Researchers at Texas A&M have found a previously unknown self-healing mechanism in one type of ceramic: it works at room temperature.
Under mechanical stress, ceramics often crack, so a product made of it is easy to break. Some ceramics can be repaired after a crack, but this usually requires chemical reactions that occur at very high temperatures.
The authors of the new work, in the course of a new study, found a certain type of ceramic – chromium aluminum carbide – it can slow down the propagation of cracks and even heal itself at room temperature.
The new ceramic consists of alternating layers of material, it is this structure that allows the product to repair cracks. When a crack appears, defects form between the different layers, they are called inflection lines. The crystals in the fold lines rotate when pressure is applied to prevent further crack propagation.
Also, these rotating crystals actively heal the crack and are almost impossible to detect.
The researchers note that this type of self-healing ceramic can be used to repair cracks that form in materials subjected to high stress. For example, in jet engines, hypersonic aircraft and nuclear reactors. The authors believe that a similar effect can be obtained when working with other materials with a similar layered structure.