In order to enhance the tribological properties of lubricating oil, suitable surfactants such as Tween-20, Tween-60, Span-20 and Sodium sodecylbenzenesulfonate were selected and lubricating oils containing CeO2 and Ti...In order to enhance the tribological properties of lubricating oil, suitable surfactants such as Tween-20, Tween-60, Span-20 and Sodium sodecylbenzenesulfonate were selected and lubricating oils containing CeO2 and TiO2 nanoparticles were prepared. The morphology and size of CeO2 and TiO2 nanoparticles were examined with a transmission electron microscope (TEM). The tribological properties of the oils were tested using an MRS-1J four-ball tribotester. The research results show that when the proportion by weight of CeO2 nanoparticles to TiO2 nanoparticles is 1:3, and the total weight fraction is 0.6%, the lubricating oil has optimal anti-wear and friction reducing properties. The addition of CeO2 nanoparticles reduces the required amount of TiO2 nanoparticles.展开更多
In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural ...In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.展开更多
Fluorosilicone oil is polysiloxane with alkyl side chains containing fluorine, and because of its excellent thermal oxidation stability, cold flow property and cryogenic property, it can be widely used as a high tempe...Fluorosilicone oil is polysiloxane with alkyl side chains containing fluorine, and because of its excellent thermal oxidation stability, cold flow property and cryogenic property, it can be widely used as a high temperature lubricant in the field of military aerospace industry. Two kinds of fluorosilicone oils, FSiO-a and FSiO-b, were synthesized by different pro- cessing means. FTICR MS was used to collect the information on composition and structure of the two polymers, respec- tively. The test results show that the two fluorosilicone oils have different contents of fluorine-containing chain segments (m/ n value), the maximum distribution of m/n value of FSiO-a oil ranges from 0.22 to 0.25, and that of FSiO-b oil ranges from 0.4 to 0.67. Difference in synthesis techniques makes this discrepancy and affects the quality and thermal stability of the fluoro- silicone oils.展开更多
The contact angle phenomena and wetting behavior of fatty acids,alcohols and ester used as additives in lubricants onto the rolled copper foil(RCF)surface were studied by the static sessile drop method.Semi-empirical ...The contact angle phenomena and wetting behavior of fatty acids,alcohols and ester used as additives in lubricants onto the rolled copper foil(RCF)surface were studied by the static sessile drop method.Semi-empirical quantum-chemical method studies on the contact angle of these compounds onto surface using several structural parameters were carried out.Molecular refractivity as well as several structural parameters were adopted in the development of quantitative structure-property relationships(QSPR)using genetic function approximation(GFA)statistical analysis method.The results show that quantum parameters are a better choice when predicting the contact angle and wettability of lubricants onto the RCF surface.Contact angle of the compounds serves as a function of their viscosity,interfacial tension,and physicochemical parameters.Alog P,molecular refractivity,molecular flexibility,total molecular mass,solvent surface area,element count,total energy and dipole are the most sensitive ones among the major contributing parameters.Notably,studies of lubricants on the RCF surfaces allow wetting theories to be tested down to the microcosmic scale,which can bring about new insight to predict wettability of lubricants onto RCF surface.展开更多
The 2,5-bis(ethyldisulfanyl)-l,3,4-thiadiazole (T561), benzotriazole (BTA),1-N, N-bis (2-ethylhexyl) aminomethyl-4-methyl-lh-benzotriazole (IRGAMET39) and I-IN, N-bis (2-ethylhexyl) aminomethyl] methyl ben...The 2,5-bis(ethyldisulfanyl)-l,3,4-thiadiazole (T561), benzotriazole (BTA),1-N, N-bis (2-ethylhexyl) aminomethyl-4-methyl-lh-benzotriazole (IRGAMET39) and I-IN, N-bis (2-ethylhexyl) aminomethyl] methyl benzotriazole (TT- LX) have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefficient of friction increased by 35.6% and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confocal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.展开更多
