Method for manufacturing friction material
[Object] 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.
1. A method of manufacturing a friction material including a scorching step of scorching a surface of the friction material with a laser beam, wherein
said friction material comprises 5-25 weight % of one or more types of a black raw materials relative to the total amount of the friction material, and
L* of the CIE Lab of the surface of the friction material before scorching step is 20-60.
2. The method of manufacturing the friction material of claim 1 , wherein
a pre-heating step is performed immediately before the scorching step.
3. The method of manufacturing the friction material of claim 2 , wherein
the pre-heating step is a heat treatment step.
4. The method of manufacturing the friction material of claim 1 , wherein
a light source of the laser beam is a vertical cavity surface emitting laser module.
5. The method of manufacturing the friction material of claim 4 , wherein
a pre-heating step is performed immediately before the scorching step.
6. The method of manufacturing the friction material of claim 5 , wherein
the pre-heating step is a heat treatment step.
7. The method of manufacturing the friction material of claim 1 , wherein
an energy density of the laser beam in the scorching step is 150-2000 kW/m 2,
a distance between the laser beam irradiation surface and the surface of the friction material is 15 to 300 mm, and
a time required for the scorching step is 0.5 to 60 seconds.
8. The method of manufacturing the friction material of claim 7 , wherein
a pre-heating step is performed immediately before the scorching step.
9. The method of manufacturing the friction material of claim 8 , wherein
the pre-heating step is a heat treatment step.
10. The method of manufacturing the friction material of claim 7 , wherein
a light source of the laser beam is a vertical cavity surface emitting laser module.
11. The method of manufacturing the friction material of claim 10 , wherein
a pre-heating step is performed immediately before the scorching step.
12. The method of manufacturing the friction material of claim 11 , wherein
the pre-heating step is a heat treatment step.