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
Si/Cu3Si@C composites encapsulated in CNTs network(SCC-CNTs) were synthesized via the combination of ball-milling and CVD methods. SCC-CNTs consist of conductive Cu3Si, amorphous carbon layer, cross-linked CNTs, and t...Si/Cu3Si@C composites encapsulated in CNTs network(SCC-CNTs) were synthesized via the combination of ball-milling and CVD methods. SCC-CNTs consist of conductive Cu3Si, amorphous carbon layer, cross-linked CNTs, and the etched pores, which can play the synergistic effects on the improvement of electronic conductivity and Li^+ diffusion. The volume expansion of Si anode is also suppressed during the electrochemical process. The SCC-CNTs composites demonstrate a remarkably improved electrochemical performance compared with pure Si, which can deliver a discharge capacity of 2 171 mAh·g^-1 at 0.4 A·g^-1 with ICE of 85.2%, and retain 1197 mAh· g^-1 after 150 cycles. This work provides a facile approach to massively produce the high-performance Si-based anode materials for next-generation LIBs.展开更多
Cu matrix composite reinforced with 10%（volume fraction） carbon nanotubes（CNTs/Cu） and pure Cu bulk were prepared by powder metallurgy techniques under the same consolidation processing condition.The effect of ele...Cu matrix composite reinforced with 10%（volume fraction） carbon nanotubes（CNTs/Cu） and pure Cu bulk were prepared by powder metallurgy techniques under the same consolidation processing condition.The effect of electrical current on tribological property of the materials was investigated by using a pin-on-disk friction and wear tester.The results show that the friction coefficient and wear rate of CNTs/Cu composite as well as those of pure Cu bulk increase with increasing the electrical current without exception,and the effect of electrical current is more obvious on tribological property of pure Cu bulk than on that of CNTs/Cu composite;the dominant wear mechanisms are arc erosion wear and plastic flow deformation,respectively;CNTs can improve tribological property of Cu matrix composites with electrical current.展开更多
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Funded by the National Key R&D Program of China(No.2016YFB0100302)
文摘Si/Cu3Si@C composites encapsulated in CNTs network(SCC-CNTs) were synthesized via the combination of ball-milling and CVD methods. SCC-CNTs consist of conductive Cu3Si, amorphous carbon layer, cross-linked CNTs, and the etched pores, which can play the synergistic effects on the improvement of electronic conductivity and Li^+ diffusion. The volume expansion of Si anode is also suppressed during the electrochemical process. The SCC-CNTs composites demonstrate a remarkably improved electrochemical performance compared with pure Si, which can deliver a discharge capacity of 2 171 mAh·g^-1 at 0.4 A·g^-1 with ICE of 85.2%, and retain 1197 mAh· g^-1 after 150 cycles. This work provides a facile approach to massively produce the high-performance Si-based anode materials for next-generation LIBs.
基金Project(2007CB607603)supported by the National Basic Research Program of China
文摘Cu matrix composite reinforced with 10%（volume fraction） carbon nanotubes（CNTs/Cu） and pure Cu bulk were prepared by powder metallurgy techniques under the same consolidation processing condition.The effect of electrical current on tribological property of the materials was investigated by using a pin-on-disk friction and wear tester.The results show that the friction coefficient and wear rate of CNTs/Cu composite as well as those of pure Cu bulk increase with increasing the electrical current without exception,and the effect of electrical current is more obvious on tribological property of pure Cu bulk than on that of CNTs/Cu composite;the dominant wear mechanisms are arc erosion wear and plastic flow deformation,respectively;CNTs can improve tribological property of Cu matrix composites with electrical current.
