Brake rotor with a multifunctional coating

Abstract

A brake rotor with a multifunctional coating and a method are provided. The brake rotor comprises an annular body, which further includes a core made of an aluminum-silicon alloy (Al-Si alloy) and at least one annular disk with an annular surface and a multilayer coating arranged on at least one section of the core. The multilayer coating comprises a metal binder layer arranged on the annular surface, a heat-resistant layer arranged on the metal binder layer, and a wear-resistant layer arranged on the heat-resistant layer. The metal binder layer contains nickel-cobalt-chromium-aluminum-yttrium (NiCoCrAlY) and / or nickel-chromium-aluminum (NiCrAl). The heat-resistant layer contains yttrium oxide-stabilized zirconium dioxide (YSZ) and cerium oxide-stabilized zirconium dioxide (CSZ).The wear-resistant layer contains stainless steel and carbide insert material.

Description

INTRODUCTION

[0001] The present disclosure relates to a brake rotor and in particular to a brake rotor formed from an aluminium-silicon alloy and having a multifunctional coating.

[0002] Disc brake assemblies in motor vehicles consist of a disc or rotor with a pair of annular friction surfaces on opposing sides. The rotor may be mounted on a rotating axle of the vehicle, which may be connected to a wheel. During braking, the outer circumference of the rotor is clamped between a pair of opposing brake pads, which engage with the friction surfaces of the rotor, slowing or stopping the rotation of the rotor and wheel. Motor vehicle brake discs are often made of cast iron, which can withstand the high frictional forces and temperatures encountered during braking. However, cast iron can be heavy and prone to corrosion. Cast iron can also increase particulate emissions.

[0003] While current iron-based brake rotors may serve their purpose under certain circumstances, there is a need for lighter brake motors that can withstand higher operating temperatures and reduce vehicle weight. SUMMARY

[0004] According to several aspects of the present disclosure, a brake rotor with a multifunctional coating is provided. The brake rotor includes an annular body that defines opposing friction surfaces. The annular body contains a core made of an aluminum-silicon alloy (Al-Si) and at least one annular disc with an annular surface and a multilayer coating arranged on at least one section of the core. The multilayer coating is configured to provide wear resistance and increase the operating temperature. The multilayer coating includes a metal binder layer arranged on the annular surface, a heat-resistant layer arranged on the metal binder layer, and a wear-resistant layer arranged on the heat-resistant layer.The metal binder layer contains nickel-cobalt-chromium-aluminum-yttrium (NiCoCrAlY) and / or nickel-chromium-aluminum (NiCrAl). The heat-resistant layer contains yttrium oxide-stabilized zirconium dioxide (YSZ) and cerium oxide-stabilized zirconium dioxide (CSZ). The wear-resistant layer contains stainless steel and carbide insert material.

[0005] According to another aspect of the disclosure, the metal binder layer has a thickness of between about 10 and 100 micrometers (µm).

[0006] According to another aspect of the disclosure, the metal binder layer contains between about 55 and 65% nickel (Ni), between about 10 and 30% cobalt (Co), between about 10 and 20% chromium (Cr), between about 5 and 10% aluminum (Al), and between about 0.1 and 0.5% yttrium (Y).

[0007] According to another aspect of the disclosure, the metal binder layer contains a nickel-chromium-aluminium (NiCrAl) alloy with between about 30 and 45% chromium (Cr), between about 2 and 6% aluminum (Al) and a remainder of nickel (Ni).

[0008] According to another aspect of the disclosure, the heat-resistant layer contains approximately 75% yttrium oxide-stabilized zirconium dioxide (YSZ) and approximately 25% cerium oxide-stabilized zirconium dioxide (CSZ).

[0009] According to another aspect of the disclosure, the yttrium oxide-stabilized zirconium dioxide (YSZ) contains ZrO2, which is stabilized with approximately 5-10% Y2O3.

[0010] According to another aspect of the disclosure, the cerium oxide-stabilized zirconium dioxide (CSZ) contains ZrO2, which is stabilized with approximately 5-10% CeO2.

