What are the characteristics and application characteristics of thermal barrier coatings?

       Thermal barrier coatings have low thermal conductivity, act as a thermal barrier to prevent the base material from reaching its melting point, and also have the effect of transferring radiant heat. Its general characteristics and applications are:

(1) It must be resistant to oxidation under the working environment temperature;

(2) The cyclical change of temperature will affect the thermal fatigue resistance and thermal shock resistance of the coating. The larger the temperature change range and the faster the cooling rate, the greater the tendency of the coating to peel off;

(3) Coating and base material body materials should have similar thermal expansion coefficients;

(4) fully consider the duration of exposure;

(5) The lower the emissivity of the coating (the ratio of the radiant energy emissivity of the coating to that of the ideal radiator), the better its function as an insulator;

(6) Low-density coatings are better thermal insulators, and are less sensitive to thermal shock;

(7) Thermal barrier coatings are used in induction coils of high temperature furnaces, rocket engine combustion chambers, rocket engine propulsion chambers, brazing and heat treatment fixtures, etc.;

(8) The thermal barrier coating can be made of high temperature oxide coating AI2O3 or ZrO2 stabilized with CaO, MgO, Y2O3, etc.