Many properties of Mg matrix composites are mutually incompatible,and even completely repel each other.Here,we constructed a magnetic layered component in Mg matrix composite reinforced with reduced graphene oxide(RGO...Many properties of Mg matrix composites are mutually incompatible,and even completely repel each other.Here,we constructed a magnetic layered component in Mg matrix composite reinforced with reduced graphene oxide(RGO)through an in-situ interface reaction strategy,achieving simultaneous improvement in the strength,ductility,and electromagnetic shielding performance of the composite.The magnetic component is generated by the in-situ reaction of Fe_(2)O_(3)nanoparticles encapsulated on RGO with the Mg matrix.The superior strength-ductility synergy originates from layered heterostructure,which actives non-basal dislocations and enables a stable microcrackmultiplication.The heterogeneous layered structure strengthens the multi-level reflection of electromagnetic wave(EMW)inside the composite.The in-situ interfacial reaction introduces abundant of heterogeneous interfaces into the composites,which improves the interfacial polarization loss ability of the composites.The magnetic RGO layer can provide shape anisotropy that breaks the Snoek limit,thus improving the magnetic loss ability of composite in high-frequency electromagnetic fields.The synergistic action of multiple EMW loss mechanisms improves the electromagnetic shielding performance of composite.The current study emphasizes the influence of interface structure on the mechanical and functional properties of composites,and presents a promising approach for the development of structure/functional integrated composites with enhanced properties.展开更多
Press-hardened steel(PHS)with an ultimate tensile strength(UTS)of 1500 MPa has been widely used in automotive body-in-white in the last two decades,due to its ultra-high strength and excellent formability that is achi...Press-hardened steel(PHS)with an ultimate tensile strength(UTS)of 1500 MPa has been widely used in automotive body-in-white in the last two decades,due to its ultra-high strength and excellent formability that is achieved by hot stamping process.However,the application of PHS with UTS exceeding 1500 MPa in automotive industry could be deferred due to the increased risk of hydrogen embrittlement.To reduce this kind of risk,recent research efforts have been focused on various ways to optimize the microstructure of PHS.The present review intends to summarize these efforts,to highlight present solutions to address hydrogen embrittlement,and to shed light on directions for future improvement.The influence of microstructure on the hydrogen embrittlement of PHS has been discussed in terms of both the steel substrate and the surface condition.The substrate part covers the influence of martensite,carbides,inclusions,and retained austenite,while the surface part covers decarburization and oxidation,pre-coating,and trimming.展开更多
This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen...This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.展开更多
基金supported by Yunnan Major Scientific and Technological Projects(grant No 202202AG050004,202202AG050011)the National Natural Science Foundation of China(grant No 52061021)Yunnan Industrial Technology Innovation Talent Project.
文摘Many properties of Mg matrix composites are mutually incompatible,and even completely repel each other.Here,we constructed a magnetic layered component in Mg matrix composite reinforced with reduced graphene oxide(RGO)through an in-situ interface reaction strategy,achieving simultaneous improvement in the strength,ductility,and electromagnetic shielding performance of the composite.The magnetic component is generated by the in-situ reaction of Fe_(2)O_(3)nanoparticles encapsulated on RGO with the Mg matrix.The superior strength-ductility synergy originates from layered heterostructure,which actives non-basal dislocations and enables a stable microcrackmultiplication.The heterogeneous layered structure strengthens the multi-level reflection of electromagnetic wave(EMW)inside the composite.The in-situ interfacial reaction introduces abundant of heterogeneous interfaces into the composites,which improves the interfacial polarization loss ability of the composites.The magnetic RGO layer can provide shape anisotropy that breaks the Snoek limit,thus improving the magnetic loss ability of composite in high-frequency electromagnetic fields.The synergistic action of multiple EMW loss mechanisms improves the electromagnetic shielding performance of composite.The current study emphasizes the influence of interface structure on the mechanical and functional properties of composites,and presents a promising approach for the development of structure/functional integrated composites with enhanced properties.
基金M.X.Huang acknowledges the support from Guangzhou Municipal Science and Technology Project(No.202007020007)Guangdong Basic and Applied Basic Research Foundation of China(No.2020B1515130007).
文摘Press-hardened steel(PHS)with an ultimate tensile strength(UTS)of 1500 MPa has been widely used in automotive body-in-white in the last two decades,due to its ultra-high strength and excellent formability that is achieved by hot stamping process.However,the application of PHS with UTS exceeding 1500 MPa in automotive industry could be deferred due to the increased risk of hydrogen embrittlement.To reduce this kind of risk,recent research efforts have been focused on various ways to optimize the microstructure of PHS.The present review intends to summarize these efforts,to highlight present solutions to address hydrogen embrittlement,and to shed light on directions for future improvement.The influence of microstructure on the hydrogen embrittlement of PHS has been discussed in terms of both the steel substrate and the surface condition.The substrate part covers the influence of martensite,carbides,inclusions,and retained austenite,while the surface part covers decarburization and oxidation,pre-coating,and trimming.
文摘This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.
