PMMC Friction Ring Surface Structuring for Brake Disc Wear Control

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Solution Overview

Problem

Existing particle metal matrix composite (PMMC) brake disks with aluminum matrix composite friction rings face challenges in achieving optimal friction layer formation and wear resistance due to low surface roughness, and chemical etching methods are hazardous and unpredictable.

Innovation Solution

A mechanical surface structuring method introducing microgrooves transversely to the rotation direction of the friction ring increases surface roughness, accelerating the run-in phase and ensuring a homogeneous friction layer application without damaging the hard particles, reducing wear and tear during normal operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If chemical etching is used to expose hard particles, then surface roughness is improved, but safety hazards and process complexity increase

Engineering Contradiction:

Improvesurface roughnessVSAvoidsafety hazards from caustic substances

Core Design Contradiction:

ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent replaces chemical etching with a mechanical surface structuring method. A machining tool with a structured cutting edge (featuring grooves or teeth) mechanically imprints microgrooves on the friction surface during normal machining operations, eliminating the need for hazardous chemical treatments while achieving the desired surface roughness for friction layer formation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary structured cutting edge as a mediator between the machining process and the friction surface. This cutting edge with predefined grooves or teeth serves as a template that transfers a controlled surface structure to the friction ring, replacing the chemical etching process and its associated hazards.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Shape

If chemical etching is used to expose hard particles, then surface roughness is improved, but wear predictability deteriorates

Engineering Contradiction:

Improvesurface roughnessVSAvoidwear predictability

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the approach from chemical parameter control to mechanical parameter control. By defining the geometry of the cutting edge (groove depth, spacing, pattern) and machining parameters (feed rate, speed), the surface structure becomes precisely controllable and repeatable, improving wear predictability compared to chemical etching.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If mechanical surface structuring is applied, then friction layer formation is accelerated, but manufacturing complexity increases

Engineering Contradiction:

Improvefriction layer formation speedVSAvoidmanufacturing process complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the surface structuring function with the existing machining process. The cutting edge of the machining tool is given a specific structure (grooves or teeth) that simultaneously performs material removal and surface texturing in one operation, eliminating the need for separate surface treatment steps and reducing overall manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The structured cutting edge serves multiple functions: it removes material to achieve the desired geometry and simultaneously creates the microgroove surface structure needed for friction layer formation. This multi-functionality accelerates friction layer formation without adding separate manufacturing steps.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

This approach results in faster, more homogeneous friction layer formation, higher performance, and lower overall wear of brake discs and pads over their service life, without the need for hazardous chemical treatments or additional work steps.

Implementation Method 1

a mechanical surface structuring method introducing microgrooves transversely to the rotation direction of the friction ring increases surface roughness

Methodology Applied

Scientific EffectMechanical Abrasion: Abrasion

Implementation Method 2

accelerating the run-in phase and ensuring a homogeneous friction layer application

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP3625475B1Friction ring for a brake disc, brake disc, and corresponding manufacturing method

Publication Date: 2021.11.10 CONTINENTAL TEVES AG & CO OHG

Figure 1a~2

AI summary

The invention relates to a brake disc (12) comprising a friction ring (1) or a friction ring (1) which has a PMMC (particle metal matrix composite) material at least in the region of the frictional surface of the friction ring or consists of said material. The aim of the invention is to achieve a reduced and predictable degree of wear with an optimal frictional resistance and a simplified production process. According to the invention, this is achieved in that the frictional surface (2) of the friction ring (1) is provided with microgrooves (4) which are mechanically introduced and which extend in a radial direction with respect to the circumferential rotational direction (8) of the friction ring (1) in a non-tangentially angled manner relative thereto.