Method for manufacturing a three-layer integrated brake disc

Abstract

The application relates to a preparation method of a three-layer integrated brake disc. The setting of the annular spacer can effectively avoid mutual invasion of the disc body friction material and the disc cap structure material in the powder filling process; the pre-pressing punch is used to press a surface which is basically the same as the inner surface before mold closing and pressing, so that the problem that the upper mold pressing surface is in contact with the uneven powder surface and is easy to cause the powder to be scattered can be effectively avoided; the above steps are coordinated, the disc body friction material and the disc cap structure material are in their respective positions, the interface consistency of the three-layer integrated brake disc can be effectively ensured, so that the performance of the disc body and the disc cap is ensured, and the batch stability is ensured.

Description

Preparation method of three-layer integrated brake disc Technical Field

[0001] This invention relates to the field of brake disc manufacturing technology, and in particular to a method for manufacturing a three-layer integrated brake disc. Background Technology

[0002] Lightweighting is one of the most effective means of achieving energy conservation and emission reduction in automobiles and other transportation vehicles. Replacing steel with high-performance lightweight metal materials in key moving parts of transportation equipment, such as engines and brake discs, can not only reduce the overall vehicle weight and the momentum of high-speed moving parts, but also significantly improve the power performance of transportation equipment while reducing energy consumption.

[0003] Silicon carbide particle-reinforced aluminum matrix composites have low density, high specific strength and specific stiffness, high thermal conductivity, and excellent antibacterial, wear-resistant and corrosion-resistant properties. They have broad application prospects in the field of lightweight structural components. Replacing traditional brake disc materials with silicon carbide particle-reinforced aluminum matrix composites has also become a major research direction in the lightweighting of transportation vehicles.

[0004] However, most brake discs currently manufactured using casting methods struggle to exceed the 20% ceramic particle content limit, hindering significant improvements in wear resistance and limiting their widespread application. While brake discs manufactured using powder metallurgy can achieve a ceramic particle content of up to 75%, resulting in a substantial improvement in wear resistance, the manufacturing process also becomes more challenging.

[0005] CN111442039A discloses a method for preparing a lightweight, wear-resistant aluminum-based powder metallurgy composite automotive brake disc. The method involves filling wear-resistant aluminum-based composite powder and aluminum-based structural material powder into corresponding areas of an automotive brake disc mold, cold-pressing at room temperature, demolding, and obtaining an automotive brake disc blank. The blank is then sintered, hot-pressed, and finally machined. However, this method is only suitable for preparing a three-layer integrated disc where the disc body friction layer and the disc cap sidewall are directly bonded. When used to prepare the three-layer integrated disc with the disc body friction layer and the disc cap connection part as described in this application, an interface inconsistency problem will occur. Besides affecting the product appearance, this interface inconsistency will also lead to inconsistent dynamic balance removal amounts for each disc, resulting in significant weight differences in the finished discs, affecting batch stability. Furthermore, the friction material and structural material will interact, affecting the performance of both the disc body and the disc cap. Summary of the Invention

[0006] Therefore, it is necessary to provide a method for preparing a three-layer integrated brake disc that can guarantee interface consistency.

[0007] A method for manufacturing a three-layer integrated brake disc, the three-layer integrated brake disc comprising an annular disc body and a disc cap, the disc cap comprising an end, a sidewall extending axially along the end, and a connecting portion extending radially along the sidewall, the annular disc body being connected to the connecting portion, the side of the disc cap protruding relative to the disc body being the outer surface, and the opposite side of the outer surface being the inner surface, the method for manufacturing the three-layer integrated brake disc comprising the following steps:

[0008] A brake disc mold is provided, the brake disc mold including an upper mold, a lower mold and a female mold arranged coaxially. After the mold is closed, the upper mold and the lower mold surround the female mold to form a mold cavity. The pressing surface of the lower mold is adapted to the outer surface, and the pressing surface of the upper mold is adapted to the inner surface.

[0009] An annular spacer is provided, wherein the outer diameter of the annular spacer is less than or equal to the outer diameter of the connecting portion;

[0010] Provide friction materials and structural materials;

[0011] A pre-pressing punch is provided, wherein the pressing surface of the pre-pressing punch is adapted to the inner surface, and a notch is provided that is adapted to the annular spacer.

[0012] The annular partition is placed coaxially in the mold cavity, and the mold cavity is divided into a disc body mold cavity and a disc cap mold cavity. The structural material is laid in the disc cap mold cavity, and the friction material and structural material are laid in the disc body mold cavity, resulting in a disc structure with structural material in the middle and friction material on both sides.

[0013] The pre-pressing punch is pressed down, and after pressing out a surface that is roughly the same as the inner surface, the pre-pressing punch and the annular partition are removed, the mold is closed and pressed, and the mold is demolded to obtain a green blank.

[0014] The green blank is sintered and then cooled in a protective gas atmosphere to obtain a three-layer integrated brake disc.

