The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Jianbin Luo - One of the best experts on this subject based on the ideXlab platform.
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Influence of structural evolution on Sliding Interface for enhancing tribological performance of onion-like carbon films via thermal annealing
Applied Surface Science, 2021Co-Authors: Ting Luo, Xinchun Chen, Philipp G. Grützmacher, Andreas Rosenkranz, Jianbin LuoAbstract:Abstract The onion-like carbon (OLC) possesses a micro-spherical structure with a diameter of approximately 7 nm consisting of 0.35 nm-spaced carbon layers, and the OLC film is capable of providing excellent solid lubrication performances because of the high content of sp2-bonded carbon phase. However, the unfavorable durability severely restricts the lubrication application in practice. For the purpose of addressing this issue, heat treatment is employed to improve the lubrication robustness of the loose OLC film. The wear resistance was significantly improved with a duration of 60,000 Sliding cycles at least when the OLC-coated samples were annealed at 600 °C in vacuum. Furthermore, the systematic analyses, particularly providing deep insights into the microstructural characterization, indicate that the structural reinforcement of OLC and the net-like adhering structures formed on the steel substrates annealed at specific temperature can effectively promote lubrication characteristics in two different stages. We propose that annealing treatment can improve the stability of micro-spherical OLC structures, thereby increasing the duration of lubrication. The evolution mechanism of OLC structures at the Sliding Interface is the key factor for maintaining the lubrication duration in dry contact.
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Graphene-induced reconstruction of the Sliding Interface assisting the improved lubricity of various tribo-couples
Materials & Design, 2020Co-Authors: Xuan Yin, Xinchun Chen, Chenhui Zhang, Jianbin LuoAbstract:Abstract Graphene has emerged as one of the most promising solid lubricants owing to their exceptional lubricity. The atomically thin nature and its ability to conformally adsorb on the Sliding surfaces provide unprecedented pathways for modifying the friction and wear behaviors of the mechanical moving parts. Here, the tribological responses of several representative tribo-couples including bare steel, diamond-like carbon and ceramic materials are investigated to explore the potentials of graphene as surface modifier. Specific emphasis is devoted to the graphene-induced reconstruction of the Sliding Interface and the growth mechanism of nanostructured tribofilms formed on the contact surface using high-resolution microscopic technique. The results reveal the unique properties of graphene regarding the friction reduction and wear protection irrespective of the types of counterpart materials, graphene-processed methods, dry or humid tests environments. Nevertheless, the interfacial features and the bonding characteristics of the tribofilms are diversified in each specific rubbing case, demonstrating the distinguished adaption capacity of graphene to the tribo-testing conditions. The present findings shed light on the lubrication phenomenon of graphene at the microscale and may provide useful design criterion for 2D-based solid lubricants.
A. C. Agarwal - One of the best experts on this subject based on the ideXlab platform.
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Pressure distribution in Sliding Interface of spherical bridge bearing : Structures
Transportation Research Record, 1997Co-Authors: T I Campbell, N. C. Koppens, M. F. Green, A. C. AgarwalAbstract:Relevant literature indicates that the critical parameters relating to load transfer in the curved, Sliding, compression-only, polytetrafluoroethylene (PTFE)-metal Interface of a spherical bearing under an external applied horizontal load are the ratio of the horizontal load to the vertical load and the ratio of the radius of curvature to the plan diameter of the interfacing spherical surfaces. An experimental program measuring the stress-displacement relationship of confined PTFE discs under uniaxial and eccentric compressive loadings is described, and a bilinear stress-displacement relationship is proposed. This stress-displacement relationship is incorporated into a displacement model to predict the stress distribution in the PTFE in the curved Interface, and results from the model are compared with those from a finite-element model. The displacement model is used to develop design charts for spherical bearings under combined vertical and horizontal loads.
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PRESSURE DISTRIBUTION IN Sliding Interface OF SPHERICAL BRIDGE BEARING
Transportation Research Record, 1997Co-Authors: T I Campbell, N. C. Koppens, M. F. Green, A. C. AgarwalAbstract:Relevant literature indicates that the critical parameters relating to load transfer in the curved, Sliding, compression-only, polytetra-fluoroethylene (PTFE)-metal Interface of a spherical bearing under an external applied horizontal load are the ratio of the horizontal load to the vertical load and the ratio of the radius of curvature to the plan diameter of the interfacing spherical surfaces. An experimental program measuring the stress-displacement relationship of confined PTFE discs under uniaxial and eccentric compressive loadings is described, and a bilinear stress-displacement relationship is proposed. This stress-displacement relationship is incorporated into a displacement model to predict the stress distribution in the PTFE in the curved Interface, and results from the model are compared with those from a finite-element model. The displacement model is used to develop design charts for spherical bearings under combined vertical and horizontal loads.
