Antioxidant Carbon Coatings Using Lanthanum Phosphate

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Solution Overview

Problem

Carbon components used in high-temperature applications, such as aircraft brakes, are prone to oxidation due to exposure to catalytic oxidation, leading to premature wear and increased downtime due to frequent replacement.

Innovation Solution

Application of an antioxidant coating comprising an inorganic acid, such as phosphoric acid, and a hydrophobic agent like lanthanum phosphate, which repels oxidizing materials and enhances compatibility with the substrate and underlying coatings, providing better protection against oxidation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If carbon components are used in high-temperature applications, then they can withstand elevated temperatures, but they are prone to oxidation and premature wear

Engineering Contradiction:

Improvetemperature resistanceVSAvoidoxidation resistance

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent applies a multi-layer coating system comprising a barrier coating layer and an antioxidant coating layer on the carbon component surface. This composite structure combines the high-temperature resistance of the carbon substrate with the oxidation protection of the coating layers, allowing the component to withstand both thermal and oxidative environments simultaneously.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The antioxidant coating acts as an intermediary layer between the oxidizing environment and the carbon component surface. It contains hydrophobic agents and antioxidants that actively repel oxidizing materials and prevent direct contact with the carbon substrate, thereby protecting the component without interfering with its high-temperature performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If traditional coating methods are used, then coating can be applied, but the application process is complex and time-consuming

Engineering Contradiction:

Improvecoating protectionVSAvoidapplication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into a single antioxidant coating formulation that includes hydrophobic agents, antioxidants, and bonding agents. This unified coating composition can be applied in a single step while providing both hydrophobic protection and oxidation resistance, eliminating the need for multiple separate coating processes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The coating formulation uses specific chemical composition parameters including hydrophobic agents with contact angles of at least 90 degrees and antioxidants in controlled concentrations. By optimizing these parameters, the coating achieves effective protection while allowing for simple application methods such as brushing, coating, or spraying.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If oxidizing materials contact the brake substrate, then oxidation occurs, but frequent replacement is required

Engineering Contradiction:

Improvecomponent longevityVSAvoiddowntime for replacement

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The antioxidant coating is applied in advance to the carbon component surface before the component enters service. This preliminary protection layer prevents oxidation from occurring during normal operation, extending the component's service life and eliminating the need for frequent replacements and associated downtime.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coating system converts the hydrophobic property, which naturally repels water and aqueous oxidizing materials, into a protective mechanism. By incorporating hydrophobic agents that create high contact angles, the coating turns the repulsion of oxidizing environments into an active protection system that continuously prevents oxidation without requiring active maintenance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 antioxidant coating reduces oxidation, extends the operational life of carbon components, and simplifies application processes compared to traditional methods.

Implementation Method 1

a hydrophobic agent including lanthanum phosphate. For example, a hydrophobic agent including lanthanum phosphate may repel oxidizing materials (e.g., aqueous de-icers) that may contact brakes or wheel assemblies

Methodology Applied

Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

Lanthanum phosphate may protect against oxidation of a substrate including carbon (e.g., a brake disc)

Methodology Applied

Scientific EffectOxidation resistance: Oxidation

Data Source

PatentEP4613817A1Antioxidant coatings for carbon components

Publication Date: 2025.09.10 HONEYWELL INTERNATIONAL INC

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AI summary

An antioxidant coating composition may include an inorganic acid, and a hydrophobic agent including lanthanum phosphate. An article may include a substrate including carbon, and an antioxidant coating applied to at least a portion of the substrate. The antioxidant coating may include the inorganic acid, and the hydrophobic agent. A technique may include applying the antioxidant coating composition to at least the portion of the substrate, and allowing the antioxidant coating composition to dry or cure to form the antioxidant coating.