The deformation behaviors of as-sintered CNT/Al-Cu composites were investigated by isothermal compression tests performed in the temperature range of 300-550°C and strain rate range of 0.001-10 s-1 with Gleeble 3...The deformation behaviors of as-sintered CNT/Al-Cu composites were investigated by isothermal compression tests performed in the temperature range of 300-550°C and strain rate range of 0.001-10 s-1 with Gleeble 3500 thermal simulator system.Processing maps based on dynamic material model(DMM)were established at strains of 0.1-0.6,and microstructures before and after hot deformation were characterized by scanning electron microscopy(SEM),electron backscatter diffraction(EBSD)and high-resolution transmission electron microscopy(HRTEM).The results show that the strain has a significant influence on the processing maps,and the optimum processing domains are at temperatures of 375-425°C with strain rates of 0.4-10 s-1 and at 525-550°C with 0.02-10 s-1 when the strain is 0.6.An inhomogeneous distribution of large particles,as well as a high density of tangled dislocations,dislocation walls,and some sub-grains appears at low deformation temperatures and strain rates,which correspond to the instability domain.A homogeneous distribution of fine particles and dynamic recrystallization generates when the composites are deformed at 400 and 550°C under a strain rate of 10 s-1,which correspond to the stability domains.展开更多
Deformation behaviors of CNTs/Al alloy composite fabricated by the method of flake powder metallurgy were investigated by hot compression tests, which were performed in the temperature range of 300?550 °C and str...Deformation behaviors of CNTs/Al alloy composite fabricated by the method of flake powder metallurgy were investigated by hot compression tests, which were performed in the temperature range of 300?550 °C and strain rate range of 0.001? 10 s?1 with Gleeble?3500 thermal simulator system. Processing maps of the CNTs/Al alloy at different strains were calculated to study the optimum processing domain. Microstructures before and after hot compressions were characterized by electron backscattered diffraction (EBSD) method. Stress?strain curves indicate that the flow stress increases with the increase of strain rate and the decrease of temperature. The processing maps of the CNTs/Al alloy at different strains show that the optimum processing domain is 500?550 °C, 10 s?1 for hot working. EBSD analysis demonstrates that fully dynamic recrystallization occurs in the optimum processing domain (high strainrate 10 s?1), whereas the main soften mechanism is dynamic recovery at low strain rate (0.001 s?1).展开更多
This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum （CNT/A1） composites. Much research work has been conducted to reveal the evolution of CNT/A1 interfa...This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum （CNT/A1） composites. Much research work has been conducted to reveal the evolution of CNT/A1 interface in producing the composite with the purpose of achieving uniform distribution of CNTs and tight interfacial bonding. The effect and principles of coating were reviewed along with the illustration of ＂intermetallic interphases＂ design. Different roles of CNT/Al interface in structural and functional application were elucidated, and the future work that needs attention was addressed.展开更多
Young＇s modulus is a critical parameter for designing lightweight structure, but Al and its alloys only demonstrate alimited value of 70-72 GPa. The introduction of carbon nanotubes （CNTs） is an effective way to ma...Young＇s modulus is a critical parameter for designing lightweight structure, but Al and its alloys only demonstrate alimited value of 70-72 GPa. The introduction of carbon nanotubes （CNTs） is an effective way to make Al and its alloysstiffer. However, little research attention has been paid to Young＇s modulus of CNT/Al nanocomposites attributed to theuncertain measurement and unconvincing stiffening effect of CNTs. In this work, improved Young＇s modulus of 82.4 ± 0.4 GPa has been achieved in 1.5 wt% CNT/Al nanocomposite fabricated by flake powder metallurgy, which wasdetermined by resonance test and 13.5% higher than 72.6 ± 0.64 GPa of Al matrix. A comparative study and statisticalanalysis further revealed that Young＇s modulus determined by tensile test was relatively imprecise （83.1 ± 4.0 GPa） dueto the low-stress microplasficity or interface decohesion during tensile deformation of CNT/Al nanocomposite, while thevalue （98-100 GPa） was highly overestimated by nanoindentation due to the ＂pile-up＂ effect. This work shows an in-depthdiscussion on studying Young＇s modulus of CNT/Al nanocomposites.展开更多
基金Project(KJ1601321)supported by Scientific and Technological Research Program of Chongqing Municipal Education Commission,ChinaProject(cstc2017jcyjAX0378)supported by the Chongqing Research Program of Basic Research and Frontier Technology,China
文摘The deformation behaviors of as-sintered CNT/Al-Cu composites were investigated by isothermal compression tests performed in the temperature range of 300-550°C and strain rate range of 0.001-10 s-1 with Gleeble 3500 thermal simulator system.Processing maps based on dynamic material model(DMM)were established at strains of 0.1-0.6,and microstructures before and after hot deformation were characterized by scanning electron microscopy(SEM),electron backscatter diffraction(EBSD)and high-resolution transmission electron microscopy(HRTEM).The results show that the strain has a significant influence on the processing maps,and the optimum processing domains are at temperatures of 375-425°C with strain rates of 0.4-10 s-1 and at 525-550°C with 0.02-10 s-1 when the strain is 0.6.An inhomogeneous distribution of large particles,as well as a high density of tangled dislocations,dislocation walls,and some sub-grains appears at low deformation temperatures and strain rates,which correspond to the instability domain.A homogeneous distribution of fine particles and dynamic recrystallization generates when the composites are deformed at 400 and 550°C under a strain rate of 10 s-1,which correspond to the stability domains.
