Electroplated Fan Blade Sheath for Impact-Resistant Composite Edges

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Thermoplastic or thermoset composite fan blades face issues with through-thickness impact capability, leading to delamination and damage due to tip deflections, and current adhesive-based titanium sheaths are costly and unreliable in dynamic impacts.

Innovation Solution

An electroplated sheath is applied to the composite fan blade surfaces, including the leading edge, trailing edge, and tip, using a nickel alloy plating material, with a bond coat for enhanced adhesion, extending from the platform portion to the tip and along the airfoil portion, providing mechanical locking and improved impact resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If adhesively bonded titanium sheath is used, then corrosion resistance is improved, but manufacturing cost increases and reliability deteriorates in dynamic impact

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidadhesive bond reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent replaces the adhesive bonding system with an electroplated metal sheath system. Instead of relying on chemical adhesive bonds to attach titanium sheath to composite fan blade, the invention uses electroplating to create a metallurgical bond between the sheath and substrate, substituting mechanical/chemical bonding with an electrochemical deposition process that creates a more reliable structural attachment resistant to dynamic impact forces

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

Solution Approach 2:

The patent creates a composite structure consisting of the electroplated metal sheath layer combined with the composite fan blade substrate. This composite material system integrates the corrosion resistance of metal plating with the lightweight properties of composite materials, while the electroplated layer provides both protective and structural functions simultaneously

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If adhesively bonded titanium sheath is used, then corrosion resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidmachining complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical machining operations with an electroplating process. Instead of requiring precise machining of titanium details and complex adhesive bonding procedures, the invention uses electrochemical deposition to form the protective sheath, significantly simplifying the manufacturing process while maintaining corrosion resistance

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

Solution Approach 2:

The patent changes the manufacturing approach from mechanical processing (machining and adhesive bonding) to electrochemical processing (electroplating). This parameter change in the manufacturing method transforms a complex multi-step mechanical process into a more straightforward electrochemical deposition process, reducing manufacturing complexity while achieving the same protective function

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If electroplated sheath is used, then manufacturing cost is reduced, but impact resistance must be maintained

Engineering Contradiction:
Improvemanufacturing costVSAvoidimpact resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent creates a composite structure where the electroplated metal sheath works synergistically with the composite fan blade substrate to provide impact resistance. The composite material system combines the ductility and toughness of metal plating with the high strength-to-weight ratio of composite materials, achieving superior impact resistance compared to either material alone while maintaining cost effectiveness

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

The electroplated sheath enhances impact resistance, reduces manufacturing costs, eliminates bonding-related issues, and ensures uniform coverage with minimal weight increase, offering improved structural integrity and corrosion resistance.

Implementation Method 1

a sheath electroplated to a surface of the composite fan blade proximate at least one of the leading edge, the trailing edge and the tip

Methodology Applied
Scientific EffectElectroplating: Electroplating

Data Source

PatentEP4663955A1In-situ electroplated sheath for composite fan blade
Publication Date: 2025.12.17 RTX CORP
  • EP4663955A1 patent drawingFigure 1
  • EP4663955A1 patent drawingFigure 2
  • EP4663955A1 patent drawingFigure 3

AI summary

An electroplated sheath for a composite fan blade including a root portion adjacent a platform portion and an airfoil portion adjacent the platform portion and a tip adjacent the airfoil portion opposite the root portion; the airfoil portion defines a blade chord between a leading edge and a trailing edge; the airfoil portion defines a concave pressure side and a convex suction side defined between the leading edge and the trailing edge; and a sheath electroplated to a surface of the composite fan blade proximate at least one of the leading edge, the trailing edge and the tip.