In-situ friction self-adapting gray cast iron brake disc and manufacturing method thereof

Abstract

The application discloses an in-situ friction self-adapting gray cast iron brake disc which comprises a brake disc body and a plurality of accommodating cavities which are uniformly arranged in the brake disc body and are communicated with the other end face of the working surface of the brake disc body; and an alloy element container is fixed in the accommodating cavities, and the elements in the alloy element container diffuse and react with the brake disc body under high temperature. The application can realize the diffusion of the alloy elements in the alloy element container by using friction high temperature as driving force, and the alloy elements can react with graphite in the gray cast iron matrix to generate carbide. The generation of the carbide can serve as a reinforcing phase to significantly improve the hardness of the gray cast iron and further improve the wear resistance, and on the other hand, a large amount of friction heat can be consumed in the reaction process, so that the interface temperature is greatly reduced, and the wear is also reduced.

Description

Technical Field

[0001] This invention belongs to the field of brake disc technology, and particularly relates to an in-situ friction adaptive gray cast iron brake disc and its manufacturing method. Background Technology

[0002] Ceramic brake pads are environmentally friendly, wear-resistant, and highly heat-resistant, maintaining good performance even under high-speed emergency braking conditions, meeting the safety requirements of high-speed vehicle operation and demonstrating great application potential. However, these demanding braking conditions pose a severe challenge to their counterpart—the brake disc. Currently, brake discs are mostly made of gray cast iron. When subjected to intense friction with ceramic brake pads, the interface temperature rises to as high as 1200℃, accelerating wear on the gray cast iron brake disc and reducing its service life. The main reason for this is that high temperatures induce softening of the brake disc, reducing its strength and consequently decreasing its wear resistance.

[0003] Therefore, an in-situ friction adaptive gray cast iron brake disc and its manufacturing method are proposed to improve the hardness of gray cast iron, thereby improving its wear resistance, while reducing interfacial friction problems and reducing brake disc wear. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes an in-situ friction-adaptive gray cast iron brake disc and its manufacturing method. This method utilizes the high temperature of friction as a driving force, causing alloying elements within the alloying element container to diffuse and react with graphite in the gray cast iron matrix, generating carbides. The formation of these carbides serves two purposes: firstly, it acts as a reinforcing phase, significantly increasing the hardness of the gray cast iron and thus improving its wear resistance; secondly, the reaction process consumes a large amount of frictional heat, greatly reducing the interface temperature and also contributing to reduced wear.

[0005] To achieve the above objectives, the present invention provides an in-situ friction adaptive gray cast iron brake disc, comprising,

[0006] Brake disc body;

[0007] Several receiving cavities are evenly formed in the brake disc body, and the receiving cavities are connected to the other end face opposite to the working surface of the brake disc body;

[0008] An alloy element container is fixed inside the receiving cavity, and the elements in the alloy element container diffuse upon exposure to high temperature and react with the brake disc body.

[0009] Furthermore, the brake disc body contains 91%–95% Fe, 2%–5% C, 2.5%–3.5% Si, and 0.05%–0.15% Mn.

[0010] Furthermore, the alloy element container includes Cr, Ni, Mn, Fe, W, and B elements, wherein the Cr content in the alloy element container is 20%–30%; the Ni content is 3%–5%; the Mn content is 1%–3%; the Fe content is 59%–75%; the W content is 1%–3%; and the B content is 0.5%–1.5%.

[0011] Furthermore, the distance between the upper wall surface of the cavity near the working surface and the working surface is 0.4cm to 0.6cm.

[0012] A method for manufacturing an in-situ friction adaptive gray cast iron brake disc, comprising the following steps:

[0013] S1. Precast block material: Heat iron to 1550℃ to obtain molten iron, add Cr powder, Ni powder and Mn powder to the molten iron, stir evenly and place it into a block material mold to cool and obtain block material.

[0014] S2. Preparation of filamentous materials: Process the bulk material into filaments, ball mill and mix W powder and B powder with polyacrylamide to make a slurry, apply the slurry to the filamentous material and dry it;

[0015] S3. Preparation of alloy element container: Cutting filamentous material to a predetermined length to form an alloy element container;

[0016] S4. Alloy element container implantation: Insert an alloy element container into the bottom of the brake disc mold;

[0017] S5. Brake disc body manufacturing: The brake disc is prepared and smelted to obtain a smelted product, which is then poured into the brake disc mold and cooled.

[0018] Furthermore, in step S2, the block material is squeezed or pulled to form the filamentous material, and the cross-sectional diameter of the filamentous material is 3mm to 6mm.

[0019] Furthermore, in step S2, the drying temperature of the filamentous material is 110℃~150℃, and the drying time of the filamentous material is 2h.

[0020] Furthermore, in step S3, the length of the alloy element container is 0.5cm to 2.5cm.

[0021] Furthermore, in steps S4 and S5, the brake disc mold includes an upper mold and a lower mold. The top of the lower mold has a casting groove that matches the shape of the brake disc body. The alloy element container is fixed to the inner wall at the bottom of the casting groove. The side wall of the lower mold has a sprue that communicates with the casting groove. The upper mold has an exhaust port that communicates with the casting groove.

