Novel water-based nanolubricants using TiO2 nanoparticles(NPs)were synthesised by adding sodium dodecyl benzene sulfonate(SDBS)and glycerol,which exhibited excellent dispersion stability and wettability.The tribologic...Novel water-based nanolubricants using TiO2 nanoparticles(NPs)were synthesised by adding sodium dodecyl benzene sulfonate(SDBS)and glycerol,which exhibited excellent dispersion stability and wettability.The tribological performance of the synthesised nanolubricants was investigated using an Rtec ball-on-disk tribometer,and their application in hot steel rolling was evaluated on a 2-high Hille 100 experimental rolling mill,in comparison to those without SDBS.The water-based nanolubricant containing 4 wt%TiO2 and 0.4 wt%SDBS demonstrated superior tribological performance by decreasing coefficient of friction and ball wear up to 70.5%and 84.3%,respectively,compared to those of pure water.In addition to the lubrication effect,the suspensions also had significant effect on polishing of the work roll surface.The resultant surface improvement thus enabled the decrease in rolling force up to 8.3%under a workpiece reduction of 30%at a rolling temperature of 850◦C.The lubrication mechanisms were primarily ascribed to the formation of lubricating film and ball-bearing effect of the TiO2 NPs.展开更多
The investigation of local thermal transport rate in the nanolubricants is significant.These lubricants are broadly used in environmental pollution,mechanical engineering and in the paint industry due to high thermal ...The investigation of local thermal transport rate in the nanolubricants is significant.These lubricants are broadly used in environmental pollution,mechanical engineering and in the paint industry due to high thermal performance rate.Therefore,thermal transport in ZnO-SAE50 nanolubricant under the impacts of heat generation/absorption is conducted.The colloidal suspension is flowing between parallel stretching disks in which the lower disk is positioned at z=0 and upper disk apart from distance d.The problem is transformed in dimensionless version via described similarity transforms.In the next stage,an analytical technique(VPM)is implemented for the solution purpose.The graphical results against multiple flow parameters were furnished over the region of interest and explained comprehensively.It is imperative to mention that the results are plotted for ZnO-SAE50 and conventional liquid as well.Further,rapid motion of the fluid is perceived against high Reynolds andγparameters.The wall shear stresses at the upper end rises for multiple Reynolds andγwhile;decrement is detected at the lower end.The significant contribution of an internal heat source is noted for thermal performance rate at the upper end.Foremost,the local heat transport rate declines at the lower disk.By altering Reynolds number,prompt heat transfer rate is gained at the upper disk and increasing behavior of the local heat transport rate is slow at the lower disk.From the study,it is concluded that the nanolubricants have high thermal characteristics.Therefore,such fluids are reliable to use in above stated areas.展开更多
This study presents a comprehensive investigation into the synthesis,dispersion behavior,and performance evaluation of surfactant-free copper oxide(CuO)nanoballs(NBs)dispersed in polyalphaolefin(PAO)oil.CuO NBs were s...This study presents a comprehensive investigation into the synthesis,dispersion behavior,and performance evaluation of surfactant-free copper oxide(CuO)nanoballs(NBs)dispersed in polyalphaolefin(PAO)oil.CuO NBs were synthesized via a modified precipitation technique and characterized via X-ray diffraction(XRD),Raman spectroscopy,Fourier transform infrared(FTIR)spectroscopy,scanning electron microscopy(SEM),and transmission electron microscopy(TEM),confirming their monoclinic crystal structure and spherical morphology with particle sizes ranging from 25 to 132 nm.The dispersion quality and long-term stability of the nanolubricants were assessed via UV-Vis spectroscopy and zeta potential analysis,which indicated that 0.01 wt%CuO achieved the highest stability(zeta potential:154.3 mV)and minimal sedimentation for up to 10 days.Rheological measurements revealed Newtonian behavior across all concentrations,with the highest relative viscosity observed at 0.05 wt%and 100°C.The viscosity index improved at lower concentrations,supporting the lubricant’s thermal adaptability under dynamic shear conditions.The thermal conductivity increased with CuO addition,peaking at 0.01 wt%,primarily due to enhanced Brownian motion and reduced nanoparticle agglomeration.Tribological performance,evaluated using a reciprocating tribometer under a 10 N load and 840 m stroke length,revealed that 0.01 wt%CuO achieved a 37%reduction in the coefficient of friction(COF 0.055)and the lowest specific wear rate among all the tested samples.Surface analysis via three-dimensional(3D)profilometry and SEM-energy dispersive X-ray spectroscopy(EDS)revealed smoother contact surfaces and no evidence of CuO deposition,suggesting that a rolling friction mechanism was the dominant lubrication mode.These findings confirm that surfactant-free CuO NBs significantly enhance the tribological,rheological,and thermal properties of PAO oil,offering a cost-effective and environmentally friendly solution for highperformance industrial lubrication systems.展开更多