[0015] In one embodiment, the step of laying the friction material and structural material in the disk cavity to obtain a disk structure with structural material in the middle and friction material on both sides is as follows:

[0016] After the friction material is laid in the mold cavity of the disc, a first mating surface with regular pits or grooves is pressed out. After the structural material is laid on the first mating surface, a second mating surface with mirror symmetry to the first mating surface is pressed out. After the friction material is laid on the second mating surface, a disc structure with structural material in the middle and friction material on both sides is obtained.

[0017] In one embodiment, the depth of the pit or groove is 5mm to 10mm.

[0018] In one embodiment, the thickness of the annular spacer is 0.5 mm to 1.0 mm.

[0019] In one embodiment, the outer diameter of the annular spacer is 10 mm to 15 mm smaller than the outer diameter of the connecting portion.

[0020] In one embodiment, the pressure applied by the pre-pressurized punch is 1.5 kPa to 5 kPa.

[0021] In one embodiment, the pressure of the mold clamping is 180MPa to 250MPa, and the pressure is held for 8s to 15s.

[0022] In one embodiment, the sintering temperature is 560°C to 650°C.

[0023] In one embodiment, during the sintering process, the green blank is placed with the side corresponding to the outer surface facing upwards.

[0024] In one embodiment, the cooling condition is: cooling with the furnace to below 300°C.

[0025] The above-mentioned method for preparing a three-layer integrated brake disc effectively avoids mutual invasion between the disc body friction material and the disc cap structural material during the powder filling process by setting an annular spacer. Before mold pressing, a surface that is roughly the same as the inner surface is pressed out using a pre-pressing punch, which can effectively avoid the upper mold pressing surface from contacting the uneven powder surface, which can easily lead to powder scattering. The above steps work together to ensure that the disc body friction material and the disc cap structural material are in their proper positions, which can effectively ensure the interface consistency of the three-layer integrated brake disc, thereby ensuring both the performance of the disc body and the disc cap and the batch stability. Detailed Implementation

[0026] To facilitate understanding of the present invention, a more comprehensive description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0027] It should be noted that when a component is referred to as "set" on another component, it can be directly on the other component or there may be an intervening component. When a component is referred to as "connected" to another component, it can be directly connected to the other component, or there may be an intervening component.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] It should be noted that the three-layer integrated brake disc of this application includes an annular disc body and a disc cap, wherein the disc cap includes an end, a side wall extending axially along the end, and a connecting portion extending radially along the side wall, and the annular disc body is connected to the connecting portion.

[0030] For ease of description, the side of the three-layer integrated brake disc cap that protrudes relative to the disc body is the outer surface, and the opposite side of the outer surface is the inner surface.

[0031] The above-mentioned method for preparing a three-layer integrated brake disc includes the following steps S110 to S170:

[0032] S110, Provide brake disc mold.

[0033] The brake disc mold includes an upper mold, a lower mold, and a female mold arranged coaxially. After the mold is closed, the upper mold and the lower mold enclose the female mold to form a mold cavity.

[0034] Furthermore, the pressing surface of the lower die is adapted to the outer surface, and the pressing surface of the upper die is adapted to the inner surface.

[0035] It should be noted that the mold cavity formed after the above-mentioned brake disc mold is closed is compatible with the three-layer integrated brake disc to be prepared. Therefore, the desired product can be obtained by subsequent sintering densification without the need for shaping.

[0036] S120, provides annular spacers.

[0037] The outer diameter of the annular spacer is less than or equal to the outer diameter of the connecting part to prevent the structural material used to prepare the disc cap from intruding into the friction material of the disc body, thereby affecting the friction and wear performance of the friction surface.

[0038] Furthermore, the outer diameter of the annular spacer is 10mm to 15mm smaller than the outer diameter of the connecting part. It is understandable that if the outer diameter of the annular spacer is too much smaller than the outer diameter of the connecting part, the friction layer of the disk body will be too close to the side wall of the disk cap, thus affecting the structural strength of the disk cap.

[0039] Furthermore, the thickness of the annular spacer is 0.5 mm to 1.0 mm. If the annular spacer is too thick, it will easily cause the surrounding powder to move when it is removed later, thus failing to ensure the uniformity of the interface; if the annular spacer is too thin, the preparation cost will be high and it will not be able to guarantee an effective barrier effect during powder filling and pre-compression.

[0040] S130 provides friction materials and structural materials.

[0041] In this embodiment, the friction material consists of 40% to 55% ceramic particles by mass and the balance being a dihedral aluminum alloy. The structural material consists of 10% to 15% ceramic particles and the balance being a dihedral aluminum alloy.

[0042] Among them, the bi-series aluminum alloys are aluminum alloys with copper as the main alloying element, including 2A16 grade aluminum alloy (which is mainly composed of 0.3% Si, 0.3% Fe, 6.0% to 7.0% Cu, 0.4% to 0.8% Mn, 0.05% Mg, 0.10% Zn, 0.10% to 0.20% Ti, 0.20% Zr and the balance Al) and 2324 grade aluminum alloy (which is mainly composed of 3.8% to 4.9% Cu, 0.3% to 1.0% Mn, 1.2% to 1.8% Mg, 0.10% Cr, 0.50% Si, 0.25% Zn and the balance Al), etc.

