posted on 2017-09-29, 00:00authored byYunya Zhang, Xiaodong Li
Nacre, commonly referred
to as nature’s armor, has served
as a blueprint for engineering stronger and tougher bioinspired materials.
Nature organizes a brick-and-mortar-like architecture in nacre, with
hard bricks of aragonite sandwiched with soft biopolymer layers. However,
cloning nacre’s entire reinforcing mechanisms in engineered
materials remains a challenge. In this study, we employed hybrid graphene/Al2O3 platelets with surface nanointerlocks as hard
bricks for primary load bearer and mechanical interlocking, along
with aluminum laminates as soft mortar for load distribution and energy
dissipation, to replicate nacre’s architecture and reinforcing
effects in aluminum composites. Compared with aluminum, the bioinspired,
graphene/Al2O3 doubly reinforced aluminum composite
demonstrated an exceptional, joint improvement in hardness (210%),
strength (223%), stiffness (78%), and toughness (30%), which are even
superior over nacre. This design strategy and model material system
should guide the synthesis of bioinspired materials to achieve exceptionally
high strength and toughness.