METHOD FOR MANUFACTURING A BRAKE DISC WITH A DECORATIVE INSERT

Abstract

Method for forming a decorative insert (110, 112) on a brake pad wear surface (106, 406) of a brake disc (100, 400), the method comprising: Positioning an insert material in a mold; Casting a brake disc (100, 400) in the mold around the insert material; and Machining the brake disc (100, 400) by cutting, grinding, sandblasting, scraping or polishing so that at least part of the insert material is visible on the brake pad wear surface (106, 406), wherein the thickness of the decorative insert (110, 112) is 0.5 to 3.0 millimeters, and wherein: a coefficient of friction between the decorative insert (110, 112) and a brake pad is the same as a coefficient of friction between the brake pad wear surface (106, 406) and the brake pad; and a wear rate of the decorative insert (110, 112) is equal to or greater than a wear rate of the brake pad wear surface (106, 406).

Description

INTRODUCTION

[0001] The present invention relates to a method for manufacturing a brake disc with a decorative insert.

[0002] Disc brakes are commonly used to slow down or stop the rotation of a vehicle wheel. A disc brake system generally consists of a brake rotor and a caliper, which are connected to the wheel and / or axle of the vehicle. Many manufactured components, such as brake rotors, are unmarked due to marking problems. For components that are subject to wear during use, effective marking is difficult or impossible. For example, on brake discs, any marking, including printing, labeling, or etching on a friction surface, can wear away quickly in response to daily driving conditions.

[0003] A brake rotor with a visible design feature is known from US patent 2013 / 0081776A1. During the manufacturing process, at least one porous structure is positioned in a mold for the rotor before molten metal is introduced into the mold. The presence of this porous structure forms the visible design feature on the outer surface of the component.

[0004] US patent 2006 / 0042886A1 discloses a heating element embedded in the outer surface of a brake rotor, such that heating causes the element to glow. The glowing element is visually visible to bystanders.

[0005] Further state of the art can also be found in DE 10 2012 221 365 A1.

[0006] The object of the present invention is to provide a method for the effective and permanent marking of components without increasing the cost of the manufacturing process or impairing the quality of the components. SUMMARY

[0007] This problem is solved by a method characterized by the features of claim 1.

[0008] In an unclaimed embodiment, a brake rotor comprises a brake pad wear surface, a cap surface, and a decorative insert comprising an inlay material. The decorative insert is arranged on the cap surface or on both the cap surface and the brake pad wear surface. At least one of the coefficients of friction between the decorative insert and a brake pad is substantially equal to a coefficient of friction between the brake pad wear surface and the brake pad, a wear rate of the decorative insert is substantially equal to or greater than a wear rate of the brake pad wear surface, or a wear rate of the decorative insert is substantially equal to or greater than a wear rate of the cap surface. At least a portion of the decorative insert is visible on the cap surface or on both the cap surface and the brake pad wear surface.

[0009] In addition to one or more of the features described herein, the inlay material comprises a metallic material, a ceramic material, a mineral material, a glass material or a combination thereof.

[0010] In one embodiment, the inlay material comprises aluminium, copper, manganese, a porcelain enamel, titanium, steel, stainless steel, nickel, zirconium, silicon carbide, boron carbide, tungsten carbide, nickel oxide, zirconium oxide, chromium carbide, aluminium oxide, aluminium titanium, magnesium zirconate, silicon nitride, boron nitride, titanium diboride, a silicate mineral or a combination comprising at least one of the aforementioned.

[0011] In one embodiment, the decorative use defines an individual design feature.

[0012] In one embodiment, the brake disc comprises iron, titanium, steel, copper, carbon, silicon carbide, nickel, titanium boride, aluminum, boron nitride, cobalt, magnesium, manganese, an alloy thereof, a metal matrix composite thereof, or a combination comprising at least one of the aforementioned.

[0013] In one embodiment of the method according to the invention, the insert material comprises a metallic material, a ceramic material, a mineral material, a glass material or a combination thereof.

[0014] In one embodiment of the method according to the invention, the inlay material comprises aluminium, copper, manganese, a porcelain enamel, titanium, steel, stainless steel, nickel, zirconium, silicon carbide, boron carbide, tungsten carbide, nickel oxide, zirconium oxide, chromium carbide, aluminium oxide, aluminium titanium, magnesium zirconate, silicon nitride, boron nitride, titanium diboride, a silicate mineral or a combination comprising at least one of the aforementioned.

