# US 8,147,912 B2 · Braking band composite structure of a brake disc > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,147,912 B2 - Document ID: US8147912B2 - Status: Granted - Kind: B2 - Application number: 12/307,707 - Filed: 2007-07-13 - Published: 2009-12-24 - Granted: 2012-04-03 - Earliest claimed: 2006-07-14 - Assignees: Freni Brembo S.p.A. - Inventors: Ralf Siegfried Golleb; Bernardino Mauri; Marco Orlandi - Web page: https://patentgrep.com/patent/US8147912B2 ## CPC - C04B 41/87: Ceramics - C04B 35/565: based on silicon carbide - C04B 35/573: obtained by reaction sintering {or recrystallisation} - C04B 35/80: Fibres, filaments, whiskers, platelets, or the like - C04B 38/0022: {obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors} - C04B 41/009: {characterised by the material treated} - C04B 41/5031: {Alumina} - F16D 69/023: {Composite materials containing carbon and carbon fibres or fibres made of carbonizable material} - C04B 2111/00362: {Friction materials, e.g. used as brake linings, anti-skid materials} - C04B 2235/3826: Silicon carbides - C04B 2235/425: Graphite - C04B 2235/48: Organic compounds becoming part of a ceramic after heat treatment, e.g. carbonising phenol resins - C04B 2235/524: Non-oxidic, e.g. borides, carbides, silicides or nitrides - C04B 2235/5244: Silicon carbide - C04B 2235/5248: Carbon, e.g. graphite - F16D 2200/0047: Ceramic composite, e.g. C/C composite infiltrated with Si or B, or ceramic matrix infiltrated with metal - F16D 2250/0038: Surface treatment - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES ## Abstract A method for making a composite structure or a portion of a composite structure of a braking band of a brake disc, unusually capable of obtaining a structure with an especially long life, comprising at least the following steps: making a composite ceramic structure, comprising carbon fibre filaments, silicon and silicon carbides, obtaining a body of a braking band comprising at least one braking surface; processing said braking surface removing a surface layer so as to have carbon not bonded with the silicon on surface; removing at least partly the carbon not bonded with silicon from the surface; depositing an anchoring substrate on said braking surface; and depositing a protective coating on said anchoring substrate. ## Claims ### Claim 1 A method for making a composite structure or a portion of a composite structure of a braking band of a brake disc comprising at least the following steps: making a composite ceramic structure, comprising silicon, silicon carbides and carbon not bonded to silicon, obtaining a body of a braking band comprising at least one braking surface, said carbon not bonded to silicon being present substantially in the form of carbon fibre filaments; processing said braking surface removing a surface layer so as to have said carbon not bonded with silicon on the surface; removing at least partly and mainly selectively the carbon not bonded with silicon from the surface, leaving silicon and silicon carbides; and depositing a protective coating on said surface from which at least partly and mainly selectively the carbon not bonded with the silicon has been removed. ### Claim 2 (depends on 1) A method according to claim 1, wherein at the end of said step of removing at least partly the carbon not bonded with silicon, said composite structure exhibits a surface layer at said braking surfaces, consisting of silicon and silicon carbide, which exhibits micro-cavities due to the removal of the carbon not bonded with silicon, the carbon not bonded with silicon present in said composite ceramic structure thus being away from said braking surface. ### Claim 3 (depends on 2) A method according to claim 2, wherein said surface layer has a thickness comprised between 100 μm and 600 μm. ### Claim 4 (depends on 1) A method according to claim 1, wherein during said removal step, the carbon not bonded with silicon is removed up to a depth comprised within the range between 0.1 mm and 0.6 mm and preferably within the range between 0.2 mm and 0.5 mm. ### Claim 5 (depends on 1) A method according to claim 1, wherein said step of removing the carbon not bonded with silicon is carried out by cleaning said braking surfaces with abrasive jet. ### Claim 6 (depends on 1) A method according to claim 1, wherein said step of removing the carbon not bonded with silicon is carried out by combustion of said braking surfaces. ### Claim 7 (depends on 1) A method according to claim 1, comprising a step of depositing an anchoring substrate directly on said braking surface from which the carbon not bonded with silicon has been at least partly and mainly selectively removed, said