Patent ID: 7008674
Filing Date: 2006-03-07
Classification: C23C,F01D,F02C,F05D,Y10T

Abstract:
1. A method for preparing a thermal barrier coating on a bond coat layer that is adjacent to and overlies an underlying metal substrate, the method comprising the steps of: 1. forming on the bond coat layer an inner layer comprising a non-alumina ceramic thermal barrier coating material in an amount up to 100% by weight, wherein the inner layer is formed by plasma spraying the non-alumina ceramic thermal barrier coating material on the bond coat layers; and 2. codepositing on the inner layer a non-alumina ceramic thermal barrier coating material and alumina so as to form an outer layer of different composition than the inner layer having an exposed surface by combining the non-alumina ceramic thermal barrier coating material and alumina to form a substantially homogeneous mixture and then plasma spraying the mixture on the inner layer, the outer layer comprising from about 80 to about 90% by weight of the non-alumina ceramic thermal barrier coating material and from about 10 to about 20% by weight alumina and in an amount sufficient to protect the thermal barrier coating at least partially against environmental contaminants that become deposited on the exposed surface.