[0015] In one embodiment of the method according to the invention, the method further comprises carrying out at least one process, comprising: a nitriding process; a carburizing process; a boronizing process; or an oxidation process to produce the brake disc after the casting step.

[0016] In an unclaimed embodiment, a method for producing a decorative insert on a hat surface or on the hat surface and a brake pad wear surface of a brake disc comprises providing the brake rotor with at least one recess on the hat surface or on both the hat surface and the brake pad wear surface. An insert material is applied to the at least one recess to form the decorative insert. At least one of the coefficients of friction between the decorative insert and a brake pad is substantially equal to a coefficient of friction between the brake pad wear surface and the brake pad, a wear rate of the decorative insert is substantially equal to or greater than a wear rate of the brake pad wear surface, or a wear rate of the decorative insert is substantially equal to or greater than a wear rate of the hat surface.At least one section of the decorative insert is visible on the cap surface or on both the cap surface and the brake pad wear surface.

[0017] In one embodiment, further comprising chemically or mechanically shaping the at least one depression on the brake pad wear surface, the hat surface or both.

[0018] In one embodiment, the at least one depression has a depth of about 0.5 to about 10 millimeters, preferably about 0.5 to about 5 millimeters, preferably 0.5 to about 3.0 millimeters.

[0019] In one embodiment, the insert material is applied by at least one of the following processes: laser powder deposition welding, laser spraying, laser coating, chemical vapor deposition, physical vapor deposition, sputtering, powder coating, thermal spraying, plasma spraying, sintering, electroplating, vacuum coating or a combination thereof.

[0020] In one embodiment, the insert material comprises a metallic material, a ceramic material, a mineral material, a glass material or a combination thereof.

[0021] In one embodiment, the inlay material comprises aluminium, copper, manganese, a porcelain enamel, titanium, steel, stainless steel, nickel, zirconium, silicon carbide, boron carbide, tungsten carbide, nickel oxide, zirconium oxide, chromium carbide, aluminium oxide, aluminium titanium, magnesium zirconate, silicon nitride, boron nitride, titanium diboride, a silicate mineral or a combination comprising at least one of the aforementioned.

[0022] In one embodiment, the method further comprises carrying out at least one process comprising: a nitriding process; a carburizing process; a boronizing process; or an oxidation process to the brake rotor after the step of applying the insert material.

[0023] The above-mentioned properties and advantages, as well as other properties and functions of the present invention, will become readily apparent from the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, advantages and details appear only as examples in the following detailed description of the embodiments, the detailed description referring to the drawings, wherein the following applies: Fig. 1 is a top view of a brake disc according to one embodiment; Fig. Figure 2 is a perspective view of a brake disc according to one embodiment; Fig. Figure 3 is a cross-sectional view of a brake disc according to one embodiment; Fig. Figure 4 is a schematic representation of a method according to one embodiment; Fig. Figure 5 is a schematic representation of a method according to one embodiment; Fig. Figure 6 is a top view of a brake rotor according to one embodiment; and Fig. Figure 7 is a perspective view of a brake disc according to one embodiment. DETAILED DESCRIPTION

[0025] The following description is merely exemplary. Although the terms first, second, third, etc., may be used herein to describe different elements, components, and / or sections, these elements, components, and / or sections should not be limited by these terms. These terms are used only to distinguish one element, component, or section from another. Thus, a first element, component, or section discussed below could be referred to as a second element, component, or section without departing from the teachings of the present invention.

[0026] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meanings as they would normally be understood by a person skilled in the art in the field to which this invention belongs. Furthermore, it is understood that terms such as those used in commonly used dictionaries should be interpreted as consistent in their meaning within the context of the relevant technology and the present invention, and not in an idealized or overly formal sense, unless expressly defined otherwise herein.

[0027] According to an exemplary embodiment, a brake rotor is provided with a decorative insert. The decorative insert comprises an inlay material and is positioned on the brake pad wear surface, the top surface, or both of the brake disc. In the case of the brake disc, at least a portion of the decorative insert is visible on the brake pad wear surface, the top surface, or both.

[0028] As used herein, a decorative insert positioned on the brake pad wear surface, the cap surface, or both, means that at least part of the decorative insert is visible on one or more of these surfaces of the brake disc. In other words, parts of the decorative insert may be located on these visible surfaces of the brake disc, while parts of the decorative insert may also be located below these visible surfaces of the brake disc.