Owing to the significance of improving fuel economy, reducing emissions, and extending the durability of engine components, this study focused on the tribological performance of nano-additives. In this study, copper (...Owing to the significance of improving fuel economy, reducing emissions, and extending the durability of engine components, this study focused on the tribological performance of nano-additives. In this study, copper (Cu) and graphene (Gr) nanomaterials were dispersed in a fully formulated engine oil (5W-30) with different concentrations. The tribological trials were investigated under various speeds and loads, utilizing a reciprocating tribometer to mimic the ring/liner interfaces in the engine. The frictional surface morphologies were com-prehensively analyzed using electron probe X-ray microanalysis (EPMA), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS), and three dimensional (3D) surface profilometry to explore the mechanisms responsible for improving the tribological performance of the frictional sliding parts in the engine. The tribological test results illustrated that lubrication by nano-additives reduced the wear rate (WR) and friction coefficient (COF) by 25%–30% and 26.5%–32.6%, respectively, as compared with 5W-30. The results showed that this is a promising approach for increasing the durability and lifespan of frictional sliding components and fuel economy in automobile engines.展开更多
Using nanoadditives in lubricants is one of the most effective ways to control friction and wear,which is of great significance for energy conservation,emission reduction,and environmental protection.With the scientif...Using nanoadditives in lubricants is one of the most effective ways to control friction and wear,which is of great significance for energy conservation,emission reduction,and environmental protection.With the scientific and technological development,great advances have been made in nanolubricant additives in the scientific research and industrial applications.This review summarizes the categories of nanolubricant additives and illustrates the tribological properties of these additives.Based on the component elements of nanomaterials,nanolubricant additives can be divided into three types:nanometal-based,nanocarbon-based,and nanocomposite-based additives.The dispersion stabilities of additives in lubricants are also discussed in the review systematically.Various affecting factors and effective dispersion methods have been investigated in detail.Moreover,the review summarizes the lubrication mechanisms of nanolubricant additives including tribofilm formation,micro-bearing effect,self-repair performance,and synergistic effect.In addition,the challenges and prospects of nanolubricant additives are proposed,which guides the design and synthesis of novel additives with significant lubrication and antiwear properties in the future.展开更多
Lubricants for compressor oil significantly enhance the energy efficiency and performance of heat pump(HP)systems.This study compares prognostic machine learning(ML)models designed to predict the thermal conduc-tivity...Lubricants for compressor oil significantly enhance the energy efficiency and performance of heat pump(HP)systems.This study compares prognostic machine learning(ML)models designed to predict the thermal conduc-tivity and viscosity of nanolubricants used in HP compressors.Nanodiamond(ND)nanoparticles were mixed in Polyolester(POE)oil at volume concentrations ranging from 0.05 to 0.5 vol.%and temperatures ranging from 10 to 100◦C.The data collected from the experimental research were used to build prognostic models using modern supervised ML techniques,including Gaussian process regression(GPR)and boosted regression tree(BRT).The GPR model demonstrated superior performance compared to the BRT model,achieving coefficient of correlation(R)values of 0.9996 and 0.9991 for thermal conductivity and viscosity,respectively.The reliability of the GPR and BRT models was further validated through comprehensive validation,sensitivity analysis,and extrapolation assessment using both empirical and unseen dataset references from the literature.When validated against an empirical correlation,the ML models exhibited a mean absolute error(MAE)of 0.17%for thermal conductivity and below 8%for viscosity.Additionally,when the GPR-based model was extended up to 120℃,the parametric analysis confirmed the reliability and accuracy of thermal conductivity and viscosity within a relative error of 5%.Furthermore,in the extrapolation analysis,despite changes in oil grade and nanolubricant concentrations,the GPR-based model showed a maximum absolute error(AE)of 19%compared to non-trained experimental data.Overall,the developed ML models can aid in designing and optimizing ND/POE nanolubricants for HP applications,achieving desired performance parameters while remaining economically viable and reducing the need for time-consuming laboratory-based testing.展开更多