In order to investigate the influening factors of organic modification procedure and find out connections between organic modification and the properties of bentonite greases, organic montmorillonite(OMMT) thickeners ...In order to investigate the influening factors of organic modification procedure and find out connections between organic modification and the properties of bentonite greases, organic montmorillonite(OMMT) thickeners with different surfactant dosages and constituents were synthesized through intercalation reaction between sodium montmorillonite(NaM MT) and quaternary ammonium surfactants in aqueous solvents. The lubricating greases were prepared with the resulting organoclays, while the penetration and oil separation of lubricating greases were evaluated, respectively. The surface modification process of montmorillonite(MMT) was analyzed and the thickening mechanism of OMMT was discussed in this study. The experimental results showed that, with an increasing amount of surfactant, the basal spacing between the clay platelets was increasing and the structure of modifier molecules layer in the interlayer was changing from lateral bilayer to paraffin-type bilayer. The optimal properties of lubricating greases were achieved, when the structure of surfactant molecules loaded in the interlayer was the paraffin-type monolayer, which meant that the dosage of modifier was equal to 120—140 mmol/(100g). Meanwhile, it was found that the thickening performance, colloid stability, anti-wear and friction-reducing performance of lubricating greases were improved, when the surfactants were mixed with octadecyl trimethyl ammonium chloride(OTAC) and hexadecyl trimethyl ammonium chloride(HTAC). And the optimum mole ratio of two surfactants is was 1:1.展开更多
By using PAO-10 as the base oil, the tribological behavior of 11 additives under high vacuum condition was evaluated. By adopting some surface analytical instruments, such as scanning electron microscopy(SEM), energy ...By using PAO-10 as the base oil, the tribological behavior of 11 additives under high vacuum condition was evaluated. By adopting some surface analytical instruments, such as scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS), the tribological mechanisms of these additives were studied. In air, O_2 can react with metal to form metal oxide that can protect the surfaces of rubbing pair during the tribological tests. According to the theory of the competitive adsorption, the function of some active elements is weakened. In a vacuum environment, the additives contributed more to the lubrication performance. The sulfur-containing additives could react with Fe to produce Fe Sx and "M—C" bonds("M" represents metal). They both had contributions to the lubrication. As for the phosphorus-containing additives, they only generated the phosphates during the tests. When the sulfur and phosphorus-containing additives were applied, the generated phosphates and Fe Sx had the primary contribution to the lubrication performance during the tests.展开更多
The application of cutting fluids in machining brings out many benefits, but their use is accompanied by health and enviroment hazards. MQL (Minimum Quantity Lubricant) has become a preciously alternative solution f...The application of cutting fluids in machining brings out many benefits, but their use is accompanied by health and enviroment hazards. MQL (Minimum Quantity Lubricant) has become a preciously alternative solution for lubrication against dry machinning and flood cooling lubricant, and this is a step toward green machining. This paper presents a comprehensively experiemental study on investigation of MQL performance in hard milling of S60C steel for multiple responses, including surface quality, cutting forces and tool wear. Compared to dry milling, even-enhanced surfaces finish quality, 20% less cutting force (Ft) and almost 112% prolonged tool lifetime are achieved by using MQL with 5% Emulsion in hard milling. In addition, this study compared the performances of MQL milling by using 5% Emulsion to the peanut oil completely harmless to the enviroment. This encouraging result, therefore, reveals that the MQL-employed hard milling can enable significant improvement in productivity, product quality, and overall machining economy even after covering the additional cost of designing and implementing MQL system. Moreover, this study also shows the limitation of peanut oils employed in MQL and proposes the further research in novel additives to enhance the performance of cooling lubricant for vegetable oils.展开更多
