Effect of Equal-Channel Angular Pressing on the Structure, Mechanical Characteristics, and Aging Behavior of Cu–7% Cr and Cu–10% Fe Alloys

The effect of equal-channel angular pressing (ECAP) and subsequent aging on the structure and mechanical properties of Cu–7% Cr and Cu–10% Fe alloys is studied. ECAP is shown to substantially refine the structure of both alloys. The average grain and subgrain sizes of the Cu–7% Cr and Cu–10% Fe alloys subjected to ECAP are 250 ± 13 and 155 ± 7 nm, respectively. Moreover, the presence of shear bands ~100 nm wide is found for the alloys. The structure refinement results in a substantial increase in the strength of the alloys and a simultaneous decrease in their plasticity. In this case, additional aging of the alloys, which is performed after quenching, increases their microhardness, electrical conductivity, and strength; simultaneously, the plasticity decreases. Aging of the alloys subjected to ECAP leads to an increase in the sizes of the structural components (both shear bands and grains and subgrains) and to the precipitation of chromium and iron phases from the Cu–7% Cr and Cu–10% Fe alloys, respectively. The average sizes of shear bands, grains, and subgrains of the Cu–7% Cr and Cu–10% Fe alloys subjected to ECAP and aging are 130 ± 7 and 317 ± 24 nm and 220 ± 9 and 357 ± 27 nm, respectively. Aging does not affect the strength of the deformed Cu–7% Cr alloy and leads to a softening of the deformed Cu–10% Fe alloy. Aging of both alloys subjected to ECAP leads to an increase in their plasticity and electrical conductivity. In the case of the Cu–7% Cr alloy, treatment, which consists in quenching, ECAP, and aging, ensures reaching a better combination of the strength (~470 MPa), plasticity (~18%), and electrical conductivity (~81% IACS).