Saeid Akhavan - Department of Materials Engineering, Isfahan University of Technology ۸۴۱۵۶-۸۳۱۱۱, Isfahan, Iran
Alireza Saghaian nejad - Department of Materials Engineering, Isfahan University of Technology ۸۴۱۵۶-۸۳۱۱۱, Isfahan, Iran
Mohamreza Toroghinejad - Department of Materials Engineering, Isfahan University of Technology ۸۴۱۵۶-۸۳۱۱۱, Isfahan, Iran
Ahmad Tahvilian - Department of Materials Engineering, Isfahan University of Technology ۸۴۱۵۶-۸۳۱۱۱, Isfahan, Iran

Accumulative roll bonding (ARB) is a severe plastic deformation process for achieving ultra-fine grains in metallic sheets without changing the sample dimensions. A high-purity Al(1100) alloy and a Al-Mg(5083) alloy were ARB process up to 6 cycles at ambient temperature to generate sheet composite material consisting of alternating layers of Al and Al-Mg. Sample properties were studied by employing hardness measurements, tensile test, SEM and TEM characterizations. The deformation structure within these layers consisted of lamellar bands aligned parallel to the rolling direction. With increasing the strain, mean spacing of lamellar boundaries decreased. Finally, continuous recrystallization resulted in a microstructure covered with small recrystallized grains with an average diameter below 100 nm at the end of four cycle. The tensile strength and hardness of the 6 cycle ARB processed composite sheet increased about 2 times of the initial 5083 Al alloy values and about five times of the initial 1100 Al alloy values, respectively. Fracture surfaces observations showed that failure mode in ARB processed composite is shear ductile rupture with elongated small dimples.

Accumulative roll bonding ; Severe plastic deformation ; Aluminum 5083 ; Aluminum 1100 ; Nano-Grain