According to the different functions of the coating, the application of nano-ceramic coatings can be roughly divided into the following categories:


1
Nanostructured ZrO2 thermal barrier coatings
Thermal barrier coatings (TBCs) are mainly used in high-temperature atmospheres or hot-corrosive static and dynamic atmospheres. They can significantly reduce the surface temperature of turbine components, increase gas turbine power, and improve thermal efficiency. They have been successfully applied to aircraft engines and will be extended to diesel engines as well as automobile and motorcycle engines. Nanostructured thermal barrier coatings have been widely studied and applied due to their superior performance. Nanostructured ZrO2 coatings have low thermal conductivity, thermal expansion coefficients similar to those of metals, and good stability at high temperatures. They are currently the representative of thermal barrier coatings. The main reasons are:


(1) Reducing the length of cracks in the coating and improving the fracture toughness of the coating;


(2) The grain boundary scattering of photoelectrons is enhanced, which reduces the thermal conductivity of the coating;


(3) By introducing controllable micropores, the electron and photon scattering and radiation between the grain boundaries and layers in the coating are changed.