Cold-Sprayed Metal Layers for Delamination-Free Composite Bends

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Solution Overview

Problem

Metallization of curved composite parts is challenging, especially with limited Z-axis movement in robot applications, and existing methods struggle to form metalized composite parts with complex geometries without delamination.

Innovation Solution

A method involving cold spraying metal particles onto a thermoplastic composite part to form a metal layer, followed by heating and molding to introduce a bend without delamination, using a controlled gas stream and propellant to achieve adhesion and conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metallization methods are used on curved composite parts, then metal layer deposition is achieved, but delamination occurs during molding

Engineering Contradiction:
Improveadhesion of metal layerVSAvoidmolding process capability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by controlling the thermal history of the metal layer through specific heating and cooling rates during molding. The metal layer is heated to a temperature below its melting point but above the composite matrix melting point, then cooled at a controlled rate to achieve a microstructure that prevents delamination while maintaining adhesion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure within the metal layer itself by controlling the solidification process to form a specific microstructure. This internal composite structure of the metal layer, with controlled grain formation and phase distribution, provides both adhesion to the composite substrate and resistance to delamination during subsequent molding operations.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If robot-based metallization is used for curved surfaces, then metal layer application is possible, but Z-axis movement limitations prevent proper coverage

Engineering Contradiction:
Improvesurface geometry coverageVSAvoidrobot movement capability
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by depositing the metal layer on the composite part before the part is molded into its final curved shape. The metal layer is applied to a flat or minimally curved surface where robot access is unrestricted, then the composite part is molded to achieve the desired complex geometry. This sequence allows complete surface coverage without Z-axis movement limitations.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If metal layer is deposited on thermoplastic composite, then EMI shielding and lightning protection are achieved, but delamination occurs during bending

Engineering Contradiction:
ImproveEMI resistance and lightning protectionVSAvoidbond strength between metal layer and composite
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent controls the thermal parameters during molding to prevent delamination. By heating the metal layer to a temperature below its melting point but above the composite matrix melting point, and then controlling the cooling rate, the process creates strong interfacial bonding between the metal layer and composite substrate. This thermal parameter control ensures the metal layer remains attached during bending while maintaining EMI shielding and lightning protection properties.

Inventive Principle:
Principle #35Parameter changes

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

Enables the production of metallized composite parts with complex geometries that maintain adhesion and conductivity, providing EMI shielding, lightning protection, and electrochemical resistance, while avoiding delamination during molding.

Implementation Method 1

introducing particles comprising at least one metal into a gas stream; directing the gas stream toward a surface of a thermoplastic composite part, thereby depositing a metal layer on the composite part

Methodology Applied
Scientific EffectCold spraying:

Implementation Method 2

heating the metal layer at an anneal temperature

Methodology Applied
Scientific EffectAnnealing: Annealing

Data Source

PatentEP4269653B1Molding composite part with metal layer
Publication Date: 2025.08.06 THE BOEING CO
  • EP4269653B1 patent drawingFigure 1
  • EP4269653B1 patent drawingFigure 2~5
  • EP4269653B1 patent drawingFigure 6

AI summary

A method of molding a metalized composite part. The method comprises: introducing particles comprising at least one metal into a gas stream; directing the gas stream toward a surface of a thermoplastic composite part, thereby depositing a metal layer on the composite part to form a metallized composite part; heating the metal layer (102) at an anneal temperature, and molding the metallized composite part to introduce a bend without delamination of the metal layer from the metallized composite part.