[0029] Fig. 1 and Fig. Figure 2 shows views of a brake disc according to exemplary embodiments. The brake disc 100 includes a brake pad wear surface 106 and a cap surface 104. The cap surface 104 includes bolt holes 108 for receiving bolts that connect the brake disc 100 to the wheel and the vehicle body—i.e., an axle hub (not shown). Fig. Figure 3 shows the interaction between a brake pad 120 and the brake pad wear surface 106; other components, including a second brake pad on the opposite side of the brake disc 100, are omitted for simplicity. As in Fig. As shown in Figure 3, the brake pad wear surface 106 is positioned adjacent to a brake pad 120 when installed in a vehicle. During operation, when the driver applies the brakes, the brake pad 120 contacts the brake pad wear surface 106 while the brake disc 100 rotates, thus braking the brake disc 100 and consequently the vehicle. For this purpose, the brake disc 100 must be very robust, and the brake pad wear surface 106 must be able to withstand high intermittent frictional forces over the service life of the brake disc 100.

[0030] The decorative inserts 110 / 112 can be positioned at any location on the brake pad wear surface 106 and / or the cap surface 104 of the brake disc 100. In one embodiment, the decorative insert 110 / 112 is located at several locations, both on the brake pad wear surface 106 and on the cap surface 104. In yet another embodiment, the brake disc 100 can include several decorative inserts 110 / 112 that differ in size, material composition, depth, appearance, and shape. In one embodiment, the cap surface 104 includes the decorative insert 112. In another embodiment, the decorative insert 110 is located (i.e., arranged) on the brake pad wear surface 106.

[0031] In one embodiment, the decorative insert 110 / 112 defines a custom design feature. The custom design feature can include company symbols, designs, graphics, logos, alphanumeric symbols, and images, such as a picture of a vehicle. In the illustrated embodiment, the decorative insert is a symbol for the Chevrolet® automotive brand, the so-called "bowtie" logo. The custom design feature can also include custom symbols, designs, graphics, logos, alphanumeric symbols, and images. The shape of the decorative insert can be used to create a visually distinctive appearance, for example, to indicate the source, owner, or type of the marked component. The marking can be used for identification purposes—for example,for identifying the part in connection with inventorying, distribution, ownership and / or sale, for branding, individualization, or aesthetic purposes. As a specific example, the decorative insert 110 / 112 can serve as a distinguishing feature that is visible during the operation of the vehicle—i.e., while the brake disc 100 is in its operating position on the vehicle.

[0032] In one embodiment, the decorative insert 110 / 112 has a thickness of approximately 0.5 to approximately 10 millimeters (mm), approximately 0.5 to approximately 7.5 mm, approximately 0.5 to approximately 5 mm, approximately 0.5 to approximately 4 mm, approximately 0.5 to approximately 3 mm, approximately 0.5 to approximately 2 mm, or approximately 0.5 to approximately 1 mm. The decorative insert 110 / 112 also has, for example, a thickness of approximately 0.75 to approximately 8 mm, approximately 1.0 to approximately 6 mm, approximately 1.25 to approximately 4 mm, approximately 1.5 to approximately 3 mm, or approximately 1.75 to approximately 2.0 mm. As used herein, the thickness is the largest feature of the decorative insert 110 / 112 in the plane perpendicular to the brake pad wear surface 106 and the cap surface 104. In yet another embodiment, a plurality of decorative inserts 110 / 112 are provided, each decorative insert having an independent thickness as described.

[0033] In one embodiment, the decorative insert 110 / 112 has a width of approximately 10 to approximately 150 mm, approximately 25 to approximately 150 mm, approximately 50 to approximately 150 mm, or approximately 75 to approximately 150 mm. For example, the decorative insert 110 / 112 has a width of approximately 20 to approximately 120 mm, approximately 20 to approximately 100 mm, or approximately 20 to approximately 80 mm. As used herein, the width is the widest horizontal feature of the decorative insert 110 / 112 in the plane of the brake pad wear surface 106 and the cap surface 104. In yet another embodiment, a plurality of decorative inserts 110 / 112 are provided, each decorative insert 110 / 112 independently having a width as described.

[0034] In one embodiment, a plurality of decorative inserts 110 / 112 are included, having a spacing of approximately 0.5 to approximately 150 mm, approximately 0.5 to approximately 100 mm, approximately 0.5 to approximately 50 mm, approximately 0.5 to approximately 25 mm, approximately 0.5 to approximately 15 mm, approximately 0.5 to approximately 10 mm, approximately 0.5 to approximately 5 mm, approximately 0.5 to approximately 2.5 mm, or approximately 0.5 to approximately 1.0 mm. In yet another embodiment, a plurality of decorative inserts 110 / 112 are provided, each decorative insert 110 / 112 having an independent spacing from an adjacent decorative insert 110 / 112 as described.

