The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform
Yulin Yang - One of the best experts on this subject based on the ideXlab platform.
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self repairing characteristics of serpentine mineral powder as an Additive on steel chromium plating pair under high temperature
Tribology Transactions, 2013Co-Authors: Xiaowen Qi, Zhining Jia, Hongmei Chen, Yulin Yang, Zhen WuAbstract:Friction and wear experiments on steel–chromium plating pairs were carried out with nanoscale serpentine (a magnesium silicate mineral) as a lubricating Oil Additive at 400°C. The tribological test results showed that self-repairing protective layers formed on the contact surfaces of both the steel matrix and hard chromium coating. Field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the morphology and elements of self-repairing layers were in accordance with that of serpentine. A generation mechanism of the layer was proposed that suggests that isomorphic replacement between Fe/Cr and serpentine mineral silicate occurs, which is the wear mechanism of the tribochemical reaction.
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Characterization and auto-restoration mechanism of nanoscale serpentine powder as lubricating Oil Additive under high temperature
Tribology International, 2011Co-Authors: Xiaowen Qi, Yulin YangAbstract:Abstract Friction and wear experiments were carried out with nanoscale serpentine (a magnesium silicate mineral) and heat-treated serpentine as lubricating Oil Additives at 400 °C. The tribological test results showed that the self-repairing protective layers could be well formed on the contact surfaces, whether nanoscale serpentine or heat-treated serpentine powder was added into lubricating Oil. SEM and EDAX analysis demonstrate that the morphology and elements of self-repairing layers are in accordance with that of serpentine. A generation mechanism of the layer was proposed from the view of isomorphic replacement theory in mineralogy and petrology, and friction-induced chemical reaction.
Xiaowen Qi - One of the best experts on this subject based on the ideXlab platform.
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self repairing characteristics of serpentine mineral powder as an Additive on steel chromium plating pair under high temperature
Tribology Transactions, 2013Co-Authors: Xiaowen Qi, Zhining Jia, Hongmei Chen, Yulin Yang, Zhen WuAbstract:Friction and wear experiments on steel–chromium plating pairs were carried out with nanoscale serpentine (a magnesium silicate mineral) as a lubricating Oil Additive at 400°C. The tribological test results showed that self-repairing protective layers formed on the contact surfaces of both the steel matrix and hard chromium coating. Field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the morphology and elements of self-repairing layers were in accordance with that of serpentine. A generation mechanism of the layer was proposed that suggests that isomorphic replacement between Fe/Cr and serpentine mineral silicate occurs, which is the wear mechanism of the tribochemical reaction.
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Characterization and auto-restoration mechanism of nanoscale serpentine powder as lubricating Oil Additive under high temperature
Tribology International, 2011Co-Authors: Xiaowen Qi, Yulin YangAbstract:Abstract Friction and wear experiments were carried out with nanoscale serpentine (a magnesium silicate mineral) and heat-treated serpentine as lubricating Oil Additives at 400 °C. The tribological test results showed that the self-repairing protective layers could be well formed on the contact surfaces, whether nanoscale serpentine or heat-treated serpentine powder was added into lubricating Oil. SEM and EDAX analysis demonstrate that the morphology and elements of self-repairing layers are in accordance with that of serpentine. A generation mechanism of the layer was proposed from the view of isomorphic replacement theory in mineralogy and petrology, and friction-induced chemical reaction.
Rehan Zahid - One of the best experts on this subject based on the ideXlab platform.
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Tribological performance of nanoparticles as lubricating Oil Additives
Journal of Nanoparticle Research, 2016Co-Authors: M. Gulzar, H H Masjuki, M. A. Kalam, M. Varman, N. W. M. Zulkifli, R. A. Mufti, Rehan ZahidAbstract:The prospect of modern tribology has been expanded with the advent of nanomaterial-based lubrication systems, whose development was facilitated by the nanotechnology in recent years. In literature, a variety of nanoparticles have been used as lubricant Additives with potentially interesting friction and wear properties. To date, although there has been a great deal of experimental research on nanoparticles as lubricating Oil Additives, many aspects of their tribological behavior are yet to be fully understood. With growing number of possibilities, the key question is: what types of nanoparticles act as a better lubricating Oil Additive and why? To answer this question, this paper reviews main types of nanoparticles that have been used as lubricants Additives and outlines the mechanisms by which they are currently believed to function. Significant aspects of their tribological behavior such as dispersion stability and morphology are also highlighted.
Hružík Lumír - One of the best experts on this subject based on the ideXlab platform.
