Investment Casting Core Strengthening Coating for Fine Detail Integrity

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Solution Overview

Problem

Investment casting processes for gas turbine engine components face challenges in maintaining the integrity and surface smoothness of complex geometries, particularly with fine details like film cooling holes, which are prone to breakage due to surface roughness and structural weaknesses.

Innovation Solution

A strengthening coating, comprising metal oxides, nitrides, or carbides, is applied to the core and/or shell using methods like vapor deposition or spray coating, focusing on fine details and portions susceptible to damage, to enhance structural integrity and surface smoothness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a core is used to form complex geometries with fine details, then the component's geometric complexity is improved, but the fine details are prone to breakage due to surface roughness and structural weaknesses

Engineering Contradiction:
Improvegeometric complexityVSAvoidfine detail integrity
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The patent applies a strengthening coating comprising metal oxide, nitride, or carbide materials to the core surface. This creates a composite structure where the coating layer reinforces the ceramic core material, providing enhanced strength and surface smoothness to fine details while maintaining the core's geometric complexity capability

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The strengthening coating is selectively applied to portions of the core that require enhanced strength and surface smoothness, such as fine details and complex geometries. This localized application provides targeted reinforcement without unnecessarily coating entire surfaces, addressing the specific vulnerability of fine details while preserving geometric complexity

Inventive Principle:
Principle #3Local quality

2Strength

If a strengthening coating is applied to the core, then the fine detail integrity is improved, but the manufacturing process complexity increases

Engineering Contradiction:
Improvefine detail integrityVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The strengthening coating is applied to the core before the shell is formed and before casting. This preliminary action ensures that fine details are reinforced in advance, preventing breakage during subsequent handling and casting operations without requiring additional complex equipment or processes later in the manufacturing sequence

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If the core surface is rough, then the manufacturing process is simpler, but the casting surface finish deteriorates

Engineering Contradiction:
Improvecore fabrication easeVSAvoidsurface smoothness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The strengthening coating provides a smooth surface layer on top of the potentially rougher core material. This composite approach maintains the ease of core fabrication while the coating layer itself provides the required surface smoothness for high-quality castings

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The coating is applied to provide surface smoothness specifically where required for casting quality, while allowing the core fabrication process to remain simple. The coating layer locally improves surface finish without complicating the overall core manufacturing process

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 coating reinforces the core and shell, reducing surface roughness and preventing breakage of fine features, thereby improving the casting process's reliability and quality by providing a smoother, more durable surface.

Implementation Method 1

A strengthening coating, comprising metal oxides, nitrides, or carbides, is applied to the core and/or shell using methods like vapor deposition or spray coating

Methodology Applied
Scientific EffectVapor deposition: Physical Vapour Deposition

Implementation Method 2

A strengthening coating, comprising metal oxides, nitrides, or carbides, is applied to the core and/or shell using methods like vapor deposition or spray coating

Methodology Applied
Scientific EffectSpray coating: Spray

Data Source

PatentEP3246109B1Casting system for investment casting process
Publication Date: 2023.08.16 RTX CORP
  • EP3246109B1 patent drawingFigure 1
  • EP3246109B1 patent drawingFigure 2
  • EP3246109B1 patent drawingFigure 3~5

AI summary

An investment casting system (100) includes a core (122) having at least one fine detail, a shell (124) positioned relative to said core (122), and a strengthening coating (126) applied at least to the at least one fine detail.