During the metal cutting process,especially in continuous contact conditions like turning,the challenge of lubricants failing to effectively reach the cutting point remains unresolved.Micro-textured cutting tools offe...During the metal cutting process,especially in continuous contact conditions like turning,the challenge of lubricants failing to effectively reach the cutting point remains unresolved.Micro-textured cutting tools offer a potential solution for tool-chip contact challenges.Inspired by the evolutionary achievements of the biosphere,micro-textures are expected to overcome lubrication limitations in cutting zones.Drawing on the anti-gravity water transport seen at the mouth edge of the Nepenthes plant,an innovative microchannel with Nepenthes-shaped contours was designed on the rake face to enable controlled lubricant transport.However,the dynamics of lubricant delivery on textured surfaces are not fully understood.This study first analyzed the microstructure and water transport mechanism of Nepenthes to reconstruct a micro-textured surface for controlled lubricant transport.A dynamic model was then developed to describe lubricant transport within open microchannels,with mathematical simulations predicting transport speed and flow distance.To validate this model,diffusion experiments of alumina soybean oil nanolubricant on polycrystalline diamond(PCD)cutting tool surfaces were conducted,showing an average prediction deviation of 5.01%.Compared with the classical Lucas-Washburn model,the new model improved prediction accuracy by 4.72%.Additionally,comparisons were made to examine droplet spreading and non-uniform diffusion on textured surfaces,revealing that the T2 surface exhibited the strongest unidirectional diffusion characteristics.The contact angle ratio,droplet unidirectional spreading ratio,and droplet spreading aspect ratio were 0.48,1.75,and 3.99,respectively.Finally,the anti-wear,friction-reducing,and efficiency-enhancing mechanisms of micro-textured surfaces in minimum quantity lubrication turning were analyzed.This approach may support continuous cutting of difficult-tomachine materials.展开更多
Nanolubricant mixing the normal lubricant with nanoparticles, gradually becomes a new trend study for metal cutting enhancement. An addition of the nanoparticles improves lubricating properties and convective heat tra...Nanolubricant mixing the normal lubricant with nanoparticles, gradually becomes a new trend study for metal cutting enhancement. An addition of the nanoparticles improves lubricating properties and convective heat transfer coefficient (cooling properties) of nanolubricants. In the present work, nanolubricant is formulated by using dispersions of 0.3% Al2O3 nanoparticles in normal industrial oil VG46 for enhancement of gear machining performance of SCM420 steel. Comparative study of flank wear, crater wear and gear profile error in gear hobbing with normal oils in the existing production line as well as nanolubricant is studied. This study clearly reveals that tool wear, and gear profile error are reduced by the use of nanolubricant compared to that of normal oils. The paper results not only contribute the deeper understanding of the novel performance of nanoparticles in conventional cutting fluids, but also show a very promising solution to achieve the engineering economy effectiveness in gear machining.展开更多
Machining-induced damages encountered during the grinding of titanium alloys are a major setback for processing different components from these materials. Recent studies have shown that nanofluid (NF)-based minimum qu...Machining-induced damages encountered during the grinding of titanium alloys are a major setback for processing different components from these materials. Recent studies have shown that nanofluid (NF)-based minimum quantity lubrication (MQL) systems improved the machining lubrication and the titanium alloys’ machinability. In this work, the tribological characteristics of a palm oil-based tripartite hybrid NF (ZnO/Al_(2)O_(3)/Graphene Oxide, GO) are studied. The novel usage of the developed lubricants in MQL systems was examined during the grinding of Ti6-Al-4V (TC4) alloy. The NF was produced by mixing three weight percent mixtures (i.e., 0.1, 0.5, and 1 wt.