Al–Ca, Al–Ce, and Al–La Eutectic Aluminum Alloys Processed by High‐Pressure Torsion

Abstract

A systematic study of structure and hardening of two‐phase Al–8% Ca, Al–10% Ce, and Al–10% La eutectic aluminum alloys under high‐pressure torsion (HPT) has been carried out. HPT leads to an increase in microhardness as a result of the formation of a nanocrystalline structure with a high density of crystal defects in the Al–8% Ca alloy and a nano‐ and submicrocrystalline structure with a low density of crystal defects in the Al–10% Ce and Al–10% La alloys, as well as the eutectic particle refinement in all alloys. The predominant crystallite sizes after HPT through five turns are 70–210, 60–120, and 25–45 nm, respectively, in the Al–10% La, Al–10% Ce, and Al–8% Ca alloys. The change in the shape of the curve of the microhardness distribution over the samples’ surface with an increase in the number of turns from 1 to 5 is different for three alloys. The results demonstrate the ultrafine‐grained microstructure development varied depending on the binary alloy systems. Initial as‐cast eutectic particles have a significant effect on the structure and hardening of alloys through their morphology, volume fraction, hardness, and orientational ratio with the aluminum base.