A reinforced prepreg which is applied to a wear-resistant layer structure of a braking track is provided. The reinforced prepreg includes a fiber fabric and a mixture mixed with the fiber fabric. The mixture includes a resin and a plurality of needle-shaped crystals having microscale or nanoscale sizes mixed with the resin.

A complex oxide powder contains cerium, zirconium, and aluminum and, has a specific surface area of 0.5 m.sup.2/g or more and 10 m.sup.2/g or less.

There is provided a friction material including: a friction modifier; a binder; and a fibrous material. A phosphate-based dispersant is contained as the friction modifier. Preferably, a content of the phosphate-based dispersant is 0.2 mass % to 2.0 mass %. Preferably, the phosphate-based dispersant is at least one selected from a group consisting of sodium hexametaphosphate, sodium polyphosphate, and sodium pyrophosphate.

A phenol resin for a wet friction material of the invention contains a resol-type phenol resin having, in one molecule, a structural unit A which is derived from a phenol compound having one phenolic hydroxyl group and a structural unit B which is derived from a polyfunctional phenol compound having two phenolic hydroxyl groups.

[Object]

To provide the disc brake pad including the friction material having the friction surface with the scorch treatment that can provide sufficient braking effectiveness while preventing the fading phenomenon at the initial stage of the disc brake pad usage.

[Means to Resolve]

In the disc brake pad including the friction material having the friction surface with the heat history due to the scorch treatment, the friction surface has the mixed areas including the area with the large heat history of the scorch treatment and the area with relatively small heat history of the scorch treatment. The following formula needs to be satisfied where the reduction rate of the mass of the inside of the friction material without the heat history due to the scorch treatment when performing the thermogravimetric analysis of the friction material at 500 centigrade is A, the reduction rate of the mass of the friction surface area with the largest heat history due to the scorch treatment when performing the thermogravimetric analysis at 500 centigrade is B1, and the reduction rate of the mass of the friction surface area with the relatively small heat history due to the scorch treatment relative to the friction surface area with the largest heat history when performing the thermogravimetric analysis at 500 centigrade is B2.

30≤B1/A×100≤90

50≤B2/A×100

B2/A×100−B1/A×100≤60  Formula:

A friction material including a friction modifier, a binder, and a fiber base material. A steel fiber is contained as the fiber base material. A natural graphite is contained as a lubricant. A content of copper is 0.5% by mass or less in terms of copper element. A titanate is not contained.

Provided are a yaw brake pad and a method of producing the same, which relate to the technical field of friction material. The yaw brake pad is prepared from, by weight, the following main ingredients: 70-75 parts of polyether ether ketone, 10-20 parts of carbon fiber, 3-5 parts of glass fiber and 3-5 of graphite. It alleviates the technical problem that the metal-based friction materials generally for producing current international and domestic yaw brake pads are likely to rust, harmful to dual discs, and produce screechy. It has not only significantly improved mechanical properties and high temperature tolerance, much lower hardness, less wear to dual discs, and lower noise, but also improved friction stability and adaptability to working conditions, and thus can effectively satisfy the demand of the wind driven generator for yaw braking at a low speed.

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 a first embodiment of the present invention is characterized by having a sulfur content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less. The iron oxide powder for a brake friction material according to a second embodiment of the present invention is characterized by having an average particle size of 1.0 μm or more, a chlorine content of 150 ppm or less as measured by combustion ion chromatography, and a saturation magnetization of 20 emu/g or less.

Brake pads are prepared using a LS (Low Steel) or NAO (Non-Asbestos Organics) type friction material formulation and at least one friction surface of a brake disc intended to cooperate in use with a brake pad that is coated with an anti-wear and anti-corrosion coating with adequate plasticity in order to have a reduced propensity to form micro-cracks under conditions of tribo-mechanical stress, chosen from the amongst the group consisting in: particles of chromium carbide (Cr.sub.3C.sub.2) dispersed within a metallic matrix consisting of an alloy of NiCr; particles of a combination of several metallic materials in order to create a metallic compound consisting of an alloy of FeNiCrMoSiC (iron-nickel-chromium-molybdenum-silicon-carbon).

A preform for making a component of a braking system having a fibre-reinforced ceramic composite material, obtained by forming and subsequent pyrolysis of a pre-preg is described. Also described is a component of a braking system made wholly or in part from the preform, and a method for making a preform in a fibre-reinforced ceramic composite material.