DE102011056307A1 - Brake disc, used for motor car, includes brake disc pot, and brake disc ring provided with friction surfaces, where brake disc ring consists of cast iron material, which is coated with protective coating in region of the friction surfaces - Google Patents

Abstract

The brake disc comprises a brake disc pot (11), and a brake disc ring (12) provided with friction surfaces (13), where the brake disc ring consists of a cast iron material, which is coated with a protective coating (14) in a region of the friction surfaces. The friction surfaces of the brake disk ring are contoured microscopically homogeneous or inhomogeneous. A wear-resistant coating is applied directly or indirectly with an interposition of an adhesive layer (17) on the microscopic contoured friction surfaces of the brake disc ring. The brake disc comprises a brake disc pot (11), and a brake disc ring (12) provided with friction surfaces (13), where the brake disc ring consists of a cast iron material, which is coated with a protective coating (14) in a region of the friction surfaces. The friction surfaces of the brake disk ring are contoured microscopically homogeneous or inhomogeneous. A wear-resistant coating is applied directly or indirectly with an interposition of an adhesive layer (17) on the microscopic contoured friction surfaces of the brake disc ring. The cast iron material is designed as iron alloy material having a flake graphite. The wear protective coating is further applied directly or indirectly on the friction surfaces of the brake disk ring and/or on the friction surfaces of the brake disc pot. The wear protective coating and the cast iron material have thermal expansion coefficients. An anti-corrosive coating does not applied on the friction surfaces of the brake disc ring and/or the brake disc pot. Hard material particles are stored in the wear protective coating. An independent claim is included for a method for producing a brake disc.

Description

The invention relates to a brake disk for a motor vehicle and a method for producing the same.

From the DE 10 2007 030 468 B4 a brake disc of a motor vehicle is known, which comprises a brake disc hub and a brake disc ring formed as a separate component, wherein the brake disc hub and the brake disc ring are connected via connecting elements.

From the DE 296 14 774 U1 is a brake disc of a motor vehicle is known, in which brake disc hub and brake disc ring are monolithic. From the DE 296 14 774 U1 Furthermore, it is already known to produce the brake disk from a cast iron material or cast iron material and to coat the same in the region of the friction surfaces of the brake disk ring with a protective coating via thermal spraying, namely via flame spraying.

Proceeding from this, the present invention, the object of a novel brake disc for a motor vehicle with increased life and a method for producing the same to create.

This object is achieved by a brake disc according to claim 1. Thereafter, the friction surfaces of the brake disk ring are microscopically homogeneous or inhomogeneously contoured, wherein a wear protection coating is applied directly or indirectly with the interposition of an adhesion-promoting layer on the microscopically contoured friction surfaces of the brake disk ring as a protective coating. Such a brake disc has a particularly good adhesion of the anti-wear coating on the cast iron material of the brake disc ring and thus an increased life.

According to a first advantageous development of the invention, the cast iron material is designed as an iron alloy material with lamellar graphite in the hypereutectic state and has, in addition to iron in the rest, at least a silicon content of more than 4% by weight and less than 8% by weight, one tailored to the silicon content, hypereutectic carbon content of more than 4% by weight and less than 7% by weight, a phosphorus content of less than 0.025% by weight and a sulfur content of less than 0.025% by weight.

According to a second alternative advantageous development of the invention, the cast iron material is formed as an iron alloy material with Vermiculargrafit and has in addition to iron in the rest at least a silicon content of more than 1.5 wt .-% and less than 4 wt .-%, one tailored to the silicon content , hypereutectic carbon content of greater than 3.0% by weight and less than 4.0% by weight, a phosphorus content of less than 0.025% by weight, and a sulfur content of less than 0.025% by weight.

According to a third, further alternative advantageous development of the invention, the cast iron material is formed as austenitic iron alloy material and has, in addition to iron in the rest at least a carbon content of more than 0.3 wt .-% and less than 0.4 wt .-%, a manganese content of more than 3 wt% and less than 4 wt%, a chromium content of more than 23 wt% and less than 25 wt%, and a nickel content of more than 37 wt% and less than 40 wt% .-% on.

The above three alternatives of the cast iron material are particularly preferred for providing a longer life brake disk. The wear protection coating applied directly or indirectly to the friction surfaces of the brake disk ring and thus to the cast iron material and the cast iron material have mutually adapted thermal expansion coefficients. In combination, an optimal adhesion of the wear protection coating on the cast iron material of the brake disc ring and thus an increased life is guaranteed.

