Abradable Coating Wear Indication via Embedded Microspheres

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Solution Overview

Problem

Current methods for determining the thickness of abradable coatings in high-temperature mechanical systems, such as gas turbine engines, lack a simple and accurate visual inspection method, which can lead to inefficiencies and reduced performance due to unclear wear indicators.

Innovation Solution

Incorporating a plurality of microspheres with distinct visual characteristics into the abradable coating, which are embedded at a predetermined depth, allowing for visual inspection to estimate the coating thickness and wear level, facilitating on-wing inspection and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional abradable coating is used without visual indicators, then the coating provides sealing function, but the thickness and wear level cannot be accurately determined

Engineering Contradiction:
Improvecoating thickness measurementVSAvoidinspection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent incorporates microspheres with distinct visual characteristics (different colors or reflectivity) at predetermined depths within the abradable coating. As the coating wears, these microspheres become exposed at the surface, providing visual indicators of the remaining coating thickness. This allows maintenance personnel to accurately assess coating wear levels through simple visual inspection without requiring complex measurement equipment.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If complex inspection methods are used to determine coating thickness, then measurement precision improves, but ease of operation deteriorates

Engineering Contradiction:
Improvewear indicator accuracyVSAvoidinspection simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The abradable coating is designed to be self-indicating through the embedded microspheres. The coating itself provides the measurement information through visible visual cues (color changes or reflectivity differences) as it wears down. Maintenance personnel can perform simple visual inspections to determine coating thickness and wear levels without requiring specialized equipment or complex procedures, making the inspection process accessible and straightforward.

Inventive Principle:
Principle #25Self-service

3Loss of information

If visual indicators are added to the coating, then coating thickness can be determined, but manufacturing complexity increases

Engineering Contradiction:
Improvewear information visibilityVSAvoidcoating application process
Core Design Contradiction:
Loss of informationVSEase of manufacture

Solution Approach 1:

The patent combines the functional abradable coating material with visual indicator microspheres into a single integrated coating system. The microspheres are incorporated into the coating matrix during the coating application process, allowing the coating to be applied in a single step that provides both sealing functionality and wear indication capabilities. This merging of functions reduces the need for separate application processes and simplifies manufacturing.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2962844B1Visual indicator of coating thickness
Publication Date: 2024.09.04 ROLLS ROYCE CORP
  • EP2962844B1 patent drawingFigure 1
  • EP2962844B1 patent drawingFigure 2
  • EP2962844B1 patent drawingFigure 3

AI summary

In some examples, a coating may include at least one feature that facilitates visual determination of a thickness of the coating. For example, the coating may include a plurality of microspheres disposed at a predetermined depth of the coating. The plurality of microspheres may define a distinct visual characteristic. By inspecting the coating and viewing at least one of the microspheres, the thickness of the coating may be estimated. In some examples, the plurality of microspheres may be embedded in a matrix material, and the distinct visual characteristic of the microspheres may be different than the visual characteristic of the matrix material. In other examples, the at least one feature may include at least one distinct layer in the coating system that includes a distinct visual characteristic, such as a color of the distinct layer.