A method of preparing a superalloy component to receive a ceramic thermal barrier coating without an intermediate bond coat is disclosed. The superalloy substrate is degreased, abrasively cleaned, ultrasonically cleaned, washed in an aqueous bath containing a wetting agent, rinsed at least once, and then heat treated in an atmosphere that is non-reactive with the substrate and alumina at a temperature and time sufficient to form a surface alumina layer which is predominantly alumina.