基金Project(2012AA030311)supported by the National High-tech Research and Development Program of ChinaProject(51421001)supported by the National Natural Science Foundation of ChinaProject(106112015CDJXY130002)supported by the Fundamental Research Funds for the Central Universities,China
文摘Deformation behaviors of CNTs/Al alloy composite fabricated by the method of flake powder metallurgy were investigated by hot compression tests, which were performed in the temperature range of 300?550 °C and strain rate range of 0.001? 10 s?1 with Gleeble?3500 thermal simulator system. Processing maps of the CNTs/Al alloy at different strains were calculated to study the optimum processing domain. Microstructures before and after hot compressions were characterized by electron backscattered diffraction (EBSD) method. Stress?strain curves indicate that the flow stress increases with the increase of strain rate and the decrease of temperature. The processing maps of the CNTs/Al alloy at different strains show that the optimum processing domain is 500?550 °C, 10 s?1 for hot working. EBSD analysis demonstrates that fully dynamic recrystallization occurs in the optimum processing domain (high strainrate 10 s?1), whereas the main soften mechanism is dynamic recovery at low strain rate (0.001 s?1).
基金financially supported by the National Basic Research Program of China (No.2012CB619600)the National Natural Science Foundation of China (Nos.51131004,51071100,and 51001071)+1 种基金the National High Technology Research and Development Program of China (No.2012AA030311)Shanghai Science & Technology Committee (Nos.11JC1405500)
文摘This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum （CNT/A1） composites. Much research work has been conducted to reveal the evolution of CNT/A1 interface in producing the composite with the purpose of achieving uniform distribution of CNTs and tight interfacial bonding. The effect and principles of coating were reviewed along with the illustration of ＂intermetallic interphases＂ design. Different roles of CNT/Al interface in structural and functional application were elucidated, and the future work that needs attention was addressed.
基金supported by the National Key Research and Development Program of China(Nos.2016YFB1200506,2017YFB1201105)the Natural Science Foundation of China(Nos.51671130,51771110,51771111,51371115)+2 种基金the Ministry of Education of China(Nos.62501036031,B16032)Aeronautical Science Foundation of China(2016ZF57011)Shanghai Science&Technology Committee(Nos.17ZR1441500,15JC1402100,14DZ2261200 and 14520710100)
文摘Young＇s modulus is a critical parameter for designing lightweight structure, but Al and its alloys only demonstrate alimited value of 70-72 GPa. The introduction of carbon nanotubes （CNTs） is an effective way to make Al and its alloysstiffer. However, little research attention has been paid to Young＇s modulus of CNT/Al nanocomposites attributed to theuncertain measurement and unconvincing stiffening effect of CNTs. In this work, improved Young＇s modulus of 82.4 ± 0.4 GPa has been achieved in 1.5 wt% CNT/Al nanocomposite fabricated by flake powder metallurgy, which wasdetermined by resonance test and 13.5% higher than 72.6 ± 0.64 GPa of Al matrix. A comparative study and statisticalanalysis further revealed that Young＇s modulus determined by tensile test was relatively imprecise （83.1 ± 4.0 GPa） dueto the low-stress microplasficity or interface decohesion during tensile deformation of CNT/Al nanocomposite, while thevalue （98-100 GPa） was highly overestimated by nanoindentation due to the ＂pile-up＂ effect. This work shows an in-depthdiscussion on studying Young＇s modulus of CNT/Al nanocomposites.
