Brake body for a motor vehicle and method for producing a brake body

Abstract

The invention relates to a brake body (1) for a motor vehicle, having an at least partially planar base body (G), on the planar side (Fa) of which at least two structure layers (B1, B2) are respectively applied at least partially. A surface is configured by the structure layers (B1, B2), which surface serves as a friction surface (12) for a brake pad in the mounted state of the brake body (1) at the motor vehicle. According to the invention it is proposed that a junction region (A) is present, in which not only the material of the base body (G) but also the material of the structure layer (B1) adjoining this is present, wherein the junction region (A) has a thickness (d3) perpendicular to the planar extension (F) of the planar side (Fa), which thickness is less than 10 micrometers.

Description

Technical Field

[0001] This invention relates to a brake element for a motor vehicle. The invention also relates to a method for manufacturing such a brake element. Background Technology

[0002] Brake components, such as brake discs or brake disc friction rings, are typically made of gray cast iron. The advantages of gray cast iron, especially its high volumetric heat capacity and relatively good thermal shock resistance, are accompanied by various disadvantages. These disadvantages include high weight, strong corrosion susceptibility, and high wear during vehicle operation.

[0003] The visual defects are caused by corrosion because the brake disc is the only part of a motor vehicle that develops red rust in the shortest amount of time. Additionally, the brake disc can be directly seen through the frequently used, open aluminum rims.

[0004] In economical driving conditions or at high recycling rates (when braking is infrequent), the tendency of materials to corrode can, in some cases, cause such significant damage to the brake element that it must be replaced prematurely.

[0005] In addition, friction and wear of the brake components lead to the emission of fine dust, the amount of which can significantly exceed the fine dust emissions of modern combustion engines.

[0006] To eliminate these drawbacks, in addition to completely replacing the brake body material with a harder and corrosion-resistant material (such as ceramic), it is known to protect the friction surfaces of the brake body with a suitable coating.

[0007] Thus, different solutions exist for coatings, particularly for the highly stressed friction surfaces of brake bodies, which should be used for combined wear and corrosion protection. Coatings are applied by thermal spraying methods for applying oxide ceramics or coatings containing hard materials. Thus, using different coating materials based on metal alloys or composites consisting of ceramic or hard metal particles in a metal matrix, these coating materials provide improved behavior relative to corrosion and wear.

[0008] Examples of thermal spraying methods include high-speed mud spraying, plasma spraying, cold air spraying, or electric arc wire spraying.

[0009] A common problem in thermal spray coatings is the adhesion of the layer to the substrate under high thermomechanical loads acting on the brake body. To address this, solutions are known in which the surface of the brake body is roughened prior to thermal spraying by radiation with hard material particles (DE 10 2008 035 894 A1), by ultrasonic / laser beam treatment (DE 10 2011 089152 A1), or by electron beam treatment (DE 10 2011 012 320 A1).

[0010] Furthermore, to improve the adhesion of thermally sprayed coatings, it is known to use an adhesion relay layer as an intermediate layer. This is known, for example, from DE 10 2011 089 923 A1, in which an intermediate layer composed of nickel, copper, and / or chromium, consisting of chemically or electrochemically cold-separated elements, is described as the base of a thermally sprayed abrasion protection layer.

[0011] The adhesion of thermally sprayed layers (independent of roughening methods or the use of intermediate layers) is based almost solely on the principle of mechanical bonding between the impacted sprayed particles and the substrate.

[0012] Significantly stronger bonds can be achieved through metallurgical bonding, which requires thermal energy to enable atomic diffusion at the interface between the substrate and the cladding. Two alternatives are available: On the one hand, the substrate can be heated before the spraying process, so that the diffusion process can take place directly when the sprayed particles hit (see, for example, DE 10 2008 035 849 A1).

[0013] The second possibility is a melting process, in which heating occurs after the spraying process, as described in DE 10 2005 008569 A1.

[0014] The disadvantage of the spraying method is the very costly additional process steps, because high temperatures are required and the process must be carried out in a vacuum furnace in part.

[0015] Besides thermally sprayed coatings, DE 10 2006 035 948 A1 describes an electrolytically applied coating in which a rigid material is embedded in a malleable metal matrix. Problems with this solution include poor coating adhesion and very low malleability, which can lead to peeling during operation. Furthermore, achieving the required layer thickness is methodologically challenging and associated with high costs.