It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe fri...It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe friction and wear.Fullerenol,a kind of highly water-soluble nanoparticle,was synthesized and then used to ameliorate the tribological properties of Si 3 N 4 sliding against Al 2 O 3 in pure water.With the addition of fullerenol,the running-in period was shortened from 30 min to 100 s at a speed of 250 mm/s.The speed threshold above which ultralow friction can be obtained in a short time was expanded from 450 mm/s to 80 mm/s.Meanwhile,the load-carrying ability of water film was increased.The role of fullerenol was discussed based on observation of the wear scar by an optical interferometer and XPS characterization of the tribo-film on the wear track.展开更多
The tribological properties of combinative addition of nano-MoS2 and nano-SiO2 to the base oil have been investigated with a reciprocating ball-on-plate tribotester for magnesium alloy-steel contacts. The results demo...The tribological properties of combinative addition of nano-MoS2 and nano-SiO2 to the base oil have been investigated with a reciprocating ball-on-plate tribotester for magnesium alloy-steel contacts. The results demonstrate that the optimum mass ratio of nano-SiO2 to nano-MoS2 is 0.25:0.75. The optimum combinative addition into the base oil reduces the friction coefficient by 43.8% and the surface roughness (Sa) by 31.7% when compared to that found with the base oil. Meanwhile, the combinative addition of nano-MoS2 and nano-SiO〉 in comparison with single nanoparticles addition, is more pronounced in terms of the lubrication film stability. The excellent tribological properties of the SiO2/MoS2 combinations are attributed to the formation of physical adsorption films and tribochemical products during the rubbing process and the micro-cooperation of various nano- particles with different shapes and lubrication mechanisms.展开更多
Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane ...Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane trioleate, TMPTO) with 15 kinds of amine additives and its molecular structure. Correlation coefficient of the cross-validation (include internal q2 and external qpred 2 ) and conventional correlation coefficient showed the model to be both stable and good predictive. The electron-donating group and larger steric effects group are adopted at the para-position or meta-position of amido on the benzene ring, and suitably decreasing the branch chain near the para-position, these indicate that the antioxidant performance of amine additives can be enhanced. The results not only can help us understanding the rule of antioxidant performance, but also providing guidance(s) to predict antioxidant performance of existing amine additives and to design or modify new amine additives in lubricating oil.展开更多
基金Supported by the Shanghai Municipal Education Commission(06FZ008)Shanghai Municipal Education Commission Key Disciplines(J50603)
文摘In order to enhance the tribological properties of lubricating oil, suitable surfactants such as Tween-20, Tween-60, Span-20 and Sodium sodecylbenzenesulfonate were selected and lubricating oils containing CeO2 and TiO2 nanoparticles were prepared. The morphology and size of CeO2 and TiO2 nanoparticles were examined with a transmission electron microscope (TEM). The tribological properties of the oils were tested using an MRS-1J four-ball tribotester. The research results show that when the proportion by weight of CeO2 nanoparticles to TiO2 nanoparticles is 1:3, and the total weight fraction is 0.6%, the lubricating oil has optimal anti-wear and friction reducing properties. The addition of CeO2 nanoparticles reduces the required amount of TiO2 nanoparticles.
基金the financial support of this study provided by the National Natural Science Foundation of China(No.51274037)the Cooperation Program between USTB and SINOPEC(No.112116)
文摘In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.
文摘Fluorosilicone oil is polysiloxane with alkyl side chains containing fluorine, and because of its excellent thermal oxidation stability, cold flow property and cryogenic property, it can be widely used as a high temperature lubricant in the field of military aerospace industry. Two kinds of fluorosilicone oils, FSiO-a and FSiO-b, were synthesized by different pro- cessing means. FTICR MS was used to collect the information on composition and structure of the two polymers, respec- tively. The test results show that the two fluorosilicone oils have different contents of fluorine-containing chain segments (m/ n value), the maximum distribution of m/n value of FSiO-a oil ranges from 0.22 to 0.25, and that of FSiO-b oil ranges from 0.4 to 0.67. Difference in synthesis techniques makes this discrepancy and affects the quality and thermal stability of the fluoro- silicone oils.