%) of the nanoparticles in palm oil. A comprehensive tribological and physical investigation was conducted on different percentage compositions of the developed NF to determine the optimum mix ratio of the lubricant. The findings indicate that increasing the NF concentration caused an increment in the dynamic viscosity and frictional coefficient of the NFs. The tripartite hybrid NF exhibited superior tribological and physicochemical properties compared with the pure palm and monotype-based NFs. Moreover, the dynamic viscosity of the tripartite-hybrid-based NFs increased by 12%, 5%, and 11.5% for the Al_(2)O_(3), GO, and ZnO hybrid NFs, respectively. In addition, the machining results indicate that the tripartite hybrid NF lowered the surface roughness, specific grinding, grinding force ratio, tangential, and normal grinding forces by 42%, 40%, 16.5%, 41.5%, and 30%, respectively. Hence, the tripartite hybrid NFs remarkably enhanced the tribology and machining performance of the eco-friendly lubricant.展开更多
This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nano...This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nanocomposities, and rare-earth compounds are generalized. The influence of nanoparticle size, morphology, surface functionalization, and concentration on friction and wear is analyzed. The lubrication mechanisms of nanolubricants are discussed. The problems and prospects for the development of metal-containing nanomaterials as lubricant additives are considered. The bibliography includes articles published during the last five years.展开更多
A hybrid lubricant with improved thermal and tribological properties was developed by blending multiwalled carbon nanotubes(MWCNTs) with alumina-based nanoparticles into cutting fluid at fixed volumetric proportions(1...A hybrid lubricant with improved thermal and tribological properties was developed by blending multiwalled carbon nanotubes(MWCNTs) with alumina-based nanoparticles into cutting fluid at fixed volumetric proportions(10:90). The hybrid cutting fluid was prepared in different volumetric concentrations(0.25, 0.75, and 1.25 vol%), and the tribological properties and contact angles were measured using pin-on-disc tribometry and goniometry, respectively. The study showed a reduction in wear and friction coefficient with increasing nanoparticle concentration. The cutting fluid performance was investigated using minimum quantity lubrication(MQL) in the turning of AISI 304 stainless steel. Regression models were developed for measuring the temperature and tool flank wear in terms of cutting speed, feed, depth of the cut, and nanoparticle concentration using response surface methodology. The developed hybrid nanolubricants significantly reduced the tool flank wear and nodal temperature by 11% and 27.36%, respectively, as compared to alumina-based lubricants.展开更多
Due to their encouraging results,nanolubricants have been revolutionary in the field of lubrication.The degree,to which the new material may improve the tribology,energy savings,and durability,is a crucial considerati...Due to their encouraging results,nanolubricants have been revolutionary in the field of lubrication.The degree,to which the new material may improve the tribology,energy savings,and durability,is a crucial consideration for any new additive to a conventional lubricant.The results of the earlier research on carbon,metal,metal oxide,and their composites and hybrid nanolubricants as well as their effects on tribology,are summarized in this review paper.The most popular measuring methodologies,the tribology results for lubricants with an oil base,biodegradable base,and a water base,as well as the reasons that explain these tribological advancements,are all included in this study.Finally,prospects for more study in this area are emphasized.展开更多
基金The authors acknowledge the financial supports from Baosteel-Australia Joint Research&Development Center(BAJC)under the project of BA17004 and Australian Research Council(ARC)under Linkage Project Program(LP150100591)。
文摘Novel water-based nanolubricants using TiO2 nanoparticles(NPs)were synthesised by adding sodium dodecyl benzene sulfonate(SDBS)and glycerol,which exhibited excellent dispersion stability and wettability.The tribological performance of the synthesised nanolubricants was investigated using an Rtec ball-on-disk tribometer,and their application in hot steel rolling was evaluated on a 2-high Hille 100 experimental rolling mill,in comparison to those without SDBS.The water-based nanolubricant containing 4 wt%TiO2 and 0.4 wt%SDBS demonstrated superior tribological performance by decreasing coefficient of friction and ball wear up to 70.5%and 84.3%,respectively,compared to those of pure water.In addition to the lubrication effect,the suspensions also had significant effect on polishing of the work roll surface.The resultant surface improvement thus enabled the decrease in rolling force up to 8.3%under a workpiece reduction of 30%at a rolling temperature of 850◦C.The lubrication mechanisms were primarily ascribed to the formation of lubricating film and ball-bearing effect of the TiO2 NPs.
