases. In particular, when the temperature is low, a small increase in the amount of water (i.e., absolute humidity) in the air can significantly reduce the coefficient of friction. At high humidity levels, a water molecule film can keep the generated haematite on the surfaces, counterbalancing the effect of rising humidity.
