Oxidation resistant protective coating system for gas turbine components, and process for preparation of coated components

Claim 2

A composition of a coating for protecting a component of a gas turbine from damage at elevated temperatures, consisting essentially of an alloy of ingredients in about the following weight percentages: ______________________________________ chromium 15-35 aluminum 8-20 tantalum 1-10 tantalum + niobium 1-10 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-1 cobalt 0-10 nickel balance totalling 100 percent ______________________________________

Claim 3

The composition of claim 1, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 17-23 aluminum 10-13 tantalum + niobium 3-8 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 4

The composition of claim 1, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 20 aluminum 11 tantalum + niobium 7 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 5

The composition of claim 1, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 20 aluminum 11 tantalum 7 niobium 0-trace hafnium 1 silicon 1 yttrium 0-trace cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 6

The composition of claim 1, wherein the coating is present on the surface of a turbine component substrate and further contains minor amounts of elements normally present in the substrate which enter the coating during exposure at elevated temperatures, and wherein some ingredients initially present in the coating are depleted after diffusion.

Claim 7

A coated component for use in a gas turbine engine, comprising: a substrate; and a coating on said substrate, said coating consisting essentially of an alloy of ingredients in about the following weight percentages: ______________________________________ chromium 15-35 aluminum 8-20 tantalum 1-10 tantalum + niobium 1-10 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-1 cobalt 0-10 nickel balance totalling 100 percent ______________________________________

Claim 8

A coated component for use in a gas turbine engine, comprising: a substrate; and a coating on said substrate, said coating consisting essentially of an alloy of ingredients in about the following weight percentages: ______________________________________ chromium 15-35 aluminum 8-20 tantalum 1-10 tantalum + niobium 1-10 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-1 cobalt 0-10 nickel balance totalling 100 percent ______________________________________

Claim 9

The component of claim 6, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 17-23 aluminum 10-13 tantalum + niobium 3-8 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 10

The component of claim 6, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 20 aluminum 11 tantalum + niobium 7 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 11

The component of claim 6, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 20 aluminum 11 tantalum 7 niobium 0-trace hafnium 1 silicon 1 yttrium 0-trace cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 12

The component of claim 6, wherein said substrate is formed to a shape selected from the group consisting of a turbine blade and a turbine vane.

Claim 13

The component of claim 6, wherein said substrate is of a single crystal alloy material.

Claim 14

The component of claim 6, wherein the coating further contains minor amounts of elements normally present in the substrate which have entered the coating during exposure at elevated temperature, and wherein some elements initially present in the coating are depleted after diffusion.

Claim 15

A process for protecting a gas turbine component from the adverse effects of elevated temperature operation, comprising the steps of: furnishing a coating starting material; and applying the coating starting material to the surface of the component so that the composition of the coating in place on the component is an alloy consisting essentially of the following weight percentages of ingredients: ______________________________________ chromium 15-35 aluminum 8-20 tantalum 1-10 tantalum + niobium 1-10 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-1 cobalt 0-10 nickel balance totalling 100 percent ______________________________________

Claim 16

A process for protecting a gas turbine component from the adverse effects of elevated temperature operation, comprising the steps of: furnishing a coating starting material; and applying the coating starting material to the surface of the component so that the composition of the coating in place on the component is an alloy consisting essentially of the following weight percentages of ingredients: ______________________________________ chromium 15-35 aluminum 8-20 tantalum 1-10 tantalum + niobium 1-10 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-1 cobalt 0-10 nickel balance totalling 100 percent ______________________________________

Claim 17

The process of claim 13, wherein said step of applying is performed by an overlay method.

Claim 18

The process of claim 13, wherein said step of applying is performed by a method selected from the group consisting of plasma spraying, electron beam physical vapor deposition, and sputtering.

Claim 19

The process of claim 13, wherein the coating starting material is an alloy consisting essentially of the following weight percentages of ingredients: ______________________________________ chromium 15-35 aluminum 8-20 tantalum + niobium 1-10 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-10 nickel balance totalling 100 percent ______________________________________

Claim 20

The process of claim 13, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 20 aluminum 11 tantalum + niobium 7 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 21

The process of claim 13, wherein the ingredients are present in about the following amounts: ______________________________________ chromium 20 aluminum 11 tantalum + niobium 7 silicon 0.1-1.5 hafnium 0.1-1.5 yttrium 0-0.8 cobalt 0-trace nickel balance totalling 100 percent ______________________________________

Claim 22

A component prepared in accordance with claim 13.

Claim 23

The process of claim 13, wherein the coating starting material has substantially the same composition as the coating in place on the component.

Claim 24

The process of claim 13, including the additional step of exposing the coated components to elevated temperature so that the chemical composition of the coating is altered by diffusion.

Claim 25

A component prepared in accordance with claim 21.