Brake Disc AlSi Diffusion Layer for Durable Wear and Corrosion Resistance

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Solution Overview

Problem

Conventional brake discs suffer from short-term corrosion protection, leading to rapid wear and corrosion of friction surfaces, especially in electric and hybrid vehicles, resulting in noise issues and reduced braking performance, and are costly due to hard material coatings like tungsten carbide.

Innovation Solution

A brake disc with a metal base body of steel or gray cast iron featuring a diffusion layer of iron, aluminum, and silicon, applied through a thermal treatment process, providing a graded layer system with enhanced hardness and adhesion, integrated into the friction surfaces, contact surfaces, and ventilation ducts to prevent corrosion and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional coating is applied to the friction surface, then short-term corrosion protection is achieved, but the coating is quickly worn away during braking maneuvers

Engineering Contradiction:
Improvecorrosion protectionVSAvoidservice life of coating
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by creating a diffusion layer before the friction surface is subjected to wear and corrosion. The aluminum-containing coating is applied and thermally treated in advance to form a graded diffusion layer that becomes an integral part of the substrate, providing long-term protection before service begins.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by transforming the aluminum-containing coating into a diffusion layer through thermal treatment at 250-650°C. This thermal parameter change enables aluminum atoms to diffuse into the steel substrate, creating a graded concentration profile that provides durable corrosion and wear resistance.

Inventive Principle:
Principle #35Parameter changes

2Strength

If hard material coatings like tungsten carbide are applied, then wear resistance is improved, but manufacturing costs increase significantly

Engineering Contradiction:
Improvewear resistanceVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces expensive hard material coatings with a cost-effective aluminum-containing coating that forms a diffusion layer. This approach uses readily available aluminum-based materials instead of costly tungsten carbide or chromium carbide coatings, significantly reducing material and manufacturing costs while maintaining adequate wear resistance.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent achieves wear resistance through parameter changes - specifically, thermal treatment that creates a graded diffusion layer with optimized aluminum concentration. This transforms a simple aluminum coating into a functionally graded structure with enhanced surface properties without requiring expensive hard materials.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the friction surface is mechanically processed, then surface quality is improved, but the surface becomes more susceptible to corrosion

Engineering Contradiction:
Improvesurface qualityVSAvoidcorrosion susceptibility
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by mechanically processing the surface first to achieve the required geometry and surface quality, then subsequently applying the aluminum-containing coating and thermal treatment to protect the processed surface from corrosion. This sequence ensures both surface quality and corrosion protection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The aluminum-containing diffusion layer acts as an intermediary between the mechanically processed steel substrate and the corrosive environment. This intermediate layer protects the exposed grain boundaries and surface defects from corrosion while allowing the underlying mechanically processed surface to maintain its geometric precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution achieves durable protection against corrosion and wear, extending the service life of the brake disc, reducing noise and maintenance needs, and lowering production costs by eliminating the need for additional surface coatings.

Implementation Method 1

a diffusion layer made of iron, aluminum and silicon is present, which has a layer thickness of 0.1 mm to 0.6 mm and is formed in conjunction with the steel or gray cast iron of the metallic base body by diffusion processes

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

a diffusion layer made of iron, aluminum and silicon is present, which has a layer thickness of 0.1 mm to 0.6 mm and is formed in conjunction with the steel or gray cast iron of the metallic base body by diffusion processes

Methodology Applied
Scientific EffectThermal treatment: Heat Treatment

Data Source

PatentEP4085158B1Brake disc provided with protection from wear and corrosion and method for production thereof
Publication Date: 2023.05.31 C4 LASER TECH GMBH
  • EP4085158B1 patent drawingFigure 1~2

AI summary

The present invention concerns the field of vehicle technology and industrial-plant technology and relates to a brake disc provided with protection from wear and corrosion and to a method for production thereof. The known solutions have the disadvantage that the coating for providing protection from corrosion and wear is applied to the frictional surfaces of the brake disc and is rubbed off straight away during the first braking operations. The present invention addresses the problem of providing a brake disc that has improved and durable protection from corrosion and wear. The significantly improved properties of the brake disc in terms of protection from corrosion and wear are achieved according to the invention by at least the region of the frictional surfaces (2) having an AlSi-based diffusion layer (3), which has a layer thickness of 0.1 mm to 0.6 mm and is formed in the process of interaction with the steel or grey cast iron of the metal main body (1). The brake disc according to the invention can be used for example in vehicles or as a braking system for industrial brakes or in wind turbines.