Layered Carbon-Ceramic Brake Disc for Cost-Strength Balance

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Solution Overview

Problem

Carbon-ceramic brake discs face challenges in achieving superior mechanical performance while maintaining low manufacturing costs, with short-fiber discs prone to surface cracks and long-fiber discs being cost-prohibitive.

Innovation Solution

A carbon-ceramic brake disc design incorporating long fiber layers on opposite sides of a short fiber layer, with specific fiber length and thickness ratios, along with a manufacturing method using mixed powders and curing processes to create a three-layered structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If short fiber reinforced carbon-ceramic brake discs are used, then manufacturing cost is reduced, but mechanical strength and durability deteriorate due to surface cracks

Engineering Contradiction:
Improvemanufacturing costVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies composite materials by combining short fiber reinforced layers with long fiber reinforced layers to create a multi-layer carbon-ceramic brake disc. The short fiber layers provide cost-effective bulk structure while the long fiber layers (with fibers ≥60mm) provide enhanced surface strength and crack resistance where braking forces are applied, thus resolving the contradiction between manufacturing cost and mechanical strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent implements local quality by using different fiber lengths in different layers of the brake disc. The long fiber layers are positioned at the surfaces where mechanical strength is most critical for withstanding braking shear forces, while the short fiber layers are used in intermediate or non-critical areas to reduce manufacturing cost. This localized optimization resolves the contradiction between cost and strength.

Inventive Principle:
Principle #3Local quality

2Strength

If long fiber reinforced carbon-ceramic brake discs are used, then mechanical strength and durability are improved, but manufacturing cost increases

Engineering Contradiction:
Improvemechanical strengthVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses composite materials structure with multiple layers having different fiber characteristics. By combining long fiber layers (for strength) with short fiber layers (for cost efficiency), the overall mechanical strength is improved compared to pure short fiber discs, while the manufacturing cost is reduced compared to pure long fiber discs, thus resolving the contradiction between strength and manufacturing cost.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by strategically placing long fiber layers only where mechanical strength is most needed (surface layers contacting brake pads), while using shorter fibers in other regions. This localized approach ensures improved strength at critical areas without incurring the full manufacturing cost of using long fibers throughout the entire disc.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If short fiber carbon-ceramic discs are used, then manufacturing cost is low, but service life deteriorates due to surface cracks from shear forces

Engineering Contradiction:
Improvemanufacturing costVSAvoidservice life
Core Design Contradiction:
Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent employs composite materials by integrating long fiber reinforced layers into the short fiber carbon-ceramic disc structure. The long fibers (≥60mm) in the surface layers provide enhanced resistance to shear forces and surface crack formation, thereby extending service life, while the majority of the disc structure uses cost-effective short fibers, maintaining low manufacturing cost.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent implements local quality by reinforcing only the critical surface layers with long fibers that are resistant to shear forces and cracking, while keeping the core or non-critical layers with short fibers. This localized reinforcement extends service life at the crack-prone surfaces without significantly increasing manufacturing cost across the entire disc.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4722183A1Carbon-ceramic brake disc and manufacturing method therefor, and vehicle
Publication Date: 2026.04.08 BYD CO LTD
  • EP4722183A1 patent drawingFigure 1
  • EP4722183A1 patent drawingFigure 2
  • EP4722183A1 patent drawingFigure 3

AI summary

A carbon-ceramic brake disc and a manufacturing method therefor, and a vehicle. The carbon-ceramic brake disc comprises long fiber layers and a short fiber layer; the long fiber layers are arranged on the two opposite sides of the short fiber layer; the fiber length S2 of the long fiber layers is greater than or equal to 60 mm, and the fiber length S1 of the short fiber layer is less than or equal to 30 mm.