3D-printed polyurea-toughened Al <sub>2</sub>O <sub>3</sub> cellular ceramic structures: Bioinspired dual-phase interpenetrating design for superior mechanical properties
Xueqin Zhang, Ruyue Su, Xiong Gao, Jingyi Chen, Rujie He
Abstract
Cellular ceramic structures (CCSs) are promising candidates for structural components due to their low density and superior load-bearing capacity. However, the brittleness and poor energy-absorbing ability of CCSs severely limit their applications. Inspired by composites in natural materials, whose stiff and tough constituents are arranged in a dual-phase interpenetrating architecture, we proposed a dual-phase interpenetrating architecture to achieve superior strength and toughness of CCSs simultaneously. Polyurea-toughened Al<sub>2</sub>O<sub>3</sub> CCSs (P/CCSs) were fabricated via three-dimensional (3D) printing and infiltration. Effects of structural configuration and relative density on mechanical properties of P/CCSs under quasi-static and dynamic compressive loading were systematically discussed. It was demonstrated that polyurea effectively improved the mechanical properties of CCSs. Load-bearing capacity and energy-absorbing ability of P/CCSs under quasi-static compressive loading were 1.22–3.64 and 57–519 times those of CCSs. Additionally, dynamic compressive strength and energy absorption of P/CCSs were 1.07–1.85 and 3.31–10.94 times those of CCSs. Furthermore, due to the incorporation of polyurea, P/CCSs maintained structural integrity under large deformation, rather than undergoing catastrophic fracture. This work provides an effective solution to mitigate the adverse effect of ceramic brittleness, rendering P/CCSs promising candidates for structural components that require superior load-bearing capacity and energy-absorbing ability simultaneously.