Enhanced mechanical properties in an Al-Mg-Cu alloy processed by the combination of cyclic deformation and aging heat treatment

Aging is a traditional strengthening method used for heat-treatable Al alloys. Cyclic strengthening has recently received widespread attention as a novel method for alloy strengthening. This study applied cyclic deformation to introduce dislocations and promote cluster formation in an Al-Mg-Cu alloy. Cyclically-strengthened (CS) samples have higher strength and ductility than peak-aged samples. The aging behaviors of the CS samples and the effect of pre-aging (artificial aging prior to cyclic deformation) on cyclic strengthening were also studied. Recovery and precipitation promotion were found during the aging of the CS samples regardless of pre-aging for 20 min. The pre-aged CS samples show higher strength than the CS samples without pre-aging. Interestingly, after subsequent aging, the mechanical properties of the CS samples with and without 20 min of pre-aging became the same. In summary, aging and cyclic deformation methods were combined to maximize the effects of precipitation strengthening and work-hardening. The strength limit obtained by individual aging or cyclic deformation methods was successfully overcome. This study provides new insights into alloy strengthening. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study applied cyclic deformation to an Al-Mg-Cu alloy and found that it increased the strength and ductility of the alloy by introducing dislocations and promoting cluster formation. The aging behaviors of the cyclically-strengthened (CS) samples were studied, and it was found that recovery and precipitation promotion occurred regardless of pre-aging. Pre-aged CS samples showed higher strength, but interestingly, after subsequent aging, the mechanical properties of pre-aged and non-pre-aged CS samples became the same.