Cu/Al multilayers were produced by high-temperature accumulative roll bonding(ARB)methods up to three passes.To achieve a high bonding strength,prior to ARB processing,the Cu and Al sheets were heated to 350,400,450 a...Cu/Al multilayers were produced by high-temperature accumulative roll bonding(ARB)methods up to three passes.To achieve a high bonding strength,prior to ARB processing,the Cu and Al sheets were heated to 350,400,450 and 500 ℃,respectively.The mechanical properties were evaluated by tensile tests.The microstructure was examined by optical microscopy and scanning electron microscopy equipped with energy dispersive spectrometry.The ultimate tensile stress,the grain size and the thickness of diffusion layer of lamellar composites increase with rolling temperature.When the rolling temperature is 400 ℃,the laminates show the highest ductility,but the yield stress is the lowest.As the rolling temperature further increases,both the yield stress and the ultimate tensile stress increase and the ductility decreases slightly.The mechanical properties of lamellar composites processed by low and high temperature ARB are determined by grain size and the thickness of diffusion layer,respectively.展开更多
The Al0.3CoCrFeNi high-entropy alloy(HEA)particles reinforced Cu matrix composites(CMCs)were fabricated by mechanical alloying and sintering.Transition layer structure was obtained by multi-step ball milling to invest...The Al0.3CoCrFeNi high-entropy alloy(HEA)particles reinforced Cu matrix composites(CMCs)were fabricated by mechanical alloying and sintering.Transition layer structure was obtained by multi-step ball milling to investigate the related influence on element diffusion behavior and wear properties of CMCs.The results indicate that a new Cu transition layer is generated,and the thickness is about 5μm.Cr element diffuses into the interface via the transition layer,which forms the complex oxide.Because of the structure of Cu transition layer,the diffusion rates of Ni,Co and Fe increase,especially the Ni element.The wear resistance of CMCs is improved by 30%,which is due to the improvement of interface bonding strength,compared with the CMCs without transition layer.This method is applicable to the development of advanced HEA reinforced metallic matrix composites.展开更多
The microstructure,diffusional and mechanical bonding behavior and microhardness distribution of laminated composites fabricated by ECAP process were investigated.Al?Cu and Cu?Ni laminated composites were produced by ...The microstructure,diffusional and mechanical bonding behavior and microhardness distribution of laminated composites fabricated by ECAP process were investigated.Al?Cu and Cu?Ni laminated composites were produced by ECAP process up to4passes at room temperature and high temperature(300°C).The results of microstructure characterization by SEM and shear strength test revealed that the joints between the layers of4-pass ECAPed samples were considerably stronger than those of1-pass ECAPed samples due to tolerating higher values of plastic deformations during ECAP.Furthermore,shear strength data showed that increasing ECAP temperature caused a notable increase in shear strength of the specimens.The reason lies in the formation of diffusional joint between the interface of both Al/Cu and Cu/Ni layers at high temperature.The shear bonding strength of ECAPed Cu/Ni/Cu composite at high temperature was remarkably higher than that of ECAPed Cu/Al/Cu composite.展开更多
基金Project(51674303) supported by the National Natural Science Foundation of ChinaProject supported by National Youth Thousand Plan of China+2 种基金Project(2018RS3015) supported by Huxiang High-Level Talent Gathering Program of Hunan Province,ChinaProject(2019CX006) supported by Innovation Driven Program of Central South University,ChinaProject supported by the Research Fund of the Key Laboratory of High Performance Complex Manufacturing at Central South University,China
文摘Cu/Al multilayers were produced by high-temperature accumulative roll bonding(ARB)methods up to three passes.To achieve a high bonding strength,prior to ARB processing,the Cu and Al sheets were heated to 350,400,450 and 500 ℃,respectively.The mechanical properties were evaluated by tensile tests.The microstructure was examined by optical microscopy and scanning electron microscopy equipped with energy dispersive spectrometry.The ultimate tensile stress,the grain size and the thickness of diffusion layer of lamellar composites increase with rolling temperature.When the rolling temperature is 400 ℃,the laminates show the highest ductility,but the yield stress is the lowest.As the rolling temperature further increases,both the yield stress and the ultimate tensile stress increase and the ductility decreases slightly.The mechanical properties of lamellar composites processed by low and high temperature ARB are determined by grain size and the thickness of diffusion layer,respectively.
基金Projects(51701061,51705129) supported by the National Natural Science Foundation of ChinaProject(17391001D) supported by the Department of Science and Technology of Hebei Province,ChinaProject(2017-Z02) supported by the State Key Lab of Advanced Metals and Materials,China
文摘The Al0.3CoCrFeNi high-entropy alloy(HEA)particles reinforced Cu matrix composites(CMCs)were fabricated by mechanical alloying and sintering.Transition layer structure was obtained by multi-step ball milling to investigate the related influence on element diffusion behavior and wear properties of CMCs.The results indicate that a new Cu transition layer is generated,and the thickness is about 5μm.Cr element diffuses into the interface via the transition layer,which forms the complex oxide.Because of the structure of Cu transition layer,the diffusion rates of Ni,Co and Fe increase,especially the Ni element.The wear resistance of CMCs is improved by 30%,which is due to the improvement of interface bonding strength,compared with the CMCs without transition layer.This method is applicable to the development of advanced HEA reinforced metallic matrix composites.
文摘The microstructure,diffusional and mechanical bonding behavior and microhardness distribution of laminated composites fabricated by ECAP process were investigated.Al?Cu and Cu?Ni laminated composites were produced by ECAP process up to4passes at room temperature and high temperature(300°C).The results of microstructure characterization by SEM and shear strength test revealed that the joints between the layers of4-pass ECAPed samples were considerably stronger than those of1-pass ECAPed samples due to tolerating higher values of plastic deformations during ECAP.Furthermore,shear strength data showed that increasing ECAP temperature caused a notable increase in shear strength of the specimens.The reason lies in the formation of diffusional joint between the interface of both Al/Cu and Cu/Ni layers at high temperature.The shear bonding strength of ECAPed Cu/Ni/Cu composite at high temperature was remarkably higher than that of ECAPed Cu/Al/Cu composite.
