Shaping Deformation—How Interface Roughness and Alignment Drive Bimetal Mechanics

The microstructural characteristics of multi-phase materials, particularly bimetal interfaces, play a critical role in governing their deformation and failure mechanisms under extreme conditions. At high strain rates or during shock interactions, these interfaces significantly influence the evolution of dislocations and twinning, directly impacting the material’s overall strength and resilience. Despite this importance, a substantial knowledge gap remains between the observed material behavior and the effects of interface roughness and alignment, limiting the ability to design robust, high-performance components used in sectors such as defense, energy, aerospace, and infrastructure. Current experimental approaches often lack sufficient microstructural insight, and traditional metrics like grain size and distribution fail to capture the complexities of atomic arrangements at bimetal interfaces. To address this, we conducted large-scale Molecular Dynamics (MD) simulations of various Al-Ti bimetal interfaces to explore their role in deformation mechanisms. This study investigates how interface roughness (flat vs. waveform interfaces) and alignment affect material behavior under high-strain rate deformation. In addition to defined interfaces, we also simulated atom deposition to mimic welding processes, further exploring the influence of interface formation on material behavior. Furthermore, by rotating these interfaces relative to the loading direction, we clarify how alignment influences deformation mechanisms, providing valuable insights for optimizing bimetal microstructures. | LA-UR-24-29709