Leading Edge Shield Forming With Additive Reinforcement

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Solution Overview

Problem

Current methods for manufacturing leading edge shields, typically made of titanium alloys, face challenges such as significant tool wear, numerous manufacturing steps, material waste, and difficulty in achieving thin thicknesses and small radii due to complex aerodynamic shapes, leading to high costs and inefficiencies.

Innovation Solution

A method involving initial plastic deformation of intrados and extrados sheets, addition of reinforcement via additive manufacturing, closure around a core, and subsequent compression to form a shield with thin fins and a thicker central section, largely avoiding material machining and ensuring strong bonding and precise tolerances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If traditional forging methods are used to manufacture leading edge shields, then the shields can be made with complex aerodynamic shapes, but significant tool wear and a large number of manufacturing steps occur, leading to high costs

Engineering Contradiction:
Improvecomplex aerodynamic shapeVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The shield manufacturing process is divided into separate stages: initial plastic deformation to form basic shape, additive manufacturing for reinforcement features, and final compression forming. This segmentation allows each stage to focus on specific geometric requirements, reducing overall process complexity while achieving complex final shapes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The initial plastic deformation step pre-forms the shield components (intrados and extrados fins) before the final compression stage. This preliminary shaping reduces the complexity of the final forming operation and allows for better control of the complex aerodynamic geometry.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If traditional forging methods are used, then shields can be manufactured, but a large number of manufacturing steps are required, increasing production time and cost

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidmanufacturing efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

Multiple manufacturing operations are merged into a single integrated process: the initial plastic deformation, additive manufacturing of reinforcements, and final compression forming are combined into one continuous workflow. This eliminates the need for separate manufacturing steps and significantly improves productivity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The manufacturing process maintains continuous useful action by transitioning directly from initial plastic deformation to additive manufacturing, and then to final compression forming without intermediate handling or setup changes. This continuous process eliminates idle time and maximizes manufacturing efficiency.

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If machining is used to create thin fins and small radii, then precise dimensions can be achieved, but significant material waste and tool wear occur

Engineering Contradiction:
Improvedimensional accuracyVSAvoidmaterial waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

Traditional mechanical machining operations are replaced with plastic deformation and additive manufacturing processes. The initial plastic deformation and subsequent compression forming reshape the material without removal, while additive manufacturing builds reinforcement features directly. This substitution eliminates material waste and tool wear associated with machining while maintaining precise dimensional control.

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

Solution Approach 2:

The manufacturing approach changes from subtractive (machining) to formative (plastic deformation and additive manufacturing). By changing the fundamental manufacturing parameter from material removal to material shaping and addition, the process achieves precise dimensions for thin fins and small radii without the associated material waste and tool wear of traditional machining.

Inventive Principle:
Principle #35Parameter changes

4Loss of substance

If additive manufacturing is used to add reinforcement, then material waste is reduced, but the surface roughness may affect the quality of outer surfaces

Engineering Contradiction:
Improvematerial efficiencyVSAvoidsurface quality
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The additive manufacturing process is applied to the inner surfaces of the shield components during the initial plastic deformation stage, before final forming. By operating in this intermediate dimensional state and positioning reinforcements on inner surfaces, the process achieves material efficiency while the subsequent compression forming smooths and finalizes the outer surfaces, separating the reinforcement addition from the final surface quality requirement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 enables economical manufacturing of leading edge shields with complex shapes while minimizing material waste and tool wear, achieving high resistance to fatigue and maintaining aerodynamic performance.

Implementation Method 1

additive manufacturing method, such as for example selective melting by laser

Methodology Applied
Scientific EffectSelective melting by laser: Laser

Implementation Method 2

deposition by plasma

Methodology Applied
Scientific EffectDeposition by plasma: Plasma Spray

Implementation Method 3

initial plastic deformation of at least one sheet from among an intrados sheet and an extrados sheet

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 4

a subsequent plastic deformation, by compression against an outer surface of the core

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3194112B1Method of manufacturing a leading edge shield
Publication Date: 2021.05.19 SAFRAN AIRCRAFT ENGINES SAS
  • EP3194112B1 patent drawingFigure 1~3
  • EP3194112B1 patent drawingFigure 4~5C
  • EP3194112B1 patent drawingFigure 5D~5H

AI summary

The invention relates to the field of rotary blades and more particularly to a method of manufacturing a leading edge shield intended to protect such a blade. This method involves at least the steps of initial plastic deformation of at least one sheet out of a pressure-face sheet (17) and a suction-face sheet (18), using additive manufacturing to add a reinforcer (15, 16) with fibrous insert (14) to at least one of said pressure-face and suction-face sheets (17, 18), closing said pressure face and suction-face sheets (17, 18) around a core (20), after said initial plastic deformation and the addition of each reinforcer (15, 16), subsequent plastic deformation, by compression against an external surface of the core (20) of said pressure-face and suction-face sheets (17, 18) after they have been closed around the core (20), and extracting the core (20).