Optimized designation of mesoscopic configuration of Zr/Ti layered metal composites for strength-ductility synergy improvement

Zirconium (Zr) and its alloys are highly promising for extreme service environments due to their excellent radiation and corrosion resistance. However, a major challenge in Zr-based materials lies in the strength-ductility trade-off, which limits their broader structural applications. This study aims to address this challenge by fabricating Zr/Ti layered metal composites (LMCs) with different layer thickness ratios (LTRs) and investigating the effects of LTR on the mechanical properties of Zr/Ti LMCs. Zr/Ti LMCs with varying LTRs were fabricated to explore how mesoscopic configurations influence their deformation mechanisms. The results reveal that an optimized layer thickness (∼50 μm for Zr and ∼40 μm for Ti) maximizes the hetero-deformation-induced (HDI) strengthening effect, resulting in a synergy improvement in strength and ductility. Stable and constrained cracks observed in the Zr layers contributed to local stress relief and improved ductility. The anisotropic deformation between the Zr and Ti layers transformed the local stress states into triaxial states. In addition, the localized stress state and inter-layer strain transmission also promote prismatic slip near the interfaces. This study provides key insights into the design of Zr-based composites with improved mechanical performance, offering potential solutions for their application in demanding environments. [Display omitted]