[0035] In the case of the brake disc 100, at least one of the coefficients of friction between the decorative insert 110 and a brake pad 120 is essentially equal to a coefficient of friction between the brake pad wear surface 106 and the brake pad 120, a wear rate of the decorative insert 110 is essentially equal to or greater than a wear rate of the brake pad wear surface 106, or a wear rate of the decorative insert 110 is essentially equal to or greater than a wear rate of the cap surface 104.In other words, at least one of the sections of the brake pad wear surface 106 that includes the decorative insert 110 has a coefficient of friction between the decorative insert 110 and the brake pad 120 that is substantially equal to the coefficient of friction between the brake pad wear surface 106 and the brake pad 120 for the section of the brake pad wear surface 106 that does not include the decorative insert 110, wherein the part of the brake pad wear surface 106 that includes the decorative insert 110 has a wear rate that is substantially equal to or greater than the wear rate of the brake pad wear surface 106 that does not include the decorative insert 110, and wherein the section of the cap surface 104 that includes the decorative insert 110 has a wear rate that is substantially equal to or greater than the wear rate of the cap surface 104 that does not include the decorative insert 110. contains.

[0036] In one embodiment, the coefficient of friction between the decorative insert 110 and a brake pad 120 corresponds to ±0.1, ±0.08, ±0.05, or ±0.03 of the coefficient of friction between the brake pad wear surface 106 and the brake pad 120. In another embodiment, the coefficient of friction between the decorative insert 110 and a brake pad 120 is 10%, ±8%, ±5%, or ±0.3% of the coefficient of friction between the brake pad wear surface 106 and the brake pad 120. Suitable brake pads include those available in the art and may include organic brake pads, semi-metallic brake pads, ceramic brake pads, or similar materials. Brake pad materials include, but are not limited to, glass, fibers, rubber, carbon, Kevlar, steel, iron, copper, manganese, graphite, ceramics, ceramic composites or the like.The coefficient of friction can be measured using industry-standard methods, including but not limited to JASO C-406 or SAE J2430.

[0037] In one embodiment, the wear rate of the decorative insert 110 is approximately 10% greater, approximately 8% greater, approximately 5% greater, approximately 3% greater, or approximately 1% greater than the wear rate of the brake pad wear surface 106. In another embodiment, the wear rate of the decorative insert 110 is approximately 10% greater, approximately 8% greater, approximately 5% greater, approximately 3% greater, or approximately 1% greater than the wear rate of the cap surface 104. The wear rate can be measured using industry-standard methods, including, but not limited to, JASO C427-83 or SAE J2707.

[0038] The inlay material can be a metallic material, a ceramic material, a mineral material, a glass material, or a combination thereof. In one embodiment, the inlay material comprises aluminum, copper, manganese, a porcelain enamel, titanium, steel, stainless steel, nickel, zirconium, silicon carbide, boron carbide, tungsten carbide, nickel oxide, zirconium oxide, chromium carbide, aluminum oxide, aluminum titanium, magnesium zirconate, silicon nitride, boron nitride, titanium diboride, a silicate mineral, or a combination comprising at least one of the aforementioned.

[0039] In one embodiment, the ceramic material may include, among other things, barium titanate, boron oxide, boron nitride, ferrite, porcelain, earthenware, silicon aluminum oxynitride, silicon carbide, silicon nitride, magnesium silicates, titanium carbide, zinc oxide, zirconium dioxide, titanium dioxide, aluminum oxide, beryllium oxide, cerium oxide, zirconium oxide, carbon fiber, alloys thereof, composites thereof, metal matrices thereof, or combinations comprising at least one of the aforementioned.

[0040] In one embodiment, the mineral material may include one or more of a silicate mineral, a carbide mineral, a phosphide mineral, a sulfide mineral, a sulfosalt mineral, a halide mineral, an oxide mineral, a spinel group, a hydroxide mineral, a carbonate mineral, a nitrate mineral, a borate mineral, a sulfate mineral or a phosphate mineral.

[0041] In one embodiment, the porcelain enamel may contain a composition comprising quartz, feldspar, marble, kaolin, boric acid, borax, Na₂O, K₂O, Li₂O, MnO, silicon, ZrO₂, BaO, ZnO, SnO, CaO, MgO, CoO, Fe₂O₃, F₂, NiO, P₂O₅, Al₂O₃, TiO₂, or a combination thereof. In some embodiments, the porcelain enamel may contain metal nanoparticles selected from gold, silver, platinum, palladium, iron, chromium, copper, cobalt, manganese, alloys thereof, and combinations thereof.

