Self-Crack Healing of Engineering Ceramics

Abstract

The purpose in its simplicity is to heal the damage in a sample composed of ceramic particles through the heat treatment or through applying another source to heal the damage might be through using a laser source at room temperature to reduce the cost of wasting efforts and materials. The system can be designed to include a sensor to sense the damage in the component and a healing agent like loose particles or a specific source that provides an immediate treatment through the heating in order to create or generate the glassy phase. Self-crack-healing materials are able to sense the crack and heal it. The notion of not giving up on things can be considered as the motive for such type of research. Most ceramics are brittle and hence they are sensitive to flaws and cracks. Ceramics are subjected to thermal and mechanical stresses during service. Residual stresses may eventually cause microcracks (internal and surface cracks) and the failure of the component in use. This limits their use as structural engineering materials, and thus applying or inducing a self-crack healing ability would be a solution to overcome this problem. Great benefits can be expected from the components in use while applying the self-healing ability, such as reducing maintenance, inspection, and the cost of machining and polishing as well, which enhances the reliability of the component in use, and hence achieving a higher structural integrity*. Developing new materials with increasing resistance to wear and corrosion is the goal for many researchers and manufacturers as well. Consequently, an attempt to imitate the mechanisms employed by nature through the biological systems have been made to design self-healing materials and coatings for corrosion protection which can result in complete recovery*. Ceramics can be used in many applications including aeroengine turbine blades, gas turbine blades, high performance bearings and many other applications that require high temperature service *. However, these ceramics have low fracture toughness, which means that they are brittle and sensitive to flaws such as micro and macro cracks, which limit their applications as structural components. The present research is focused on the self-crack healing ability of Spinel nanocomposites and SiC bonded Kaolinite. The self-crack healing behavior was investigated as a function of the healing conditions (time, temperature, and chemical composition) as well as the mechanism responsible for healing the cracks.