[0016] As an alternative, DE 10 345 000 A1 describes a welding method for wear protection using laser beams, plasma, or arc welding. A carrier material (substrate) is melted by an energy source, and the coating material is supplied in a solid state to the molten pool (Schmelzbad). Alternatively, it is proposed to melt the carrier material after applying the coating material. The coating can be metallic, ceramic, or composite material and can be applied in a whole-surface or strip-like manner. Due to the large localized temperature changes caused by the process, significant cracks can appear in coatings with high hardness or a high proportion of hard materials. These cracks allow corrosive media to penetrate the base material and result in significant visual defects.

[0017] Finally, EP 3 034 902 B1, which features the features of the preamble of the parallel claims, describes a multilayer coating for a brake disc by means of laser welding. Here, a base layer without highly fusible particles is applied directly to the brake disc. An additional layer is then applied on top of this base layer, the additional layer containing particles with a higher melting point than the disc body of the brake disc. Summary of the Invention

[0018] The objective of this invention is to provide a brake element for motor vehicles having a coating with high wear resistance and high corrosion protection, and which can be manufactured cost-effectively. Furthermore, the objective of this invention is to provide a method for manufacturing such a brake element, which can be carried out cost-effectively.

[0019] This task is solved by the brake body according to the invention and by the method for manufacturing the brake body according to the invention.

[0020] Regarding the claims, the present invention relates to a brake body for a motor vehicle having a base that is at least partially flat, on which at least two structural layers are applied at least partially (i.e., at least in the region of the surface swept by the brake pads) on the planar side. The structural layers construct a surface that serves as a friction surface for the brake pads in the assembled state of the brake body in the motor vehicle.

[0021] The present invention now proposes the existence of a connecting region in which not only the material of the substrate is present but also the material of the structural layer adjacent to the substrate, wherein the planar extension of the connecting region perpendicular to the planar side has a thickness of less than 10 micrometers, preferably less than 5 micrometers.

[0022] In other words, the brake body according to the invention has a degree of mixing (the proportion of the base material in the material of the adjacent structural layer) in the region of the coating, which is significantly lower than the degree of mixing in a conventional welding process.

[0023] The presence of this bonding region with the aforementioned thickness prevents negative effects (grain formation, hardening) that could occur due to the mixing of the substrate material. Nevertheless, excellent adhesion of the structural layer to the substrate is still achieved, with adhesion tensile strengths well exceeding 50 MPa. This provides the fundamental prerequisites for high wear resistance and high corrosion protection.

[0024] For example, a brake disc or brake disc friction ring can be understood as a brake body in the sense of this invention.

[0025] According to a first improvement of the invention, a first structural layer adjacent to the substrate and a second structural layer applied to the first structural layer are provided. Viewed from a planar extension perpendicular to the planar side, the first structural layer has a thickness in the range of about 40 micrometers to about 120 micrometers, preferably in the range of about 60 micrometers to about 100 micrometers. Viewed from a planar extension perpendicular to the planar side, the second structural layer has a thickness in the range of about 60 micrometers to about 420 micrometers, preferably in the range of about 80 micrometers to about 400 micrometers.

[0026] It has been shown that, in this implementation scheme of structural layer thickness, the first structural layer can optimally satisfy the purposes of corrosion protection and crack suppression from the second structural layer.

[0027] The second structural layer provides high wear resistance due to the thickness range, which results in a significant reduction in the emission of particulate matter from frictional wear of the brake body.

[0028] In one advantageous construction embodiment of the present invention, the first structural layer is composed of austenitic chromium-nickel-molybdenum steel. This first structural layer possesses particularly ductile and tough properties, which can stop crack propagation and thus better protect the substrate of the brake element. This protection is crucial for protecting the substrate from corrosion and ensuring the overall lifespan of the brake element.

[0029] It is particularly suitable here that the material of the first structural layer has such material properties as it corresponds to material 1.4404 according to standard EN10027-2 or material 316L according to standard AISI.

