Turbine Blade Multi-Coating Isolation to Prevent Chloride Damage

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Solution Overview

Problem

Conventional two-step coating processes for gas turbine engine components, such as chromide and aluminide coatings, suffer from chloride gas leakage that damages the airfoil and leads to depletion of aluminum, resulting in low engine performance and high scrap rates.

Innovation Solution

A method and kit for simultaneously depositing multiple coatings on a gas turbine engine component by isolating different portions using a masking chamber and maskant, applying a chromium-based powder to one portion and an aluminum-based coating via diffusion to another portion, ensuring both coatings are applied without damaging each other.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a two-step coating process is used (chromide then aluminide), then both corrosion-resistant and oxidation-prohibiting coatings can be applied, but chloride gases leak from the pack during chromide coating and damage the airfoil

Engineering Contradiction:

Improvecoating integrityVSAvoidchloride gas damage to airfoil

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The blade is divided into two separate coating zones using a masking chamber that physically separates the airfoil and shank. The airfoil portion is masked off from the chromide coating pack, allowing chromide to be applied to the shank without chloride gases reaching the airfoil. This segmentation eliminates the harmful interaction while maintaining both coating types.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A masking chamber serves as an intermediary structure between the chromide coating pack and the airfoil surface. This intermediate barrier prevents chloride gases from directly contacting the airfoil while still allowing the chromide coating to be applied to the shank portion of the blade.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If sequential coating is used (chromide first, then aluminide), then proper isolation can be achieved, but the process time and complexity increase

Engineering Contradiction:

Improvecoating isolation qualityVSAvoidtotal coating process time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent combines what would traditionally be sequential operations into a single simultaneous process. By using the masking chamber to isolate zones, both chromide coating on the shank and aluminide coating on the airfoil can be applied at the same time in one continuous operation, eliminating the need for separate coating cycles and reducing total process time.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The masking chamber enables continuous simultaneous coating operations without interruption. While traditional sequential processes require stopping and resetting between coating types, this system maintains continuous coating action on different portions of the blade at the same time, improving productivity without sacrificing coating quality.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If chromide coating is applied to the entire blade, then complete corrosion protection is achieved, but aluminum depletion occurs in internal coatings leading to high scrap rate

Engineering Contradiction:

Improvecorrosion protection coverageVSAvoidaluminum depletion in internal coatings

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

Instead of applying chromide coating uniformly across the entire blade, the masking chamber enables localized application only to the shank portion where corrosion protection is most needed. The airfoil portion receives only aluminide coating, which provides oxidation protection without the aluminum depletion issues associated with chromide. This local differentiation eliminates harmful aluminum depletion while maintaining necessary protection.

Inventive Principle:

Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method reduces time and costs associated with coating processes while preventing degradation of coatings, enhancing engine performance and reducing scrap rates.

Implementation Method 1

applying a chromium-based powder to one portion and an aluminum-based coating via diffusion to another portion

Methodology Applied

Scientific EffectDiffusion coating: Diffusion

Implementation Method 2

isolating different portions using a masking chamber and maskant

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP3255250B1Method for simultaneously depositing multiple coatings on a turbine blade of a gas turbine engine

Publication Date: 2026.04.01 GENERAL ELECTRIC CO

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AI summary

The present disclosure is directed to a method for coating a component of a gas turbine engine (10). The method includes isolating a first portion (105) of the component of the gas turbine engine (10) from a second portion (108) of the component. The method also includes simultaneously depositing a first coating material (112) on the first portion (105) of the component and a second coating material (114) on the second portion (108) of the component, wherein the first and second coating materials (112, 114) are different.