Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly...Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly from 1.7×10^(-7) to 9.8× 10^(-7) mm^3/mm under the load lower than 300 N, and then increased dramatically to the climax of 216×10^(-7) mm^3/mm under the load over 300 N, which indicated the transition of wear mechanism with the increase of applied load. The wear mechanism mainly was plastic deformation and abrasive wear under the load less than 300 N. As the applied load was more than 300 N, the wear mechanism of Cu-15Ni-8Sn alloy primarily was delamination wear. Besides, the transition can also be confirmed from the different morphologies of worn surface, subsurface and wear debris. It is distinctly indicated that the appearance of flaky debris at the applied load over 300 N may be a critical point for the change of wear mechanism.展开更多
In the present study, the performance of a 4-stroke diesel engine was experimentally evaluated upon adding Al2O3 or SiO2 nanoparticles to the engine oil （SAEISW40）. The viscosity and density of the resulting nanolub...In the present study, the performance of a 4-stroke diesel engine was experimentally evaluated upon adding Al2O3 or SiO2 nanoparticles to the engine oil （SAEISW40）. The viscosity and density of the resulting nanolubricants were determined while varying both the nanoparticle volume fraction and the temperature. Field emission scanning electron microscopy （FE-SEM） showed that the nanoparticles had a spherical morphology and dynamic light scattering analysis determined some aggregation of the nanoparticles in the engine oil. A pin-on-disc test apparatus was used for friction and wear analysis in the presence of the nanolubricants. Examination of wear scars by FE-SEM and energy dispersive spectroscopy found evidence of ball bearing and surface polishing effects, which were responsible for improvements in the tribological properties of the oil. The performance of these nanolubricants in a 4- stroke diesel engine test rig was assessed, and the greatest improvements in the tribological behavior and engine performance were observed when employing 0.3 vol% Al2O3.展开更多
基金Project(2016YFB0301402)supported by the National Key Research and Development Program of ChinaProject(CSU20151024)supported by the Innovation-driven Plan in Central South University,China
文摘Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly from 1.7×10^(-7) to 9.8× 10^(-7) mm^3/mm under the load lower than 300 N, and then increased dramatically to the climax of 216×10^(-7) mm^3/mm under the load over 300 N, which indicated the transition of wear mechanism with the increase of applied load. The wear mechanism mainly was plastic deformation and abrasive wear under the load less than 300 N. As the applied load was more than 300 N, the wear mechanism of Cu-15Ni-8Sn alloy primarily was delamination wear. Besides, the transition can also be confirmed from the different morphologies of worn surface, subsurface and wear debris. It is distinctly indicated that the appearance of flaky debris at the applied load over 300 N may be a critical point for the change of wear mechanism.
文摘In the present study, the performance of a 4-stroke diesel engine was experimentally evaluated upon adding Al2O3 or SiO2 nanoparticles to the engine oil （SAEISW40）. The viscosity and density of the resulting nanolubricants were determined while varying both the nanoparticle volume fraction and the temperature. Field emission scanning electron microscopy （FE-SEM） showed that the nanoparticles had a spherical morphology and dynamic light scattering analysis determined some aggregation of the nanoparticles in the engine oil. A pin-on-disc test apparatus was used for friction and wear analysis in the presence of the nanolubricants. Examination of wear scars by FE-SEM and energy dispersive spectroscopy found evidence of ball bearing and surface polishing effects, which were responsible for improvements in the tribological properties of the oil. The performance of these nanolubricants in a 4- stroke diesel engine test rig was assessed, and the greatest improvements in the tribological behavior and engine performance were observed when employing 0.3 vol% Al2O3.
