Method for Providing a Thermal Barrier Coating and Substrate Having Such Coating
OwnerThijs Joost Nijdam, Lars Petrus Henricus Jeurgens +1inventors
InventorsThijs Joost Nijdam, Lars Petrus Henricus Jeurgens, Willem Gerrit Sloof
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Abstract
Method for providing a thermal barrier coating and substrate. The thermal barrier coating (5) is provided on a thermally grown oxide (4) which is grown on a metallic bond coating (3) provided on the substrate (1) Adhesion between the bond coating (3) and thermally grown oxide coating (4) is improved by providing projections at the interface of yttriaalumina garnet (4) compounds. Service life at relatively high temperature of the thermally grown oxide coating (4) is improved by having alumina grain (6) with relatively large size. These are obtained by pre-annealing the bond coating (3) in an inert gas atmosphere followed by controlled preoxidation.
Claims12
1-11. (canceled)
A method for providing a thermal barrier coating on a substrate comprising the provision of a metal bond coating on said substrate, followed by the provision of a thermally grown alumina on said metal coating, after which a ceramic coating is applied, wherein said thermally grown alumina is realized by a pre-oxidation treatment of said bond coating, wherein after provision of said bond coating and before the pre-oxidation treatment thereof the bond coating is annealed by subjecting to a temperature 1000-1200° C. during 5-60 min. at a pressure lower than 10−3 Pa.
Substrate comprising a thermal barrier coating having a bond coating, a thermally grown alumina and a ceramic layer, wherein at the interface between said bond coating and said thermally grown layers protrusions comprising an impurities scavenging element oxide surrounded by alumina, such as an yttria alumina garnet are provided, wherein the grain size of the aluminum oxides in said thermally grown oxide layer is larger than 1 μm.
Turbine blade comprising an Ni or Co based alloy substrate comprising a thermal barrier coating having a bond coating, a thermally grown alumina and a ceramic layer, wherein at the interface between said bond coating and said thermally grown layers protrusions comprising an impurities scavenging element oxide surrounded by alumina, such as an yttria alumina garnet are provided, wherein the grain size of the aluminum oxides in said thermally grown oxide layer is larger than 1 μm.
Dependencies are inferred from the claim text.