Silicate-Graphite Coating for High-Temperature Wear and Corrosion

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Solution Overview

Problem

Existing non-stick coatings lack temperature stability beyond 350°C, exhibit low wear resistance, and are complex to apply, with inadequate corrosion protection and non-stick effects.

Innovation Solution

A coating composition comprising a silicate matrix with integrated graphite and silicon carbide, applied through hydrolysis and polycondensation of silanes, providing a thermally stable, corrosion-resistant, and tribologically effective layer up to 800°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional non-stick coatings (fluorosilanes) are used, then anti-adhesive properties are achieved, but temperature stability is lost above 350°C

Engineering Contradiction:
Improvetemperature stabilityVSAvoidcoating integrity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The invention uses a composite coating system consisting of a silicate base layer and a fluorosilane top layer. The silicate base layer provides high-temperature stability up to 800°C, while the fluorosilane top layer provides the non-stick properties. This composite structure allows the coating to maintain both anti-adhesive properties and temperature stability, resolving the contradiction between using fluorosilanes for non-stick performance and maintaining coating integrity at high temperatures.

Inventive Principle:
Principle #40Composite materials

2Reliability

If organic components are added to improve non-stick properties, then anti-adhesive performance increases, but wear resistance decreases

Engineering Contradiction:
Improvenon-stick propertiesVSAvoidwear resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The coating combines inorganic silicate components with organic fluorosilane components in a composite structure. The silicate base matrix provides wear resistance and mechanical strength, while the fluorosilane additive (0.1-10 wt%) provides enhanced non-stick properties. This composite approach allows the coating to achieve both low friction coefficients and high wear resistance, resolving the contradiction between improving non-stick performance and maintaining wear resistance.

Inventive Principle:
Principle #40Composite materials

3Reliability

If complex application methods (plasma, sintering) are used, then coating performance improves, but manufacturing complexity increases

Engineering Contradiction:
Improvecoating performanceVSAvoidapplication complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the need for complex plasma treatment and sintering processes by using a sol-gel coating method that forms a stable silicate base layer through controlled hydrolysis and condensation. The coating can be applied by simple dip-coating or spray methods and cured at moderate temperatures (400-600°C), removing the requirement for expensive and complex plasma equipment or high-temperature sintering furnaces while maintaining excellent coating performance.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of manufacture

If acidic sol is used for coating application, then coating formation is achieved, but corrosion protection is reduced due to lack of passivation

Engineering Contradiction:
Improvecoating formationVSAvoidcorrosion protection
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The invention changes the pH parameter of the coating sol from acidic to basic (pH 9-11) by using alkaline catalysts such as ammonium hydroxide, sodium hydroxide, or potassium hydroxide. This parameter change enables the sol to form a stable silicate base layer that provides excellent corrosion protection through passivation of the metal substrate, while still achieving proper coating formation and adhesion. The basic pH condition promotes the formation of a protective oxide layer on the metal surface.

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

The coating composition achieves high-temperature corrosion and wear protection with anti-adhesive properties, maintaining corrosion protection and electrical conductivity while ensuring the layer remains intact and functional up to 800°C.

Implementation Method 1

The silicate is obtainable by a process comprising the hydrolysis and polycondensation of one or more silanes

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

The silicate is obtainable by a process comprising the hydrolysis and polycondensation of one or more silanes

Methodology Applied
Scientific EffectPolycondensation:

Implementation Method 3

coatings with temperature stability up to 800°C can be obtained

Methodology Applied
Scientific EffectThermal stability:

Implementation Method 4

the corrosion protection according to DIN 50021 SS of the base matrix (silicate) remains fully intact

Methodology Applied
Scientific EffectCorrosion protection:

Implementation Method 5

the electrical conductivity of the coating can be selectively adjusted within certain limits by choosing the graphite content

Methodology Applied
Scientific EffectElectrical conductivity: Conduction (electrical)

Implementation Method 6

contact angles to water of over 90° are achieved with the coating composition according to the invention

Methodology Applied
Scientific EffectAnti-adhesive properties:

Data Source

PatentEP2125649B1Coating composition
Publication Date: 2022.11.30 LEIBNIZ INSTITUT FUR NEUE MATERIALIEN GMBH
  • EP2125649B1 patent drawingFigure 1
  • EP2125649B1 patent drawingFigure 2
  • EP2125649B1 patent drawingFigure 3

AI summary

The present invention relates to a coating composition, particularly for coating metal or glass-like surfaces. The present invention further relates to a method for coating metal or glass-like surfaces with a glass-like layer. The present invention further relates to a sol-gel method for coating surfaces, particularly metal or glass-like surfaces. The present invention further relates to an object, particularly made of metal or glass, which is characterized in that it has a coating made of a coating composition according to the invention. The present invention further relates to the use of a coating composition according to the invention for coating metal or glass substrates.