Biomimetic preparation of a ceramic combined with sea urchin stereom structure and nacre mineral bridge structure.

Multibiological multiscale biomimetic design is a novel bionic idea that involves multi-mechanisms. Porous ceramics with a sea urchin stereom structure on a micrometre scale and a nacre mineral bridge structure on a submicron scale have been fabricated via organic foam impregnation and controlled crystallisation. The microstructure and mechanical properties of biomimetic ceramics are, respectively, characterised using scanning electron microscopy and universal testing machine. Moreover, the porosity, reliability and grain boundary stress of biomimetic ceramics are calculated via Archimedes method, Weibull theory and finite element method, respectively. Results show that the ceramic produced in this work has a porosity of 88.16% and an average pore size of 284.65 μm. Mineral bridges of Al 2 TiO 5 with a thickness of 30–230 nm are widely and randomly distributed in the grain boundary glass phase of Al 2 O 3 and improved the compressive strength (2.32 MPa) and Weibull modulus (7.85) of ceramics by the multi-mechanisms of crack deflection, reducing maximum stress and homogenising stress on the grain boundary. These investigations would be of great value to the design and synthesis of novel biomimetic materials. Unlabelled Image • A new ceramic combined with stereom structure of sea urchin and mineral bridges of nacre is successfully fabricated. • The double-biologically inspired ceramics have a high porosity of 88.16% but excellent Weibull modulus of 7.85. • The Al 2 TiO 5 mineral bridge forest first reported on the boundary/surface of Al 2 O 3 grains causes the crack deflection. • The mineral bridges can reduce the maximum grain boundary stress by 15.85% and homogenize the stress. • The flexural strength and Weibull modulus of ceramic are increased by about 2.7 times with the mineral bridge introduction. [ABSTRACT FROM AUTHOR]