Fracture Diodes: Directional asymmetry of fracture toughness

TL;DR

This paper introduces fracture diodes, artificial materials with asymmetric fracture toughness, enabling directional control of crack propagation to improve material durability and safety.

Contribution

It demonstrates how microstructure design can induce directional asymmetry in fracture toughness, a novel concept in material science.

Findings

Asymmetric fracture toughness can be engineered in artificial materials.

Microstructure control enables crack path guidance.

Potential applications in enhancing material safety and durability.

Abstract

Toughness describes the ability of a material to resist fracture or crack propagation. It is demonstrated here that fracture toughness of a material can be asymmetric, i.e., the resistance of a medium to a crack propagating from right to left can be significantly different from that to a crack propagating from left to right. Such asymmetry is unknown in natural materials, but we show that it can be built into artificial materials through the proper control of microstructure. This paves the way for control of crack paths and direction, where fracture -- when unavoidable -- can be guided through pre-designed paths to minimize loss of critical components.