METHOD FOR PRODUCING A BRAKE DISC, AND A BRAKE DISC

Abstract

In a method for producing a brake disc, a friction surface layer is sprayed onto the base body or onto an intermediate layer applied on the base body by cold gas spraying a particle mixture which consists 25 to 75% by weight of a metal matrix material and 75 to 25% by weight of a carbide material. The metal matrix material consists of an iron-based alloy, nickel-based alloy, titanium or titanium alloy. The carbide material consists of tungsten carbide, titanium carbide, iron carbide, silicon carbide, chromium carbide or niobium carbide.

Claims

1. Method for producing a brake disc which has a base body and, on at least one side of the base body, a friction surface layer having a friction surface, wherein the friction surface layer is sprayed onto the base body or onto an intermediate layer applied on the base body via cold gas spraying of a particle mixture, wherein the particle mixture consists 25 to 75% by weight of a metal matrix material and 75 to 25% by weight of a carbide material, wherein the metal matrix material consists of one of the following materials: iron-based alloy nickel-based alloy titanium titanium alloy, and wherein the carbide material consists of one of the following materials: tungsten carbide titanium carbide iron carbide silicon carbide chromium carbide niobium carbide.

2. Method according to claim 1, wherein the intermediate layer is sprayed onto the base body via cold gas spraying of a particulate metal matrix material, wherein the particulate metal matrix material consists of one of the following materials: iron-based alloy nickel-based alloy titanium titanium alloy.

3. Method according to claim 1, wherein the iron-based alloy contains 5 to 40% by weight chromium.

4. Method according to claim 1, wherein the titanium alloy contains 5.5 to 6.75% by weight aluminium and 3.5 to 4.5% by weight vanadium.

5. Method according to claim 1, wherein the base body is brushed mechanically, chemically or by means of a laser, before being sprayed in a region onto which the particle mixture forming the friction surface layer or the particulate metal matrix material forming the intermediate layer is sprayed.

6. Brake disc for a disc brake, wherein the brake disc has a base body and, on at least one side of the base body, a friction surface layer having a friction surface, wherein the friction surface layer consists of a composite material, which is produced by cold gas spraying a particle mixture onto the base body or onto an intermediate layer applied on the base body, wherein the particle mixture consists 25 to 75% by weight of a metal matrix material and 75 to 25% by weight of a carbide material, wherein the metal matrix material consists of one of the following materials: iron-based alloy nickel-based alloy titanium titanium alloy, and wherein the carbide material consists of one of the following materials: tungsten carbide, titanium carbide, iron carbide, silicon carbide, chromium carbide, niobium carbide.

7. Brake disc according to claim 6, wherein the intermediate layer consists at least predominantly of a particulate metal matrix material sprayed onto the base body via cold gas spraying, which consists of one of the following materials: iron-based alloy nickel-based alloy titanium titanium alloy.

8. Brake disc according to claim 6, wherein the iron-based alloy contains 5 to 40% by weight chromium.

9. Brake disc according to claim 6, wherein the titanium alloy contains 5.5 to 6.75% by weight aluminium and 3.5 to 4.5% by weight vanadium.

10. Brake disc according to claim 6, wherein the base body is brushed mechanically, chemically or by means of a laser, in a region onto which the particle mixture forming the friction surface layer or the particulate metal matrix material forming the intermediate layer is sprayed.

11. Brake disc according to claim 6, wherein the base body consists partially or entirely of cast steel, grey cast iron, cast aluminium, polymer or composite materials.

12. Brake disc for a disc brake, wherein the brake disc has a base body and, on at least one side of the base body, a friction surface layer having a friction surface, wherein the friction surface layer consists of a composite material, which is produced by cold gas spraying a particle mixture onto the base body or onto an intermediate layer applied on the base body, wherein the particle mixture consists 25 to 75% by weight of a metal matrix material and 75 to 25% by weight of a carbide material, wherein the metal matrix material comprises one of the following materials: iron-based alloy nickel-based alloy titanium titanium alloy, and wherein the carbide material consists of one of the following materials: tungsten carbide, titanium carbide, iron carbide, silicon carbide, chromium carbide, niobium carbide.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Example embodiments of the invention are illustrated in more detail in the following by means of the drawings. In the drawings:

[0046] FIG. 1: shows a cross-sectional view through a brake disc according to a first exemplary embodiment of the invention;

[0047] FIG. 2: shows the detail II of FIG. 1 in an enlarged depiction; and

[0048] FIG. 3: shows a cross-sectional view of a second exemplary embodiment of the invention corresponding to FIG. 2.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0049] FIG. 1 shows a brake disc 1 for a disc brake of vehicles, for example cars, trucks, motorbikes, bicycles or rail vehicles.