[0042] In one embodiment, the silicate mineral may contain one or more of the following: mica, olivine, quartz, feldspar, zeolite, mullite, titanite, chondrodite, humite, clinohumite, andalusite, kyanite, sillimanite, dumortierite, topaz, staurolite, datolite, zircon, thorite, hafnite, phenakite, willemite, forsterite, fayalite, tephroite, pyrope, almandine, spessartine, grossular, uvarovite, andratite, hemimorphite, lawsonite, axinite, ilvaite, epidote, zoisite, tanzanite, clinozoisite, allanite, benitoite, beryl, bazzite, sugilite, tourmaline, pezzottaite, osumilite, cordierite, secaninaite, enstatite, ferrosilite, dove stone, diopside, augite, jadeite, accite, wollastonite, rhodonite, Pectolite, tremolite, antigorite, chyrsotile, lizard, halloysite, kaolinite, illite, montmorillonite, vermiculite, talc, sepiolite, palygorskite, pyrophyllite, biotite, fuchsite, muscovite, phylogopty, lepidolite, margarite, glauconite, chlorite, leucite, sodalite, petalite, marialite, meionite, natrolite, Contain erionite or mordenite.

[0043] In one embodiment, the glass material can be one or more of the following: SiO2, Al2O3, Na2O, K2O, Li2O, CaO, MgO, BaO, CaO, MgO, SrO, Sb2O3, Fe2O3, MnO2, CeO2, SnO2, TiO2, ZnO, P2O5, Sb2O3, 2MgO·Sb2O5, 7MgO·Sb2O5, 2ZnO·Sb2O5, 7ZnO·Sb2O5, 3CaO·Sb2O5, 6CaO·Sb2O5, 2SrO·Sb2O5, 6SrO·Sb2O5, BaO·Sb2O5, 4BaO·Sb2O5, Li2O·Sb2O5, 2Li2O·Sb2O5, K2O·Sb2O5, LaSbO4, SbNbO5, Sr(Ca 0.33 Sb 0.67 )O3, LiZnSbO4, Li 1.0 Sb 0.5 O4, Ba2Al 0.5 Sb 0.5 O6, Ba2Ce 0.75 SbO6, ZrSbPO7, Ba (Sb 0.5 Sn 0.5 )O3, LiSiSbO5, Li2Zr2Sb2SiO 11 , NaNO3, KNO3, Ba(NO3)2, Na2SO4, K2SO4, CaSO4, BaSO4, NaCl, KCl, CaCl2, CaF2, Na2SiF6, LiF, KF or inorganic elements such as Al, Si, Zn, Ga, Fe, Sn.

[0044] In one embodiment, the brake disc, including the decorative insert, is modified by one or more nitriding, carburizing, boronizing, or oxidation processes after the application of the insert material. Any suitable nitriding, carburizing, boronizing, and / or oxidation process can be used, including those available in the art, to ensure the diffusion of N, C, B, and / or O into the brake disc. Details of these processes are described below.

[0045] According to a further exemplary embodiment, a method for producing a decorative insert on a brake pad wear surface, a cap surface, or both of a brake rotor involves positioning an insert material in a mold and casting a brake disc in the mold around the insert material. The brake disc is then machined such that at least part of the insert material is visible on the brake pad wear surface, the cap surface, or both. In the method, at least one of the coefficients of friction between the decorative insert and a brake pad is substantially equal to a coefficient of friction between the brake pad wear surface and the brake pad, a wear rate of the decorative insert is substantially equal to or greater than a wear rate of the brake pad wear surface, or a wear rate of the decorative insert is substantially equal to or greater than a wear rate of the cap surface.

[0046] Fig. Figure 4 schematically shows the steps of the inventive method 200 for forming a decorative insert 110 / 112 on a brake pad wear surface 106, a cap surface 104, or both, or on a brake disc 100. It should be noted that the steps of method 200 are not necessarily shown in a specific order and that all or some of the steps can be carried out in a different sequence. The steps are shown in Fig. Figure 3 is listed for the sake of simplicity and illustration. The steps can be added, omitted, or performed simultaneously without deviating from the scope of the attached claims.

