title: Emergence of stable interfaces under extreme plastic deformation.
abstract: Atomically ordered bimetal interfaces typically develop in near-equilibrium epitaxial growth (bottom-up processing) of nanolayered composite films and have been considered responsible for a number of intriguing material properties. Here, we discover that interfaces of such atomic level order can also emerge ubiquitously in large-scale layered nanocomposites fabricated by extreme strain (top down) processing. This is a counterintuitive result, which we propose occurs because extreme plastic straining creates new interfaces separated by single crystal layers of nanometer thickness. On this basis, with atomic-scale modeling and crystal plasticity theory, we prove that the preferred bimetal interface arising from extreme strains corresponds to a unique stable state, which can be predicted by two controlling stability conditions. As another testament to its stability, we provide experimental evidence showing that this interface maintains its integrity in further straining (strains > 12), elevated temperatures (> 0.45 Tm of a constituent), and irradiation (light ion). These results open a new frontier in the fabrication of stable nanomaterials with severe plastic deformation techniques.
authors.affiliation: Theoretical Division, Materials Physics and Application Division, and Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545.
authors.forename: Irene J
authors.initials: IJ
authors.lastname: Beyerlein
authors.forename: Jason R
authors.initials: JR
authors.lastname: Mayeur
authors.forename: Shijian
authors.initials: S
authors.lastname: Zheng
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Mara
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Amit
authors.initials: A
authors.lastname: Misra
keywords: atomistic simulation; radiation resistance; texture; thermal stability