The inventive method for producing the brake disc is defined in claim 11.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

1 a schematic cross section of a brake disc for a motor vehicle together with an enlarged detail.

The present invention relates to a brake disc for a motor vehicle and a method for producing the same.

1 shows a fragmentary, schematic cross section through a brake disc 10 a motor vehicle, wherein the brake disc 10 a brake disk pot 11 and a brake disc ring 12 includes, wherein brake disk pot 11 and brake disc ring 12 in the embodiment shown are made in one piece or monolithic.

In the illustrated embodiment, in which the brake disk pot 11 and the brake disk ring are made in one piece or monolithic, are the brake disk hub 11 and brake disc ring 12 made of an identical cast iron material.

It should be noted at this point that, in particular when the brake disk hub and the brake disk ring are designed as separate components, which are connected to each other, for example via connecting elements, brake disk hub and brake disk ring can be made of different materials.

In the embodiment of 1 represents the brake disc ring 12 friction surfaces 13 ready with a wear-resistant coating 14 are coated. At the friction surfaces 13 These are tribologically stressed surfaces of the brake disc ring 12 , which helps to increase the life of the brake disc 10 with the wear protection coating 14 are coated.

In the embodiment of 1 is another tribologically stressed friction surface 15 radially inward on the brake disc pot 11 executed, which also with a wear protection coating 16 is coated.

For the purposes of the present invention, at least the friction surfaces 13 of brake disc ring 12 and, if present, preferably also the friction surfaces 15 the brake disk pot 11 microscopically contoured, namely either microscopically homogeneous or microscopically inhomogeneous, wherein on the microscopically contoured friction surfaces the wear protection coating 14 directly or indirectly with the interposition of an adhesive layer 17 is applied.

According to a first preferred embodiment of the invention, it is the cast iron material of the brake disk ring 12 and preferably the brake disk pot 11 an iron alloy material with lamellar graphite.

The after the first advantageous development of the invention for the brake disc ring 12 and preferably for the brake disk pot 11 In addition to iron in the remainder, used iron alloy material with lamellar graphite has at least a silicon content of more than 4 wt .-% and less than 8 wt .-%, a matched to the silicon content, highly hypereutectic carbon content of more than 4 wt .-% and less than 7 Wt .-%, a phosphorus content of less than 0.025 wt .-% and a sulfur content of less than 0.025 wt .-% to.

Due to the above silicon content of more than 4 wt .-% and less than 8 wt .-%, a particularly advantageous scale resistance and ferritization of the iron alloy material is ensured. The carbon content matched to this silicon content ensures a high thermal conductivity of the iron alloy material. The above phosphorus content reduces the risk of stasis and embrittlement of the iron alloy material. The above sulfur content also avoids embrittlement of the iron alloy material and increases its impact resistance.

Preferably, the cast iron material formed as a lamellar graphite iron alloy material has a silicon content between 5 and 6% by weight and a carbon content between 4 and 5% by weight.

The lamellar graphite iron alloy material preferably has a molybdenum content of greater than 1 weight percent and less than 2 weight percent, preferably a molybdenum content of about 1 weight percent, thereby increasing the resistance of the cast iron alloy material to the formation of thermal cycling cracks can.

Preferably, in the lamellar graphite iron alloy material, the manganese content is less than 1 wt%, preferably less than 0.5 wt%, whereby a particularly preferable setting of the sulfur in the iron alloy material can be ensured.

The titanium content of the iron alloy material with lamellar graphite is preferably at most 0.04 wt .-%, whereby a TiN formation in the iron alloy material can be avoided.

In a specific embodiment, the lamellar graphite iron alloy material contains 5% by weight of silicon, 4.5% by weight of carbon, 1.5% by weight of molybdenum, 0.01% by weight of phosphorus, 0.01% by weight. Sulfur, 0.04 wt .-% manganese, 0.04 wt .-% titanium and iron in the remainder.

After provision of a brake disk ring 12 as a separate component or as together with the brake disk pot 11 Integrated component made of such an iron alloy material with lamellar graphite is a surface treatment of the friction surfaces 13 of brake disc ring 12 forming the microscopically homogeneous or inhomogeneous contoured friction surfaces 13 , wherein the formation of a microscopically homogeneous contouring of the friction surfaces 13 preferably by milling or laser etching. The provision or formation of a microscopically inhomogeneous contouring on the friction surfaces 13 he follows preferably by blasting, such as by glass blasting, sand blasting or high pressure water blasting.