[0047] In Fig. In step 204, process 200 begins with the positioning of the insert material in the mold cavity. In step 206, a melt is introduced into the mold cavity. In step 208, the brake disc, including the decorative inserts, is removed from the mold. In step 210, the brake disc is heat-treated to relieve or eliminate residual stresses. In step 212, the brake disc is machined according to specifications and tolerances. Step 214 involves ferritic nitrocarburizing (FNC) to obtain the finished brake disc with the decorative inserts.

[0048] In one embodiment, the insert material can be positioned in the cavity of a mold by any suitable means. For example, the insert material can be attached to the sides of the mold cavity with another material that dissolves the insert material during or after the casting process or otherwise releases it from its attachment to the sides of the mold cavity. In another embodiment, the insert material is positioned in an arrangement within the cavity of the mold that reflects the desired position of the desired decorative insert 110 / 112.

[0049] In one embodiment, the casting process also includes introducing a molten metal into the cavity of the mold using a suitable method. The molten metal can contain iron, titanium, aluminum, steel, stainless steel, or a combination thereof. In another embodiment, the molten metal contains the material of the brake disc.

[0050] After the casting process, the mold is opened and the brake disc 100 is removed from the cavity to provide the brake disc 100. The brake disc 100, including the decorative insert 110 / 112, is then machined so that at least part of the inlay material, such as the decorative insert 110 / 112, is visible on the brake pad wear surface 106, the cap surface 104, or both of the brake disc 100. Suitable machining processes include cutting, grinding, machining, sandblasting, scraping, polishing, or the like.

[0051] In one embodiment, the method further includes performing at least one process on the brake disc 100 after the casting step, including a nitriding process, a carburizing process, a boronizing process, or an oxidation process. Any suitable nitriding, carburizing, boronizing, and / or oxidation process can be used, including those available in the art, to ensure the diffusion of N, C, B, and / or O into the brake disc. The process can also include a combined process, such as nitrocarburizing. In one embodiment, after performing the at least one additional process, at least a portion of the decorative insert 110 / 112 is visible on the brake pad wear surface 106, the cap surface 104, or both of the brake disc 100.

[0052] In one embodiment, the nitriding process can involve immersing the brake disc 100 in an anhydrous molten salt bath, through which a suitable nitrogen-releasing gaseous substance, e.g. dry gaseous ammonia, is introduced depending on the temperature used, in order to ensure the dissociation of the ammonia and to effect optimal nitrogen uptake by the brake disc 100.

[0053] In one embodiment, the carburizing process can involve plasma carburizing in a vacuum with a hydrocarbon gas at a temperature sufficient to generate a glow discharge and form the brake disc 100 into a cathode. Following plasma carburizing, the absorbed carbon in the brake disc 100 can be diffused to form a carburized layer of a suitable thickness by diffusion treatment.

[0054] In one embodiment, the boronization process can involve pre-coating the brake disc 100 with an organic binder and subsequently encapsulating the pre-coated brake disc 100 with boron, followed by heating. The boronization process can be further modified and / or improved by additives such as halides, metal oxides, and the like.

[0055] In one embodiment, the oxidation process may involve microarc oxidation or other suitable electrochemical surface processes to generate metal oxide layers in a metal substrate.

[0056] In a further embodiment, the process can also include a ferritic nitrocarburizing (FNC) process. The brake discs 100 can be case-hardened after the FNC process to increase wear and corrosion resistance. In the FNC process, nitrogen and carbon are diffused into the brake disc 100—e.g., into a surface region including the surface and beyond the surface to a certain depth within the component. The FNC process can be performed on a ferrous metal that has a subcritical temperature for the metal. In one embodiment, the temperature can be approximately 525 °C to approximately 625 °C. Particularly in FNC, the component material (e.g.,Steel or another iron alloy) exhibits a temperature in this range, at which the component material is in its ferritic phase, and not a temperature at which the material is in an austenitic phase. Four main types or classes are available for FNC machining: gas, salt bath, ion, plasma, and fluidized bed. The use of FNC machining on brake discs is described in US patent application US 2008 / 0000550A1. The brake discs can also be stress-relieved after casting or machining to achieve thermal stability and distortion resistance that can be induced by the FNC process.

[0057] According to a further unclaimed embodiment, another method for forming a decorative insert 110 / 112 on a brake pad wear surface 106, a cap surface 104 or both, or on a brake disc 100 is provided. With reference to the present Fig. 6 and Fig. 7 The method comprises providing the brake disc 400 with at least one recess 410 / 412 on the brake pad wear surface 406, the cap surface 404, or both. An insert material is applied to the at least one recess 410 / 412 to form the brake disc 100, including the decorative inserts 110 / 112, the structure of which is as described above ( Fig. 1-2).