基金Researchers supporting Project number(RSP-2020/33),King Saud University,Riyadh,Saudi Arabia。
文摘The investigation of local thermal transport rate in the nanolubricants is significant.These lubricants are broadly used in environmental pollution,mechanical engineering and in the paint industry due to high thermal performance rate.Therefore,thermal transport in ZnO-SAE50 nanolubricant under the impacts of heat generation/absorption is conducted.The colloidal suspension is flowing between parallel stretching disks in which the lower disk is positioned at z=0 and upper disk apart from distance d.The problem is transformed in dimensionless version via described similarity transforms.In the next stage,an analytical technique(VPM)is implemented for the solution purpose.The graphical results against multiple flow parameters were furnished over the region of interest and explained comprehensively.It is imperative to mention that the results are plotted for ZnO-SAE50 and conventional liquid as well.Further,rapid motion of the fluid is perceived against high Reynolds andγparameters.The wall shear stresses at the upper end rises for multiple Reynolds andγwhile;decrement is detected at the lower end.The significant contribution of an internal heat source is noted for thermal performance rate at the upper end.Foremost,the local heat transport rate declines at the lower disk.By altering Reynolds number,prompt heat transfer rate is gained at the upper disk and increasing behavior of the local heat transport rate is slow at the lower disk.From the study,it is concluded that the nanolubricants have high thermal characteristics.Therefore,such fluids are reliable to use in above stated areas.
文摘This study presents a comprehensive investigation into the synthesis,dispersion behavior,and performance evaluation of surfactant-free copper oxide(CuO)nanoballs(NBs)dispersed in polyalphaolefin(PAO)oil.CuO NBs were synthesized via a modified precipitation technique and characterized via X-ray diffraction(XRD),Raman spectroscopy,Fourier transform infrared(FTIR)spectroscopy,scanning electron microscopy(SEM),and transmission electron microscopy(TEM),confirming their monoclinic crystal structure and spherical morphology with particle sizes ranging from 25 to 132 nm.The dispersion quality and long-term stability of the nanolubricants were assessed via UV-Vis spectroscopy and zeta potential analysis,which indicated that 0.01 wt%CuO achieved the highest stability(zeta potential:154.3 mV)and minimal sedimentation for up to 10 days.Rheological measurements revealed Newtonian behavior across all concentrations,with the highest relative viscosity observed at 0.05 wt%and 100°C.The viscosity index improved at lower concentrations,supporting the lubricant’s thermal adaptability under dynamic shear conditions.The thermal conductivity increased with CuO addition,peaking at 0.01 wt%,primarily due to enhanced Brownian motion and reduced nanoparticle agglomeration.Tribological performance,evaluated using a reciprocating tribometer under a 10 N load and 840 m stroke length,revealed that 0.01 wt%CuO achieved a 37%reduction in the coefficient of friction(COF 0.055)and the lowest specific wear rate among all the tested samples.Surface analysis via three-dimensional(3D)profilometry and SEM-energy dispersive X-ray spectroscopy(EDS)revealed smoother contact surfaces and no evidence of CuO deposition,suggesting that a rolling friction mechanism was the dominant lubrication mode.These findings confirm that surfactant-free CuO NBs significantly enhance the tribological,rheological,and thermal properties of PAO oil,offering a cost-effective and environmentally friendly solution for highperformance industrial lubrication systems.
