Friction Material Laser Scorching for Uniform Deep Surface Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing friction materials for disc and drum brakes fail to achieve uniform scorching deep into the surface layer in a short time, leading to brake fade issues due to decomposition gases generated during high-temperature friction.
Innovation Solution
Incorporating 5-25% black raw materials like carbon fiber, graphite, and triiron tetraoxide into the friction material composition, and using a vertical cavity surface emitting laser with specific energy density and distance settings to achieve uniform scorching, ensuring efficient heat propagation and rapid surface layer treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional heating methods (heating plate or direct fire) are used to scorch the friction material surface, then the scorching process is simple to implement, but the scorching time is long and uniform deep scorching cannot be achieved
Solution Approach 1:
The patent replaces conventional mechanical heating methods (heating plate contact or direct fire) with a laser-based optical heating system. The laser beam delivers concentrated energy to the friction material surface, enabling rapid and uniform scorching to a controlled depth without the limitations of conventional thermal conduction methods.
Solution Approach 2:
The patent controls the scorching process by adjusting laser parameters including energy density (150-2000 kW/m²), scanning speed, and number of passes. By optimizing these parameters, the process achieves uniform scorching to a depth of 0.5-5mm within 1-60 seconds, resolving the contradiction between speed and uniformity.
2Length of stationary object
If high energy density laser is used to scorch deep into the friction material, then the scorching depth increases, but the scorching time increases and surface uniformity decreases
Solution Approach 1:
The patent employs multiple scanning passes with the laser beam rather than a single high-energy pass. The laser scans the surface 1-10 times with energy density of 150-2000 kW/m², progressively achieving deep uniform scorching (0.5-5mm depth) while controlling total processing time to 1-60 seconds through optimized scan parameters.
3Manufacturing precision
If black raw materials are added to the friction material composition, then the laser absorption efficiency increases and scorching uniformity improves, but the material composition complexity increases
Solution Approach 1:
The patent utilizes the optical property of black-colored raw materials (carbon fiber, graphite, activated carbon, tire rubber powder) which have high laser beam absorption coefficients. These materials convert laser optical energy to thermal energy efficiently, enabling uniform scorching. The black pigments are incorporated at 1-50 parts by weight relative to 100 parts of friction material composition.
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 method enables uniform scorching of the friction material's deep surface layer in a short period, enhancing braking performance by preventing brake fade and maintaining wear resistance.
Implementation Method 1
heat-treating the surface of the friction material with an infrared laser as disclosed in Patent Document 1 or heat-treating the surface of the friction material with a high-power diode laser as disclosed in Patent Document 2
Implementation Method 2
an energy density of the laser beam in the scorching step is 150 to 2000 kw/m2
Implementation Method 3
the inventors of the present invention had intensively studied the raw friction materials forcing on the fact that the black raw material tends to absorb the energy of the laser easily among various raw materials contained therein
Implementation Method 4
When a temperature of the friction material reaches a high temperature due to frictional contact between the friction material and a metal disc rotor or a brake drum upon braking the automobile, decomposition gas is generated by heating the binder and the organic friction modifier in the friction material
Implementation Method 5
an entire frictional surface of the friction material after molding is heated at a high temperature called 'scorching' so as to remove organic substances or the like that cause the brake fade by burning the same
Data Source
Figure 1
Figure 2
Figure 3
AI summary
To provide the method of manufacturing the friction material that is capable of uniformly scorching into the deep part of the surface layer of the friction material in a short period of time. [Means to Resolve] In the method of manufacturing the friction material including the scorching step of scorching the surface of the friction material with the laser, the friction material contains 5 to 25% by weight of one or more types of black materials relative to the total amount of the friction material composition, and the L* of the CIE Lab of the surface of the friction material before scorching is 20 to 60.