The influence of layer thickness on the deformation and fracture of layered metals: Insights from synchrotron Laue microdiffraction and mechanistic model

Abstract

Layer thickness behaves as a crucial parameter in determining the mechanical properties of multi-layered composites. Recently, a synchronous improvement in the strength and ductility of Ti/Al layered materials was observed with the thickening of Ti layers. To address the underlying mechanism, Synchrotron Laue X-ray microdiffraction and electron backscatter diffraction were performed to study the dislocation behaviors at the initial and large deformation stages. We also developed a mechanistic model to elucidate the influence of layer thickness, as well as to determine the threshold thickness that governs the transition of deformation and fracture behaviors. Our experimental and model efforts suggest that the contribution of layer thickness lies in its role in the dislocation dynamics and strain distribution, which helps with the design of next-generation high-performance layered composites.