基金The authors would like to express their deep appreciations for the support by the National Natural Science Foundation of China (No. 51875423)the support from Hubei Key Laboratory of Advanced Technology for Automotive Components (Wuhan University of Technology)Mohamed Kamal Ahmed ALI acknowledges the financial support from Minia University during his post-doctoral study.
文摘Owing to the significance of improving fuel economy, reducing emissions, and extending the durability of engine components, this study focused on the tribological performance of nano-additives. In this study, copper (Cu) and graphene (Gr) nanomaterials were dispersed in a fully formulated engine oil (5W-30) with different concentrations. The tribological trials were investigated under various speeds and loads, utilizing a reciprocating tribometer to mimic the ring/liner interfaces in the engine. The frictional surface morphologies were com-prehensively analyzed using electron probe X-ray microanalysis (EPMA), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS), and three dimensional (3D) surface profilometry to explore the mechanisms responsible for improving the tribological performance of the frictional sliding parts in the engine. The tribological test results illustrated that lubrication by nano-additives reduced the wear rate (WR) and friction coefficient (COF) by 25%–30% and 26.5%–32.6%, respectively, as compared with 5W-30. The results showed that this is a promising approach for increasing the durability and lifespan of frictional sliding components and fuel economy in automobile engines.
基金This work is supported by the National Natural Science Foundation of China(51905027)National Key R&D Program of China(2018YFB2000801)+3 种基金Fundamental Research Funds for the Central Universities(BUCTRC201908)Tribology Science Fund of State Key Laboratory of Tribology(SKLTKF18A02)Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning(2016-01098)Swedish Research Council(2019-04941)。
文摘Using nanoadditives in lubricants is one of the most effective ways to control friction and wear,which is of great significance for energy conservation,emission reduction,and environmental protection.With the scientific and technological development,great advances have been made in nanolubricant additives in the scientific research and industrial applications.This review summarizes the categories of nanolubricant additives and illustrates the tribological properties of these additives.Based on the component elements of nanomaterials,nanolubricant additives can be divided into three types:nanometal-based,nanocarbon-based,and nanocomposite-based additives.The dispersion stabilities of additives in lubricants are also discussed in the review systematically.Various affecting factors and effective dispersion methods have been investigated in detail.Moreover,the review summarizes the lubrication mechanisms of nanolubricant additives including tribofilm formation,micro-bearing effect,self-repair performance,and synergistic effect.In addition,the challenges and prospects of nanolubricant additives are proposed,which guides the design and synthesis of novel additives with significant lubrication and antiwear properties in the future.
文摘Lubricants for compressor oil significantly enhance the energy efficiency and performance of heat pump(HP)systems.This study compares prognostic machine learning(ML)models designed to predict the thermal conduc-tivity and viscosity of nanolubricants used in HP compressors.Nanodiamond(ND)nanoparticles were mixed in Polyolester(POE)oil at volume concentrations ranging from 0.05 to 0.5 vol.%and temperatures ranging from 10 to 100◦C.The data collected from the experimental research were used to build prognostic models using modern supervised ML techniques,including Gaussian process regression(GPR)and boosted regression tree(BRT).The GPR model demonstrated superior performance compared to the BRT model,achieving coefficient of correlation(R)values of 0.9996 and 0.9991 for thermal conductivity and viscosity,respectively.The reliability of the GPR and BRT models was further validated through comprehensive validation,sensitivity analysis,and extrapolation assessment using both empirical and unseen dataset references from the literature.When validated against an empirical correlation,the ML models exhibited a mean absolute error(MAE)of 0.17%for thermal conductivity and below 8%for viscosity.Additionally,when the GPR-based model was extended up to 120℃,the parametric analysis confirmed the reliability and accuracy of thermal conductivity and viscosity within a relative error of 5%.Furthermore,in the extrapolation analysis,despite changes in oil grade and nanolubricant concentrations,the GPR-based model showed a maximum absolute error(AE)of 19%compared to non-trained experimental data.Overall,the developed ML models can aid in designing and optimizing ND/POE nanolubricants for HP applications,achieving desired performance parameters while remaining economically viable and reducing the need for time-consuming laboratory-based testing.
