In order to improve the comprehensive properties of the Cu-11.9Al-2.5Mn shape memory alloy(SMA),multilayer graphene(MLG)carried by Cu_(51)Zr_(14)inoculant particles was incorporated and dispersed into this alloy throu...In order to improve the comprehensive properties of the Cu-11.9Al-2.5Mn shape memory alloy(SMA),multilayer graphene(MLG)carried by Cu_(51)Zr_(14)inoculant particles was incorporated and dispersed into this alloy through preparing the preform of the cold-pressed MLG-Cu_(51)Zr_(14)composite powders.In the resultant novel MLG/Cu-Al-Mn composites,MLG in fragmented or flocculent form has a good bonding with the Cu-Al-Mn matrix.MLG can prevent the coarsening of grains of the Cu-Al-Mn SMA and cause thermal mismatch dislocations near the MLG/Cu-Al-Mn interfaces.The damping and mechanical properties of the MLG/Cu-Al-Mn composites are significantly improved.When the content of MLG reaches 0.2 wt.%,the highest room temperature damping of 0.0558,tensile strength of 801.5 MPa,elongation of 10.8%,and hardness of HV 308 can be obtained.On the basis of in-depth observation of microstructures,combined with the theory of internal friction and strengthening and toughening theories of metals,the relevant mechanisms are discussed.展开更多
In order to develop high strength,high damping and low density Al matrix composites,the Al/Zn composite bar samples with Zn mass fraction of 10%-40%were prepared by powder extrusion.The tensile strength and damping pr...In order to develop high strength,high damping and low density Al matrix composites,the Al/Zn composite bar samples with Zn mass fraction of 10%-40%were prepared by powder extrusion.The tensile strength and damping properties of the samples are improved by controlling both the Zn/Al diffusion degree and the precipitation of the interfacial phases.The results show that the tensile strength of the samples with Zn mass fraction of 10%-30%increases with the increases of both the Zn content and annealing temperature.When the Zn mass fraction increases to 40%,the tensile strength of the sample remains basically unchanged or decreases slightly,and the plasticity decreases gradually.Alloying of Al matrix and the formation of Zn/Al interface layer are mainly responsible for improving the strength of the annealed samples.The damping properties increase with the increases of both the Zn content and annealing temperature.The Zn/Al eutectoid lamella eliminates the detrimental effects on damping properties due to both alloying of the Al matrix and reduction of pure Zn in the Al matrix.The Al-30%Zn sample annealed at 350°C for 0.5 h has good comprehensive properties,including the tensile strength of 330 MPa,the elongation to failure of 10%and the room-temperature damping properties(tanθ)of 0.025.展开更多
The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal ten...The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal tensile testing machine and dynamic mechanical analyzer(DMA).The mechanisms for damping capacity of referred alloys were discussed by Granato-Lücke theory.The results show that Y additions remarkably reduce grain size(the average grain size is 21.6,13.0,8.6 and 4.0μm,respectively),and the tensile properties are enhanced with grain refining(the yield tensile strength increases to 292 MPa from 210 MPa and ultimate tensile strength increases to 330 MPa from 315 MPa).For the ZK60-xY(x=0,1.5%,4.0%)alloys,the damping capacity decreases with the increase of Y content.However,for the ZK60-xY(x=2.5%)alloy,the damping capacity improves abnormally,which is possibly related to the formation of Mg3Y2Zn3(W)FCC phase in this alloy.展开更多
基金supported by the Natural Science Foundation of Hebei Province,China(No.E2021202017)the National Natural Science Foundation of China(No.52061038)+3 种基金the Foundation Strengthening Program,China(No.2019-JCJQ-ZD-142-00)the Hebei Province Graduate Innovation Funding Project,China(No.CXZZBS2022032)the Jiangsu Provincial Policy Guidance Program(Special Project for the Introduction of Foreign Talents)Talent Introduction Program,China(No.BX2021024)the Science Plan Foundation of Tianjin Municipal Education Commission,China(No.2021KJ026)。
文摘In order to improve the comprehensive properties of the Cu-11.9Al-2.5Mn shape memory alloy(SMA),multilayer graphene(MLG)carried by Cu_(51)Zr_(14)inoculant particles was incorporated and dispersed into this alloy through preparing the preform of the cold-pressed MLG-Cu_(51)Zr_(14)composite powders.In the resultant novel MLG/Cu-Al-Mn composites,MLG in fragmented or flocculent form has a good bonding with the Cu-Al-Mn matrix.MLG can prevent the coarsening of grains of the Cu-Al-Mn SMA and cause thermal mismatch dislocations near the MLG/Cu-Al-Mn interfaces.The damping and mechanical properties of the MLG/Cu-Al-Mn composites are significantly improved.When the content of MLG reaches 0.2 wt.%,the highest room temperature damping of 0.0558,tensile strength of 801.5 MPa,elongation of 10.8%,and hardness of HV 308 can be obtained.On the basis of in-depth observation of microstructures,combined with the theory of internal friction and strengthening and toughening theories of metals,the relevant mechanisms are discussed.
基金Project(2016YFB0300901)supported by the National Key Research and Development Program of China
文摘In order to develop high strength,high damping and low density Al matrix composites,the Al/Zn composite bar samples with Zn mass fraction of 10%-40%were prepared by powder extrusion.The tensile strength and damping properties of the samples are improved by controlling both the Zn/Al diffusion degree and the precipitation of the interfacial phases.The results show that the tensile strength of the samples with Zn mass fraction of 10%-30%increases with the increases of both the Zn content and annealing temperature.When the Zn mass fraction increases to 40%,the tensile strength of the sample remains basically unchanged or decreases slightly,and the plasticity decreases gradually.Alloying of Al matrix and the formation of Zn/Al interface layer are mainly responsible for improving the strength of the annealed samples.The damping properties increase with the increases of both the Zn content and annealing temperature.The Zn/Al eutectoid lamella eliminates the detrimental effects on damping properties due to both alloying of the Al matrix and reduction of pure Zn in the Al matrix.The Al-30%Zn sample annealed at 350°C for 0.5 h has good comprehensive properties,including the tensile strength of 330 MPa,the elongation to failure of 10%and the room-temperature damping properties(tanθ)of 0.025.
基金Project(10876045)supported by the National Natural Science Foundation Commission of China and China Academy of Engineering PhysicsProject(50725413)supported by the National Natural Science Foundation of China+1 种基金Project(2007CB613704)supported by the National Basic Research Program of ChinaProject(CSTS2008AB4114)supported by Chongqing Science and Technology Commission(CQ CSTC)
文摘The microstructure,mechanical properties and damping capacity of ZK60-xY(x=0,1.5%,2.5%,4.0%,mass fraction) magnesium alloys were investigated by using the optical microscope(OM),X-ray diffractometer(XRD),universal tensile testing machine and dynamic mechanical analyzer(DMA).The mechanisms for damping capacity of referred alloys were discussed by Granato-Lücke theory.The results show that Y additions remarkably reduce grain size(the average grain size is 21.6,13.0,8.6 and 4.0μm,respectively),and the tensile properties are enhanced with grain refining(the yield tensile strength increases to 292 MPa from 210 MPa and ultimate tensile strength increases to 330 MPa from 315 MPa).For the ZK60-xY(x=0,1.5%,4.0%)alloys,the damping capacity decreases with the increase of Y content.However,for the ZK60-xY(x=2.5%)alloy,the damping capacity improves abnormally,which is possibly related to the formation of Mg3Y2Zn3(W)FCC phase in this alloy.