基金the financial assistance provided by the Introducing the Talent Research Start-up Fund(No.YKJ201706)the National Natural Science Foundation of China(No.51474025)
文摘The contact angle phenomena and wetting behavior of fatty acids,alcohols and ester used as additives in lubricants onto the rolled copper foil(RCF)surface were studied by the static sessile drop method.Semi-empirical quantum-chemical method studies on the contact angle of these compounds onto surface using several structural parameters were carried out.Molecular refractivity as well as several structural parameters were adopted in the development of quantitative structure-property relationships(QSPR)using genetic function approximation(GFA)statistical analysis method.The results show that quantum parameters are a better choice when predicting the contact angle and wettability of lubricants onto the RCF surface.Contact angle of the compounds serves as a function of their viscosity,interfacial tension,and physicochemical parameters.Alog P,molecular refractivity,molecular flexibility,total molecular mass,solvent surface area,element count,total energy and dipole are the most sensitive ones among the major contributing parameters.Notably,studies of lubricants on the RCF surfaces allow wetting theories to be tested down to the microcosmic scale,which can bring about new insight to predict wettability of lubricants onto RCF surface.
基金financially supported by the National Natural Science Foundation of China (No.51274037)the Key Science and Technology Project of China (No.2011BAE23B00)the Cooperation Program between USTB and SINOPEC (No.112116)
文摘The 2,5-bis(ethyldisulfanyl)-l,3,4-thiadiazole (T561), benzotriazole (BTA),1-N, N-bis (2-ethylhexyl) aminomethyl-4-methyl-lh-benzotriazole (IRGAMET39) and I-IN, N-bis (2-ethylhexyl) aminomethyl] methyl benzotriazole (TT- LX) have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefficient of friction increased by 35.6% and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confocal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.
基金financially supported by the Chongqing Construction Project of Innovation Teams in Colleges and Universities-Petroleum Products Application Engineering and Technology(Project No.KJTD201342)the Chongqing Project of Innovation Research by Postgraduates(Project No.CYB16130)
文摘In order to investigate the influening factors of organic modification procedure and find out connections between organic modification and the properties of bentonite greases, organic montmorillonite(OMMT) thickeners with different surfactant dosages and constituents were synthesized through intercalation reaction between sodium montmorillonite(NaM MT) and quaternary ammonium surfactants in aqueous solvents. The lubricating greases were prepared with the resulting organoclays, while the penetration and oil separation of lubricating greases were evaluated, respectively. The surface modification process of montmorillonite(MMT) was analyzed and the thickening mechanism of OMMT was discussed in this study. The experimental results showed that, with an increasing amount of surfactant, the basal spacing between the clay platelets was increasing and the structure of modifier molecules layer in the interlayer was changing from lateral bilayer to paraffin-type bilayer. The optimal properties of lubricating greases were achieved, when the structure of surfactant molecules loaded in the interlayer was the paraffin-type monolayer, which meant that the dosage of modifier was equal to 120—140 mmol/(100g). Meanwhile, it was found that the thickening performance, colloid stability, anti-wear and friction-reducing performance of lubricating greases were improved, when the surfactants were mixed with octadecyl trimethyl ammonium chloride(OTAC) and hexadecyl trimethyl ammonium chloride(HTAC). And the optimum mole ratio of two surfactants is was 1:1.
基金Financial support from the SINOPEC Research Program(No.ST13164-19]) is gratefully acknowledged
文摘By using PAO-10 as the base oil, the tribological behavior of 11 additives under high vacuum condition was evaluated. By adopting some surface analytical instruments, such as scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS), the tribological mechanisms of these additives were studied. In air, O_2 can react with metal to form metal oxide that can protect the surfaces of rubbing pair during the tribological tests. According to the theory of the competitive adsorption, the function of some active elements is weakened. In a vacuum environment, the additives contributed more to the lubrication performance. The sulfur-containing additives could react with Fe to produce Fe Sx and "M—C" bonds("M" represents metal). They both had contributions to the lubrication. As for the phosphorus-containing additives, they only generated the phosphates during the tests. When the sulfur and phosphorus-containing additives were applied, the generated phosphates and Fe Sx had the primary contribution to the lubrication performance during the tests.
