The influence of pre-deformation and heat treatment on mechanicalproperties of as-extruded ZK60 alloy was investigated.The experimentalresults indicated that the solid solution,pre-cold rolling and artificialaging tre...The influence of pre-deformation and heat treatment on mechanicalproperties of as-extruded ZK60 alloy was investigated.The experimentalresults indicated that the solid solution,pre-cold rolling and artificialaging treatments remarkably improved the mechanicalstrength of alloys compared with the asextruded condition.Especially,pre-cold rolling in 5% reduction combined with artificialaging at 150 ℃ for 20 h was determined as the optimum heat treatment condition,which resulted in a yield strength of 333 MPa with an increment of 87 MPa and ultimate tensile strength of 373 MPa.High density of nanoscale precipitates in α-Mg matrix observed in this sample was beneficialto enhancing the strength.The as-extruded sample showed a typicalbrittle fracture while the solution treated sample exhibited ductile-fragile failure characterized by cleavage fractures,river patterns,and tear ridges.And the sample after pre-cold rolling combined with aging presented more equiaxialdimples with a great amount of cracked particles in them.The above-mentioned observations were analyzed in terms of microstructure and possible strengthening mechanism in the extruded ZK60 alloy.展开更多
We perform a scanning tunneling microscopy and spectroscopy study on the electronic structures of √3×√3- silicene on Ag（111）. It is found that the coupling strength of √3×√3-silicene with the Ag-（111...We perform a scanning tunneling microscopy and spectroscopy study on the electronic structures of √3×√3- silicene on Ag（111）. It is found that the coupling strength of √3×√3-silicene with the Ag-（111） substrate is variable in different regions, giving rise to notable effects in experiments. This evidence of decoupling or variable interaction of silicene with the substrate is helpful to in-depth understanding of the structure and clectronic properties of silieene.展开更多
基金Funded by the National Natural Science Foundation of China(No.51571043)the International Science&Technology Cooperation Program of China(No.2014DFG52810)the Fundamental Research Funds for the Central Universities(No.106112015CDJZR135515)
文摘The influence of pre-deformation and heat treatment on mechanicalproperties of as-extruded ZK60 alloy was investigated.The experimentalresults indicated that the solid solution,pre-cold rolling and artificialaging treatments remarkably improved the mechanicalstrength of alloys compared with the asextruded condition.Especially,pre-cold rolling in 5% reduction combined with artificialaging at 150 ℃ for 20 h was determined as the optimum heat treatment condition,which resulted in a yield strength of 333 MPa with an increment of 87 MPa and ultimate tensile strength of 373 MPa.High density of nanoscale precipitates in α-Mg matrix observed in this sample was beneficialto enhancing the strength.The as-extruded sample showed a typicalbrittle fracture while the solution treated sample exhibited ductile-fragile failure characterized by cleavage fractures,river patterns,and tear ridges.And the sample after pre-cold rolling combined with aging presented more equiaxialdimples with a great amount of cracked particles in them.The above-mentioned observations were analyzed in terms of microstructure and possible strengthening mechanism in the extruded ZK60 alloy.
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB921703 and 2013CB921702the National Natural Science Foundation of China under Grant Nos 11334011 and 91121003the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDB07000000
文摘We perform a scanning tunneling microscopy and spectroscopy study on the electronic structures of √3×√3- silicene on Ag（111）. It is found that the coupling strength of √3×√3-silicene with the Ag-（111） substrate is variable in different regions, giving rise to notable effects in experiments. This evidence of decoupling or variable interaction of silicene with the substrate is helpful to in-depth understanding of the structure and clectronic properties of silieene.
