What material is used for bonding the bottom layer of thermal barrier coating, and the role of each component

       A typical bonding primer material is MCrAIX alloy. Cr plays the role of improving anti-oxidation and high-temperature corrosion resistance, and Al plays the role of anti-oxidation (a film of aluminum oxide is formed during high-temperature use). M is the basic constituent element of the bonding bottom layer, generally iron group elements or high melting point metal elements and combinations of these elements, such as Ni, Co, Fe, Ni-Co, Ni-Fe; X is an active metal, which is to increase the bonding strength And elements added to improve the oxidation resistance of the coating, including more active elements such as Y, Hf, Sc, Ce, La, Th, etc., the most commonly used is Y, Y to enhance the bonding performance of the aluminum oxide film.



The aluminum-rich layer is prepared on the surface of the bonding bottom layer by aluminizing process, which can reduce the oxidation rate of the bonding bottom layer and improve the service life of TBC; adding Re and Ta to CoNiCrAIY can significantly improve the oxidation resistance and mechanical properties of the bonding bottom layer.