[0058] The brake disc 400 can be an automotive component prepared, for example, by suitable casting or forming processes. The brake disc can comprise suitable materials, including iron, titanium, steel, copper, carbon, silicon carbide, nickel, titanium boride, aluminum, aluminum oxide, boron nitride, cobalt, magnesium, manganese, an alloy thereof, a metal matrix composite thereof, or a combination of at least one of the aforementioned materials. For example, the brake disc can be made of cast iron, gray cast iron, stainless steel, carbon fiber reinforced carbon (carbon-carbon), carbon fiber reinforced silicon carbide, a ceramic matrix composite, mullite, aluminum metal matrix composite (MMC), carbon fiber, graphite, aluminum oxide, and the like. In one embodiment, the brake disc comprises cast iron.Other alloying and / or matrix elements include, for example, C, Si, Mn, P, S, Cr, Fe, Ni, Cu, V, Al, N, Ti, W, Mo, Li, Na, K, Mg, B, Zr or other suitable elements.

[0059] Fig. Figure 5 schematically shows the steps of an unclaimed method 300 for forming a decorative insert 110 / 112 on a brake pad wear surface 106, a cap surface 102, or both, and on a brake disc 100. It should be noted that the steps of method 300 are not necessarily shown in a specific order, and all or some of the steps can be performed in a different sequence. The steps are in Fig. Figure 5 is listed for the sake of simplicity and illustration. The steps can be added, omitted, or performed simultaneously without deviating from the scope of the attached claims.

[0060] In Fig.In step 5, the unclaimed process 300 begins with step 304 and forms the at least one recess 410 / 412 in the brake pad wear surface 406, the cap surface 404, or both. In step 306, an insert material is applied to the at least one recess 410 / 412. In step 308, the insert material is further processed, for example, by sintering or hardening. In step 310, the brake disc is machined according to specifications to correct tolerances. Step 312 includes ferritic nitrocarburizing (FNC) to obtain the finished brake disc 100 with the decorative inserts 110 / 112.

[0061] In one embodiment, the method further comprises the chemical or mechanical formation of the at least one recess 410 / 412 on the brake pad wear surface 406, the cap surface 404, or both. The recesses 410 / 412 can be formed using any suitable method, including those available in the art. In one embodiment, the recesses 410 / 412 can be formed by laser cutting, mechanical cutting, chemical etching, milling, ablation, drilling, plasma cutting, sandblasting, flux cutting, arc cutting, or electrical discharge machining. In another embodiment, the method for forming the recesses 410 / 412 includes casting a brake disc 400 with pre-formed recesses 410 / 412, for example, with recesses 410 / 412 formed during or by the casting process. The recesses 410 / 412 can optionally be cleaned, smoothed, or polished by any suitable method.

[0062] In one embodiment, the at least one recess 410 / 412 can be used to define the shape of the decorative insert 110 / 112. For example, a specific indentation pattern can be formed using a mechanical method. Alternatively, a mask can be applied to the brake disc around an area with the shape of the decorative insert 110 / 112, after which the etching agent can be applied and the mask removed to reveal the recess 410 / 412. Any suitable etching and masking agents can be used, for example, based on the material of the brake disc 100 / 400.

[0063] In one embodiment, the at least one recess 410 / 412 has a depth of approximately 0.5 to approximately 10 millimeters (mm), approximately 0.5 to approximately 7.5 mm, approximately 0.5 to approximately 5 mm, approximately 0.5 to approximately 4 mm, approximately 0.5 to approximately 3 mm, approximately 0.5 to approximately 2 mm, or approximately 0.5 to approximately 1 mm. The at least one recess 410 / 412, for example, has a depth of approximately 0.75 to approximately 8 mm, approximately 1.0 to approximately 6 mm, approximately 1.25 to approximately 4 mm, approximately 1.5 to approximately 3 mm, or approximately 1.75 to approximately 2.0 mm. As used herein, the depth is the largest feature of the at least one recess 410 / 412 in the plane perpendicular to the brake pad wear surface 406 and the cap surface 404. In yet another embodiment, a plurality of recesses 410 / 412 are provided, each recess 410 / 412 having a thickness as described independently of the others.

