Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal...Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal forming processes,nanoparticles have been used as additives.This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process.The experimental PTCAP tests have been fulfilled under three lubrication conditions and the comparison between the PTCAP processed tubes has been performed in terms of the maximum forming force,surface roughness,and microhardness.The experimental results indicate that adding the mentioned nanoparticles has caused at least a 50% reduction in the maximum deformation load.Moreover,a remarkable decrement in the surface roughness of the formed tubes has been obtained.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
文摘Due to the biological risks of using the conventional lubricants,the vegetable oils have been considered nowadays.Besides,to improve the tribological properties of the vegetable oils in various applications like metal forming processes,nanoparticles have been used as additives.This research evaluated the lubrication performance of the Al2O3 and TiO2 nanoparticles dispersed in rapeseed oil during the parallel tubular channel angular pressing (PTCAP) process.The experimental PTCAP tests have been fulfilled under three lubrication conditions and the comparison between the PTCAP processed tubes has been performed in terms of the maximum forming force,surface roughness,and microhardness.The experimental results indicate that adding the mentioned nanoparticles has caused at least a 50% reduction in the maximum deformation load.Moreover,a remarkable decrement in the surface roughness of the formed tubes has been obtained.
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.
