Composite Structures Metal Substrate Galvanic Corrosion

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Solution Overview

Problem

Composite structures with metal substrate layers are prone to galvanic corrosion when in contact with conductive reinforcing materials, necessitating the use of isolation layers that increase weight and cost, while providing thermal or electrical conductivity.

Innovation Solution

A composite structure with a metal substrate coated conformally with an organic coating, allowing direct contact with a more noble reinforcing material, such as carbon fiber, to prevent galvanic corrosion without the need for additional isolation layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal substrate layers are added to provide thermal or electrical conductivity, then conductivity is improved, but galvanic corrosion occurs when in direct contact with conductive reinforcing materials

Engineering Contradiction:

ImproveconductivityVSAvoidgalvanic corrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a polymer-impregnated fibrous isolation layer as an intermediary between the metal substrate and carbon fiber reinforcement. This isolation layer prevents direct galvanic contact while maintaining thermal and electrical conductivity pathways, thus resolving the contradiction between conductivity and corrosion prevention

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If isolation layers are used to prevent galvanic corrosion, then corrosion resistance is improved, but weight increases

Engineering Contradiction:

Improvegalvanic corrosionVSAvoidcomposite weight

Core Design Contradiction:

Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent employs a thin polymer-impregnated fibrous isolation layer that provides corrosion protection while minimizing weight addition. The thin film approach maintains structural efficiency while preventing galvanic corrosion between dissimilar materials

Inventive Principle:

Principle #30Flexible shells and thin films

3Object-affected harmful factors

If isolation layers are added to prevent galvanic corrosion, then corrosion resistance is improved, but manufacturing cost increases

Engineering Contradiction:

Improvegalvanic corrosionVSAvoidmanufacturing cost

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent combines the isolation layer function with the existing polymer matrix material, using polymer-impregnated fibrous material that integrates into the composite manufacturing process. This merging approach reduces the need for separate isolation layer materials and simplifies manufacturing steps

Inventive Principle:

Principle #5Merging (Combining)

4Object-affected harmful factors

If isolation layers are added to prevent galvanic corrosion, then corrosion resistance is improved, but manufacturing cycle time increases

Engineering Contradiction:

Improvegalvanic corrosionVSAvoidmanufacturing cycle time

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent incorporates the polymer-impregnated fibrous isolation layer into the pre-preg or molding compound before composite assembly, performing the isolation layer integration in advance. This preliminary action eliminates separate isolation layer installation steps and reduces overall manufacturing cycle time

Inventive Principle:

Principle #10Preliminary action

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 conformal organic coating on the metal substrate reduces galvanic corrosion, maintaining structural integrity and reducing weight and cost by eliminating the need for isolation layers, while maintaining conductivity.

Implementation Method 1

a layer comprising a metal substrate and a conformal organic coating present on at least a portion of the surface

Methodology Applied

Scientific EffectConformal coating: Coatings

Implementation Method 2

the reinforcing material is more noble than the metal substrate... to prevent galvanic corrosion without the need for additional isolation layers

Methodology Applied

Scientific EffectGalvanic corrosion prevention:

Implementation Method 3

When thermal or electrical conductivity is desired, metal substrate layers have been added to composites

Methodology Applied

Scientific EffectThermal conductivity: Conduction (thermal)

Implementation Method 4

When thermal or electrical conductivity is desired, metal substrate layers have been added to composites

Methodology Applied

Scientific EffectElectrical conductivity: Conduction (electrical)

Data Source

PatentUS20240253326A1Composite structures comprising metal substrates

Publication Date: 2024.08.01 PRC DESOTO INTERNATIONAL INC

AI summary

The present disclosure is directed to a composite structure comprising at least one reinforced polymer layer comprising a reinforcing material; a layer comprising a metal substrate comprising a surface and a conformal organic coating present on at least a portion of the surface; wherein the layer comprising the metal substrate is in direct contact with the reinforced polymer layer, and the reinforcing material is more noble than the metal substrate. Also disclosed is a method of making a composite structure, a surfacing film, and a test method for evaluating the galvanic corrosion resistance of a metal substrate test piece.