Strong and super tough: Layered ceramic‐polymer composites with bio‐inspired morphology

Abstract

Bio‐inspired layered ceramic‐polymer composites with high strength and toughness were prepared from sintered aluminum oxide ceramic sheets and cationically curing epoxy resins toughened with poly(ε‐caprolactone) (PCL). The architecture of the composite is inspired by nacre but is arranged on a larger scale. Ceramic sheets with a nominal thickness of 250 μm were assembled into composite plates by adhesive layers with a nominal thickness of 20 μm. Before the manufacturing of the composites, the stress‐strain properties of the polymer component were tailored by the variation in the PCL content between 0 and 39 wt%. For composites with 4 and 15 ceramic layers, the bending strengths achieved 327 MPa and 376 MPa, which are higher than that of pure ceramic sheets. Moreover, composites with 15 ceramic layers show a 16 times higher toughness compared to that of the pure ceramic sheets. The results indicate that the toughness of the layered composites increases significantly with the number of layers. Inspired by the geometrical ratio of the natural sheet composite nacre, we have achieved a similar strength but a 2 times higher toughness than nacre by only adding up to 6 vol% of the polymer.

Highly strengthening and toughening biomimetic ceramic structures fabricated via a novel coaxially printing

“…Higher tensile stress in flexible epoxy resin generated a larger stress gradient, which could eliminate stress concentrations in the brittle silicate components. Such reinforcing mechanism primarily accounts for the significant improvement of toughness for biomimetic silicate-epoxy ceramic composites [19,47,48]. As a result, the stress in the section B was divided into two characteristic zones (zone I in tension and zone II in compression) as shown in Fig.…”

“…Inspired by the enamel microstructure, the biomimetic ceramic composites with polymer polyvinyl alcohol serving as an elastic phase has demonstrated high fracture strength (1.6 GPa) and good elongation capacity (6.2%) [15−18]. For instance, the silicatehydrogel biomimetic composites with a unidirectional and highly ordered microstructure realized a significant increase in flexural strength (4.73±0.34 MPa) and toughness (14,071±153 kJ/m 3 ) [19]. The structural biomimetic and flexible modification strategies have offered a combined effective pathway to synergistically enhance strength and toughness of engineering materials beyond the intrinsic brittle limitation of any individual constituent [20−24].…”

Enhanced mechanical properties of porcelain ceramic tile/Kevlar fabric composite with bio‐inspired shell‐like structure

“…[10][11][12] For instance, Ben et al 13 applied the Florentine mechanical model to advanced ceramic composites, indicating that an appropriate density arrangement of layers would improve the impact resistance. Pogorelov et al 14 reported the bioinspired ceramic-polymer composite achieved excellent toughness performance, which was nearly two times higher than conch-shell, by only adding up to 6.0 vol% of the polymer. However, these bio-inspired composites are common in advanced ceramics, but rarely in traditional ceramic manufacturing due to the high costs of corresponding techniques.…”

“…applied the Florentine mechanical model to advanced ceramic composites, indicating that an appropriate density arrangement of layers would improve the impact resistance. Pogorelov et al 14 . reported the bio‐inspired ceramic‐polymer composite achieved excellent toughness performance, which was nearly two times higher than conch‐shell, by only adding up to 6.0 vol% of the polymer.…”

Tough metal-ceramic composites with multifunctional nacre-like architecture

“…Artificial materials that mimic the nacreous architecture of mollusk shells are prominent examples of how evolved hierarchical structures made by living organisms can be harnessed to fabricate synthetic counterparts with outstanding properties and new functionalities 1 – 3 . By combining design principles of nacre’s brick-and-mortar structure with the rich variety of chemistries available in synthetic systems, current nacre-like materials exhibit mechanical properties that even surpass those of the natural counterparts 4 – 9 . As opposed to conventional materials, such bio-inspired structures can be designed to showcase antagonistic properties, such as high stiffness and fracture toughness, that are not accessible through the optimization of chemical compositions alone 7 , 10 , 11 .…”