基金Supported by National Natural Science Foundation of China(Grant Nos.52375447,52305477 and 52105457)Shandong Provincial Natural Science Foundation(Grant Nos.ZR2023QE057,ZR2024QE100 and ZR2024ME255)+2 种基金Qingdao Municipal Science and Technology Planning Park Cultivation Plan(Grant No.23-1-5-yqpy-17-qy)the Science and Technology SMEs Innovation Capacity Improvement Project of Shandong Province(Grant No.2022TSGC1115)the Special Fund of Taishan Scholars Project。
文摘During the metal cutting process,especially in continuous contact conditions like turning,the challenge of lubricants failing to effectively reach the cutting point remains unresolved.Micro-textured cutting tools offer a potential solution for tool-chip contact challenges.Inspired by the evolutionary achievements of the biosphere,micro-textures are expected to overcome lubrication limitations in cutting zones.Drawing on the anti-gravity water transport seen at the mouth edge of the Nepenthes plant,an innovative microchannel with Nepenthes-shaped contours was designed on the rake face to enable controlled lubricant transport.However,the dynamics of lubricant delivery on textured surfaces are not fully understood.This study first analyzed the microstructure and water transport mechanism of Nepenthes to reconstruct a micro-textured surface for controlled lubricant transport.A dynamic model was then developed to describe lubricant transport within open microchannels,with mathematical simulations predicting transport speed and flow distance.To validate this model,diffusion experiments of alumina soybean oil nanolubricant on polycrystalline diamond(PCD)cutting tool surfaces were conducted,showing an average prediction deviation of 5.01%.Compared with the classical Lucas-Washburn model,the new model improved prediction accuracy by 4.72%.Additionally,comparisons were made to examine droplet spreading and non-uniform diffusion on textured surfaces,revealing that the T2 surface exhibited the strongest unidirectional diffusion characteristics.The contact angle ratio,droplet unidirectional spreading ratio,and droplet spreading aspect ratio were 0.48,1.75,and 3.99,respectively.Finally,the anti-wear,friction-reducing,and efficiency-enhancing mechanisms of micro-textured surfaces in minimum quantity lubrication turning were analyzed.This approach may support continuous cutting of difficult-tomachine materials.
文摘Nanolubricant mixing the normal lubricant with nanoparticles, gradually becomes a new trend study for metal cutting enhancement. An addition of the nanoparticles improves lubricating properties and convective heat transfer coefficient (cooling properties) of nanolubricants. In the present work, nanolubricant is formulated by using dispersions of 0.3% Al2O3 nanoparticles in normal industrial oil VG46 for enhancement of gear machining performance of SCM420 steel. Comparative study of flank wear, crater wear and gear profile error in gear hobbing with normal oils in the existing production line as well as nanolubricant is studied. This study clearly reveals that tool wear, and gear profile error are reduced by the use of nanolubricant compared to that of normal oils. The paper results not only contribute the deeper understanding of the novel performance of nanoparticles in conventional cutting fluids, but also show a very promising solution to achieve the engineering economy effectiveness in gear machining.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52305477,52375447,52305474,and 52205481)the Major Special Projects of Aero-engine and Gas Turbine,China(Grant No.2017-VII-0002-0095)+5 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20210407)the Special Fund of Taishan Scholars Project,China(Grant No.tsqn202211179)the Youth Talent Promotion Project in Shandong,China(Grant No.SDAST2021qt12)Qingdao Postdoctoral Researchers Applied Research Project,China(Grant No.QDBSH20230102050)the Support plan for Outstanding Youth Innovation Team in Universities of Shandong Province,China(Grant No.2023KJ114)Qingdao Science and Technology Planning Park Cultivation Plan(Grant No.23-1-5-yqpy-17-qy).
