The(CrNbTiAlV)N_(x)high-entropy nitride films were fabricated by adjusting nitrogen flow via magnetron sputtering.The microstructure,mechanical,electrochemical and tribocorrosion performances of the films were studied...The(CrNbTiAlV)N_(x)high-entropy nitride films were fabricated by adjusting nitrogen flow via magnetron sputtering.The microstructure,mechanical,electrochemical and tribocorrosion performances of the films were studied.The results show that the films transform from amorphous to nanocrystalline structure as nitrogen flow increased.The nanocrystalline films show super hardness(>40 GPa)and adhesion strength(>50 N).The amorphous film has a pretty anti-corrosion in static corrosion,while not in tribocorrosion condition.The film deposited at nitrogen flow of 38 sccm exhibits the optimal tribocorrosion performance in artificial seawater,with the highest open circuit potential(∼−0.1 V vs.Ag/AgCl),the lowest friction coefficient(∼0.162)and wear rate(∼7.48×10^(−7)mm^(3)N^(−1)m^(−1)).展开更多
Superlubricity,a novel lubricity mode ascribing to moirésuperlattice(MSL),has attracted attention in ultra-precise manufacture,microelectronic devices,and national defense areas.Based on incommensurate MSL,nearly...Superlubricity,a novel lubricity mode ascribing to moirésuperlattice(MSL),has attracted attention in ultra-precise manufacture,microelectronic devices,and national defense areas.Based on incommensurate MSL,nearly zero friction can be achieved by eliminating sliding lock-in and offsetting lateral force in principle,and the theoretical foundations are still under extensive investigation.Here,the effects of MSL-induced lattice distortion onπbond and tribological performance in twist MoS_(2)/graphene and MoS_(2)/BN heterointerfaces were studied by first-principles calculations comprehensively.Various contributions of 2pz orbital electron polarization among AA-,AB-,and AC-stacking symmetry areas in different MSL were reflected by band structures to explain the sensitivity ofπbond to MSL.Theπbond perpendicular to the atomic plane depended closely on interfacial distortion,which can not only influence the local distribution of intralayer bond strength but also determine the interlayer charge redistribution.Meanwhile,the interfacial potential energy was changed with the interlayer interaction fluctuation caused by twist angle and atomic stacking modes.Through evaluating the energy barriers and lateral force,MoS_(2)/BN with a twist angle of 20.79°exhibited superlubricity.Moreover,the connection among sliding energy barriers,twist angles,and specific electronic structures has been bridged paving a path to reveal the superlubricity mechanism of two-dimensional materials withπbond.展开更多
基金the financial support of the National Natural Science Foundation of China(Nos.51835012 and 51975554)the National Key R&D Plan of China(No.2018YFB0703803)+1 种基金the program of“Science&Technology International Cooperation Demonstrative Base of Metal Surface Engineering along the Silk Road(No.2017D01003)”CAS“Light of West China”。
文摘The(CrNbTiAlV)N_(x)high-entropy nitride films were fabricated by adjusting nitrogen flow via magnetron sputtering.The microstructure,mechanical,electrochemical and tribocorrosion performances of the films were studied.The results show that the films transform from amorphous to nanocrystalline structure as nitrogen flow increased.The nanocrystalline films show super hardness(>40 GPa)and adhesion strength(>50 N).The amorphous film has a pretty anti-corrosion in static corrosion,while not in tribocorrosion condition.The film deposited at nitrogen flow of 38 sccm exhibits the optimal tribocorrosion performance in artificial seawater,with the highest open circuit potential(∼−0.1 V vs.Ag/AgCl),the lowest friction coefficient(∼0.162)and wear rate(∼7.48×10^(−7)mm^(3)N^(−1)m^(−1)).
基金financially supported by the National Key Re-search and Development Program of China(Nos.2018YFB0703801 and 2018YFB0703802)the Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2021064)。
文摘Superlubricity,a novel lubricity mode ascribing to moirésuperlattice(MSL),has attracted attention in ultra-precise manufacture,microelectronic devices,and national defense areas.Based on incommensurate MSL,nearly zero friction can be achieved by eliminating sliding lock-in and offsetting lateral force in principle,and the theoretical foundations are still under extensive investigation.Here,the effects of MSL-induced lattice distortion onπbond and tribological performance in twist MoS_(2)/graphene and MoS_(2)/BN heterointerfaces were studied by first-principles calculations comprehensively.Various contributions of 2pz orbital electron polarization among AA-,AB-,and AC-stacking symmetry areas in different MSL were reflected by band structures to explain the sensitivity ofπbond to MSL.Theπbond perpendicular to the atomic plane depended closely on interfacial distortion,which can not only influence the local distribution of intralayer bond strength but also determine the interlayer charge redistribution.Meanwhile,the interfacial potential energy was changed with the interlayer interaction fluctuation caused by twist angle and atomic stacking modes.Through evaluating the energy barriers and lateral force,MoS_(2)/BN with a twist angle of 20.79°exhibited superlubricity.Moreover,the connection among sliding energy barriers,twist angles,and specific electronic structures has been bridged paving a path to reveal the superlubricity mechanism of two-dimensional materials withπbond.