[0011] According to another aspect of the disclosure, the heat-resistant layer has a thickness of between approximately 50 and 200 micrometers (µm).

[0012] According to another aspect of the disclosure, the heat-resistant layer has a thermal conductivity of between about 0.4 and 1.5 watts per meter-kelvin (W / mK).

[0013] According to another aspect of the disclosure, the wear-resistant layer has a thickness of between approximately 100 and 300 micrometers (µm).

[0014] According to another aspect of the disclosure, the stainless steel contains at least one of the following steels: 430L steel, 316L steel or 318LN steel.

[0015] According to another aspect of the disclosure, the carbide feed material contains tungsten carbide (WC), titanium carbide (TiC), chromium carbide (Cr3C2) and / or niobium carbide (NbC).

[0016] According to another aspect of the disclosure, the wear-resistant layer has a thermal conductivity of between about 18 and 50 watts per meter-kelvin (W / mK).

[0017] According to another aspect of the disclosure, the wear-resistant layer has a Vickers hardness number between approximately 400 and 700 (HV).

[0018] According to several aspects of the present disclosure, a brake rotor with a multifunctional coating is provided. The brake rotor includes an annular body that defines the first and second friction surfaces. The annular body contains a core made of an aluminum-silicon alloy (Al-Si) and includes a first and a second annular disc separated from each other axially by a plurality of ribs. The first and second annular discs each have a first and a second annular surface. The annular body also includes a first and a second multilayer coating arranged on the first and second annular surfaces, respectively. The first and second multilayer coatings are configured to provide wear resistance and increase the operating temperature.The first and second multilayer coatings each contain a first and second metal binder layer, respectively, applied to the first and second annular surfaces; a first and second heat-resistant layer, respectively, applied to the first and second metal binder layers; and a first and second wear-resistant layer, respectively, applied to the first and second heat-resistant layers. The first and second metal binder layers contain nickel-cobalt-chromium-aluminum-yttrium (NiCoCrAlY) and / or nickel-chromium-aluminum (NiCrAl). The first and second heat-resistant layers contain yttrium oxide-stabilized zirconia (YSZ) and cerium oxide-stabilized zirconia (CSZ). The first and second wear-resistant layers contain stainless steel and carbide insert material, and the first and second wear-resistant layers define the first and second friction surfaces of the annular body, respectively.

[0019] According to another aspect of the disclosure, the first and second metal binder layers contain nickel-cobalt-chromium-aluminium-yttrium (NiCoCrAlY) and / or nickel-chromium-aluminium (NiCrAl).

[0020] According to another aspect of the disclosure, the first and second heat-resistant layers contain yttrium oxide-stabilized zirconium dioxide (YSZ) and cerium oxide-stabilized zirconium dioxide (CSZ).

[0021] According to another aspect of the disclosure, the first and second wear-resistant layers contain stainless steel and carbide insert material.

[0022] According to several aspects of the present disclosure, a method for manufacturing a brake rotor is provided. The method includes casting an Al-Si alloy into the shape of a rotor core having at least one annular disk with an annular surface, identifying a thickness-dependent heat and temperature distribution for the annular surface, determining a multilayer coating for the annular surface of the brake rotor based on the thickness-dependent heat and temperature distribution, and depositing the multilayer coating onto the annular surface of the brake rotor using a directed energy deposition (DED) process to form a wear-resistant layer.The multi-layered coating contains a metal binder layer arranged on the ring-shaped surface, a heat-resistant layer arranged on the metal binder layer, and a wear-resistant layer arranged on the heat-resistant layer.

[0023] According to another aspect of the disclosure, the metal binder layer contains nickel-cobalt-chromium-aluminium-yttrium (NiCoCrAlY) and / or nickel-chromium-aluminium (NiCrAl), the heat-resistant layer contains yttrium oxide-stabilized zirconium dioxide (YSZ) and cerium oxide-stabilized zirconium dioxide (CSZ), and the wear-resistant layer contains stainless steel and carbide insert material.

