A disc brake for railway vehicles comprising a pad and a disk on which the pad acts is provided. The pad comprises a base plate and a plurality of friction elements fixed to the base plate. The friction elements comprise first friction elements made of a first material and second friction elements made of a second material. The second material has a compressibility modulus (e.g., the pressure needed to compress the material by 1 mm) that is at least 5 MPa less smaller than the compressibility modulus of the first material. There may be more of the first friction elements than the second friction elements.

[object]

To provide the friction material for the disc brake pad, which is manufactured by forming the NAO friction material composition that does not contain the copper component and does not generate the creeping groan and the seizure to mating surface due to corrosion but possessing sufficient braking effectiveness and wear resistance.

[means to resolve]

For the friction material composition, the friction material composition having 2-10 weight %, relative to the entire amount of the friction material composition, of the calcium silicate as one of the inorganic friction modifiers, 15-30 weight %, relative to the entire amount of the friction material composition, of the non-whisker-like titanate as one of the inorganic friction modifiers, 1-9 weight %, relative to the entire amount of the friction material composition, of the metal sulfide as one of the lubricants and 3-10 weight %, relative to the entire amount of the friction material composition, of the graphite as one of the lubricants, is used.

Expanded graphite and/or vermiculite are introduced into the friction lining mixture to eliminate or substantially reduce the amount of binder present therein. The friction lining at most contains from 2.5% by weight of binder. By omitting/reducing binder, the production is very stable and the friction linings can be easily reproduced. The process steps of hardening (including the hardening furnace) and scorching (including the necessary equipment) can be omitted when making such friction linings.

The present application discloses a high-performance metal matrix composite (MMC) vehicle braking component, two methods of making a porous ceramic insert, a method of making an MMC comprising a porous ceramic insert, and a method of making an MMC not comprised of a porous ceramic insert. In one exemplary embodiment the porous ceramic insert is comprised of a ceramic compound and a sacrificial insert. In another exemplary embodiment the porous ceramic insert is comprised of one or more ceramic compounds and one or more ceramic preforms. The high performance MMC vehicle braking component has two distinct friction portions that extended from the outer surfaces to the thermal management portion of the high performance MMC vehicle braking component.

A friction material, such as those belonging to the NAO or LS classes. The friction material is substantially free from copper and includes non-spherical particles in the form of powders and/or fibres each constituted by a preferably ferrous metallic core and by an at least partial coating of core formed at least partially or totally by tin and/or tin compounds, such as intermetallic Fe—Sn compounds.

A sintered friction material, in which a content of a copper component is 0.5 mass % or less, is provided. The sintered friction material includes a titanate and a metal material other than copper, as a matrix. A content of the metal material other than copper is 10.0 volume % to 34.0 volume %. A method for manufacturing a sintered friction material is provided. The method includes a mixing step of mixing raw materials containing a titanate and a metal material other than copper, a molding step of molding the raw materials mixed in the mixing step, and a sintering step of sintering, at 900° C. to 1300° C., a molded product molded in the molding step. In the sintered friction material, the titanate and the metal material other than copper form a matrix, and a content of the metal material other than copper is 10.0 volume % to 34.0 volume %.

The invention relates to an environment-friendly friction material, which consists of the following components in parts by weight: 8-15 parts of a binding material, 3-8 parts of an organic fiber, 3-8 parts of an inorganic fiber, 3-8 parts of an anti-friction material, 15-25 parts of granite powder, 35-40 parts of marble powder, 6-10 parts of a modified organic filling material, 5-10 parts of an acidity or alkalinity regulating material, and 0.5-4.5 parts of a non-copper metal material, wherein the modified organic filling material consists of the following components in parts by weight: 25-50 parts of tyre powder, 15-25 parts of a shoe sole waste, 10-15 parts of a sepiolite fiber, 2-3 parts of a silane coupling agent, 2-5 parts of a cashew nut shell liquid, and 0.5-2 parts of an activator, with the shoe sole waste including 15-30% of POE and 5-15% of EPDM. The invention is reasonable in compatibility, and has excellent properties such as reduced noise, heat resistance and little damage to mating plates while ensuring a moderate and stable friction coefficient, thereby changing waste materials into objects of value and achieving energy conservation and environmental protection effects.

Method for creating a brake pad with a block of friction material, in which sodium hydroxide and sodium silicate are dissolved in water, the aqueous solution of sodium hydroxide and sodium silicate is mixed with commercial metakaolin until a wet paste is obtained, the wet paste is formed and dried until a dried geopolymeric aggregate is obtained, the aggregate is ground to a powder, the dried ground aggregate is used as an exclusive or almost-exclusive inorganic geopolymeric binder in a friction material compound and the raw compound is hot-molded under a pressure greater than a water saturation pressure at the molding temperature.

A friction material composition imparts superior friction coefficient, abrasion resistance, aggressiveness against an opposite member, and brake noise preventive characteristics in high speed and high load braking to a friction material, although containing no copper, which can pollute rivers, lakes, the ocean, or other environments, or containing copper in an amount of at most 0.5 mass. Moreover, a friction material and a friction member each uses the friction material composition. The friction material composition includes a binder, an organic filler, an inorganic filler, and a fibrous base material, and the friction material composition contains copper in an amount of at most 0.5 mass % as an element or contains no copper. The binder contains silicone-rubber dispersed phenolic resin in an amount of 5 to 10 mass %. The inorganic filler contains zirconium oxide in an amount of 20 to 33 mass %.

A brake pad according to an embodiment includes a friction material containing copper at 0.5 wt % or less, a back plate, and an under-layer material laminated between the friction material and the back plate and having an average loss modulus of 500 MPa or more at −50° C. to 0° C. in a bending mode.