microcracking

Microcracking is a mechanism that enhances the fracture toughness of ceramics. This occurs in polycrystalline ceramics where grains have different mechanical properties depending on their orientation. When a main crack propagates, tiny microcracks form on either side of its path. These microcracks absorb energy, increasing the force needed for the main crack to advance. Additionally, as the main crack moves forward, these microcracks behind it tend to close the main crack, further resisting its propagation. This process makes the ceramic stronger the farther a crack travels.1

While microcracking improves toughness, ceramics remain brittle materials susceptible to damage from impact or stress. Soluble salts can also cause damage by crystallizing within the ceramic's pores, leading to microfracturing.2