阅读说明：本技术 钎焊式铝制制动盘及其制作方法 (Brazing type aluminum brake disc and manufacturing method thereof ) 是由 李珮豪 彭波 于 2020-06-05 设计创作，主要内容包括：本发明属于机动车制动器技术领域,尤其涉及一种钎焊式铝制制动盘,包括：(1)转子体,为一由铝或铝合金制成的带帽圆盘,带帽圆盘包括圆盘、位于圆盘中心并带有中心孔的帽；(2)摩擦环,由铝基复合材料制成的圆环,转子体的圆盘两侧表面分别与摩擦环连接；(3)铝钎焊材料层,设置在转子体与摩擦环的连接面之间,通过钎焊工艺将转子体和摩擦环连接；其中,摩擦环的铝基复合材料为硬质颗粒增强铝合金复合材料。本发明还提供了一种钎焊式铝制制动盘的制作方法。本发明的有益效果是：实现了制动盘轻量化目的,总体提高了制动盘连接强度；制作工艺简单可靠,降低了铝基复合材料的用量,进而降低了产品成本。(The invention belongs to the technical field of motor vehicle brakes, and particularly relates to a brazing type aluminum brake disc, which comprises: (1) the rotor body is a disc with a cap made of aluminum or aluminum alloy, and the disc with the cap comprises a disc and a cap which is positioned in the center of the disc and is provided with a central hole; (2) the friction ring is a circular ring made of an aluminum-based composite material, and the surfaces of the two sides of the circular disc of the rotor body are respectively connected with the friction ring; (3) the aluminum brazing material layer is arranged between the connecting surface of the rotor body and the friction ring, and the rotor body and the friction ring are connected through a brazing process; wherein, the aluminum-based composite material of the friction ring is a hard particle reinforced aluminum alloy composite material. The invention also provides a manufacturing method of the brazing type aluminum brake disc. The invention has the beneficial effects that: the purpose of light weight of the brake disc is realized, and the connection strength of the brake disc is improved overall; the preparation process is simple and reliable, and the dosage of the aluminum matrix composite material is reduced, so that the product cost is reduced.)

1. A brazed aluminum material brake disc, comprising: a rotor body, a capped disc made of aluminum or aluminum alloy, the capped disc including a disc, a cap positioned at the center of the disc and having a central hole; the friction ring is a circular ring made of an aluminum-based composite material, and the surfaces of the two sides of the circular disc of the rotor body are respectively connected with the friction ring; the aluminum brazing material layer is arranged between the connecting surface of the rotor body and the friction ring, and the rotor body and the friction ring are connected through a brazing process; wherein, the aluminum-based composite material of the friction ring is a hard particle reinforced aluminum alloy composite material.

2. Brake disc according to claim 1, characterised in that the hard particle reinforced aluminium alloy composite contains hard reinforcing particles in an amount of 5-30 wt% based on the total weight of the aluminium alloy composite, with a particle size of 1-400 μm and a mohs hardness of the hard reinforcing particles not lower than 8.

3. Brake disc according to claim 2, characterized in that the hard reinforcing particles are at least one of oxides, carbides, borides.

4. Brake disc according to claim 3, characterized in that the oxide is chosen from Al₂O₃、SiO₂、TiO₂The carbide is selected from WC, SiC and TiC, and the boride is selected from TiN and Si₃N₄、AlN。

5. Brake disc according to claim 3, characterized in that the hard reinforcing particles are SiC.

6. The brake disc according to claim 1, wherein the friction ring is manufactured using any one of powder metallurgy, pressure casting, gravity casting, stir casting, pressureless infiltration, spray deposition, etc.; the rotor body is manufactured by any one of sand molding, pressure casting, injection molding, and the like.

