Abradable Coating Construction via Slurry Lamination and Laser Sintering

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Solution Overview

Problem

The existing methods for constructing abradable coatings, which involve plasma spraying with a mask, face inefficiencies due to mask clogging and the need for frequent mask replacement, hindering construction efficiency and free-cutting ability.

Innovation Solution

A method that forms sintered layers using ceramic slurries with varying particle ratios and laser sintering, eliminating the need for masks by laminating layers with high adhesiveness and free-cutting ability, and incorporating a pore-forming material to enhance free-cutting capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plasma spraying with a mask is used to form ceramic layers, then the coating can be formed on the base material, but the mask slits may close (clog) during spraying, requiring frequent mask replacement and reducing construction efficiency

Engineering Contradiction:
Improvemask durabilityVSAvoidconstruction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention removes the mask component entirely from the coating formation process. Instead of using plasma spraying with a mask, the patent employs a slurry application method where the ceramic slurry is directly applied to the base material without any masking, thereby eliminating mask clogging and replacement issues while maintaining coating formation capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical plasma spraying system with a chemical slurry-based system. Instead of using plasma spray deposition through mask slits, the patent uses slurry application followed by drying and heat treatment, substituting the mechanical spraying process with a chemical deposition approach that avoids mask-related problems

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If a uniform abradable coating layer is formed on complex surfaces (curved, concave, or convex), then free-cutting ability is improved, but mask-based methods cannot achieve uniform coverage on such surfaces

Engineering Contradiction:
Improvecoating uniformityVSAvoidsurface compatibility
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The invention changes the application method parameters from fixed mask-based plasma spraying to flexible slurry application. The slurry can be applied in a manner that adapts to surface geometry, and subsequent heat treatment parameters are optimized to ensure uniform sintering and coating formation across complex surfaces, achieving both uniformity and surface compatibility

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If coarse ceramic particles are used in high proportion to improve free-cutting ability, then material removal is enhanced, but coating adhesiveness and structural integrity may be compromised

Engineering Contradiction:
Improvefree-cutting abilityVSAvoidcoating adhesiveness
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The invention applies different ceramic particle compositions to different regions or layers of the coating. By controlling the spatial distribution of coarse and fine particles, the coating achieves high free-cutting ability at the cutting interface while maintaining adequate adhesiveness and structural integrity in the bulk coating structure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention creates a composite ceramic coating structure combining coarse and fine particles in specific proportions and arrangements. This composite structure leverages the cutting advantages of coarse particles while using fine particles to fill gaps and enhance bonding, achieving both high free-cutting ability and coating adhesiveness

Inventive Principle:
Principle #40Composite materials

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

This method streamlines the construction of abradable coatings with high free-cutting ability on complex surfaces, improving efficiency and accuracy, and allows for the reuse of slurry materials, while enhancing the abradable coating's porosity and adhesiveness.

Implementation Method 1

irradiating a laser beam to the ceramic slurry layer and thus sinters the ceramic slurry layer

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

sinters the ceramic slurry layer and thus forms a sintered layer

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 3

scanning the hardened thin green layer with a directed high-power energy beam along a pre-determined path so as to sinter and bond ceramic molecules locally by heat fusion

Methodology Applied
Scientific EffectHeat fusion: Melting

Data Source

PatentEP3427843B1Method for constructing abradable coating, and shroud
Publication Date: 2024.12.04 MITSUBICHI HEAVY IND AERO ENGINES LTD
  • EP3427843B1 patent drawingFigure 1
  • EP3427843B1 patent drawingFigure 2
  • EP3427843B1 patent drawingFigure 3

AI summary

A method for constructing an abradable coating comprises: a slurry layer formation step S2 in which a slurry layer 31 is formed on the surface of a base material 30 using a slurry containing ceramic particles and a solvent; a calcination step S3 in which the slurry layer 31 formed on the surface of the base material 30 is sintered and a sintered layer 35 to be a portion of an abradable coating layer 22 is formed; and a slurry removal step S5 in which extraneous slurry is removed after the abradable coating layer 22 has been formed on the surface of the base material 30, a plurality of the sintered layers 35 having been laminated in the abradable coating layer 22 through a plurality of repeated cycles of the slurry layer formation step S2 and the calcination step S3.