Modification of oxide layer in plasma-sprayed thermal barrier coatings

Formation of Ni(Cr,Al)2O4 and NiO in plasma-sprayed thermal barrier coatings (TBCs) is believed to be detrimental to the durability of TBC systems. Therefore, a heat treatment to the as-sprayed TBC in a low-pressure oxygen environment is developed to produce a uniform thin alumina (Al2O3) layer at the ceramic/bond coat interface, which suppresses the growth of Ni(Cr,Al)2O4 and NiO during later thermal exposure in air.