Friction material composition and friction material
A friction material composition including a fiber base material, a friction modifier and a binder. A content of copper in the friction material composition is 0.5% by mass or less. The friction material composition includes a partially graphitized coke and muscovite. A friction material is formed by molding the friction material composition.
1. A friction material composition comprising a fiber base material, a friction modifier and a binder, wherein a content of copper in the friction material composition is 0.5% by mass or less and the friction material composition comprises a partially graphitized coke and muscovite, wherein the content of the partially graphitized coke is from 3% by mass to 8% by mass based on the whole amount of the friction material composition and a content of the muscovite is from 1% by mass to 6% by mass based on the whole amount of the friction material composition.
2. The friction material composition according to claim 1 , wherein the binder is from 7% by mass to 12% by mass of a whole amount of the friction material composition.
3. The friction material composition according to claim 1 , wherein an average particle diameter of the partially graphitized coke is from 0.1 mm to 1.0 mm.
4. The friction material composition according to claim 1 , wherein an average particle diameter of the muscovite is from 5 μm to 50 μm.
5. The friction material composition according to claim 1 , wherein the friction modifier comprises 0.5% by mass to 3% by mass of zinc powder.
6. The friction material composition according to claim 5 , wherein the zinc powder has an average particle diameter of 2 μm to 20 μm.
7. A friction material formed by molding the friction material composition as described in claim 1 .