A comparison between asymmetric rolling and accumulative roll bonding as means to refine the grain structure of an Al-Mg-Si alloy

Abstract

The possibility of refining the grain structure
of a commercial Al-Mg-Si alloy was
evaluated using asymmetric rolling (ASR) and
accumulative roll bonding (ARB) in the severe
plastic deformation (SPD) regime. Bars of
annealed alloy having a thickness of 10 mm
were asymmetrically rolled down to a
thickness of 0.23 mm with a laboratory
rolling mill featuring the possibility of
independently modifying the rotational speed
of its two rolls. The effect of the rolling
temperature was investigated by tests in the
range 150-250°C. A parallel campaign was
also conducted to investigate the effects of
warm accumulative roll bonding of the same
alloy and in the same temperature range.
These tests were carried out on annealed
samples of 1 mm thickness. The experimental
characterization (both mechanical and
m i c ro s t ructural) demonstrated that
asymmetric rolling and accumulative roll
bonding can readily promote the achievement
of ultrafine grained structures in Al-Mg-Si
alloys.