ارزیابی خواص مکانیکی و الکتریکی نانوکامپوزیتهای چندلایه آلومینیوم - مس - نانولوله کربنی تولیدشده با فرآیند نورد تجمعی پیوندی

In the present study, multilayer nanocomposites fabricated by accumulative roll bonding (ARB) process. Aluminum sheets, copper sheets (with 0.1 and 0.3mm thickness) and multiwall carbon nanotubes (MWCNTs) were used as experimental materials. The rolling process continued to five cycles. Then, microstructure, hardness, tensile strength and electrical conductivity of nanocomposites were investigated. Necking and fracturing recognized as mechanisms of copper layers distribution in the aluminum matrix. The bonding strength between layers increased with the number of cycles due to the improvement of MWCNTs distribution. The results show that the hardness of aluminum increased with increasing copper layer thickness and these increases were about 30 and 32% for composites without nano reinforcements and nanocomposites contain MWCNTs, respectively. The highest hardness (147HV), is related to the sample containing carbon nanotubes and 0.3mm copper sheet, after five rolling cycles (446% increase compared to aluminum sheets). The results confirm the positive effect of copper and the MWCNTs on the improvement of strength. The highest strength and elongation is observed in the aluminum-copper-MWCNTs nanocomposite after four cycles. The results also indicated that the addition of copper and MWCNTs can simultaneously increase the strength and electrical conductivity of the resulted composites. [ABSTRACT FROM AUTHOR]