[0024] The aforementioned features and advantages, as well as other features and advantages of the system and method disclosed herein, are readily apparent from the detailed description, including the claims and examples, in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure is better understood from the detailed description and the accompanying drawings, wherein: Fig. 1 is a perspective view illustrating a brake rotor for a disc brake assembly of a motor vehicle, wherein the brake rotor includes a hub and an annular body, according to the present disclosure. Fig. 2 is a schematic cross-sectional view of the ring-shaped body, which is in Fig. 1 is shown, taken along line 2-2 of Fig. 1, wherein the annular body comprises a core and a multilayer coating arranged on at least one section of the core, according to the present disclosure. Fig. 3 is a flowchart that describes a process for manufacturing the brake rotor according to Fig. 1 and Fig. 2 illustrated, according to the present revelation. Fig. Figure 4 is a schematic cross-sectional view of a device for applying the multilayer coating to a section of the core of the annular hub, as shown in Fig. 1 and Fig. 2 illustrated, according to the present revelation. DETAILED DESCRIPTION

[0026] The following description is merely exemplary and is not intended to limit the present disclosure, application, or uses. Furthermore, it is not intended to be limited by any express or implied theory presented in the preceding introduction, summary, or the following detailed description. It is understood that in the drawings, corresponding reference numerals consistently denote identical or corresponding parts and features.

[0027] Reference is now made in detail to several examples of the disclosure, which are illustrated in the accompanying drawings. Wherever possible, the same or similar reference symbols are used in the drawings and the description to refer to identical or similar parts or steps. The drawings are presented in simplified form and are not to scale. The following description is merely exemplary and is not intended to limit the present disclosure, application, or uses.

[0028] Fig. Figure 1 shows a brake rotor 10 for a disc brake assembly of a motor vehicle (not shown) with a multifunctional or multilayer coating 11. The brake rotor 10 includes a hub 12, an annular body 14, and a central opening 16 that defines an axis of rotation 18 of the brake rotor 10. The hub 12 can be configured to mount the brake rotor 10 on a rotatable axis (not shown) of the motor vehicle. The annular body 14 extends radially from the central opening 16 and defines an outer circumference 20 of the brake rotor 10, as well as a first and a second friction surface 22, 24, which are arranged on opposite sides of the brake rotor 10.The first and second friction surfaces 22, 24 are configured to engage with brake pads (not shown) located on opposite sides of the brake rotor 10 to generate frictional forces that counteract rotation of the brake rotor 10 during braking.

[0029] The brake rotor 10 disclosed herein can also have other configurations, as an average person with expertise in the field will recognize. In some cases, for example, the hub 12 can be omitted and the brake rotor 10 can be connected to a rotatable axle of a motor vehicle in a different manner.

[0030] With the following reference to Fig. 1 and Fig. 2, wherein Fig. 2 is a schematic cross-sectional view of the ring-shaped body, which is in Fig. As recorded along line 2-2, the annular body 14 has a composite structure with a core 26 and a multilayer coating 11 arranged on at least one section of the core 26. The core 26 contains at least one annular disk 32, 34, which defines a pair of annular surfaces 38A, 38B arranged on opposite sides of the brake rotor 10 and facing away from the core 26. The core 26, which is in Fig. 1 and Fig. Figure 2 shows a pair of first and second annular discs 32, 34 arranged on opposite sides of the brake rotor 10 and spaced apart axially by a plurality of ribs 36. Each of the first and second annular discs 32, 34 has an annular surface (e.g., a first annular surface 38A, a second annular surface 38B) facing away from the core 26. The core 26 can have a thickness, measured between the opposing annular surfaces 38A, 38B, of more than or equal to about 9 millimeters to less than or equal to about 36 millimeters. The core 26 can be constructed from a single piece.

[0031] Core 26 consists of a hypereutectic aluminum alloy (Al) which, in addition to aluminum, includes at least one alloying element, including silicon (Si), and can therefore be referred to as an aluminum-silicon alloy (Al-Si alloy). The amount of silicon in the Al-Si alloy is selected to provide good castability, flowability, and wear resistance. The Al-Si alloy can contain, by mass, more than or equal to approximately 80% to less than or equal to approximately 87% aluminum and more than or equal to approximately 13% to less than or equal to approximately 20% silicon. In this context, the term "approximately" is understandable to a person with expertise in this area. Alternatively, the term "approximately" means plus or minus 1%.