[0064] In one embodiment, the at least one recess 410 / 412 has a width of about 10 to about 150 mm, about 25 to about 150 mm, about 50 to about 150 mm, or about 75 to about 150 mm. For example, the at least one recess 410 / 412 has a width of about 20 to about 120 mm, about 20 to about 100 mm, or about 20 to about 80 mm. As used herein, the width is the widest horizontal feature of the recess 410 / 412 in the plane of the brake pad wear surface 406 and the cap surface 404. In yet another embodiment, a plurality of recesses 410 / 412 are provided, each recess 410 / 412 having an independent width as described.

[0065] In one embodiment, a plurality of recesses 410 / 412 are provided, having a recess spacing of approximately 0.5 to approximately 150 mm, approximately 0.5 to approximately 100 mm, approximately 0.5 to approximately 50 mm, approximately 0.5 to approximately 25 mm, approximately 0.5 to approximately 15 mm, approximately 0.5 to approximately 10 mm, approximately 0.5 to approximately 5 mm, approximately 0.5 to approximately 2.5 mm, or approximately 0.5 to approximately 1.0 mm. In yet another embodiment, a plurality of recesses 410 / 412 are provided, each recess having an independent distance to an adjacent recess 410 / 412 as described.

[0066] In one embodiment, the insert material is applied by at least one of the following processes: laser powder deposition welding, laser spraying, laser coating, chemical vapor deposition, physical vapor deposition, sputtering, powder coating, thermal spraying, plasma spraying, sintering, electrocoating, glass-like enameling, dipping, electrospraying, or a combination thereof. The application method can be determined based on the insert material and the brake disc material. In one embodiment, the applied insert material can be further processed by methods such as sintering, curing, enameling, or other suitable processes, based on the insert material and the application method. In another embodiment, the insert material is treated by a process to obtain a porous surface that can correspond to the wear rate or other properties of the brake disc surfaces.

[0067] In one embodiment, at least a portion of the volume of the at least one recess 410 / 412 is not filled with the insert material. In another embodiment, the entire volume of the recess 410 / 412 is filled with the insert material. In still further embodiments, a plurality of recesses 410 / 412 are provided, each recess having, independently of one another, at least a portion of its volume that is not filled with the insert material, or having its entire volume filled with the insert material. In one embodiment, the volume of each recess 410 / 412 is filled independently with approximately 20, 30, 40, 50, 60, 70, 80, 90, 99, or 100 vol% of the insert material.

[0068] In a further embodiment, the at least one recess 410 / 412 is provided as a series of micro-recesses, each with a depth of approximately 0.5 to approximately 10 mm, a width of approximately 0.1 to approximately 10 mm, and a spacing between the recesses of approximately 0.1 to approximately 1 mm. One or more of the micro-recesses can be filled with the insert material. The micro-recesses can be arranged to define the individual design feature in a manner similar to the recesses 410 / 412. In other words, a user-defined design feature can be provided using adjacent filled micro-recesses to achieve a similar appearance to (or differ from) a similarly arranged pre-designed feature provided by a single recess 410 / 412.

[0069] In one embodiment, the method further includes carrying out at least one process, comprising a nitriding process, a carburizing process, a boronizing process, or an oxidation process, to produce the brake disc after the application step described above.

[0070] In yet another embodiment, the brake disc 100 can be provided with a sacrificial or barrier coating on its surface. Sacrificial coatings, such as a zinc-rich coating, can offer additional corrosion protection. These sacrificial coatings can be supplemented or replaced by barrier coatings to further prevent corrosion. Furthermore, coatings on the wheel interface of the brake disc 100 can be made of polytetrafluoroethylene (PTFE) to increase resistance to wheel engagement.

Claims

[1] Method for forming a decorative insert (110, 112) on a brake pad wear surface (106, 406) of a brake disc (100, 400), the method comprising: Positioning an insert material in a mold; Casting a brake disc (100, 400) in the mold around the insert material; and Machining the brake disc (100, 400) by cutting, grinding, sandblasting, scraping or polishing so that at least part of the insert material is visible on the brake pad wear surface (106, 406), wherein the thickness of the decorative insert (110, 112) is 0.5 to 3.0 millimeters, and wherein: a coefficient of friction between the decorative insert (110, 112) and a brake pad is the same as a coefficient of friction between the brake pad wear surface (106, 406) and the brake pad; and a wear rate of the decorative insert (110, 112) is equal to or greater than a wear rate of the brake pad wear surface (106, 406). [2] The method of claim 1, further comprising carrying out at least one method comprising: a nitriding process; a carburizing process; a boronization process; or an oxidation process on the brake disc (100, 400) after casting.

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