[0022] Furthermore, in step S5, after the brake disc body is cooled, it undergoes an aging heat treatment. The aging heat treatment temperature of the brake disc body is 500℃~600℃, and the aging heat treatment time of the brake disc body is 6h~10h.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The high temperature generated by the friction between the brake disc and the ceramic brake pads serves as the driving force, causing the alloying elements in the alloying element container to diffuse and react with the graphite in the gray cast iron matrix to form carbides. The formation of carbides serves two purposes: firstly, it acts as a reinforcing phase, significantly increasing the hardness of the gray cast iron and thus improving its wear resistance; secondly, the reaction process consumes a large amount of frictional heat, greatly reducing the interface temperature and further minimizing wear, thus constituting an adaptive protection mechanism. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 A schematic diagram showing the positional relationship between the brake disc body and the receiving cavity;

[0027] Figure 2 A schematic diagram showing the positional relationship between the alloy element container and the working surface;

[0028] Figure 3 A schematic diagram showing the positional relationship between the brake disc mold and the alloy element container;

[0029] Figure 4 This is a magnified schematic diagram of a microscopic region in an application example;

[0030] Among them, 1-brake disc body, 2-accommodating cavity, 3-working surface, 4-alloy element container, 5-upper mold, 6-lower mold, 7-casting groove, 8-sprue, 9-vent. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figures 1-3 The present invention provides an in-situ friction adaptive gray cast iron brake disc, comprising: a brake disc body 1; a plurality of receiving cavities 2 uniformly opened in the brake disc body 1, the receiving cavities 2 being connected to the other end face opposite to the working surface 3 of the brake disc body 1; and an alloy element container 4 fixed in the receiving cavity 2, wherein the elements in the alloy element container 4 diffuse upon exposure to high temperature and react with the brake disc body 1.

[0034] Understandably, the brake disc proposed in this technical solution includes a brake disc body 1 and an alloy element container 4 embedded in the brake disc body 1. During the use of the brake disc body 1, its working surface 3 comes into contact with the ceramic brake pads and generates high temperature, which promotes the diffusion of alloy elements in the alloy element container 4. The diffused alloy elements can absorb a large amount of heat and reduce the temperature of the working surface 3. At the same time, since the brake disc body 1 is a gray cast iron matrix, the diffused alloy element container 4 reacts with the graphite in the gray cast iron matrix to form carbides, thereby increasing the hardness of the brake disc body 1 and thus improving its wear resistance.

[0035] The shape of the receiving cavity 2 is formed by the alloy element container 4, that is, during casting, the alloy element container 4 is located inside the brake disc body 1 to form the shape of the receiving cavity 2.

[0036] Meanwhile, the position, size, and number of accommodating cavities 2 are adjusted according to the dimensions of the brake disc body 1.

[0037] Further optimization of the design resulted in the following: the Fe content in the brake disc body 1 was 91%–95%; the C content was 2%–5%; the Si content was 2.5%–3.5%; and the Mn content was 0.05%–0.15%.

[0038] Further optimization of the design: the alloy element container 4 includes Cr, Ni, Mn, Fe, W, and B elements. The Cr content in the alloy element container 4 is 20%–30%; the Ni content is 3%–5%; the Mn content is 1%–3%; the Fe content is 59%–75%; the W content is 1%–3%; and the B content is 0.5%–1.5%.

[0039] Among them, the brake disc body 1 is the existing ordinary brake disc type, which is made of cast iron.

[0040] All of the percentages mentioned above are mass fractions.

[0041] The scheme was further optimized so that the distance between the upper wall of the cavity 2 near the working surface 3 and the working surface 3 is 0.4cm to 0.6cm.

[0042] A method for manufacturing an in-situ friction adaptive gray cast iron brake disc, comprising the following steps:

[0043] S1. Precast block material: Heat iron to 1550℃ to obtain molten iron, add Cr powder, Ni powder and Mn powder to the molten iron, stir evenly and place it into a block material mold to cool and obtain block material.

[0044] Industrial pure iron is heated to 1550℃ to melt it and obtain molten iron. Then, Cr powder, Ni powder and Mn powder are added to the molten iron and mixed and stirred evenly. After the mixture is stirred evenly, it is poured into a block material mold and cooled to obtain a block material.

[0045] S2. Preparation of filamentous material: Process the bulk material into filaments. Ball mill and mix W powder and B powder with polyacrylamide to make a slurry. Apply the slurry to the filamentous material and dry it. Process and deform the obtained bulk material into filaments, and then apply the W powder and B powder slurry to the filamentous material, followed by drying.

[0046] S3. Preparation of alloy element container 4: Cut the filamentous material to a predetermined length to form alloy element container 4. Cut the dried filaments into small ends, wherein the length of each segment is determined according to the thickness of the brake disc body 1.

[0047] S4, Alloy Element Container 4 Implantation: Insert alloy element container 4 into the bottom of the brake disc mold.

