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

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 in-fluence 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. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Layer thickness is a crucial parameter for determining the mechanical properties of multi-layered composites. Recent observations have shown that increasing the thickness of Ti layers in Ti/Al layered materials leads to synchronous improvement in strength and ductility. A combination of synchrotron X-ray microdiffraction and electron backscatter diffraction techniques was used to study the behavior of dislocations at different deformation stages. A mechanistic model was developed to explain the influence of layer thickness and determine the threshold thickness that governs the transition of deformation and fracture behaviors. The findings from our experimental and modeling efforts highlight the role of layer thickness in dislocation dynamics and strain distribution, providing insights for designing next-generation high-performance layered composites.