protective coating being deposited on said anchoring substrate. ### Claim 8 (depends on 7) A method according to claim 7, wherein said anchoring substrate is of metal material. ### Claim 9 (depends on 8) A method according to claim 8, wherein said metal material comprises one or more metals selected from the group comprising Nickel, Aluminium, Chromium and Copper. ### Claim 10 (depends on 7) A method according to claim 7, wherein said anchoring substrate has a thickness comprised within the range between 30 and 200 μm, and preferably within the range between 50 and 100 μm. ### Claim 11 (depends on 7) A method according to claim 7, wherein said anchoring substrate only partly fills said micro-cavities due to the removal of the carbon not bonded with silicon. ### Claim 12 (depends on 7) A method according to claim 7, wherein said anchoring substrate only partly fills said micro-cavities due to the removal of the carbon not bonded with silicon, strictly following the profile of said micro-cavities. ### Claim 13 (depends on 7) A method according to claim 7, wherein said anchoring substrate is deposited by plasma deposition, which envisages the generation of a plasma jet starting from a carrier gas flow, the material used to make said anchoring substrate being injected in powder form. ### Claim 14 (depends on 13) A method according to claim 13, wherein for the deposition of said anchoring substrate, said powder material comprises powders of one or more non-oxidised metals. ### Claim 15 (depends on 14) A method according to claim 14, wherein said metals are selected from the group comprising Nickel, Aluminium, Chromium and Copper. ### Claim 16 (depends on 7) A method according to claim 7, wherein said protective coating is closely coupled to said braking surface thanks to the micro-roughness correlated to the micro-cavities which are generated by the removal of the carbon not bonded with silicon and are only partly filled by said anchoring substrate, said anchoring substrate mechanically uncoupling said protective coating from said composite ceramic structure. ### Claim 17 (depends on 1) A method according to claim 1, wherein said protective coating is deposited by plasma deposition, which envisages the generation of a plasma jet starting from a carrier gas flow, the material used to make said protective coating being injected in powder form. ### Claim 18 (depends on 17) A method according to claim 17, wherein for the deposition of said protective coating, said powder material comprises oxide powders. ### Claim 19 (depends on 18) A method according to claim 18, wherein said oxides are selected from the group comprising Al2O3, TiO2 and Cr2O3. ### Claim 20 (depends on 1) A method according to claim 1, wherein said deposition is carried out up to obtain a thickness of said protective coating comprised within the range between 200 μm and 700 μm, and preferably within the range between 200 μm and 500 μm. ### Claim 21 (depends on 1) A method according to claim 1, comprising a step of mechanical finishing of said composite ceramic structure, to be carried out after said step of deposition of a protective coating. ### Claim 22 (depends on 21) A method according to claim 21, wherein said mechanical finishing step is carried out to bring the thickness of said coating to a value comprised within the range between 100 μm and 300 μm, and preferably equal to 200 μm. ### Claim 23 A method for making a composite structure or a portion of a composite structure of a braking band of a brake disc comprising the following steps: making a composite ceramic structure, comprising silicon, silicon carbides and carbon not bonded to silicon, obtaining a body of a braking band comprising at least one braking surface, said carbon not bonded to silicon being present substantially in the form of carbon fibre filaments; processing said braking surface removing a surface layer so as to have said carbon not bonded with silicon on the surface; removing from the surface at least partly and mainly selectively the carbon not bonded with silicon, leaving the silicon and the silicon carbides, thus obtaining at said braking surfaces a surface layer, consisting of silicon and silicon carbide, which exhibits micro-cavities due to the removal of the carbon not bonded with silicon; depositing an anchoring substrate of metal material directly on said braking surface from which at least partly and mainly selectively the carbon not bonded with silicon has been removed, said anchoring layer only partly filling said micro-cavities and strictly following the profile of said micro-cavities; and depositing a protective coating made with oxides on said anchoring substrate.