[0030] In another highly advantageous embodiment of the invention, the second structural layer comprises a composite of a ferroalloy matrix and inserted tungsten carbide microparticles. Here, the volume fraction of the inserted tungsten carbide microparticles relative to the volume of the ferroalloy matrix is ​​in the range of about 20% to about 40%, preferably about 25% to about 35%. Particularly preferably, a range of about 28% to about 33% is proposed.

[0031] This volume distribution visibly reduces the tendency of the second structural layer to crack due to thermomechanical effects. Simultaneously, it results in optimal wear resistance and good friction values ​​during the use of the braking system.

[0032] The volume distribution can be easily determined by metallurgical cutting through the second structural layer.

[0033] As a material for the ferroalloy matrix, it also proves suitable to be composed of a material having such material properties as it corresponds to material 1.4404 according to the standard EN10027-2 or material 316L according to the standard AISI.

[0034] As mentioned at the beginning, the invention should also claim protection for a method of manufacturing a brake body according to the invention. Here, we begin with a method for manufacturing a brake body, wherein, in a first method step, an energy beam is directed toward the planar side of a flat substrate of the brake body by means of at least one energy source. The energy beam may be in the form of a light beam (e.g., a laser beam) or also in the form of an electron beam. In some cases, a plasma beam may also be conceived, although such a plasma beam is obviously more difficult to control or quantify. Preferably, it is in any case a high-energy beam.

[0035] Furthermore, in the first method step, a powdered first coating material is supplied to the location loaded by the energy beam so as to melt the first coating material and thereby coat the planar side of the brake body substrate with a first structural layer.

[0036] After the first structural layer is applied, in the second method step, an energy beam (preferably of equally high energy) is directed toward the surface of the first structural layer by means of at least one energy source. Here, a powdered second coating material is supplied to the location loaded by the energy beam so as to melt the second coating material and coat the first structural layer with the second structural layer.

[0037] According to the present invention, it is now proposed that, at least in the second method step, the radiation intensity of the energy beam be maintained at about 500 W / mm² when generating the second structural layer. 2 Approximately 1500 W / mm 2 Within the range, preferably around 600 W / mm 2 Approximately 1400 W / mm 2 Within the range.

[0038] It has been shown that by adhering to such a range of radiation intensity (i.e., radiation power with respect to the diameter of the beam point on the substrate surface), the second structural layer can be ensured not to overheat. As a result of overheating, tungsten carbide, as a solid phase, dissolves into a liquid phase and remains dissolved in the ferroalloy matrix of the second structural layer. Due to the dissolved material, the ferroalloy matrix becomes so brittle that cracks are generated.

[0039] Due to the selected radiation intensity, the best coating result with optimal quality and optimal adhesion of the structural layer can be obtained.

[0040] In an improved version of the method, at least in the second method step, the energy beam is fired onto the corresponding substrate in such a way that an intensity distribution of the energy beam with a top-hat profile is obtained on the impact surface of the energy beam on the corresponding substrate.

[0041] The top cap profile is one in which the intensity distribution (beam point) of the energy beam striking the substrate has an approximately constant height over the diameter of the striking energy beam. The intensity distribution thus jumps from zero to a maximum value, remains approximately constant over the diameter of the laser beam, and then jumps back to zero, depending on the type of rectangular profile.

[0042] In this way, the surface roughness of the resulting structural layer can be significantly reduced. This ultimately leads to a potential reduction in the amount of material removed during subsequent grinding processes on the surface, and thus a further reduction in cost.

[0043] In order to reliably achieve the preferred layer thickness of the brake body, it has been proven that each powdered coating material is supplied with a powder mass flow in the range of about 15 g / min to about 220 g / min, preferably in the range of about 20 g / min to about 200 g / min.

[0044] The powder grains of the coating material are preferably in a spherical shape and preferably in the size range of about 10 μm to about 55 μm, particularly preferably in the range of about 15 μm to 50 μm.

[0045] In another construction scheme of the present invention, it is proposed that the braking body be horizontally oriented on its planar side and placed in rotation in order to apply the structural layer. Here, not only the energy beam but also the corresponding coating material is supplied from above to the planar side of the braking body. In other words, not only the supply of the energy beam but also the supply of the coating material is oriented at least substantially in the direction of the acting gravity.

