Controlled oxidation of bond coat
OwnerRobert F. Latour, James W. Nealinventors
Life of this patent
Estimating the term…
Abstract
A method of processing an article includes heating the article in an atmosphere substantially free of oxygen to an oxidation temperature within a predetermined temperature range. The article includes a substrate and a bond coat disposed on the substrate. A partial pressure of oxygen is then established within the atmosphere after heating to the oxidation temperature. At least a portion of the bond coat oxidizes in the partial pressure of oxygen at the oxidation temperature to form a desired type of oxide to the substantial exclusion of forming other types of oxides. A ceramic coating is then deposited on the oxide.
Claims17
A method of processing an article, comprising:
- heating an article in an atmosphere substantially free of oxygen to an oxidation temperature within a predetermined temperature range, the article including a substrate and a bond coat disposed on the substrate;
- establishing a partial pressure of oxygen within the atmosphere after heating to the oxidation temperature;
- oxidizing at least a portion of the bond coat in the partial pressure of oxygen at the oxidation temperature to form a desired type of oxide to the substantial exclusion of forming other types of undesired oxides;
- and
- depositing a ceramic coating on the oxide.
A method of processing an article, comprising:
- heating an article in a low pressure atmosphere that is substantially free of oxygen to an oxidation temperature above about 1800° F. (982° C.), the article including a substrate and a bond coat comprising MCrAlY disposed on the substrate, wherein the M is selected from a group consisting of cobalt, nickel, iron, and combinations thereof, the Cr is chromium, the Al is aluminum, and the Y is yttrium;
- establishing a partial pressure of oxygen after heating to the oxidation temperature such that the low pressure atmosphere is at a pressure of no greater than 0.1 ton (13.3 pascals);
- oxidizing at least a portion of the bond coat in the partial pressure of oxygen at the oxidation temperature to form alpha-alumina to the substantial exclusion of forming other types of alumina;
- and
- depositing a ceramic coating on the oxide.
An article for use in a gas turbine engine, comprising:
- a substrate;
- a bond coat disposed on the substrate, the bond coat comprising MCrAlY, wherein the M is selected from a group consisting of cobalt, nickel, iron, and combinations thereof, the Cr is chromium, the Al is aluminum, and the Y is yttrium, and at least a portion of the Al is alpha-alumina oxide;
- and
- a ceramic coating disposed on the bond coat.
Dependencies are inferred from the claim text.