Abstract: An electrochemical process for selectively stripping at least one coating from the surface of a substrate is disclosed. The substrate (often a turbine engine component) is immersed in a composition through which electrical current flows. The composition includes a halide salt, such as sodium chloride, ammonium chloride, and potassium chloride. In preferred embodiments, the electrical current is direct current (DC). The process is especially useful for selectively removing portions of diffusion aluminide coatings. For example, the additive layer can efficiently be removed, without substantially affecting the underlying diffusion layer or substrate. Related stripping compositions and apparatuses are also described.

Abstract: A method for selectively removing one or more coatings from the surface of a substrate is described. The coating is treated with an aqueous composition which includes an acid of the formula HxAF6, or precursors to such an acid. In that formula, A is Si, Ge, Ti, Zr, Al, and Ga; and x is 1-6. The acid is often H2SiF6. The composition may sometimes include at least one additional acid, such as phosphoric acid. The coating being removed is often an aluminide coating or an MCrAl(X)-type material. The substrate is usually a polymer or a metal, such as a superalloy.

Abstract: An electrochemical process for selectively stripping at least one coating from the surface of a substrate is disclosed. The substrate (often a turbine engine component) is immersed in a composition through which electrical current flows. The composition includes a halide salt, such as sodium chloride, ammonium chloride, and potassium chloride. In preferred embodiments, the electrical current is direct current (DC). The process is especially useful for selectively removing portions of diffusion aluminide coatings. For example, the additive layer can efficiently be removed, without substantially affecting the underlying diffusion layer or substrate. Related stripping compositions and apparatuses are also described.

Abstract: A fluorescent probe is applied to bind to a metal oxide on a substrate and the substrate is exposed to an ultraviolet light to identify the metal oxide. A chemical cleaning or stripping solution is selected by combinatorial high throughput screening (CHTS). In the method, an array of regions is defined on a substrate, a candidate cleaning/stripping solution is deposited onto the regions to effect cleaning/stripping of the regions; a fluorescent probe is applied to bind to a metal oxide on the substrate; the substrate is exposed to an ultraviolet light to identify the metal oxide and a product of the cleaning/stripping is evaluated according to the identified metal oxide. An activated metal substrate composition is provided that comprises a metal substrate with a contaminant metal oxide coating and a fluorescent activator bound to the substrate by reaction with the metal oxide coating.

Abstract: A liquid chemical stripping or cleaning solution is selected by combinatorial high throughput screening. A high throughput screening well array assembly includes (A) a metal substrate and (B) a mask that defines an array of wells on the substrate. A combinatorial high throughput screening system includes (A) a metal substrate and (B) a mask that defines an array of wells on the substrate and a reaction vessel to receive the well array assembly.

Abstract: In a method for cleaning an engine component, an engine component is provided and is immersed in an acid solution selected from phosphoric acid, citric acid and acetic acid. A cleaning composition for an engine component comprises an agitated acid solution selected from phosphoric acid, citric acid and acetic acid.

Abstract: A fluorescent probe is applied to bind to a metal oxide on a substrate and the substrate is exposed to an ultraviolet light to identify the metal oxide. A chemical cleaning or stripping solution is selected by combinatorial high throughput screening (CHTS). In the method, an array of regions is defined on a substrate, a candidate cleaning/stripping solution is deposited onto the regions to effect cleaning/stripping of the regions; a fluorescent probe is applied to bind to a metal oxide on the substrate; the substrate is exposed to an ultraviolet light to identify the metal oxide and a product of the cleaning/stripping is evaluated according to the identified metal oxide. An activated metal substrate composition is provided that comprises a metal substrate with a contaminant metal oxide coating and a fluorescent activator bound to the substrate by reaction with the metal oxide coating.

Abstract: A method includes providing a substrate and depositing components of a test contaminant library onto regions of the substrate to form at least two test contaminant members of the library. In another method, a chemical cleaning solution is selected by combinatorial high throughput screening. In the method, components of a test contaminant library are deposited onto regions of a substrate to form at least two test contaminant members of the library. The substrate is cleaned with a cleaning solution and cleanliness of the substrate evaluated to select a cleaning solution for at least one of the contaminant members. In a final embodiment, the invention is a combinatorial high throughput screening array plate, comprising (A) a substrate and (B) a test contaminant library deposited on the substrate.

Abstract: A liquid chemical stripping or cleaning solution is selected by combinatorial high throughput screening. A high throughput screening well array assembly includes (A) a metal substrate and (B) a mask that defines an array of wells on the substrate. A combinatorial high throughput screening system includes (A) a metal substrate and (B) a mask that defines an array of wells on the substrate and a reaction vessel to receive the well array assembly.

Abstract: In a method for cleaning an engine component, an engine component is provided and is immersed in an acid solution selected from phosphoric acid, citric acid and acetic acid. A cleaning composition for an engine component comprises an agitated acid solution selected from phosphoric acid, citric acid and acetic acid.

Abstract: A liquid chemical stripping or cleaning solution is selected by combinatorial high throughput screening. A high throughput screening well array assembly includes (A) a metal substrate and (B) a mask that defines an array of wells on the substrate. A combinatorial high throughput screening system includes (A) a metal substrate and (B) a mask that defines an array of wells on the substrate and a reaction vessel to receive the well array assembly.