Sintered Brake Lining Composition for High-Temperature Rail Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sintered friction materials for high-speed railways lack sufficient thermal conductivity and wear resistance, leading to inadequate braking performance and increased production costs due to excessive hard particle content, and existing designs do not account for the sliding mechanism between brake disks and linings.
Innovation Solution
A sintered friction material with a composition of 50% Cu or more, 7.5% Fe or more, and appropriate Fe/Cu ratios, along with additives like graphite and molybdenum disulfide, to enhance thermal conductivity and wear resistance, while preventing excessive temperature increase and adhesion, thereby achieving high coefficient of friction and stable braking power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hard particles (ceramics such as silica) are added to exert mechanical action, then coefficient of friction is improved, but production cost increases significantly
Solution Approach 1:
The invention changes the material composition parameters by using Fe-based sintered material instead of conventional Cu-based material, and by controlling the particle size distribution of hard particles (1-10 μm fine particles combined with 10-50 μm coarse particles). This parameter optimization maintains sufficient friction coefficient while reducing the total amount of hard particles needed, thereby lowering production costs.
Solution Approach 2:
The invention creates a composite sintered friction material combining Fe-based matrix with dual-size hard particles (fine 1-10 μm and coarse 10-50 μm). This composite structure allows the fine particles to fill gaps and the coarse particles to provide mechanical scratching action, achieving high friction coefficient with reduced overall hard particle content compared to conventional single-size particle systems.
2Reliability
If Fe-based sintered material is used instead of Cu-based material, then frictional property at high temperature is improved, but thermal conductivity deteriorates
Solution Approach 1:
The invention optimizes the Fe content parameter within a specific range (60-90 wt%) and controls the particle size distribution of hard particles to balance thermal conductivity and frictional properties. By carefully selecting these parameters, the material achieves improved high-temperature friction performance while minimizing the negative impact on thermal conductivity.
Solution Approach 2:
The invention applies local quality enhancement by using dual-size hard particles where fine particles (1-10 μm) are distributed throughout the matrix to maintain thermal pathways, while coarse particles (10-50 μm) are strategically positioned to provide mechanical friction action. This local differentiation allows simultaneous improvement of frictional properties and preservation of thermal conductivity.
3Force
If conventional lining materials are produced by adding hard particles, then mechanical action is achieved, but braking performance at high speed is insufficient
Solution Approach 1:
The invention changes the particle size parameters from conventional single-size particles to a dual-size distribution (1-10 μm and 10-50 μm). The fine particles ensure adequate mechanical action while the coarse particles maintain structural integrity during high-speed braking. This parameter optimization enables the material to withstand high-speed braking conditions while providing sufficient mechanical friction.
Solution Approach 2:
The invention creates a composite structure with Fe-based matrix and dual-size hard particles that work synergistically. The fine particles (1-10 μm) provide continuous mechanical action, while the coarse particles (10-50 μm) provide structural support and prevent material deformation under high-speed braking loads, achieving both mechanical action and high-speed braking reliability.
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 material achieves high braking power and excellent wear resistance at high temperatures, suitable for high-speed railway applications, with optimal Fe/Cu ratios balancing friction and wear resistance, ensuring reliable braking performance.
Implementation Method 1
a sintered friction material consisting of a metallic phase, a lubricant, and a friction adjusting material... secure a sufficient coefficient of friction
Implementation Method 2
The matrix comprises 0.5 to 15 wt% tin power, 0.1 to 30 wt% zinc powder... and a lubricant
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Provided is a sintered friction material exhibiting high braking power, and being excellent in stability of braking power at a high temperature. The sintered friction material of the present invention includes a chemical composition containing: by mass%, Fe of 7.5% or more, Cu of 50% or more, graphite of 5 to 15%, molybdenum disulfide of 0.3 to 7%, and silica of 0.5 to 10%, wherein Fe/Cu is 0.15 to 0.40.