Multi-Layer Thermal Spray Coating for Fiber-Reinforced Composites

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Solution Overview

Problem

Fiber-reinforced composite materials exhibit poor wear resistance, inadequate adhesion, and susceptibility to corrosion, limiting their application due to poor bonding of thermal spray coatings, which often delaminate or fail to adhere effectively to the substrate.

Innovation Solution

A multi-layer coating system is applied, starting with a thermally sprayed adhesive layer of organic and metallic components, followed by a metallic intermediate layer for improved bonding and heat dissipation, and a functional top layer of metal, CERMET, or oxide ceramic for enhanced wear resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If thermal spray coating is applied directly onto fiber reinforced composite surfaces, then coating application is simplified, but adhesion is poor and coatings delaminate

Engineering Contradiction:
Improvecoating application simplicityVSAvoidcoating adhesion
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies a primer layer containing reactive particles (such as metal oxides or carbides) to the fiber reinforced composite surface before applying the final thermal spray coating. This preliminary action creates a chemically active surface that enhances subsequent coating adhesion, preventing delamination while maintaining manufacturing simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The primer layer acts as an intermediary between the fiber reinforced composite substrate and the final thermal spray coating. This intermediate layer contains reactive particles that chemically bond to both the substrate and the overlying coating, serving as a bridge that ensures strong adhesion without requiring direct bonding between incompatible materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If surface roughening is done by corundum blasting to improve adhesion, then coating bonding is enhanced, but polymer matrix erosion and fiber exposure occur

Engineering Contradiction:
Improvecoating bondingVSAvoidpolymer matrix erosion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the primer layer to include reactive particles that can chemically bond to the fiber reinforced composite surface. This chemical approach replaces the mechanical roughening method, achieving strong coating bonding without eroding the polymer matrix or exposing fibers.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical surface roughening process (corundum blasting) with a chemical bonding approach using a primer layer containing reactive particles. This substitution eliminates the harmful mechanical erosion of the polymer matrix while still achieving enhanced coating adhesion through chemical interactions.

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

3Device complexity

If single-layer thermal spray coating is applied to fiber reinforced composites, then manufacturing process is simplified, but adhesion and wear resistance are insufficient

Engineering Contradiction:
Improvecoating system complexityVSAvoidadhesion and wear resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the coating system into two distinct segments: a primer layer containing reactive particles for chemical bonding to the substrate, and a final thermal spray coating layer for providing wear resistance. This segmentation allows each layer to perform its specific function optimally, achieving both adhesion and wear resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite primer layer containing a mixture of binder materials and reactive particles (such as metal oxides or carbides). This composite structure provides both the adhesion needed to bond to the fiber reinforced composite substrate and the chemical reactivity needed to enhance subsequent coating bonding, while the final thermal spray layer provides wear resistance.

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 method significantly improves adhesion and wear resistance of fiber-reinforced composite materials, making them suitable for dynamic loads and large coating areas while maintaining structural integrity and optical/electrical properties.

Implementation Method 1

thermal spray processes

Methodology Applied
Scientific EffectThermal spray:

Implementation Method 2

a thermally sprayed layer made of a composite consisting of organic and metallic components is first applied as an adhesive layer to the surface of the fiber-reinforced plastic

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

a thermally or kinetically sprayed layer with predominantly metallic components is applied as an intermediate layer for improved bonding and heat dissipation

Methodology Applied
Scientific EffectHeat dissipation: Heat Sink

Data Source

PatentEP1943369B1Method for coating a component
Publication Date: 2013.05.01 PRAXAIR ST TECHNOLOGY INC

AI summary

The invention relates to a method for coating a component consisting of a fibre-reinforced composite material. According to said method: a) a composite consisting of organic and metallic parts is applied to a surface of the component to be coated, as an adhesive layer, by means of thermal spraying; b) a layer predominantly comprising metallic parts is applied to the adhesive layer, as an intermediate layer, by means of thermal or kinetic spraying; and c) a functional covering layer consisting of metal, a metal-carbide composite, oxide ceramics or mixtures of said materials is applied to the intermediate layer by means of thermal or kinetic spraying.