7. A method of manufacturing a brake disk of the brake disk brazing aluminum material according to any one of claims 1 to 6, characterized by comprising the steps of:

step 1: providing a friction ring of aluminum matrix composite material of a predetermined size and shape;

step 2: etching the aluminum material on the brazing connection surface of the friction ring to ensure that the exposed size of the hard reinforcing particles reaches 1/3-2/3 of the average particle size;

and step 3: placing an aluminum brazing material on the surface of the connecting surface of the eroded friction ring;

and 4, step 4: providing a rotor body of aluminium or an aluminium alloy of a predetermined size and shape;

and 5: the connecting surface of the friction ring with the aluminum brazing material is contacted with the two connecting surfaces of the rotor body, and the two connecting surfaces are assembled together to form a brazing assembly;

step 6: placing the brazing assembly on a workbench in a brazing furnace and heating to melt the aluminum brazing material and connect the rotor body and the friction ring together;

and 7: and taking out the brazed brake disc from the furnace, cooling and grinding to obtain the aluminum material brake disc.

8. The method according to claim 7, wherein the aluminum matrix composite is a hard particle reinforced aluminum alloy composite, wherein the hard reinforcing particles are at least one of an oxide, a carbide and a boride, the content of the hard reinforcing particles is 5 to 30 wt% of the total weight of the aluminum alloy composite, and the particle size of the particles is 1 to 400 μm.

9. The manufacturing method according to claim 7, wherein in the step 2, the friction ring is etched by using an etching solution, and the friction ring is soaked in the etching solution until the aluminum material on the brazing connection surface is eroded; preferably, before the friction ring is soaked in the etching solution, the method further comprises the step of coating all surfaces of the friction ring except the brazing connection surface with an anti-corrosion glue layer; preferably, step 3 is further performed before the aluminum brazing material is placed on the surface of the connecting surface of the friction ring, and the step of washing the friction ring with water to remove the anti-corrosion glue layer is further included.

10. The method according to claim 7, wherein the aluminum brazing material is applied in step 3 in an amount corresponding to the coating amountIs 60-80g/m²。

Technical Field

The invention belongs to the technical field of motor vehicle brakes, and particularly relates to a brazing type aluminum brake disc and a manufacturing method thereof.

Background

Fuel-powered motor vehicles in order to improve fuel economy, and electric and hybrid vehicles in order to increase the amount of travel, there has been a call for lighter weight motor vehicles, such as aluminum engines, heat exchangers, and other components, that have been partially or fully aluminized.

The brake device of the motor vehicle is a necessary device of the vehicle, the brake disc of the brake device is most commonly an inexpensive cast iron brake disc, but the cast iron brake disc is very heavy, and because the aluminum material is light and has good thermal conductivity, people have considered to replace the cast iron material with aluminum or aluminum alloy material, but the aluminum is soft material and can not bear the scraping of the brake disc under high speed or heavy load, therefore, the aluminum material can not be simply replaced with the cast iron material on the brake disc material, and at present, much research and effort have been made on the aspect of aluminum brake discs.

In the "wind channel brake rotor" that patent US 5544726 provided, propose SiC-aluminum matrix composite's brake disc, adopt the radial cooling channel of forked form, realized the balanced heat conduction during the braking, this type of brake disc structure is complicated, and the preparation degree of difficulty is very high, and material cost is high.

In the "molded product of metal matrix composite and the method for manufacturing the same" provided by the patent US 20030070891, an injection casting method is used, two melts, namely an aluminum matrix composite and an aluminum alloy melt, are put into an injection cylinder, so that a disc part (a part contacting with a brake pad) of a manufactured brake disc is made of the aluminum matrix composite, and a cap part is made of the aluminum alloy.

In the "friction-wear aluminum parts and related methods" provided by US 6290032, a friction part of an aluminum brake disc is used as a bottom layer, and a mixed friction-wear coating of aluminum and stainless steel is sprayed on the bottom layer, for example, by a thermal arc spraying process, so that the aluminum rotor has reasonable wear resistance, but when the rotor is subjected to high heat load and repeated impact, the coating will peel off from the aluminum bottom layer due to detuning of thermal expansion coefficient, and therefore, the aluminum rotor can only be used at low temperature and low load, and the application range is limited.

In the brake disc manufactured by various materials and the manufacturing method provided by the patent US 9562578, the cap part of the brake disc is made of aluminum material, and the rotor part is made of cast iron material, so that the aim of light weight is not completely achieved.

Because of the above-mentioned drawbacks of the current aluminum brake discs, there is still much room for improvement of aluminum brake discs.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the brazing type aluminum brake disc and the manufacturing method thereof, the obtained brake disc can be applied to brake devices of rail vehicles, trucks, saloon cars and mechanical devices, the manufacturing process is simple and reliable, the using amount of aluminum-based composite materials is reduced, and the product cost is low.

