A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations...A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations indicated that CNTs were uniformly dispersed in the matrix in both CNT/AI and CNT/6061AI composites. Mg and Si elements tended to segregate at CNT-AI interfaces in the CNT/6061AI composite during artificial aging treatment. The tensile properties of both the AI and 6061AI were increased by CNT incorporation. The electrical conductivity of CNT/AI was decreased by CNT addition, while CNT/6061AI exhibited an increase in electrical conductivity due to the Mg and Si segregation.展开更多
通过对多壁碳纳米管(MWNTS)／高密度聚乙烯(High density polyethylene,HDPE)复合材料的电阻- 温度特性进行了研究。发现MWNTs填充质量分数为1％-2％时,复合体系呈现渗流行为,表现出优异的导电性。同时体系存在特殊的V形温度系数特性(V-...通过对多壁碳纳米管(MWNTS)／高密度聚乙烯(High density polyethylene,HDPE)复合材料的电阻- 温度特性进行了研究。发现MWNTs填充质量分数为1％-2％时,复合体系呈现渗流行为,表现出优异的导电性。同时体系存在特殊的V形温度系数特性(V-PTC特性),即当MWNTs质量分数超过渗流阈值后,体系的电阻率随温度的升高先下降,出现负温度系数特性(NTC转变),然后才出现通常的正温度系数特性(PTC 转变),且具有很好的循环稳定性。V-PTC这种特性源于基体体积膨胀、MWNTs缠结链松弛以及基体的“退火”效应的协同作用。马来酸酐接枝苯乙烯-(乙烯-丁烯)-苯乙烯共聚物(MA-g-SEBS)的加入,可改善MWNTs 和HDPE之间的相互作用,并可基本上消除V-PTC特性,改善导电性。展开更多
基金the support of the National Basic Research Program,China(Grant Nos.2011CB932603 and 2012CB619600)the National Natural Science Foundation, China(Grant No.51331008)
文摘A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations indicated that CNTs were uniformly dispersed in the matrix in both CNT/AI and CNT/6061AI composites. Mg and Si elements tended to segregate at CNT-AI interfaces in the CNT/6061AI composite during artificial aging treatment. The tensile properties of both the AI and 6061AI were increased by CNT incorporation. The electrical conductivity of CNT/AI was decreased by CNT addition, while CNT/6061AI exhibited an increase in electrical conductivity due to the Mg and Si segregation.