文摘The application of cutting fluids in machining brings out many benefits, but their use is accompanied by health and enviroment hazards. MQL (Minimum Quantity Lubricant) has become a preciously alternative solution for lubrication against dry machinning and flood cooling lubricant, and this is a step toward green machining. This paper presents a comprehensively experiemental study on investigation of MQL performance in hard milling of S60C steel for multiple responses, including surface quality, cutting forces and tool wear. Compared to dry milling, even-enhanced surfaces finish quality, 20% less cutting force (Ft) and almost 112% prolonged tool lifetime are achieved by using MQL with 5% Emulsion in hard milling. In addition, this study compared the performances of MQL milling by using 5% Emulsion to the peanut oil completely harmless to the enviroment. This encouraging result, therefore, reveals that the MQL-employed hard milling can enable significant improvement in productivity, product quality, and overall machining economy even after covering the additional cost of designing and implementing MQL system. Moreover, this study also shows the limitation of peanut oils employed in MQL and proposes the further research in novel additives to enhance the performance of cooling lubricant for vegetable oils.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50805086 and 50730007)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant Nos. 51021064 and 20821003)the National Basic Research Program of China (973 Program) (Grant No.2011CB302100)
文摘It is necessary to modify the running-in process for the application of ceramics using water as a lubricant in real conditions because ceramics sliding in water are characterized by a running-in period with severe friction and wear.Fullerenol,a kind of highly water-soluble nanoparticle,was synthesized and then used to ameliorate the tribological properties of Si 3 N 4 sliding against Al 2 O 3 in pure water.With the addition of fullerenol,the running-in period was shortened from 30 min to 100 s at a speed of 250 mm/s.The speed threshold above which ultralow friction can be obtained in a short time was expanded from 450 mm/s to 80 mm/s.Meanwhile,the load-carrying ability of water film was increased.The role of fullerenol was discussed based on observation of the wear scar by an optical interferometer and XPS characterization of the tribo-film on the wear track.
基金supported by the National Natural Science Foundation of China(Grant No.51171212)Chongqing Science and Technology Commission(Grant Nos.CSTC2012JJJQ50001,CSTC2013jcyj C60001&cstc2012gg B50003)+2 种基金the National Science and Technology Program of China(Grant No.2013DFA71070)the Fundamental Research Funds for the Central Universities(Grant No.CDJZR13138801)the Fundamental Research Funds for the Yangtze Normal University(Grant No.CJSF2010C025)
文摘The tribological properties of combinative addition of nano-MoS2 and nano-SiO2 to the base oil have been investigated with a reciprocating ball-on-plate tribotester for magnesium alloy-steel contacts. The results demonstrate that the optimum mass ratio of nano-SiO2 to nano-MoS2 is 0.25:0.75. The optimum combinative addition into the base oil reduces the friction coefficient by 43.8% and the surface roughness (Sa) by 31.7% when compared to that found with the base oil. Meanwhile, the combinative addition of nano-MoS2 and nano-SiO〉 in comparison with single nanoparticles addition, is more pronounced in terms of the lubrication film stability. The excellent tribological properties of the SiO2/MoS2 combinations are attributed to the formation of physical adsorption films and tribochemical products during the rubbing process and the micro-cooperation of various nano- particles with different shapes and lubrication mechanisms.
基金supported by the National Basic Research Program of China(Grant No.2013CB632303)the National Natural Science Foundation of China(Grant No.51505341)
文摘Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane trioleate, TMPTO) with 15 kinds of amine additives and its molecular structure. Correlation coefficient of the cross-validation (include internal q2 and external qpred 2 ) and conventional correlation coefficient showed the model to be both stable and good predictive. The electron-donating group and larger steric effects group are adopted at the para-position or meta-position of amido on the benzene ring, and suitably decreasing the branch chain near the para-position, these indicate that the antioxidant performance of amine additives can be enhanced. The results not only can help us understanding the rule of antioxidant performance, but also providing guidance(s) to predict antioxidant performance of existing amine additives and to design or modify new amine additives in lubricating oil.