In order to achieve the above object, the present invention provides a brazed aluminum material brake disc comprising:

a rotor body, a capped disc made of aluminum or aluminum alloy, the capped disc including a disc, a cap positioned at the center of the disc and having a central hole;

the friction ring is a circular ring made of an aluminum-based composite material, and the surfaces of the two sides of the circular disc of the rotor body are respectively connected with the friction ring;

the aluminum brazing material layer is arranged between the connecting surface of the rotor body and the friction ring, and the rotor body and the friction ring are connected through a brazing process;

wherein, the aluminum-based composite material of the friction ring is a hard particle reinforced aluminum alloy composite material.

Preferably, the hard particle reinforced aluminum alloy composite material contains 5-30 wt% of hard reinforced particles, which are 1-400 microns in particle size, based on the total weight of the aluminum alloy composite material, and the Mohs hardness of the hard reinforced particles is not lower than 8.

Preferably, the hard reinforcing particles are at least one of oxides, carbides, borides; further preferred isEarth oxide is selected from Al₂O₃、SiO₂、TiO₂The carbide is selected from WC, SiC and TiC, and the boride is selected from TiN and Si₃N₄、AlN。

Preferably, the hard reinforcing particles are SiC.

Preferably, the aluminum brazing material in the aluminum brazing material layer comprises a fluoride flux and an aluminum silicon alloy brazing material, wherein the fluoride flux is composed of AlF₃The potassium fluoroaluminate mixed salt is formed by the aluminum-silicon alloy welding material and KF with the molar ratio of 44.5:55.5, the aluminum-silicon alloy welding material is silicon-aluminum alloy containing 2-12 wt% of silicon, and the initial melting point of the aluminum-silicon alloy welding material is 577 ℃.

Preferably, the friction ring is manufactured using any one of a powder metallurgy method, a pressure casting method, a gravity casting method, a stir-casting method, a pressureless infiltration method, a spray deposition method, and the like; the rotor body is manufactured by any one of sand molding, pressure casting, injection molding, and the like.

The invention also provides a manufacturing method of the brazing type aluminum material brake disc, which comprises the following steps:

step 1: providing a friction ring of aluminum matrix composite material of a predetermined size and shape;

step 2: etching the aluminum material on the brazing connection surface of the friction ring to ensure that the exposed size of the hard reinforcing particles reaches 1/3-2/3 of the average particle size;

and step 3: coating aluminum brazing material on the surface of the connecting surface of the eroded friction ring;

and 4, step 4: providing a rotor body of aluminium or an aluminium alloy of a predetermined size and shape;

and 5: the connecting surface of the friction ring with the aluminum brazing material is contacted with the two connecting surfaces of the rotor body, and the two connecting surfaces are assembled together to form a brazing assembly;

step 6: placing the brazing assembly on a workbench in a brazing furnace and heating to melt the aluminum brazing material and connect the rotor body and the friction ring together;

and 7: and taking out the brazed brake disc from the furnace, cooling and grinding to obtain the aluminum material brake disc.

In step 3 of the present invention, an aluminum brazing materialThe coating weight of the material is 60-80g/m²。

In step 6 of the present invention, the brazing conditions are preferably, but not limited to, nitrogen atmosphere, 605-; the invention can also be realized by selecting flame brazing, salt bath brazing or vacuum brazing according to the actual situation.

In step 2 of the invention, the friction ring with the anti-corrosion glue layer is put into etching solution to be soaked until the aluminum material on the brazing connection surface is corroded. The etching solution can be alkaline etching solution or acidic etching solution to expose the hard reinforcing particles.

In step 2 of the invention, etching the friction ring by using an etching solution, and soaking the friction ring in the etching solution until the aluminum material on the brazing connection surface is eroded; preferably, before the friction ring is soaked in the etching solution, all surfaces of the friction ring except the brazed connection surface are coated with the anti-corrosion glue layer, and before the aluminum brazing material is placed on the surface of the connection surface of the friction ring in the step 3, the friction ring is washed by water, so that the anti-corrosion glue layer is removed.