In the case of an iron alloy material with lamellar graphite, the formation of the microscopically homogeneous or inhomogeneously contoured friction surfaces ensues 13 and before applying the wear protection coating 14 preferably a surface treatment of the microscopically contoured friction surfaces such that the same graphite is removed. This removal of graphite from the microscopically contoured friction surfaces 13 the formed of an iron alloy material with lamellar graphite brake disc ring 12 is done by thermal or chemical or mechanical or physical methods.

The destruction or removal of the graphite by thermal methods can be done for example by means of a heat treatment in a strongly oxidizing atmosphere, in which case a burn-up of the graphite on the microscopically contoured friction surface of the brake disk ring 12 he follows.

During the burning of the graphite, iron oxide can form, which can either be removed chemically or on the friction surface 13 can remain.

The physical removal of the graphite can be done for example via a laser treatment.

The chemical Grafitentfernung takes place for example via a molten salt and the mechanical Grafitentfernung via rays, such as sandblasting or high-pressure water jets.

Following such a surface treatment of the friction surfaces 13 of the brake disk ring formed of an iron alloy material with lamellar graphite 12 , So then the micro-contouring of the friction surfaces 13 and the removal of the graphite, the application of the wear protection coating 14 on the correspondingly pretreated friction surface 13 , wherein the wear protection coating 14 either directly or with the interposition of an adhesive layer 17 indirectly on the microscopically contoured and almost freed from graphite friction surface 13 of brake disc ring 12 is applied.

Then, if on the iron alloy material with lamellar graphite in the area of friction surfaces 13 a wear protection coating 14 Tribaloy, a CoMoSi material, becomes the wear-resistant coating 14 preferably directly without an adhesion-promoting layer on the friction surface 13 of brake disc ring 12 applied.

Then, if on the friction surface 13 a wear protection coating 14 is applied from a NiCr material, preferably finds an adhesion-promoting layer 17 from a NiCr material use. For a wear protection coating 14 a CoCrAlY material preferably contains an adhesion-promoting layer 17 from a CoCrAlY material use. For a wear protection coating 14 from an MCrAlY material preferably finds an adhesion-promoting layer 17 from a MCrAlY material use. For example, comes with a wear protection coating 14 from a CoCrAlY material as an adhesion-promoting layer 17 preferably a layer of a CoCrAlY material used.

In the wear protection coating 14 are preferably ceramic hard material particles 18 stored, such as hard particles 18 from an Al2O3 or from a Cr3C2 or from a ZrO2 material.

The wear protection coating 14 and optionally the primer layer 17 are preferably via thermal spraying on the friction surfaces 13 of brake disc ring 12 applied.

The above material systems from wear protection layer 14 , Brake disc ring 12 and optionally adhesive layer 17 are selected so that at least the wear protection coating 14 and the iron alloy material have matched coefficients of thermal expansion to reduce the risk of cracking and chipping of the wear-resistant coating 14 from the tribologically stressed surfaces or friction surfaces 13 to avoid the brake disc.

In contrast to the variant described above, in which after the micro-contouring of the friction surfaces 13 of brake disc ring 12 is removed from the same graphite, it is also possible, even before the homogeneous or inhomogeneous micro-contouring and thus surface treatment of the friction surfaces 13 the graphite formation on the friction surfaces to be coated 13 counteract, namely preferably in that during the casting of the iron alloy material with lamellar graphite, the formation of graphite on the friction surfaces 13 counteracted.

This is preferably done by introducing, for example, magnesium turnings into a surface of a mold used for casting or by overheating the melt during casting. The overheating of the melt during casting causes less germination during casting and thus at the subsequent solidification of the melt larger crystals arise. As a result, the creep strength increases under temperature. During casting, preferably a slow cooling of the melt takes place in order to form a ferritic structure throughout the component.

According to a second variant of the invention comes as a cast iron material for the brake disc ring 12 and preferably the brake disk pot 11 an iron alloy material with vermicular graphite used.

Such a vermicular graphite cast iron material has a silicon content of more than 1.5% by weight and less than 4% by weight, a silicon-tailed hypereutectic carbon content of more than 3.0% by weight and less than 4 , 0 wt .-%, a phosphorus content of less than 0.025 wt .-% and a sulfur content of less than 0.025 wt .-%.

The above silicon content in turn provides good scale resistance and ferritization of the iron alloy material. The above carbon content provides high thermal conductivity of the iron alloy material. The phosphorus content avoids stasis, the sulfur content increases the impact resistance of the iron alloy material.

The molybdenum content of the vermicular graphite iron alloy material is preferably between 1% by weight and 2% by weight in order to provide good ferritization and resistance to thermal cracking and thus heat resistance of the iron alloy material.

