The AA6061-10 wt.%B4 C mono composite, AA6061-10 wt.%B4 C-Gr(Gr: graphite) hybrid composites containing 2.5, 5, and 7.5 wt.% Gr particles, and AA6061-10 wt.%B4 C-Mo S2 hybrid composites containing 2.5, 5, and 7.5 wt.%...The AA6061-10 wt.%B4 C mono composite, AA6061-10 wt.%B4 C-Gr(Gr: graphite) hybrid composites containing 2.5, 5, and 7.5 wt.% Gr particles, and AA6061-10 wt.%B4 C-Mo S2 hybrid composites containing 2.5, 5, and 7.5 wt.% Mo S2 particles were fabricated through stir casting. The dry sliding tribological behaviors of the mono composite and hybrid composites were studied as a function of temperature on high temperature pin-on-disc tribotester against EN 31 counterface. The wear rate and friction coefficient of the Gr-reinforced and Mo S2-reinforced hybrid composites decreased in the temperature range of 30-100 ℃ due to the combined lubrication offered by the wear protective layer and its solid lubricant phase. Scanning electron microscopy(SEM) observation of the worn pin surface revealed severe adhesion, delamination, and abrasion wear mechanisms at temperatures of 150, 200, and 250 ℃, respectively. At 150 ℃, transmission electron microscopy(TEM) observation of the hybrid composites revealed the formation of deformation bands due to severe plastic deformation and fine crystalline structure due to dynamic recrystallization.展开更多
Seven kinds of used mineral lubricating oils,including hydraulic oils,film bearing oils,steam turbine oil and gear oils,were recycled by reclamation and adding additives.Physical and chemical properties of the recycle...Seven kinds of used mineral lubricating oils,including hydraulic oils,film bearing oils,steam turbine oil and gear oils,were recycled by reclamation and adding additives.Physical and chemical properties of the recycled oils were measured and their lubrication performances were evaluated by the original and modified four-ball testers.Worn surfaces were analyzed by energy dispersive X-ray spectroscopy and Raman microscope.The recycling costs of burning,re-refined and refortified were estimated.Results showed that physical and chemical properties of the refortified oils were improved effectively and became in the industrial access standard.With the different friction materials under different loads,refortified oils provided excellent lubrication performances,much better than those of fresh oils.Because of additives replenished,the different lubrication films could form on the worn surfaces.A rough financial calculation revealed that the refortification process could produce the most economic value among the three methods.展开更多
文摘The AA6061-10 wt.%B4 C mono composite, AA6061-10 wt.%B4 C-Gr(Gr: graphite) hybrid composites containing 2.5, 5, and 7.5 wt.% Gr particles, and AA6061-10 wt.%B4 C-Mo S2 hybrid composites containing 2.5, 5, and 7.5 wt.% Mo S2 particles were fabricated through stir casting. The dry sliding tribological behaviors of the mono composite and hybrid composites were studied as a function of temperature on high temperature pin-on-disc tribotester against EN 31 counterface. The wear rate and friction coefficient of the Gr-reinforced and Mo S2-reinforced hybrid composites decreased in the temperature range of 30-100 ℃ due to the combined lubrication offered by the wear protective layer and its solid lubricant phase. Scanning electron microscopy(SEM) observation of the worn pin surface revealed severe adhesion, delamination, and abrasion wear mechanisms at temperatures of 150, 200, and 250 ℃, respectively. At 150 ℃, transmission electron microscopy(TEM) observation of the hybrid composites revealed the formation of deformation bands due to severe plastic deformation and fine crystalline structure due to dynamic recrystallization.
基金supported by the National Basic Research Program("973" Project)(Grant No.2013CB632303)the Scientific Research Plan of Hubei Education Department(Grant NO.Q20131707)
文摘Seven kinds of used mineral lubricating oils,including hydraulic oils,film bearing oils,steam turbine oil and gear oils,were recycled by reclamation and adding additives.Physical and chemical properties of the recycled oils were measured and their lubrication performances were evaluated by the original and modified four-ball testers.Worn surfaces were analyzed by energy dispersive X-ray spectroscopy and Raman microscope.The recycling costs of burning,re-refined and refortified were estimated.Results showed that physical and chemical properties of the refortified oils were improved effectively and became in the industrial access standard.With the different friction materials under different loads,refortified oils provided excellent lubrication performances,much better than those of fresh oils.Because of additives replenished,the different lubrication films could form on the worn surfaces.A rough financial calculation revealed that the refortification process could produce the most economic value among the three methods.