As the preference of the alkaline etching solution of the invention, the components comprise: 30-40g/L of sodium hydroxide, 5-20g/L of sodium phosphate, 5g/L of sodium gluconate, 3g/L of sodium citrate dihydrate, 5g/L of glycerol, 5g/L of triethanolamine, 5g/L of boric acid, 2g/L of urea and 1g/L of surfactant.

Or the etching solution is an acidic etching solution and comprises: 150g/L of ferric trichloride 100-.

It should be noted that, the etching in step 2 may use etching solutions of other formulations, and may also use other etching techniques, such as electrolysis, electric spark, laser, etc. All methods or etching solutions capable of realizing the etching exposure of the hard reinforced particles belong to the protection scope of the invention, and are not limited to the alkaline etching solution or the acidic etching solution, and the composition and content of the etching solution are not limited.

The aluminum-based composite material is a hard particle reinforced aluminum alloy composite material, wherein the hard reinforced particles are at least one of oxides, carbides and borides, the content of the hard reinforced particles is 5-30% of the total weight of the aluminum alloy composite material, and the particle size of the particles is 1-400 mu m.

The invention has the beneficial effects that: the rotor body made of aluminum or aluminum alloy ensures high mechanical strength of the brake disc, and the friction ring made of the aluminum-based composite material is used as a friction surface to provide high wear resistance for the brake disc, so that the effective combination of strength and wear resistance is realized; the brake disc integrally made of the aluminum material achieves the purpose of light weight; in addition, in the manufacturing method, exposed reinforcing particles are etched on the connecting surface of the friction ring, so that the welding connecting interface between the friction ring and the brazing material migrates towards the inside of the friction ring, metallurgical bonding is formed between the aluminum material of the friction ring and the aluminum brazing material after brazing, and meanwhile, the ceramic particle material is embedded into the aluminum brazing material according to 1/3-2/3 of the average particle size of the ceramic particle material, so that mechanical meshing between the friction ring and the aluminum brazing material is realized, the shearing strength of the brazing connecting interface is additionally improved, and the connecting strength of the brake disc is generally improved; in addition, the manufacturing process is simple and reliable, and the using amount of the aluminum matrix composite material is reduced, so that the product cost is reduced.

Drawings

FIG. 1 is a step 1 of the manufacturing process of a brazed aluminum brake disc according to the present invention;

FIG. 2 is a step 2 of the manufacturing process of the brazed aluminum brake disc of the present invention;

FIG. 3 is step 3 of the brazing aluminum brake disc manufacturing process of the present invention;

FIG. 4 is a step 4 of the manufacturing process of the brazed aluminum brake disc of the present invention;

FIG. 5 is a step 5 of the brazing aluminum brake disc manufacturing process of the present invention;

FIG. 6 is a step 6 of the manufacturing process of the brazed aluminum brake disc of the present invention;

FIG. 7 is a manufacturing process 7 of a brazed aluminum brake disc according to the present invention;

FIG. 8 is a step 8 of the brazing aluminum brake disc manufacturing process of the present invention;

FIG. 9 is a welded section of a friction ring-aluminum braze material-rotor body of a brake disc in a comparative example, wherein the aluminum matrix composite has not undergone an erosion process;

FIG. 10 is a weld section of a friction ring-aluminum braze material-rotor body of a brake disc of example 4, wherein the aluminum matrix composite has undergone an erosion process.

In the figure, 1 — the rotor body; 2-a friction ring; 3-aluminum brazing material; 4-an anticorrosive adhesive layer; 5-a container; 6-etching solution; 7-etching the layer; 8-a brazing furnace; 9-a workbench; 10-a brake disc; 11-hard reinforcing particles; 12-connection interface.

Detailed Description

The present invention will now be described in detail with reference to the drawings, which are provided for the purpose of illustrating the invention and are not to be construed as limiting the invention in any way. In the present invention, unless otherwise specified, all the percentages are by weight.

The composition of the brazed aluminum brake disc of the present invention will be described below.

