Brake Friction Iron Oxide Powder with Low Magnetization
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Solution Overview
Problem
Conventional brake friction materials containing magnetite suffer from brake noise and insufficient braking force due to high magnetization and fine particle size, leading to poor wear resistance and handling safety issues.
Innovation Solution
Iron oxide powder with an average particle diameter of 40 μm or more and saturation magnetization of 20 emu/g or less, along with specific pore volume, BET specific surface area, and peak pore diameter, is used to reduce brake noise and enhance braking performance while maintaining safety and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If magnetite with fine particle size and high magnetization is used, then braking force is improved, but brake noise increases and wear resistance deteriorates
Solution Approach 1:
The patent changes the particle size parameter from fine (conventional) to coarse (40 μm or more average diameter) and changes the magnetization parameter from high to low (20 emu/g or less). This dual parameter change resolves the contradiction by reducing brake noise while maintaining sufficient braking force through optimized particle characteristics rather than relying solely on high magnetization.
Solution Approach 2:
The patent applies local quality by creating iron oxide powder with specific localized characteristics - coarse particle size distribution and controlled magnetization - that differ from conventional fine, high-magnetization magnetite. This localized optimization of particle properties eliminates brake noise issues while preserving braking performance.
2Force
If magnetite with fine particle size is used, then braking force is improved, but wear resistance and handling safety deteriorate
Solution Approach 1:
The patent changes the particle size parameter from fine to coarse (40 μm or more average diameter), which simultaneously improves wear resistance and handling safety while maintaining adequate braking force. The parameter change trades off extreme fine particle benefits for overall system reliability.
3Force
If high content of iron oxide powder is used, then braking performance is improved, but brake noise may increase due to magnetic condensation
Solution Approach 1:
The patent changes the magnetization parameter to low levels (20 emu/g or less), which prevents magnetic condensation even at high iron oxide powder content. This parameter change allows high content usage for improved braking performance without triggering the harmful magnetic condensation effect that causes brake noise.
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 iron oxide powder effectively prevents brake noise and improves braking performance, maintaining safety and productivity by ensuring proper particle packing and adhesion, even at high content levels, without compromising wear resistance.
Implementation Method 1
a brake friction material which is to be brought into contact with a rotating (pivoting) disc in a pressing manner and has a function of controlling rotation of the disc with a frictional force
Implementation Method 2
a saturation magnetization of 20 emu/g or less... less likely to occur a problem of brake noise
Data Source
AI summary
Provided is an iron oxide powder for a brake friction material which can be suitably used in a brake friction material that is less likely to cause problems regarding brake squealing and that provides superior braking performance. The iron oxide powder for a brake friction material according to the present invention is characterized by having an average particle size of 40 μm or more and a saturation magnetization of 20 emu/g or less. The iron oxide powder preferably has a pore volume of 10-180 mm3/g. The iron oxide powder also preferably has a BET specific surface area of 0.05-1.20 m2/g.