Disc Brake Pad Friction Material for Copper-Free Edge Chipping Control
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Solution Overview
Problem
Conventional non-asbestos-organic (NAO) friction materials for disc brake pads face issues with edge chipping under high speed and high load braking conditions, and there is a regulatory requirement to reduce or eliminate copper content due to environmental concerns.
Innovation Solution
The friction material composition includes 1-10 weight % of aluminum particles or fibers, graphitic carbon particles with high recovery ratios, and 1-15 weight % of ferrous sulfide as a lubricant and friction modifier, along with conventional components like binders, fibers, and inorganic modifiers, to suppress edge chipping and maintain braking effectiveness while adhering to copper content regulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper component is added to NAO friction material to secure required performance, then braking effectiveness is improved, but environmental contamination increases and regulatory compliance deteriorates
Solution Approach 1:
The invention extracts and removes the copper component from the friction material composition entirely, replacing it with alternative materials (ferrous sulfide, aluminum particles, graphitic carbon) that do not cause environmental contamination while maintaining braking performance
Solution Approach 2:
The invention changes the chemical composition parameters by eliminating copper and introducing alternative friction modifiers and lubricants, transforming the material composition to achieve both performance and environmental goals
2Object-affected harmful factors
If copper component is reduced or eliminated to comply with regulations, then environmental compliance is improved, but edge chipping under high speed and high load braking conditions worsens
Solution Approach 1:
The invention applies different functional materials to different aspects of friction material performance: ferrous sulfide and aluminum particles provide edge strength and chipping resistance, while graphitic carbon provides lubrication, creating a composition with localized functional properties that collectively solve both problems
Solution Approach 2:
The invention creates a composite friction material composition combining multiple materials (ferrous sulfide, aluminum particles, graphitic carbon, binder, filler) where each component contributes specific properties, and their synergistic interaction provides both edge strength and copper-free formulation
3Object-affected harmful factors
If alternative materials are used to replace copper, then regulatory compliance is improved, but braking effectiveness under high speed and high load conditions deteriorates
Solution Approach 1:
The invention selects materials that perform multiple functions: ferrous sulfide acts as both friction modifier and edge strengthener, aluminum particles provide both friction enhancement and structural support, graphitic carbon provides lubrication while maintaining thermal stability, allowing the composition to maintain braking effectiveness across different operating conditions without copper
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 effectively suppresses edge chipping and maintains braking effectiveness under high speed and high load conditions while eliminating the need for copper, thus addressing both performance and regulatory compliance.
Implementation Method 1
graphitic carbon particles with high recovery ratios
Implementation Method 2
1-15 weight % of ferrous sulfide as a lubricant and friction modifier
Implementation Method 3
1-10 weight % of aluminum particles or fibers
Data Source
AI summary
The present invention provides a friction material for a disc brake pad, which is able to suppress chipping of an edge of the friction material that occurs under the high speed and high load braking conditions and further to suppress the deterioration of the braking effectiveness under the high speed and high load braking conditions while satisfying laws and regulations relating to the required amount of the content of the copper component. [MEANS TO SOLVE THE PROBLEMS] A friction material composition that contains 0.5 - 10 weight % of a resilient graphitic carbon particle relative to the total amount of the friction material composition as a carbon type lubricant and contains the total amount of a copper component contained in the friction material composition is less than 5 weight % relative to the total amount of the friction material composition. Furthermore, 1-15 weight % of a ferrous sulfide relative to the total amount of the friction material composition as a metal sulfide type lubricant is added to the above described friction material composition comprising the 0.5 -10 weight % of a resilient graphitic carbon particle. Furthermore, 1-10 weight % of one or any combination of two or more items selected from the group consisting of an aluminum particle, an aluminum fiber, an alloy particle containing aluminum as a main component, and an alloy fiber containing an aluminum as a main component relative to the total amount of the friction material composition as an inorganic friction modifier are added to the above described friction material composition comprising the 0.5 -10 weight % of a resilient graphitic carbon particle and 1-15 weight % of a ferrous sulfide.