The brazing type aluminum brake disc comprises a friction ring, a rotor body and an aluminum brazing material layer. Wherein:

first, friction ring

The friction rings are respectively arranged on the upper surface and the lower surface of the rotor body, the friction ring of the invention uses aluminum-based composite materials, the term aluminum-based composite material used herein refers to the aluminum-based composite material of which the matrix is aluminum or aluminum alloy and the reinforcing phase is hard reinforcing particles, and the hard reinforcing particles are uniformly dispersed in the aluminum matrix, so that the strength and the wear resistance of the composite material can be enhanced, and the wear of a brake disc during braking can be reduced.

In the aluminum matrix composite, the hard reinforcing particles used may be selected from the group consisting of oxides (e.g., Al)₂O₃、SiO₂And TiO₂) Carbides (e.g. WC, SiC and TiC) and borides (e.g. TiN, Si)₃N₄And AlN), although the present invention does not limit the type of the hard reinforcing particles, it is preferable that the hard reinforcing particles are not less than 8 in mohs hardness, and silicon carbide is preferable from the viewpoint of availability and practicality; from the viewpoint of reducing the wear on the friction pair (i.e., the brake pad) while having sufficient wear resistance, it is preferable that the content of the silicon carbide particles is 5 to 30% and the particle size of the silicon carbide particles is 1 to 400 μm, based on the total weight of the aluminum matrix composite.

The matrix material of the aluminum-based composite material is an aluminum or aluminum alloy matrix material, and any aluminum or aluminum alloy of a known technique can be used as the matrix material. However, since the brake discs of the present invention are made by brazing, the selected base aluminum alloy must be brazeable, requiring the solidus temperature of the aluminum alloy to be above the melting temperature of the aluminum brazing material, e.g., at least 20 ℃ above, e.g., using a BAlSi-series aluminum brazing material, typical aluminum alloys suitable for brazing including 3003, 3004, 1100, 5005, 5050, 6063, etc. The matrix aluminum alloy used in the present invention is not limited, but since the aluminum brake disc is subjected to high temperatures during braking, it is preferable that the matrix aluminum material be of the high temperature strength type, and such aluminum alloys having high temperature strength properties can be improved by incorporating certain specific elements in the aluminum, by forming intermetallic compounds, such as adding one or more of Cr, Mn, V, Mo, W, Co, Ni, Fe, Ti, Zr, Hf, Nb, Y-containing rare earth metals or misch metal, and using special aluminum alloys.

The method for manufacturing the aluminum matrix composite includes various known techniques such as powder metallurgy, pressure casting, gravity casting, stir-cast, pressureless infiltration, and spray deposition, and the like, and the friction ring may be manufactured by any one of the methods as required.

Second, rotor body

The rotor body of the brazing type aluminum brake disc comprises a capped disc made of aluminum or aluminum alloy, and the capped disc comprises a cap and a disc, wherein a central hole is formed in the cap, penetrates through an axle and is firmly fixed to the axle through a threaded hole (not shown). At the opposite end of the central hole included in the cap, a disc is formed extending along the radial direction, and two side surfaces of the disc are braze-welded connection surfaces to be braze-welded with a pair of friction rings to form a braze-welded aluminum brake disc.

The aluminum rotor body of the present invention may take any of a variety of conventional shapes, exhibiting additional functions and effects, without being limited to the shapes shown in the drawings.

The rotor body is made of aluminum or aluminum alloy material and can be made of any aluminum or aluminum alloy known in the art. However, since the brake discs of the present invention are made by brazing, the selected aluminium alloy must be brazeable, and it will be required that the aluminium alloy has a solidus temperature which is higher than the melting temperature of the aluminium brazing material, for example at least 20 ℃ above, for example a BAlSi-series aluminium brazing material, typical aluminium alloys suitable for brazing including 3003, 3004, 1100, 5005, 5050, 6063 etc. The present invention is not limited to the type of aluminum or aluminum alloy used, but because aluminum brake discs are subjected to high temperatures during braking, it is preferred that the aluminum material be of the high temperature strength type, and that such aluminum alloys having high temperature strength properties can be enhanced by incorporating certain specific elements into the aluminum, by forming intermetallic compounds, such as the addition of one or more of Cr, Mn, V, Mo, W, Co, Ni, Fe, Ti, Zr, Hf, Nb, Y-containing rare earth metals or misch metal elements, and the use of special aluminum alloys.

