Strain path effects on the development of shear bands during shear tests in aluminum alloy processed by ECAP

摘要

ECAP (Equal Channel Angular Pressing) involves the pressing of a prismatic specimen through two channels with the cross-section identical to that of the specimen and intercepting at a certain angle. The specimen undergoes shearing over a single plane but no dimensional changes, leading to a possible anisotropy in the mechanical properties of the processed specimen. In addition, multiple ECAP passes lead to a severe refinement of the material structure, which is a function of the angle between the channels and the rotation of the sample in successive passes (the so-called “processing route”). An analysis is presented of the mechanical and microstructural anisotropy along three orthogonal axes in an aluminum alloy specimen processed along three different processing routes. The mechanical properties were evaluated through shearing tests, and the stress–strain curves thus determined indicated that the mechanical behavior of the commercial purity aluminum after ECAP depends on the processing route. The analysis of the specimen surfaces after testing revealed the presence of shearing bands whose orientation also depended on the processing route.