[0050] The brake disc 1 comprises a base body 2 having a central part 3 which is cup-shaped in the depicted exemplary embodiment, and a ring-shaped disc body 4 protruding radially outward from the central part 3.

[0051] The base body 2 is formed as one part in the depicted exemplary embodiment 1, but can also be formed in multiple parts. The base body preferably consists of cast steel, grey cast iron, cast aluminium, a polymer or composite material.

[0052] The central part 3 serves to fix the brake disc 1 on a rotating part in a known way, for example on a hub of the vehicle.

[0053] The ring-shaped disc body 4 that protrudes radially outwards over the central part 3 is arranged in a main plane which runs perpendicularly to a central axis 5 of the brake disc 1. In the depicted exemplary embodiment, the disc body 4 further consists in a known way of two parallel ring disc elements 6a, 6b, which are connected to each other by means of several lamellar-shaped connecting bars 7 which are preferably regularly distributed over the circumference of the brake disc 1, and held at a distance from each other, such that a clearance is created between the ring disc elements 6a, 6b. In this way, cooling air can pass between the ring disc elements 6a, 6b, whereby the cooling of the brake disc 1 is improved.

[0054] It is also easily possible to coat full discs by means of the method according to example embodiments of the invention.

[0055] A friction surface layer 10a, 10b is applied on each of the two sides of the disc body 4, i.e., on the outer lateral surfaces 9a, 9b, by means of a cold gas spraying method. The two friction surface layers 10a, 10b are preferably formed in the same way, and can in particular consist of the same material and have the same thickness. The surfaces of the friction surface layers 10a, 10b facing laterally outward form friction surfaces 11a, 11b. The friction surface layers 10a, 10b in the depicted exemplary embodiment are formed in such a way that brake pads (not shown), which can be moved towards and away from each other on a caliper that is stationary relative to the vehicle, and which have suitable brake linings, can be pressed against the friction surfaces 11a, 11b of the friction surface layers 10a, 10b from opposite sides, wherein the frictional forces required by the brake are generated between the brake pads and the disc body 4.

[0056] The friction surface layers 10a, 10b consist of a composite material that consists of a metal matrix material and a carbide material. According to example embodiments of the invention, the metal matrix material consists of an iron-based alloy, preferably having 5 to 40% by weight chromium (with or without additional alloy components), nickel-based alloy, titanium or a titanium alloy, for example Ti6Al4V, having 5.5 to 6.75% aluminium and 3.5% vanadium.

[0057] The carbide material consists of tungsten carbide, titanium carbide, iron carbide, silicon carbide, chromium carbide or niobium carbide.

[0058] The composite material of the friction surface layers 10a, 10b is generated by spraying on a powder or particle mixture, which consists 25 to 75% by weight of metal matrix material and 75 to 25% by weight of carbide material.

[0059] A particularly good adhesion of the friction surface layers 10a, 10b on the disc body 4 can be generated when the lateral surfaces 9a, 9b of the disc body 4 are prepared in a suitable way before coating. In particular, methods can be used by which the lateral surfaces 9a, 9b are brushed. This can occur via blasting processes, mechanical brushing, chemical preparation, laser structuring etc.

[0060] FIG. 3 shows a second exemplary embodiment according to example embodiments of the invention, wherein only that portion of a brake disc is shown which is shown in connection with the first exemplary embodiment in FIG. 2. In the second exemplary embodiment, the base body 2 is identical to the base body 2 of the first exemplary embodiment, such that reference is made to the first exemplary embodiment regarding said base body.

[0061] Unlike in the first exemplary embodiment, the friction surface layers 10a, 10b are not directly sprayed onto the disc body 4 of the base body 2 in the second exemplary embodiment, but onto intermediate layers 12a, 12b, which are also sprayed onto the lateral surfaces 9a, 9b of the disc body 4 by means of the cold gas spraying method before the friction surface layers 10a, 10b are sprayed on.

[0062] The two intermediate layers 12a, 12b can be formed in the same way. Furthermore, the intermediate layers 12a, 12b consist of a metal matrix material, which can consist of an iron-based alloy (preferably having 5 to 40% chromium), nickel-based alloy, titanium or titanium alloy (e.g., Ti6Al4V, having 5.5 to 6.76% aluminium and 3.5 to 5.5% vanadium).

[0063] The metal matrix material of the intermediate layers 12a, 12b can consist of the same or of a different metal matrix material than that of the friction surface layers 10a, 10b.

[0064] In the second exemplary embodiment, it can be suitable for the lateral surfaces 9a, 9b of the disc body 4 to be pre-treated, in particular brushed, in a suitable way before the intermediate layers 12a, 12b are sprayed on. This can occur by means of the same method as described in connection with the first exemplary embodiment.