From the viewpoint of cost performance, the aluminum rotor body of the present invention can be manufactured by a conventional casting method such as sand molding, press casting, injection molding, etc., and any one of the methods can be selected for casting and then subjected to finish machining.

Third, aluminium brazing material layer

The rotor body is arranged between the connecting surfaces of the rotor body and the friction ring, and the rotor body and the friction ring are connected through a brazing process.

The aluminum brazing material of the aluminum brazing material layer of the invention consists of a fluoride flux (Nocolok flux) and a silicon aluminum alloy brazing material, which is used for connecting the rotor body and the friction ring by a brazing process.

Fluoride fluxes in aluminium brazing materials, e.g. from KF-AlF₃The potassium fluoroaluminate mixed salt is prepared with two intermediate compounds KAlF₄-K₃AlF₆Mixed salt of meta-eutectic point composition (AlF)₃The molar ratio to KF was 44.5:55.5), and the eutectic point temperature was 565 ℃.

The aluminum-silicon alloy material in the aluminum brazing material, for example, the aluminum-silicon alloy containing 2 to 12 wt% of silicon, has an initial melting point of 577 ℃.

During heating, the potassium fluoroaluminate brazing flux (450-; when the temperature is raised to about 577 ℃, the Al-Si silicon alloy starts to melt, and when the temperature is further raised to about 590-610 ℃, the melted Al-Si alloy layer forms metallurgical bonding with the rotor body and the friction ring, and forms firm welding after cooling.

The aluminum brazing material can be provided in two forms:

1. coating fluoride brazing flux powder on an Al-Si alloy foil with a preset thickness, placing the Al-Si alloy foil on a welding part of the rotor body and the friction ring, and putting into brazing;

2. preparing fluoride brazing flux powder, Al-Si alloy powder, an adhesive and a solvent into a paste to form brazing paste, coating the brazing paste on the welding part of any one of the friction ring or the rotor body, and putting into brazing.

The various components, compositional make-up and methods of use of the aluminum brazing material are known in the art and may be conveniently employed in commercial products such as the cream FLUX AL-FLUX 028 manufactured by Honeywell.

The invention further provides a manufacturing method of the brazed aluminum material brake disc, which can be illustrated by the manufacturing process flow chart shown in figures 1-8 and comprises the following steps:

step 1: providing a friction ring 2 (shown in figure 1) of aluminium matrix composite of predetermined size and shape;

step 2: coating an anticorrosive glue layer 4 on all surfaces of the friction ring 2 except the brazing connecting surface; (as shown in FIG. 2);

and step 3: the friction ring 2 with the rubber layer is placed in a container 5 containing etching solution 6 (acid or alkaline solution) for soaking until the aluminum material on the brazing connection surface is eroded, so that the exposed size of the hard reinforcing particles 11 reaches 1/3-2/3 (shown in figure 3) of the average particle size;

and 4, step 4: washing the friction ring 2 with water to remove the anti-corrosion glue layer 4 to obtain an erosion friction ring 2 with an etching layer 7, and placing an aluminum brazing material 3 (shown in figure 4) on the surface of the connecting surface of the friction ring 2;

and 5: providing a rotor body 1 (shown in fig. 5) of aluminium or an aluminium alloy of a predetermined size and shape;

step 6: the connecting surface of the friction ring 2 of the aluminum brazing material 3 is contacted with the connecting surface of the rotor body 1, and the aluminum brazing material and the connecting surface are assembled together to form a brazing assembly (shown in figure 6);

and 7: placing the brazed assembly on a worktable 9 in a brazing furnace 8 and heating to melt the aluminum brazing material 3 and connect the rotor body 1 and the friction ring 2 together (as shown in fig. 7);

and 8: the brazed brake disk 10 is removed from the furnace, cooled and ground to obtain the aluminum material brake disk 10 of the present invention (shown in fig. 8).

If a mechanical etching method is used, the surface of the friction ring 2 does not need to be coated with the anti-corrosion glue layer 4 before etching, and a process of removing the anti-corrosion glue layer 4 after etching is not needed, and the method can be selected according to the actual etching method.

The following explains the manufacturing method of the present invention by way of specific examples, with reference to fig. 1 to 10.