[0046] In this way, the coating material is exposed to the energy beam for as long as possible and can therefore interact with the energy beam as well as possible.

[0047] To achieve optimal heat generation in the braking body during the application of the structural layer, it has proven advantageous to apply the structural layer via a feed motion of the coating tool traveling radially from the inside out.

[0048] Here, it has proven advantageous in terms of economic production that the radial feed motion of the coating tool is carried out at a speed exceeding about 90 m / min, preferably exceeding about 100 m / min.

[0049] In order to ensure both rapid execution of the method and void-free coating of the substrate, it has proven suitable to coordinate the radial feed motion of the coating tool and the rotational speed of the brake body in such a way that, during the complete rotation of the brake body, the coating trajectory applied during the rotation overlaps with the coating trajectory applied previously (i.e., in the previous complete rotation) in the range of about 85% to about 95%, preferably about 90%. Attached Figure Description

[0050] Preferred embodiments of the invention are presented in the accompanying drawings and explained in more detail in the following description with the aid of the drawings. This also makes other features and advantages of the invention clearer. The same reference numerals refer to the same, similar, or functionally identical components even in different figures. Corresponding or similar features and advantages are implemented herein, even if they are not repeatedly described and mentioned. The figures are not, or at least not always, to scale. In some figures, the scale or spacing may be exaggerated so that the features of the embodiments can be highlighted more clearly. If the term “and / or” is used in a list of two or more terms or objects, this may mean that any one of the listed terms or objects can be used alone. It may also mean that any combination of two or more listed terms or objects can be used.

[0051] The following are illustrated in detail: Figure 1 A motor vehicle having a brake body according to the invention is shown. Figure 2 The cross-section of the brake element is shown separately in the illustration. Figure 3 It shows Figure 2 According to the detail diagram in detail III, Figure 4 The diagram illustrates the process steps in the manufacturing method of the brake body, and Figure 5 A diagram showing the intensity distribution of the energy beam on the corresponding substrate is presented. Detailed Implementation

[0052] First refer to Figure 1 As can be seen, the motor vehicle K is equipped with a brake body 1 according to the invention. The brake body 1 is constructed as a disc brake and is rotatably mounted on a wheel carrier (not shown in more detail) about a rotation axis R. The brake calipers 2 each contain feedable brake pads (not shown), and the brake body 1 has a friction surface constructed for the brake pads by its brake disc friction ring. If the brake pads are pressed against the friction surface of the brake body 1, the motor vehicle K is braked or stopped.

[0053] exist Figure 2 In the diagram, brake 1 is shown separately and in cross-section. Brake 1 rotates about an imaginary axis of rotation R. For rotational symmetry, only half of brake 1 is shown.

[0054] As can be seen, the brake body 1 in this embodiment is constructed as an internally ventilated brake disc having two friction rings 10a and 10b. Unlike this embodiment, a brake disc with only one friction ring is also conceivable. A ventilation gap 11 exists between the friction rings 10a and 10b. The necessary spacer ribs between the friction rings 10a and 10b are not shown. Each friction ring 10a and 10b has a surface base G with a planar side Fa or Fb. Each planar side Fa or Fb has a planar extension F and is provided with a coating B. Friction surfaces 12 that function during braking are respectively constructed through the coating B.

[0055] In one embodiment, the cladding B extends across the entire planar side Fa or Fb of the substrate G. Alternatively, it is conceivable that the cladding B is applied only to the areas of the planar sides Fa and Fb that are swept by the brake pads.

[0056] The hub of brake body 1, numbered 13, is used to assemble the brake body onto the wheel frame which is not shown.

[0057] Now from Figure 3 The details of the cross-section of the brake body 1 can be seen. In particular, it can be identified that the cladding B consists of a first structural layer B1 and a second structural layer B2.

[0058] The first structural layer B1 is applied directly to the substrate G, meaning it is directly adjacent to the substrate. The second structural layer B2 is then applied over the first structural layer B1.

[0059] It is identifiable here that the planar extension F of the first structural layer B1 perpendicular to the planar side Fa (or Fb) has a thickness d1. This thickness is preferably in the range of about 40 micrometers to about 120 micrometers. Particularly preferably, the first structural layer B1 has a thickness d1 in the range of about 60 micrometers to about 100 micrometers.

