High-strength, high-conductivity ultra-fine grains commercial pure copper produced by ARB process

Accumulative roll-bonding process is a severe plastic deformation process capable of developing grains below I gm in diameter. In this study, microstructure, mechanical properties and electrical conductivity of commercial pure copper strips processed by accumulative roll-bonding were investigated. Transmission electron microscopic micrographs of the strips produced by eight cycles of accumulative roll-bonding process showed ultra-fine grains similar to 180 nm in size with high angle grain boundaries. Also tensile strength and microhardness of the accumulative roll-bonding processed samples increased with increasing the number of accumulative roll-bonding cycles. Whereas, the elongation dropped abruptly at the first cycles, above which it increased slightly. The electrical conductivity decreased with increasing accumulative roll-bonding cycles up to 6 cycles and then increased up to 8 cycles of accumulative roll-bonding process. (C) 2009 Elsevier Ltd. All rights reserved.