Strongly interacting interfaces with other constituents in materials lead to outstanding performance beyond their inherent properties. It is closely related with the interfacial structure, generally determined by interfacial chemistry based on thermodynamics. Here, we introduce a new strategy for tailoring high-ductility aluminium alloys by developing small sub-grains induced by the wide low-angle boundary (WLAB). The WLAB is developed by the formation of the band in which oxygen atoms are interstitially located in the aluminium (called as I-Al). The band with ∼40 nm in width, which has a coherent chemical interface with a very small misfit strain, is individually dispersed in the matrix, producing the WLAB, thereby partitioning whole grains into numerous sub-grains (<1 µm). Further structural information investigated by neutron total scattering techniques supports the presence of interstitial oxygen by unveiling local structure of the WLAB and slight lattice expansion in the I-Al. During plastic deformation, the WLAB which contains pre-existing dislocations promotes dislocation interactions as the way of the formation of dislocation cells. The consequent dislocation storage capacity with very small dislocation cells the size of which is far below a critical size observed in conventional aluminium alloys renders significantly a large ductility without sacrificing tensile strength.
|Journal||Journal of Alloys and Compounds|
|Publication status||Published - 2023 Feb 10|
Bibliographical noteFunding Information:
This study was supported by the National Research Foundation of Korea (NRF) grant funded by Ministry of Science and ICT (No. NRF-2018K1A3A7A09057424 , NRF-2021M3H4A1A04092001 ). The neutron experiment at the Materials and Life Science Experimental Facility of the J-PARC was performed under a user program (Proposal No. 2019A0251).
© 2022 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry