Energy dissipation in composites with hybrid nacre-like helicoidal microstructures

TL;DR

This paper introduces a novel hybrid microstructure combining nacre-like and helicoidal arrangements in composites, fabricated via magnetically-assisted slip casting, aiming to enhance toughness and mechanical performance.

Contribution

It presents a new fabrication method for complex hybrid microstructures in composites and evaluates their mechanical properties, advancing microstructural design for improved toughness.

Findings

Hybrid microstructures can improve ductility and stiffness.

Nacre-like composites show highest strength and toughness.

Fabrication method enables complex microstructural studies.

Abstract

Natural ceramic composites present complex microstructures that lead to tortuous crack paths and confer them high toughness. Current microreinforced composites do not yet reach the same level of complexity in their microstructures, resulting in poorer properties. To achieve complex microstructuration, magnetically-assisted slip casting (MASC) was conducted using a setup with 4 degrees of freedom. Among all possible microstructures, a hybrid design between nacre-like and helicoidal arrangements was selected due to its ability to tilt and twist the crack path. The hybrid microstructured specimen fabricated, consisting of aluminum oxide micro platelets in a silicone matrix, were tested under compression and their mechanical performance compared. Although nacre-like composites exhibited the highest strength and toughness, helicoidal hybrids could show some ductility and higher stiffness. The fabrication strategy proposed here could thus be a simple route to study more complex microstructures in view of increasing the toughness of microplatelet reinforced composites.