Preferably, the manganese content is less than 1 wt%, preferably less than 0.5 wt%, and the titanium content of the iron alloy material with vermicular graphite is preferably at most 0.04 wt%. The above manganese content in turn ensures a good setting of the sulfur and the titanium content avoids TiN formation.

In a specific embodiment, the vermicular graphite iron alloy material has 3 wt% silicon, 2.5 wt% carbon, 1 wt% molybdenum, 0.01 wt% phosphorus, 0.01 wt% sulfur, 0.04 wt .-% manganese, 0.04 wt .-% titanium and the remainder iron.

The surface treatment of a brake disk ring formed from such an iron alloy material with vermicular graphite 12 in the area of his with the wear protection coating 14 directly or with the interposition of an adhesion-promoting layer 17 indirectly to be coated friction surfaces 13 takes place analogously to the surface treatment of an iron alloy material with lamellar graphite, wherein in an iron alloy material with Vermiculargrafit can be dispensed with a removal of the graphite after the micro-contouring of the friction surfaces.

Then, when an iron alloy material with vermicular graphite is used as the cast iron material for the brake disk ring, identical material systems can be used with respect to the wear protection layer 14 , Adhesion layer 17 and hard material particles 18 be used as the iron alloy material with lamellar graphite.

According to a third variant of the invention, the cast iron material used is an austenitic iron alloy material which, besides iron in the remainder, has at least a carbon content of more than 0.3% by weight and less than 0.4% by weight, a manganese content of more than 3 Wt .-% and less than 4 wt .-%, a chromium content of more than 23 wt .-% and less than 25 wt .-% and a nickel content of more than 37 Wt .-% and less than 40 wt .-%.

The above nickel content can improve the thermal shock performance of the austenitic iron alloy material. The manganese content ensures good setting of sulfur and a reduction in the hot crack susceptibility of the austenitic iron alloy material. The above carbon content increases the heat resistance of the austenitic iron alloy material.

The austenitic iron alloy material further has a molybdenum content of more than 1% by weight and less than 2.5% by weight, a silicon content of more than 0.8% by weight and less than 1.0% by weight, whereby the flowability of the melt can be improved by this silicon content.

Furthermore, the austenitic iron alloy material may have a tungsten content of more than 4 wt .-% and less than 5 wt .-% and optionally a cobalt content of up to 15 wt .-%.

In a specific embodiment, the austenitic iron alloy material has the following composition: 0.3 wt .-% carbon, 0.8 wt .-% silicon, 3 wt .-% manganese, 0.01 wt .-% phosphorus, 0.01 wt % Sulfur, 24% chromium, 38% nickel, 5% tungsten, 2% molybdenum, 10% cobalt and iron in the balance.

Even if an austenitic iron alloy material is used as the cast iron material, a surface treatment of the friction surfaces takes place 13 of brake disc ring 12 before the Apply the wear protection coating 14 , either in turn microscopically homogeneous or microscopically inhomogeneous, with a microscopically homogeneous contouring of the friction surfaces 13 Again, preferably by milling or laser etching and a microscopically inhomogeneous contouring again preferably by glass ball blasting, sand blasting or high pressure water jets.

Following the micro-contouring of the friction surfaces 13 of brake disc ring 12 becomes the wear protection coating 14 applied to the same, wherein, when using as the iron alloy material, an austenitic iron alloy material is used, is dispensed with a primer layer, and the wear protection coating 14 directly on the micro-contoured friction surface 13 is applied. It comes as wear protection coating 14 preferably a layer of the same austenitic iron alloy material with embedded hard material particles 18 made of Al2O3 or Cr3C2.

On all not tribologically stressed surfaces of the brake disc 10 , so the brake disc ring 12 as well as brake disk pot 11 , Preferably, a corrosion protection layer is applied. Such a corrosion protection layer may be, for example, by thermal spraying selectively or by a dip process completely on brake disk ring 12 as well as brake disk pot 11 be applied, wherein when the anti-corrosion layer is applied over the entire surface, then the same in the anti-wear coating 14 respectively. 16 to be coated friction surfaces 13 respectively. 15 is removed again.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007030468 B4 [0002]
• DE 29614774 U1 [0003, 0003]

Claims (14)