[0032] In some cases, the Al-Si alloy may contain carbon (C) as an alloying element. In these cases, the Al-Si alloy may contain more than or equal to approximately 4% to less than or equal to approximately 8% carbon by mass. The carbon may be present in the Al-Si alloy in the form of silicon carbide (SiC). In this case, the Al-Si alloy may contain more than or equal to approximately 10% to less than or equal to approximately 20% silicon carbide by mass. In this context, the term "approximately" is understandable to an expert. Alternatively, the term "approximately" means plus or minus 1%.

[0033] In some cases, the Al-Si alloy may contain titanium boride (TiB2) to provide higher strength, hardness, wear resistance, and thermal stability. In these cases, the Al-Si alloy may contain more than or equal to approximately 5% to less than or equal to approximately 15% titanium boride by mass. In this context, the term "approximately" is understandable to a person knowledgeable in the field. Alternatively, the term "approximately" means plus or minus 1%.

[0034] In some cases, the Al-Si alloy may contain aluminum oxide (Al₂O₃) to provide higher thermal stability and corrosion resistance. In these cases, the Al-Si alloy may contain more than or equal to approximately 10% to less than or equal to approximately 15% aluminum oxide by mass.

[0035] In this context, the term "approximately" is understandable to an expert. Alternatively, the term "approximately" means plus or minus 1%.

[0036] In some cases, the Al-Si alloy may contain titanium carbide (TiC) or zirconium oxide (ZrO2) to improve hardness and thermal shock resistance and to extend service life under harsh conditions. In these cases, the Al-Si alloy may contain, by mass, more than or equal to approximately 3% to less than or equal to approximately 10% titanium carbide and / or more than or equal to approximately 1% to less than or equal to approximately 10% zirconium oxide. In this context, the term "approximately" is understandable to a person knowledgeable in the field. Alternatively, the term "approximately" means plus or minus 1%.

[0037] Compared to cast iron, the Al-Si alloy exhibits excellent corrosion resistance, high ductility, and low density. For example, the Al-Si alloy can have a density of more than or equal to approximately 2,600 kilograms per cubic meter (kg / m³). 3 ) to less than or equal to approximately 2,800 kg / m² 3or less than or equal to approximately 2,700 kg / m² 3 exhibiting, for example, an Al-Si alloy with a density of approximately 2,700 kg / m³. 3 exhibit. In this context, the term "approximately" is understandable to a knowledgeable person. Alternatively, the term "approximately" means plus or minus 10 kg / m³. 3 The Al-Si alloy can exhibit a thermal conductivity of more than or equal to approximately 186 watts per meter-kelvin (W / mK) to less than or equal to approximately 225 W / mK and a specific heat capacity of more than or equal to approximately 0.9 kJ / kg-K to less than or equal to approximately 1.3 kJ / kg-K. In this context, the term "approximately" is understandable to a specialist. Alternatively, the term "approximately" means plus or minus 1 W / mK.

[0038] Still referring to Fig. 1 and Fig. 2 The multilayer coating 11 is arranged on at least one section of the core 26. In the specific example shown in Fig. 1 and Fig. As illustrated in Figure 2, the multilayer coating 11 is shown on the first friction surface 22 and the second friction surface 24. However, the multilayer coating 11 can also be arranged on other or additional sections of the core 26, e.g., the hub 12. The multilayer coating 11 is configured to provide wear resistance and increase the operating temperature. A first and a second multilayer coating 11A, 11B are arranged on the first and second annular surfaces 38A, 38B, respectively. The multilayer coating 11 comprises a metal binder layer 40, a heat-resistant layer 42, and a wear-resistant layer 44.

