Self‐Healing Engineering Ceramics with Oxidation‐Induced Crack Repair

Abstract

Engineering ceramics capable of restoring damage-induced surface cracking may achieve enhanced reliability and longer lifetime at high temperature applications compared with nonhealing ceramics. Selection of healing agents dispersed in ceramic matrix composites which upon oxidation with environmental oxygen may rapidly fill the volume of a surface crack and recover compromised strength are reviewed. Novel approaches envisage acceleration of crack healing to reduce healing period as well as healing temperature. Potential fields of application for self-healing ceramics operating at elevated service temperatures are presented.

Recycling of a Healing Agent by a Water‐Vapor Treatment to Enhance the Self‐Repair Ability of Ytterbium Silicate‐Based Nanocomposite in Multiple Crack‐Healing Test

“…Comparing with the composite annealed at 1423 K, the one annealed at 1523 K exhibits a higher recovery rate, obtains the original strength after around 1.4 h of annealing, and then continues to increase its strength to reach a saturation value of ≈260 MPa after 5 h. Meanwhile, the composite annealed at 1423 K, obtains the original strength after around 7.3 h of annealing, and continues the strength improvement to reach 187 MPa after 10 h. These results indicate that the healing temperature and healing time can be used to determine the strength recovery rate, and hence the activation energy of the oxidation. The activation energy Q * , for a composite with known volume fraction of healing agent depends on the minimum healing time t H to achieve full strength recovery, and the healing temperature T H as follows…”

Nanotechnology in Concrete: a Bibliometric Review

“…Applications of nanotechnology-based self-healing systems are less common since the concept of selfhealing is still not widespread in large-scale applications, although it is changing (93). In general, materials with these properties are found only in engineering materials, as they have high costs to be applied in regular applications (94,94,95). Although cheaper self-healing systems in civil construction already exist (Vermeer et al, 2021), this type of application is still relatively unknown.…”

A review of some of experimental and numerical studies of self‐crack‐healing in ceramics

“…112 Greil reviewed the kinetic and thermodynamic aspects that govern the healing process in ceramics through the solid state reaction, which facilitate the internal and surface cracks' healing, or through vapor solid oxidation reaction, to heal the surface cracks and pores. 113 Yoshitomo et al used a framework of FEM to simulate the crack generation and crack propagation of self-healing fiber-reinforced ceramic (shFRC) with high-temperature oxidation as a main mechanism to heal the crack. 114 Perrot et al proposed a numerical model that depends on an image of the cross-section of the material or on virtual meshes to simulate the self-healing process; in their model, they featured the oxidation kinetics and the flow of the glassy liquid oxide.…”

“…Reaction 97,98,104,113 In order to have a healing process of the induced cracks/to initiate the healing process in ceramics, an oxidation process has to occur. The oxidation reaction of the healing agent can be summarized as follows:…”

“…In their article, they derived a semi‐empirical oxidation cohesive zone healing model 112 . Greil reviewed the kinetic and thermodynamic aspects that govern the healing process in ceramics through the solid state reaction, which facilitate the internal and surface cracks’ healing, or through vapor solid oxidation reaction, to heal the surface cracks and pores 113 . Yoshitomo et al used a framework of FEM to simulate the crack generation and crack propagation of self‐healing fiber‐reinforced ceramic (shFRC) with high‐temperature oxidation as a main mechanism to heal the crack 114 .…”