Effects of Carbon Nanotubes on the Bonding Behavior of Cold Roll Bonded Cu Strips

A growing interest is being shown to carbon nanotubes (CNTs) due to their excellent mechanical properties as an ideal reinforcement for metal matrixes. In this study, the cold roll boding (CRB) process was used to fabricate Cu/CNT composite strips. For this purpose, the CNTs were dispersed homogeneously between two pure copper sheets which were subsequently roll bonded at room temperature. In order to evaluate the behavior of CNT particles between the Cu strips, optical microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used along with the peeling test. The microstructure of the Cu/CNT composite consists of two regions: composite regions in which most CNTs are distributed, and CNT-free regions. The results of the peeling test revealed that, compared to roll-bonded Cu strips without particles, the presence of even a small amount of CNTs at the interface could reduce significantly the peeling force for identical thickness reductions. It was also found that threshold thickness reduction decreased but the bond strength of the Cu/CNT interface increased with increasing volume fraction of CNTs.

Keywords: Metal matrix composites (MMC); Cold roll bonding; Bond strength; Copper; Carbon nanotube