[0039] The metal bonding layer 40 is arranged on at least one section of the core 26 and may contain one or more layers (e.g., a first and a second metal bonding layer). The metal bonding layer 40 is formed from at least one of the materials nickel-cobalt-chromium-aluminum-yttrium (NiCoCrAlY) or nickel-chromium-aluminum (NiCrAl). The metal bonding layer 40 provides oxidation resistance, thermal stability, and improves the adhesion between the core 26 and the heat-resistant layer 42. In a specific example, the metal bonding layer 40 has a thickness between 10 and 100 micrometers (µm). In this context, the term "approximately" is understandable to an expert. Alternatively, the term "approximately" means plus or minus 1 µm.In another specific example, the metal binder layer 40 contains between approximately 55 and 65% nickel (Ni), between approximately 10 and 30% cobalt (Co), between approximately 10 and 20% chromium (Cr), between approximately 5 and 10% aluminum (Al), and between approximately 0.1 and 0.5% yttrium (Y). In this context, the term "approximately" is understandable to a person with expertise in the field. Alternatively, the term "approximately" can be understood as plus or minus 0.5%. In another specific example, the metal binder layer 40 contains a nickel-chromium-aluminum (NiCrAl) alloy with between approximately 30 and 45% chromium (Cr), between approximately 2 and 6% aluminum (Al), and a remainder of nickel (Ni). In this context, the term "approximately" is understandable to a person with expertise in the field. Alternatively, the term "approximately" can be understood as plus or minus 0.5%.

[0040] The heat-resistant layer 42 is arranged on at least one section of the metal binder layer 40 and may contain one or more layers (e.g., a first and a second heat-resistant layer). The heat-resistant layer 42 contains yttrium oxide-stabilized zirconia (YSZ) and cerium oxide-stabilized zirconia (CSZ). Yttrium oxide-stabilized zirconia (YSZ) and cerium oxide-stabilized zirconia (CSZ) are modern ceramic materials used due to their excellent heat resistance and durability. YSZ is used for the heat-resistant layer 42 because of its low thermal conductivity. These properties help to reduce heat transfer to the brake rotor 10, thereby increasing the performance and service life of the brake rotor 10. The addition of yttrium oxide (Y₂O₃) stabilizes the zirconia in its tetragonal and cubic phases, which are more stable at high temperatures.Cerium oxide (CeO) in CSZ contributes to the stabilization of zirconium dioxide, similar to yttrium oxide, but also offers additional benefits such as improved resistance to sintering and phase transformation at high temperatures.

[0041] In a specific example, the heat-resistant layer 42 contains approximately 75% yttrium oxide-stabilized zirconia (YSZ) and approximately 25% cerium oxide-stabilized zirconia (CSZ). In this context, the term "approximately" is understandable to a person with expertise in the field. Alternatively, the term "approximately" can be understood as plus or minus 1%. Yttrium oxide-stabilized zirconia (YSZ) contains ZrO₂ stabilized with approximately 5–10% Y₂O₃. Cerium oxide-stabilized zirconia (CSZ) contains ZrO₂ stabilized with approximately 5–10% CeO₂. In a specific example, the heat-resistant layer 42 has a thickness between approximately 50 and 200 micrometers (µm). In this context, the term "approximately" is understandable to a person with expertise in the field. Alternatively, the term "approximately" means plus or minus 5 µm. In another specific example, the heat-resistant layer 42 exhibits a thermal conductivity between approximately 0.4 and 1.5 watts per meter-kelvin (W / mK).In this context, the term "approximately" is understandable to an expert. Alternatively, the term "approximately" means plus or minus 0.01 W / mK.

[0042] The wear-resistant layer 44 is arranged on at least one section of the heat-resistant layer 42 and may contain one or more layers (e.g., a first and a second wear-resistant layer). The wear-resistant layer 44 serves to improve the wear resistance, durability, and overall performance of the brake rotor 10. The wear-resistant layer 44 contains stainless steel and carbide insert material. Stainless steel is used for its excellent corrosion resistance and durability and forms a protective layer that helps prevent rust. Carbide insert material is used to reinforce the stainless steel and can be incorporated into a stainless steel matrix.

