Mechanical Behavior and Microstructural Development of 6063-T1 Aluminum Alloy Processed by Equal-Channel Angular Pressing (ECAP): Pass Number Influence

Equal-channel angular pressing (ECAP) is a very interesting method for modifying the microstructure in producing ultrafine-grained materials and nanomaterials. It consists mainly of pressing test samples through a die containing two channels that are equal in cross section and intersect at a certain angle. As a result of pressing, the sample theoretically deforms by simple shear and retains the same cross-sectional area to allow repeat pressing for several cycles. A 6063-T1 aluminum alloy was investigated in this study. The specimens were processed for up to nine passes (one, three, six, and nine ECAP passes, respectively) using a die channel angle of 90°. After ECAP, the samples were cut from each specimen and prepared for metallographic analysis and mechanical testing. The microstructures of the ECAP treated and as-received material were investigated using both optical microscopy and scanning electron microscopy. All samples (ECAP processed and as-received) were mechanically investigated in compression tests. Ultimate compressive strength, yield strength, and compression modulus were obtained. Also, all ECAP processed specimens were investigated for microhardness and compared with the as-received material.