Evidence of room-temperature shear-deformation in a Cu-Al intermetallic

Lamellar eutectics are known to evidence plastic shear in otherwise brittle intermetallics, if the lamella spacing is small enough. Here we pursue this idea of confined plasticity in intermetallics further and demonstrate room-temperature shear-deformation in a two-phase CuAl2-CuAl intermetallic nano-composite. The presence of a phase with a 3-fold symmetry is also revealed after deformation. Simulation of transmission electron microscopy images shows this to be monoclinic CuAl. These observations are made in the deformation zone underneath locations of nanoindents, of which the force-displacement curves exhibit an unusual response of continuously increasing pop-in sizes with load. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study demonstrates that lamellar eutectics in intermetallics exhibit plastic shear when the lamella spacing is small enough. Room-temperature shear deformation is achieved in a two-phase CuAl2-CuAl intermetallic nano-composite, revealing the presence of a phase with 3-fold symmetry after deformation.