Qunji Xue - One of the best experts on this subject based on the ideXlab platform.
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Improving the tribological properties of diamond-like carbon film applied under methane by tailoring Sliding Interface
International Journal of Refractory Metals and Hard Materials, 2021Co-Authors: Lin Chen, Xueqian Cao, Yan Wang, Guangan Zhang, Qunji XueAbstract:Abstract Methane fuel will be valued as a renewable and alternative energy source in the new future. Nevertheless, during transportation and application of methane, the damage to moving mechanical components results in a huge loss to the society. Diamond-like carbon (DLC) film, with lots of excellent frictional performances, is expected to resolve the above issue. Herein, experiments were performed by tailoring Sliding Interfaces under methane to explore the tribological mechanism of DLC film under methane atmosphere. It was found that initial tribological Interface had an important impact on the frictional performances of DLC film. Raman spectra demonstrated that the reconstruction, which was critical for the tribological performances of DLC film under methane, occurred at the Sliding Interface with shearing. The first principles calculation result revealed that carbon dangling bonds were passivated with the groups dissociated from methane. Combining with the hardness of wear tracks, an appropriate passivation on the Sliding Interface and suitable rigidity of the system were found to be great for the low friction of DLC film under methane atmosphere. The results indicate that DLC film exhibits outstanding lubricating and wear-resistant properties under methane by tailoring Sliding Interface.
T I Campbell - One of the best experts on this subject based on the ideXlab platform.
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Pressure distribution in Sliding Interface of spherical bridge bearing : Structures
Transportation Research Record, 1997Co-Authors: T I Campbell, N. C. Koppens, M. F. Green, A. C. AgarwalAbstract:Relevant literature indicates that the critical parameters relating to load transfer in the curved, Sliding, compression-only, polytetrafluoroethylene (PTFE)-metal Interface of a spherical bearing under an external applied horizontal load are the ratio of the horizontal load to the vertical load and the ratio of the radius of curvature to the plan diameter of the interfacing spherical surfaces. An experimental program measuring the stress-displacement relationship of confined PTFE discs under uniaxial and eccentric compressive loadings is described, and a bilinear stress-displacement relationship is proposed. This stress-displacement relationship is incorporated into a displacement model to predict the stress distribution in the PTFE in the curved Interface, and results from the model are compared with those from a finite-element model. The displacement model is used to develop design charts for spherical bearings under combined vertical and horizontal loads.
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PRESSURE DISTRIBUTION IN Sliding Interface OF SPHERICAL BRIDGE BEARING
Transportation Research Record, 1997Co-Authors: T I Campbell, N. C. Koppens, M. F. Green, A. C. AgarwalAbstract:Relevant literature indicates that the critical parameters relating to load transfer in the curved, Sliding, compression-only, polytetra-fluoroethylene (PTFE)-metal Interface of a spherical bearing under an external applied horizontal load are the ratio of the horizontal load to the vertical load and the ratio of the radius of curvature to the plan diameter of the interfacing spherical surfaces. An experimental program measuring the stress-displacement relationship of confined PTFE discs under uniaxial and eccentric compressive loadings is described, and a bilinear stress-displacement relationship is proposed. This stress-displacement relationship is incorporated into a displacement model to predict the stress distribution in the PTFE in the curved Interface, and results from the model are compared with those from a finite-element model. The displacement model is used to develop design charts for spherical bearings under combined vertical and horizontal loads.
Lin Chen - One of the best experts on this subject based on the ideXlab platform.
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Improving the tribological properties of diamond-like carbon film applied under methane by tailoring Sliding Interface
International Journal of Refractory Metals and Hard Materials, 2021Co-Authors: Lin Chen, Xueqian Cao, Yan Wang, Guangan Zhang, Qunji XueAbstract:Abstract Methane fuel will be valued as a renewable and alternative energy source in the new future. Nevertheless, during transportation and application of methane, the damage to moving mechanical components results in a huge loss to the society. Diamond-like carbon (DLC) film, with lots of excellent frictional performances, is expected to resolve the above issue. Herein, experiments were performed by tailoring Sliding Interfaces under methane to explore the tribological mechanism of DLC film under methane atmosphere. It was found that initial tribological Interface had an important impact on the frictional performances of DLC film. Raman spectra demonstrated that the reconstruction, which was critical for the tribological performances of DLC film under methane, occurred at the Sliding Interface with shearing. The first principles calculation result revealed that carbon dangling bonds were passivated with the groups dissociated from methane. Combining with the hardness of wear tracks, an appropriate passivation on the Sliding Interface and suitable rigidity of the system were found to be great for the low friction of DLC film under methane atmosphere. The results indicate that DLC film exhibits outstanding lubricating and wear-resistant properties under methane by tailoring Sliding Interface.