[0043] In a specific example, the wear-resistant layer 44 has a thickness between approximately 100 and 300 micrometers (µm). In this context, the term "approximately" is understandable to a person with expertise in this area. Alternatively, the term "approximately" means plus or minus 10 µm. The stainless steel may contain at least one of the following: 430L steel, 316L steel, 318LN steel, or another suitable stainless steel. The carbide insert material contains silicon carbide (SiC), chromium carbide (Cr3C2), tungsten carbide (WC), titanium carbide (TiC), and / or niobium carbide (NbC). Tungsten carbide (WC) offers high hardness and wear resistance. Titanium carbide (TiC) offers wear resistance and is less prone to brittle phase formation compared to silicon carbide (SiC). Niobium carbide (NbC) offers excellent wear resistance and improved metallurgical compatibility with stainless steel.In one specific example, the wear-resistant layer 44 has a thermal conductivity of approximately 18 to 50 watts per meter-kelvin (W / mK). In this context, the term "approximately" is understandable to a specialist. Alternatively, the term "approximately" means plus or minus 1 W / mK. In another specific example, the wear-resistant layer 44 has a Vickers hardness (HV) between approximately 400 and 700 HV. In this context, the term "approximately" is understandable to a specialist. Alternatively, the term "approximately" can be understood as plus or minus 5 HV.

[0044] With reference to Fig. 3 describes a method 100 for manufacturing the brake rotor 10, which is in Fig. 1 and Fig. As shown in section 2, the process begins at block 102.

[0045] Block 102 shows the casting of an Al-Si alloy into the shape of a rotor core 26 (or brake rotor 10) with at least one annular disk 32, 34 with an annular surface 38. The casting of the Al-Si alloy can, for example, involve determining the composition of the Al-Si alloy and / or producing a mold cavity with the desired shape geometry. Furthermore, the casting of the Al-Si alloy can involve the use of die casting, sand casting, or a permanent mold casting process. Method 100 then proceeds to Block 104.

[0046] Block 104 shows the identification of a thickness-dependent heat and temperature distribution for the annular surface 38. Identifying the thickness-dependent heat and temperature distribution may involve performing a computer simulation using a computer system to identify a mixing rule for the coating. Applying a mixing rule for the coating ensures that each component of the multi-component coating system and / or the multilayer coating 11 is mixed in an appropriate ratio to achieve the desired properties and to ensure that the chemical reactions proceed correctly. Procedure 100 then proceeds to Block 106.

[0047] Block 106 describes the determination of a multilayer coating 11 for the annular surface 38 of the brake rotor 10 based on the thickness-dependent heat and temperature distribution. A computer system can be used to perform a simulation of the brake rotor 10 to determine the multilayer coating. As described above, the multilayer coating 11 comprises the metal binder layer 40 arranged on the annular surface 38, the heat-resistant layer 42 arranged on the metal binder layer 40, and the wear-resistant layer 44 arranged on the heat-resistant layer 42. The procedure 100 then proceeds to Block 108.

[0048] Block 108 shows the application of the multilayer coating to the annular surface of the brake rotor using a directed energy deposition (DED) process. In some cases, the metal binder layer 40, the heat-resistant layer 42, and the wear-resistant layer 44 can be applied sequentially to the annular surfaces 38 of the core 26 by directed energy deposition processes. In these processes, a filler material 146 is applied to the annular surface 38 of the core 26 through a nozzle 148 and simultaneously melted onto it by applying a focused energy source 150. The nozzle 148 and the focused energy source 150 are moved forward along the annular surface 38 of the core 26 in a predefined pattern, leaving a layer of solidified filler material 152.The focused energy source can be a plasma arc, an electron beam, or a laser. A protective gas can be used in a zone 154 surrounding the deposition site to prevent or inhibit unwanted side reactions. The feed material can be in the form of a wire or a powder and can have essentially the same composition as the layer to be formed. For example, in the production of the first and / or second metal binder layer 40, the feed material 146 can have essentially the same composition as the material of the metal binder layer 40. In the production of the first and second heat-resistant layer 42, the feed material 146 can have essentially the same composition as that of the YSZ and CSZ materials.Likewise, the starting material 146 can have essentially the same composition as the input material of stainless steel and carbide during the formation of the first and second wear-resistant layer 44.