[0060] The second structural layer B2, on the other hand, has a thickness d2, which is preferably in the range of about 60 micrometers to about 420 micrometers. Particularly preferably, the thickness d2 is in the range of about 80 micrometers to about 400 micrometers.

[0061] Due to the range of thicknesses of these layers, corrosion protection and crack suppression from the second structural layer B2 can be optimally achieved through the first structural layer B1.

[0062] The thickness range described for the second structural layer B2 meets the requirements for high wear resistance, thereby significantly reducing particulate emissions caused by friction and wear.

[0063] Furthermore, a connecting region A is shown, which is located in the transition between the substrate G and the adjacent first structural layer B1. Connecting region A is characterized in that a certain degree of mixing occurs between the materials of the substrate G and the cladding layer B1. Connecting region A has a thickness d3 perpendicular to the planar extension F, which is very thin and less than 10 micrometers. Preferably, connecting region A has a thickness d3 of less than 5 micrometers.

[0064] It has been shown that this relatively small thickness of the connecting region A can, on the one hand, prevent grain formation and hardening of the first structural layer B1, and on the other hand, despite this, achieve good adhesion of the first structural layer B1 to the substrate G. An adhesion tensile strength far exceeding 50 MPa can be achieved. This provides the fundamental prerequisites for high wear resistance and high corrosion protection.

[0065] The materials used should now be discussed in more detail. Thus, the base G is made of gray cast iron. The base, along with the hub 13, is manufactured using conventional casting methods (see...). Figure 2 The first structural layer B1 is composed of austenitic chromium-nickel-molybdenum steel, which is therefore a particularly ductile and tough iron alloy.

[0066] Particularly preferably, the material of the first structural layer B1 has material properties such as those corresponding to material 1.4404 according to standard EN10027-2 or material 316L according to standard AISI.

[0067] The second structural layer B2 consists of a composite material of a ferroalloy matrix E and inserted tungsten carbide microparticles W. Particularly advantageously, in the second structural layer B2, the volume fraction of the inserted tungsten carbide microparticles W relative to the volume of the ferroalloy matrix E is in the range of about 20% to about 40%. Preferably, the volume fraction of the added tungsten carbide microparticles W is in the range of about 25% to about 35% of the volume of the ferroalloy matrix E.

[0068] This volume distribution can prevent the increased tendency of cracking in the second structural layer B2 on the one hand, and limit the wear of the second structural layer B2 under good friction values ​​on the other hand.

[0069] Now using Figure 4 Describe the coating B of brake body 1 (see Figure 3 The first process step in the manufacturing of the brake body 1. Thus, by means of a device not shown in more detail, the base G of the brake body 1 is first oriented vertically along its axis of rotation R, that is, along the height direction Z, so that the planar side Fa is oriented parallel to the horizontal direction Y with its planar extension F.

[0070] The substrate G, i.e. the uncoated brake disc, was manufactured in advance according to the usual mass production process (not explained in more detail).

[0071] A coating tool 3 exists approximately parallel to the axis of rotation R. The coating tool 3 can move orthogonally or radially to the axis of rotation R and parallel to the horizontal direction Y along a single axis. The coating tool has at least one laser optics system for generating a laser beam L and a nozzle for ejecting a powdered first coating material P1 (or a powdered second coating material P2). At least one laser source (not shown) and at least one powder conveyor (not shown) are connected to the coating tool 3.

[0072] Subsequently, the substrate G is subjected to rapid rotation, causing it to rotate around the axis of rotation R at a certain rotational speed n. The coating on the substrate G begins at the radially inner position Gi and advances along the radially outer position Ga of the substrate G via a radial feed motion V.

[0073] Simultaneously with the generation of the laser beam L, the aforementioned powder conveyor is activated such that the powdered first coating material P1 is conveyed at a powder mass flow m, which is in the range of about 15 g / min to about 220 g / min, preferably in the range of about 20 g / min to about 200 g / min. The powdered first coating material P1 is composed of powder particles having a spherical shape and is composed of a material corresponding to the first structural layer B1 to be manufactured.

[0074] The rotational speed n of the substrate G is adapted to the instantaneous position of the coating tool 3 in order to obtain a constant thickness of the structural layer B1 on all surfaces to be coated on the planar side Fa.