Brake disk for a motor vehicle, with a brake disk pot ( 11 ) and with a friction surfaces ( 13 ) providing brake disk ring ( 12 ), wherein at least the brake disc ring ( 12 ) consists of a cast iron material which, at least in the region of the friction surfaces ( 13 ) with a protective coating ( 14 ) is coated, characterized in that the friction surfaces ( 13 ) of the brake disk ring ( 12 ) are microscopically homogeneously or inhomogeneously contoured, and that on the microscopically contoured friction surfaces ( 13 ) of the brake disk ring ( 12 ) as a protective coating ( 14 ) a wear protection coating directly or indirectly with the interposition of an adhesion-promoting layer ( 17 ) is applied. Brake disc according to claim 1, characterized in that further as friction surfaces ( 15 ) serving surfaces of the brake disk hub ( 11 ) are microscopically homogeneously or inhomogeneously contoured, and that on the microscopically contoured friction surfaces ( 15 ) of the brake disk pot ( 11 ) as a protective coating ( 16 ) a wear protection coating is applied directly or indirectly with the interposition of an adhesion-promoting layer. Brake disc according to claim 1 or 2, characterized in that the cast iron material is formed as iron alloy material with lamellar graphite and in addition iron in the rest at least a silicon content of more than 4 wt .-% and less than 8 wt .-%, one tailored to the silicon content, hypereutectic carbon content of more than 4% by weight and less than 7% by weight, a phosphorus content of less than 0.025% by weight and a sulfur content of less than 0.025% by weight. Brake disc according to claim 1 or 2, characterized in that the cast iron material is formed as an iron alloy material with Vermiculargrafit and in addition iron in the rest at least a silicon content of more than 1.5 wt .-% and less than 4 wt .-%, one on the silicon content has a matched hypereutectic carbon content of greater than 3.0% by weight and less than 4.0% by weight, a phosphorus content of less than 0.025% by weight, and a sulfur content of less than 0.025% by weight. Brake disc according to claim 3 or 4, characterized in that the iron alloy material has a manganese content of less than 1 wt .-%, preferably less than 0.5 wt .-%, and / or a titanium content of a maximum of 0.04 wt .-% and / or and has a molybdenum content of more than 1 wt .-% and less than 2 wt .-%. Brake disc according to claim 1 or 2, characterized in that the cast iron material is formed as austenitic iron alloy material or as austenite and in addition to iron in the rest at least a carbon content of more than 0.3 wt .-% and less than 0.4 wt .-% , a manganese content of more than 3 wt .-% and less than 4 wt .-%, a chromium content of more than 23 wt .-% and less than 25 wt .-% and a nickel content of more than 37 wt .-% and less than 40% by weight. Brake disc according to claim 6, characterized in that the iron alloy material has a molybdenum content of more than 1.0 wt .-% and less than 2.5 wt .-% and / or a silicon content of more than 0.8 wt .-% and less than 1.0% by weight. Brake disc according to one of claims 1 to 7, characterized in that on the friction surfaces ( 13 ) of the brake disk ring ( 12 ) and / or on the friction surfaces ( 15 ) of Bremsscheibetopfs ( 11 ) directly or indirectly applied wear protection coating ( 14 . 16 ) and the cast iron material have matched thermal expansion coefficients. Brake disc according to one of claims 1 to 8, characterized in that not as friction surfaces ( 13 ) serving surfaces of the brake disc ring ( 12 ) and not as friction surfaces ( 15 ) serving surfaces of the brake disk hub ( 11 ) a corrosion protection coating is applied. Brake disc according to one of claims 1 to 9, characterized in that in the wear protection coating ( 14 . 16 ) Hard material particles ( 18 ) are stored. A method of manufacturing a brake disc according to any one of claims 1 to 10, comprising at least the following steps: a) providing a friction surfaces providing brake disk ring, which is formed as a separate component or an integral part of the brake disk hub; b) surface treatment of the friction surfaces of the brake disk ring to form a microscopically homogeneous or inhomogeneous contouring thereof; c) directly or indirectly with the interposition of an adhesion-promoting layer applying a wear-resistant coating on the microscopically contoured friction surfaces of the brake disk ring. A method according to claim 11, characterized in that formed as a ferroalloy material with lamellar graphite Cast iron material is removed after surface treatment of the friction surfaces of the brake disk ring and before applying the wear protection coating and optionally the primer layer on the contoured friction surfaces on the contoured friction surfaces graphite. A method according to claim 11 or 12, characterized in that the surface treatment of the friction surfaces to form a microscopically homogeneous contouring thereof by milling or laser etching. A method according to claim 11 or 12, characterized in that the surface treatment of the friction surfaces to form a microscopically inhomogeneous contouring of the same takes place by means of radiation.

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