Thermal barrier coated articles and method for coating

摘要

A coating system, coated article and method are provided which yield a thermal barrier coating (26) having good adhesion to a bond coat (24) overlying a metal superalloy substrate (22). The adhesion of the bond coat (24) and the thermal barrier coating (26) (TBC) is achieved by formation of a mature alpha -Al203 (rhombohedral) scale (28) at the bond coat/TBC interface. The adhesion of the thermal barrier coating (26) to the bond coat (24) is enhanced by utilizing one or more of the following steps (1) preoxidation of the bond coat (24), (2) inoculation of the surface of the bond coat (24), (3) surface doping of the bond coat surface, and (4) the addition of noble metals. The above step improves the formation of alpha -Al203 which improves the adhesion of the TBC to the bond coat by avoiding undesired oxide phase transformations. <IMAGE>