Patent ID: 6221512
Filing Date: 2001-04-24
Classification: C23C,Y10T

Abstract:
A metallic article comprising a bond coating on the metallic article and a ceramic thermal barrier coating on the bond coating, the ceramic thermal barrier coating comprising a plurality of columnar grains extending substantially perpendicular to the surface of the metallic article, the ceramic thermal barrier coating comprising an inner portion adjacent the bond coating, a transition portion on the inner portion and an outer portion on the transition portion, the inner portion having columnar grains grown in a competitive manner, the outer portion having columnar grains grown in a steady state manner, the transition portion having columnar grains grown in transition from competitive manner to steady state manner, in the outer portion each columnar grain having substantially constant cross-sectional area throughout its length, each columnar grain having smooth sides without the presence of sub-grains projecting therefrom and each columnar grain being separated from adjacent columnar grains by uniform clearances to minimize the stress and strain in the columnar grains and/or to minimize the stress and strain between adjacent columnar grains and thereby increase the resistance to spallation of the ceramic thermal barrier coating.