The effect of high-pressure torsion on the behaviour of intermetallic particles present in Al–1Mg and Al–3Mg

The effect of severe plastic deformation on intermetallic particles was investigated using high-pressure torsion on an Al–1Mg–0.2Si–0.2Fe–0.3Mn alloy and an Al–3Mg–0.2Si–0.2Fe–0.3Mn (wt%) alloy. Extensive optical microscopy and scanning electron microscopy was performed to analyse the intermetallic particles using image analysis software. It was found that all the intermetallic particles decreased in size with increasing strain whilst their spatial distribution was homogenised. A greater decrease in size was found for the intermetallic particles present in Al–1Mg alloy and the possible causes are discussed. Even though the strain near the centre of the sample is close to zero, refinement of intermetallic particles is substantial at this location.