[0075] In the coating method, the radiation intensity S of the laser beam L is set as follows (see also...). Figure 5 This results in a radiation intensity of approximately 500 W / m². 2 Approximately 1500W / mm 2 Within the range, preferably about 600W / mm 2 Approximately 1400W / mm 2Within the specified range. This ensures that overheating of the corresponding structural layers B1 or B2 is not observed.

[0076] In the presented coating method, the coating material, i.e., powdered coating material P1 or P2, is melted. For this purpose, the powdered coating material P1 or P2 is selectively supplied via coating tool 3 to a laser beam L, i.e., a laser spot, that strikes the substrate G. There, the powdered coating material P1 or P2 is melted, forming a melt pool SB.

[0077] The substrate G, conversely, does not itself form a molten pool, but is only locally heated to a temperature slightly below its melting temperature. Therefore, no unmelted particles of the powdered coating material P1 or P2 are introduced into the melt of the substrate G; instead, a molten pool SB is formed from the separation of the powdered coating material P1 or P2 particles. At the direct interface between the molten coating material (P1 in the image) and the locally intensely heated surfaces of the substrate (substrate G), a very good bond is formed between the coating material (P1) and the substrate (substrate G) through a diffusion process, without any additional mixing of the involved materials.

[0078] Since the powdered coating material P1 or P2 is brought into the laser beam L along or approximately along the direction of gravitational acceleration g, it can remain in the laser beam L for as long as possible and can undergo good melting.

[0079] With the help of Figure 5 The radiation intensity S of the laser beam L along the diameter D of the laser spot is shown, which is constructed on the surface of the corresponding coating layer.

[0080] In this embodiment, a laser spot with a diameter D of approximately 3 mm is preferably constructed. It can be seen that the laser intensity S remains almost constant across the entire diameter D of the laser spot. The radiation intensity S of the laser beam L thus constructs a so-called top-hat profile (or also a rectangular profile).

[0081] It should be mentioned here that during the coating process, the coating tool 3 is moved radially outward with a feed motion v, which has a speed of more than about 90 m / min, preferably more than about 100 m / min.

[0082] Furthermore, by coordinating the feed motion v of the coating tool and the rotational speed of the brake body 1, the coating trajectory applied during the complete 360-degree rotation of the brake body 1 overlaps with the previously applied coating trajectory in the range of approximately 85% to approximately 95%, preferably approximately 90%. Thus, a spiral orientation of the applied layer trajectory is generally obtained for each structural layer (B1 or B2).

[0083] Preferably, the radial feed motion v is set to approximately 0.3 mm per revolution.

[0084] If the first structural layer B1 is applied to the substrate G in the desired manner, then the second layer B2 is applied to the surface O of the first structural layer B1 in a corresponding manner.

[0085] Here, the coating tool 3 is fed radially from the inside out. However, in order to apply the second structural layer B2, the powdered second coating material P2 is now supplied to the laser beam L. Preferably, the powdered second coating material also exists in the form of powder grains with a spherical shape. This material, as already mentioned, consists of a material with a composition similar to that of iron alloy 1.4404 and additional tungsten carbide particles.

[0086] Unlike tungsten carbide particles, it is also conceivable to incorporate ceramic, metallic, or composite materials consisting of oxide ceramic, carbide, or boride particles into the ferroalloy matrix E. For example, chromium carbide, titanium carbide, or even niobium carbide are conceivable. Instead of the ferroalloy matrix E, nickel-based alloys or alternative ferroalloys may be used.

[0087] List of reference numerals 1. Braking body 2 Brake calipers 3. Coating tools 10a,b Friction Rings 11. Ventilation gap 12 Friction surfaces 13 hubs A Link Area B Coating B1 First Structural Layer B2 Second Structural Layer D diameter d1 thickness d2 thickness d3 thickness E Ferroalloy Matrix F Plane Extension Fa,Fb plane side G matrix Gi radial interior position Ga radial outer position g acceleration due to gravity K Motor Vehicle L laser beam m Powder mass flow n rotational speed O surface P1 Powdered first coating material P2 Powdered second coating material R Rotation axis S radiation intensity SB melting pool V feed motion W Tungsten carbide particles Y horizontal direction Z represents the height direction.