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Effect of rapeseed Oil on the rheological, mechanical and thermal properties of plastic lubricants
'Springer Science and Business Media LLC', 2020Co-Authors: Lapčík Lubomír, Vašina Martin, Lapčíková Barbora, Bureček Adam, Hružík LumírAbstract:A strong difference in the physico-chemical properties of the plastic lubricants studied was found in this study through pressure drop, thermal analysis, vibration damping, texture hardness and rheological measurements. Oxidation aging of the lubricant sample containing rapeseed Oil Additive was proposed. Its higher thermal sensitivity was simultaneously confirmed by frequency dependent complex shear modulus of elasticity measurements as well as by rheological testing. Rapeseed Oil modified lubricant showed a higher decrease in both storage and moduli losses due to a temperature increase from 16 to 26 degrees C compared to the rapeseed Oil free sample. Simultaneously, the flow curves were shifted to the higher shear stresses (for plastic lubricant without rapeseed Oil Additive) typical for rheopectic fluids. For the rapeseed Oil modified lubricant, the flow curves were shifted to the lower shear stresses, indicating its thixotropic fluid behaviour. The synthetic lubricant without rapeseed Oil Additive exhibited higher dissipative rheological behaviour as reflected by decreasing first resonance frequency peak position compared to the rapeseed Oil modified lubricant as obtained from vibration damping measurements. It was found that the synthetic lubricant exhibited better vibration damping properties and mechanical energy dissipation into heat due to its higher viscous friction than the rapeseed Oil modified lubricant under experimental conditions.Web of Scienc
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Effect of rapeseed Oil on the rheological, mechanical and thermal properties of plastic lubricants
'Springer Science and Business Media LLC', 2020Co-Authors: Lapčík Lubomír, Vašina Martin, Lapčíková Barbora, Bureček Adam, Hružík LumírAbstract:A strong difference in the physico-chemical properties of the plastic lubricants studied was found in this study through pressure drop, thermal analysis, vibration damping, texture hardness and rheological measurements. Oxidation aging of the lubricant sample containing rapeseed Oil Additive was proposed. Its higher thermal sensitivity was simultaneously confirmed by frequency dependent complex shear modulus of elasticity measurements as well as by rheological testing. Rapeseed Oil modified lubricant showed a higher decrease in both storage and moduli losses due to a temperature increase from 16 to 26 ° C compared to the rapeseed Oil free sample. Simultaneously, the flow curves were shifted to the higher shear stresses (for plastic lubricant without rapeseed Oil Additive) typical for rheopectic fluids. For the rapeseed Oil modified lubricant, the flow curves were shifted to the lower shear stresses, indicating its thixotropic fluid behaviour. The synthetic lubricant without rapeseed Oil Additive exhibited higher dissipative rheological behaviour as reflected by decreasing first resonance frequency peak position compared to the rapeseed Oil modified lubricant as obtained from vibration damping measurements. It was found that the synthetic lubricant exhibited better vibration damping properties and mechanical energy dissipation into heat due to its higher viscous friction than the rapeseed Oil modified lubricant under experimental conditions. © 2020, Springer Nature B.V.European Regional Development Fund in the Research Centre of Advanced Mechatronic Systems project [CZ.02.1.01/0.0/0.0/16_019/0000867
Sriram Sundararajan - One of the best experts on this subject based on the ideXlab platform.
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the effect of contact pressure and surface texture on running in behavior of case carburized steel under boundary lubrication
Wear, 2017Co-Authors: Jeremy J Wagner, Alexander D Jenson, Sriram SundararajanAbstract:Abstract Many engineering tests start with a run-in procedure, as it is commonly accepted that running-in at some fraction of the target load is beneficial due to a reduction in surface roughness. However, the choice of load and duration is often based on historical context or the experience and philosophies of the testing personnel. The objectives of this study were to (1) evaluate the effects of contact pressure and initial composite roughness on the surface evolution during the initial stage of testing, and (2) use this information to determine if there is an optimal load and time for the run-in portion of a test. These tests were conducted with a disc-type machine using carburized steel specimens with a circumferential lay direction and Oil with anti-wear Additives under specific conditions of slide-to-roll ratio, entraining velocity, Oil spin-off temperature, and Oil/Additive package. The specimen surface was inspected using non-contact profilometery every minute for the first 10 minutes of testing, with a subsequently increasing inspection interval for a total of 150 minutes. The data demonstrate that the surface roughness reduces within the first few minutes of testing and remains stable for a period of time, which is dependent on the pressure and initial composite roughness. Additionally, hardness measurements indicate that hardness gains are occurring during the test, but over a longer timeframe.