文摘Machining-induced damages encountered during the grinding of titanium alloys are a major setback for processing different components from these materials. Recent studies have shown that nanofluid (NF)-based minimum quantity lubrication (MQL) systems improved the machining lubrication and the titanium alloys’ machinability. In this work, the tribological characteristics of a palm oil-based tripartite hybrid NF (ZnO/Al_(2)O_(3)/Graphene Oxide, GO) are studied. The novel usage of the developed lubricants in MQL systems was examined during the grinding of Ti6-Al-4V (TC4) alloy. The NF was produced by mixing three weight percent mixtures (i.e., 0.1, 0.5, and 1 wt.%) of the nanoparticles in palm oil. A comprehensive tribological and physical investigation was conducted on different percentage compositions of the developed NF to determine the optimum mix ratio of the lubricant. The findings indicate that increasing the NF concentration caused an increment in the dynamic viscosity and frictional coefficient of the NFs. The tripartite hybrid NF exhibited superior tribological and physicochemical properties compared with the pure palm and monotype-based NFs. Moreover, the dynamic viscosity of the tripartite-hybrid-based NFs increased by 12%, 5%, and 11.5% for the Al_(2)O_(3), GO, and ZnO hybrid NFs, respectively. In addition, the machining results indicate that the tripartite hybrid NF lowered the surface roughness, specific grinding, grinding force ratio, tangential, and normal grinding forces by 42%, 40%, 16.5%, 41.5%, and 30%, respectively. Hence, the tripartite hybrid NFs remarkably enhanced the tribology and machining performance of the eco-friendly lubricant.
文摘This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nanocomposities, and rare-earth compounds are generalized. The influence of nanoparticle size, morphology, surface functionalization, and concentration on friction and wear is analyzed. The lubrication mechanisms of nanolubricants are discussed. The problems and prospects for the development of metal-containing nanomaterials as lubricant additives are considered. The bibliography includes articles published during the last five years.
文摘A hybrid lubricant with improved thermal and tribological properties was developed by blending multiwalled carbon nanotubes(MWCNTs) with alumina-based nanoparticles into cutting fluid at fixed volumetric proportions(10:90). The hybrid cutting fluid was prepared in different volumetric concentrations(0.25, 0.75, and 1.25 vol%), and the tribological properties and contact angles were measured using pin-on-disc tribometry and goniometry, respectively. The study showed a reduction in wear and friction coefficient with increasing nanoparticle concentration. The cutting fluid performance was investigated using minimum quantity lubrication(MQL) in the turning of AISI 304 stainless steel. Regression models were developed for measuring the temperature and tool flank wear in terms of cutting speed, feed, depth of the cut, and nanoparticle concentration using response surface methodology. The developed hybrid nanolubricants significantly reduced the tool flank wear and nodal temperature by 11% and 27.36%, respectively, as compared to alumina-based lubricants.
基金Special thanks to Universiti Sains Malaysia for the financial assistance through Bridging GRA Grant(304/PAERO/631520).
文摘Due to their encouraging results,nanolubricants have been revolutionary in the field of lubrication.The degree,to which the new material may improve the tribology,energy savings,and durability,is a crucial consideration for any new additive to a conventional lubricant.The results of the earlier research on carbon,metal,metal oxide,and their composites and hybrid nanolubricants as well as their effects on tribology,are summarized in this review paper.The most popular measuring methodologies,the tribology results for lubricants with an oil base,biodegradable base,and a water base,as well as the reasons that explain these tribological advancements,are all included in this study.Finally,prospects for more study in this area are emphasized.