Claims

1. A brake element (1) for a motor vehicle (K) having a base (G) that is at least partially flat, wherein at least two structural layers (B1, B2) are respectively applied at least partially to the planar sides (Fa, Fb) of the base, wherein, The surface constructed by the structural layers (B1, B2) serves as a friction surface (12) for brake pads in the assembled state of the brake body (1) at the motor vehicle (K). It is characterized by the presence of a connecting region (A) containing not only the material of the substrate (G) but also the material of the structural layer (B1) adjacent to the substrate. The connecting region (A) has a planar extension (F) perpendicular to its planar side (Fa, Fb) with a thickness (d3) less than 10 μm. A first structural layer (B1) adjacent to the substrate (G) and materials applied to the first structural layer (B1) are present. The second structural layer (B2) on B1), wherein, viewed from the planar extension (F) perpendicular to the planar side (Fa, Fb), the first structural layer (B1) has a thickness (d1) in the range of 40 μm to 120 μm and the second structural layer (B2) has a thickness (d2) in the range of 60 μm to 420 μm, wherein the second structural layer (B2) is composed of a composite of an iron alloy matrix (E) and inserted tungsten carbide microparticles (W), wherein the volume of the inserted tungsten carbide microparticles (W) has a proportion in the range of 20% to 40% relative to the volume of the iron alloy matrix (E).

2. The braking body (1) according to claim 1, characterized in that, The first structural layer (B1) is composed of austenitic chromium-nickel-molybdenum steel.

3. The braking body (1) according to claim 2, characterized in that, The material of the first structural layer (B1) has material properties corresponding to material 1.4404 according to standard EN10027-2 or material 316L according to standard AISI.

4. The braking body (1) according to any one of claims 1 to 3, characterized in that, The ferroalloy matrix (E) is composed of materials having material properties corresponding to material 1.4404 according to standard EN10027-2 or material 316L according to standard AISI.

5. A method for manufacturing a brake body (1) according to any one of the preceding claims, wherein, In the first method step, an energy beam is directed toward the planar side (Fa, Fb) of the substrate (G) of the actuator (1) by means of at least one energy source, and a powdered first coating material (P1) is supplied to the location loaded by the energy beam to melt the first coating material (P1) and coat the planar side (Fa, Fb) of the substrate (G) with a first structural layer (B1). After applying the first structural layer (B1), in the second method step, an energy beam is directed toward the surface (O) of the first structural layer (B1) by means of the at least one energy source, and a powdered second coating material (P2) is supplied to the location loaded by the energy beam to melt the second coating material (P2) and coat the first structural layer (B1) with a second structural layer (B2). The method is characterized in that, at least in the second method step, when generating the second structural layer (B2), the radiation intensity (S) of the energy beam is maintained at 500 W / mm². 2 Up to 1500W / mm 2 Within the range.

6. The method according to claim 5, characterized in that, At least in the second method step, the energy beam is fired onto the corresponding substrate such that an intensity distribution of the energy beam with a top-cap profile is obtained on the impact surface of the energy beam on the corresponding substrate.

7. The method according to any one of claims 5 and 6, characterized in that, Each powdered coating material (P1, P2) is supplied at a powder mass flow (m) in the range of 15 g / min to 220 g / min.

8. The method according to any one of claims 5 and 6, characterized in that, In order to apply the structural layers (B1, B2), the brake body (1) is horizontally oriented with its planar sides (Fa, Fb) and placed in rotation, wherein not only the energy beam but also the corresponding coating material (P1, P2) is supplied from above to the planar sides (Fa, Fb) of the brake body (1).

9. The method according to any one of claims 5 and 6, characterized in that, The structural layers (B1, B2) are applied by the feed motion (v) of the coating tool (3) moving radially from the inside to the outside.

10. The method according to claim 9, characterized in that, The radial feed motion (v) of the coating tool (3) is performed at a speed exceeding 90 m / min.

11. The method according to claim 9, characterized in that, The radial feed motion (v) of the coating tool (3) and the rotational speed of the brake (1) are coordinated in such a way that the coating trajectory applied during the complete rotation of the brake (1) overlaps with the previously applied coating trajectory in the range of 85% to 95%.

Images