Designing chemically adaptive nanolaminates via oxygen dynamic partitioning

Crystalline-amorphous nanolaminates (C/A NLs) have long been conceived as static composites, with their performance predetermined by layer thickness and phase fractions. Here, we introduce a paradigm shift that transforms these materials into chemically adaptive systems through oxygen dynamic partitioning. By harnessing interstitial oxygen as an in-situ chemical modulator, we show that NLs can reconfigure their local chemistry during deformation, evolving from a preset structure into a self-optimizing system. We realize this concept in FeCrNi-O/TiVNbHf-O NLs, where deformation drives oxygen redistribution from the amorphous layers and interfaces to the crystalline layers, increasing oxygen content by 1.55 at.% and amplifying intralayer chemical inhomogeneity without forming oxides. This dynamic chemical evolution progressively strengthens the crystalline phase, reduces the mechanical mismatch between the two layers, and facilitates coordinated deformation throughout the entire architecture. As a result, the two phases achieve a dynamic convergence in mechanical behavior, not by design but by evolution. This chemo-mechanical coupling yields exceptional performance, delivering an ultrahigh yield strength (∼ E /30, approaching the theoretical limit ∼ E /10) alongside a homogeneous compressive strain exceeding 50%, with no shear band formation. The approach is broadly applicable across alloy systems and establishes chemical reconfiguration as a new design paradigm for materials that adapt rather than merely serve as passive constituents.