[0048] S5. Brake disc body 1 fabrication: Brake disc materials are batched and smelted to obtain smelted products. The smelted products are then poured into the brake disc mold and cooled. The prepared alloy element container 4 is sent into the brake disc mold, and then the smelted products are poured in. After cooling, the final brake disc body 1 is obtained.

[0049] In a further optimized scheme, in step S2, the block material is extruded or drawn to form a filamentous material, the cross-sectional diameter of which is 3mm to 6mm.

[0050] Further optimization of the scheme: in step S2, the drying temperature of the filamentous material is 110℃~150℃, and the drying time of the filamentous material is 2h.

[0051] Further optimize the scheme. In step S3, the length of the alloy element container 4 is 0.5cm to 2.5cm.

[0052] Further optimize the plan, referring to Figure 3In steps S4 and S5, the brake disc mold includes an upper mold 5 and a lower mold 6. The top of the lower mold 6 is provided with a casting groove 7 that matches the shape of the brake disc body 1. The alloy element container 4 is fixed to the inner wall of the bottom end of the casting groove 7. The side wall of the lower mold 6 is provided with a sprue 8 that communicates with the casting groove 7. The upper mold 5 is provided with an exhaust port 9 that communicates with the casting groove 7.

[0053] Further optimizing the scheme, in step S5, after the brake disc body 1 is cooled, it undergoes aging heat treatment. The aging heat treatment temperature of the brake disc body 1 is 500℃~600℃, and the aging heat treatment time is 6h~10h. After the aging heat treatment of the brake disc body 1, air cooling is used for cooling. Finally, according to the assembly requirements, the brake disc body 1 is machined.

[0054] Refer to the table below for application examples:

[0055] C 3.5 / Si 2.5 / Fe 93.9 68.5 Mn 0.1 1.0 Ni / 3.0 Cr / 25.0 W / 1.5 B / 1.0

[0056] Reference Figure 4 The hardness of the transition area is around HB320, and the hardness of the brake disc body is HB220. In bench tests, the wear rate decreased from 4×10-3 mm / (N·m) to 1.7×10-3 mm / (N·m), and the service life increased by more than 1 times.

[0057] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for manufacturing an in-situ adaptive gray cast iron brake disc, characterized in that: The production steps include: S1. Precast block material: Heat iron to 1550℃ to obtain molten iron, add Cr powder, Ni powder and Mn powder to the molten iron, stir evenly and place it into a block material mold to cool and obtain block material. S2. Preparation of filamentous materials: Process the bulk material into filaments, ball mill and mix W powder and B powder with polyacrylamide to make a slurry, apply the slurry to the filamentous material and dry it; S3. Preparation of alloy element container (4): Cutting filamentous material to a predetermined length to form alloy element container (4). S4, Alloy Element Container (4) Implantation: Insert the alloy element container (4) into the bottom of the brake disc mold; S5, Brake disc body (1) Manufacturing: The brake disc is prepared and melted to obtain the molten product, and the molten product is poured into the brake disc mold and cooled; An in-situ adaptive gray cast iron brake disc manufactured using this method includes, Brake disc body (1); Several accommodating cavities (2) are evenly opened inside the brake disc body (1), and the accommodating cavities (2) are connected to the other end face opposite to the working surface (3) of the brake disc body (1); The alloy element container (4) is fixed inside the cavity (2). The elements in the alloy element container (4) diffuse when exposed to high temperature and react with the brake disc body (1).

2. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: The brake disc body (1) contains 91% to 95% Fe, 2% to 5% C, 2.5% to 3.5% Si, and 0.05% to 0.15% Mn.

3. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: The alloy element container (4) includes Cr, Ni, Mn, Fe, W, and B elements. The Cr content in the alloy element container (4) is 20% to 30%; the Ni content is 3% to 5%; the Mn content is 1% to 3%; the Fe content is 59% to 75%; the W content is 1% to 3%; and the B content is 0.5% to 1.5%.

4. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: The distance between the upper wall of the cavity (2) near the working surface (3) and the working surface (3) is 0.4cm to 0.6cm.

5. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: In step S2, the block material is squeezed or pulled to form the filamentous material, and the cross-sectional diameter of the filamentous material is 3mm to 6mm.

6. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: In step S2, the drying temperature of the filamentous material is 110℃~150℃, and the drying time of the filamentous material is 2h.

7. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: In step S3, the length of the alloy element container (4) is 0.5cm to 2.5cm.

8. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: In steps S4 and S5, the brake disc mold includes an upper mold (5) and a lower mold (6). The lower mold (6) has a casting groove (7) at its top that matches the shape of the brake disc body (1). The alloy element container (4) is fixed to the inner wall at the bottom of the casting groove (7). The side wall of the lower mold (6) has a sprue (8) that communicates with the casting groove (7). The upper mold (5) has an exhaust port (9) that communicates with the casting groove (7).

9. The method for manufacturing an in-situ adaptive gray cast iron brake disc according to claim 1, characterized in that: In step S5, the brake disc body (1) is cooled and then subjected to aging heat treatment. The aging heat treatment temperature of the brake disc body (1) is 500℃~600℃ and the aging heat treatment time of the brake disc body (1) is 6h~10h.

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