Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a l...Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a low temperature showed high catalytic activities.When calcined at high temperatures,the catalyst with Ce0.9Cu0.1O1.9 solid solution as precursor remained a high activity,while the catalyst with metal nitrates as precursors exhibited a suppressed reactivity.Therefore,the catalyst prepared with th...展开更多
Ag-Cu alloys are extensively used in sliding electric contacts due to their superior electrical conductivity,but their limited wear resistance reduces component longevity.Surface severe plastic deformation(SSPD)has em...Ag-Cu alloys are extensively used in sliding electric contacts due to their superior electrical conductivity,but their limited wear resistance reduces component longevity.Surface severe plastic deformation(SSPD)has emerged as a promising method to enhance wear resistance and reduce friction of metals without altering the matrix composition.In this study,an Ag-20 wt.%Cu alloy was subjected to SSPD for various durations,with the aim of improving tribological performance.The microstructure,hardness,and current-carrying tribological performance under different currents were systematically investigated,along with an exploration of the underlying mechanisms.The results show that in addition to introducing a high density of dislocations on the surface,SSPD also encourages the formation of(111)texture,and particularly disperses the initially long strips of Curich phase into short strips and fine particles.It promotes a tribo-film composed primarily of a mixture of Cu_(2)O and CuO that forms on the worn surface of the surface-treated sample under the 1 A current,thus significantly reducing the friction coefficient and electrical noise.Under the 10 A current,the sample treated for 60 min possesses the optimal friction coefficient(0.429),wear rate(0.791×10^(−6)mm^(3)/(N m)),and electrical noise(0.240 V).In contrast to the Ag/Cu layered structure observed on the worn subsurface of the untreated sample,a single-phase Ag(Cu)solid solution forms on the worn subsurface of the 60-min treated sample,which improves the current-carrying tribological performance.This work provides valuable insights for the development and application of electrical contact alloys with excellent performance.展开更多
基金supported by the Plan Project of Science and Technology in Zhejiang Province of China (2008C21020)
文摘Ce-Cu-O monolithic catalysts were prepared by using Ce0.9Cu0.1O1.9 solid solution or nitrate as precursors,and their catalytic performance for the combustion of ethyl acetate were studied.The catalysts calcined at a low temperature showed high catalytic activities.When calcined at high temperatures,the catalyst with Ce0.9Cu0.1O1.9 solid solution as precursor remained a high activity,while the catalyst with metal nitrates as precursors exhibited a suppressed reactivity.Therefore,the catalyst prepared with th...
文摘Ag-Cu alloys are extensively used in sliding electric contacts due to their superior electrical conductivity,but their limited wear resistance reduces component longevity.Surface severe plastic deformation(SSPD)has emerged as a promising method to enhance wear resistance and reduce friction of metals without altering the matrix composition.In this study,an Ag-20 wt.%Cu alloy was subjected to SSPD for various durations,with the aim of improving tribological performance.The microstructure,hardness,and current-carrying tribological performance under different currents were systematically investigated,along with an exploration of the underlying mechanisms.The results show that in addition to introducing a high density of dislocations on the surface,SSPD also encourages the formation of(111)texture,and particularly disperses the initially long strips of Curich phase into short strips and fine particles.It promotes a tribo-film composed primarily of a mixture of Cu_(2)O and CuO that forms on the worn surface of the surface-treated sample under the 1 A current,thus significantly reducing the friction coefficient and electrical noise.Under the 10 A current,the sample treated for 60 min possesses the optimal friction coefficient(0.429),wear rate(0.791×10^(−6)mm^(3)/(N m)),and electrical noise(0.240 V).In contrast to the Ag/Cu layered structure observed on the worn subsurface of the untreated sample,a single-phase Ag(Cu)solid solution forms on the worn subsurface of the 60-min treated sample,which improves the current-carrying tribological performance.This work provides valuable insights for the development and application of electrical contact alloys with excellent performance.