[0049] The brake rotor 10 and the method 100 of the present disclosure are advantageous and useful compared to the prior art. The brake rotor 10 offers a weight-reduced brake rotor (a mass reduction of about 2 / 3) by replacing conventional gray cast iron with a lighter material, e.g., Al-Si. This also increases the permissible operating temperatures by about 100°C–150°C. For example, the typical surface temperature of a gray cast iron rotor during use can be about 478°C and the typical core temperature during operation about 432°C. However, if a brake rotor is used that is formed from an Al-Si core with a multilayer coating applied thereon, the operating temperature of the core can be about 285°C when the surface temperature is about 552°C.Furthermore, the surface of the Al-Si alloy exhibits increased wear resistance due to the wear-resistant layer 44, and the brake rotor 10 has higher oxidation resistance compared to gray cast iron. The wear-resistant layer (i.e., a mixture of stainless steel and carbides) is comparable to current brake pad materials and enables rapid technological implementation.

[0050] This description is for illustrative purposes only and is not intended to limit the revelation, its application, or its use in any way. The comprehensive teachings of revelation can be implemented in a multitude of forms. While this revelation contains certain examples, the actual scope of the revelation should therefore not be limited to them, since other modifications will become apparent upon examination of the drawings, the description, and the following claims.

Claims

[1] Brake rotor with a multifunctional coating comprising: a ring-shaped body defining opposing friction surfaces, wherein the ring-shaped body contains: a core made of an aluminium-silicon alloy (Al-Si alloy) containing at least one annular disk with an annular surface; and a multilayer coating arranged on at least one section of the core, wherein the multilayer coating is configured to provide wear resistance and increase the operating temperature, and wherein the multilayer coating comprises the following: a metal binder layer arranged on the annular surface, wherein the metal binder layer contains at least one of nickel-cobalt-chromium-aluminium-yttrium (NiCoCrAlY) or nickel-chromium-aluminium (NiCrAl); a heat-resistant layer arranged on the metal binder layer, wherein the heat-resistant layer contains yttrium oxide-stabilized zirconium dioxide (YSZ) and cerium oxide-stabilized zirconium dioxide (CSZ); and a wear-resistant layer arranged on top of the heat-resistant layer, wherein the wear-resistant layer contains stainless steel and carbide insert material. [2] Brake rotor according to claim 1, wherein the metal binder layer has a thickness between about 10 and 100 micrometers (µm). [3] Brake rotor according to claim 1, wherein the metal binder layer contains between about 55 and 65% nickel (Ni), between about 10 and 30% cobalt (Co), between about 10 and 20% chromium (Cr), between about 5 and 10% aluminium (Al) and between about 0.1 and 0.5% yttrium (Y). [4] Brake rotor according to claim 1, wherein the metal binder layer comprises a nickel-chromium-aluminium (NiCrAl) alloy containing between about 30 and 45% chromium (Cr), between about 2 and 6% aluminum (Al) and a remainder of nickel (Ni). [5] Brake rotor according to claim 1, wherein the heat-resistant layer contains about 75% yttrium oxide-stabilized zirconium dioxide (YSZ) and about 25% cerium oxide-stabilized zirconium dioxide (CSZ). [6] Brake rotor according to claim 5, wherein the yttrium oxide-stabilized zirconium dioxide (YSZ) contains ZrO2 stabilized with about 5 - 10 % Y2O3. [7] Brake rotor according to claim 5, wherein the cerium oxide-stabilized zirconium dioxide (CSZ) contains ZrO2 stabilized with about 5 - 10% CeO2. [8] Brake rotor according to claim 1, wherein the heat-resistant layer has a thickness between about 50 and 200 micrometers (µm). [9] Brake rotor according to claim 1, wherein the heat-resistant layer has a thermal conductivity between about 0.4 and 1.5 watts per meter-kelvin (W / mK). [10] Brake rotor according to claim 1, wherein the wear-resistant layer has a thickness between about 100 and 300 micrometers (µm).

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