[0043] By using the aforementioned friction and structural materials to prepare a disc structure with structural material in the middle and friction material on both sides, the weight of the brake disc can be reduced to a greater extent, and energy consumption can be reduced to the greatest extent while meeting friction performance requirements.

[0044] S140, provides pre-pressed punches.

[0045] The pressing surface of the pre-pressing punch is adapted to the inner surface and has a notch adapted to the annular spacer. When pressed down, the pressing surface of the pre-pressing punch contacts the powder in the mold cavity of the disc body and the mold cavity of the disc cap, and the annular spacer is inserted into the notch.

[0046] S150. Place the annular partition coaxially in the mold cavity, divide the mold cavity into a disc body mold cavity and a disc cap mold cavity, lay structural material in the disc cap mold cavity, and lay friction material and structural material in the disc body mold cavity to obtain a disc structure with structural material in the middle and friction material on both sides.

[0047] Furthermore, the specific steps for laying friction material and structural material in the mold cavity of the disc to obtain a disc structure with structural material in the middle and friction material on both sides are as follows:

[0048] After laying friction material in the mold cavity of the disc, a first mating surface with regular pits or grooves is pressed out. After laying structural material on the first mating surface, a second mating surface with mirror symmetry to the first mating surface is pressed out. After laying friction material on the second mating surface, a disc structure with structural material in the middle and friction material on both sides is obtained.

[0049] Furthermore, the depth of the grooves or pits is 5mm to 10mm to increase the contact area between adjacent layers and improve the bonding force between them. It is understandable that the depth of the grooves or pits cannot be too deep, as excessive depth will excessively encroach on the area of ​​the friction surface layer, leading to damage to the friction and heat resistance of the friction surface layer.

[0050] S160. The pre-pressing punch is pressed down to press out a surface that is roughly the same as the inner surface. Then, the pre-pressing punch and the annular partition are removed, the mold is closed and pressed, and the mold is demolded to obtain the green blank.

[0051] In this embodiment, the pressure of the pre-pressing punch is 1.5 kPa to 5 kPa. The pressure of the pre-pressing punch should not be too high, otherwise the powder will be squeezed out from the gap of the pre-pressing punch; the pressure of the pre-pressing punch should not be too low either, otherwise it will be impossible to press out a surface that is approximately the same as the inner surface.

[0052] Before the mold is closed and pressed, the pre-pressing punch is used to press down and flatten the uneven surface formed by the powder filling. This allows the upper mold pressing surface to fully adhere to the powder surface during subsequent mold closing and pressing, preventing the powder from being scattered during the pressing process. This would cause the disc friction material and the disc cap structure material to invade each other, resulting in an inconsistent interface.

[0053] Furthermore, the clamping pressure is 180MPa~250MPa, and the holding pressure is 8s~15s.

[0054] S170. In a protective gas atmosphere, the above green blank is sintered and then cooled to obtain a three-layer integrated brake disc.

[0055] The protective gas atmosphere consists of inert gases such as nitrogen and argon.

[0056] Furthermore, the sintering temperature is 560℃~650℃, and during the sintering process, the side of the green blank corresponding to the outer surface is placed upwards to prevent the material from softening during the sintering process and the friction material layer from collapsing due to suspension.

[0057] Furthermore, the cooling condition is to cool the furnace to below 300°C.

[0058] The three-layer integrated brake disc is prepared using the above method. The disc cap mold cavity and the disc body mold cavity can be filled with powder at the same time. Compared with the process of pre-pressing and forming separately or pre-pressing one mold cavity first and then filling the other mold cavity with powder, the powder filling time is saved. The disc cap can be formed in the forming stage, eliminating the need for subsequent shaping and machining processes, thus saving production costs.

[0059] The following are specific examples.

[0060] Example 1

[0061] The three-layer integrated brake disc is prepared using steps S110 to S170. The friction material consists of 40% ceramic particles by mass and the remainder is 2A16 aluminum alloy. The structural material consists of 15% ceramic particles by mass and the remainder is 2A16 aluminum alloy. The depth of the recess is 5 mm, the thickness of the annular spacer is 0.5 mm, and the outer diameter of the annular spacer is 10 mm smaller than the outer diameter of the connecting part. The pressure of the pre-pressing punch is 1.5 kPa, the pressure of the mold closing is 180 MPa, the holding pressure is 15 s, and the sintering temperature is 560℃.

[0062] Observation showed that the three-layer integrated brake disc prepared in Example 1 had a uniform interface and met the dimensional accuracy requirements. The three-layer integrated brake disc prepared in Example 1 underwent bench testing and passed both the T / CAAMTB 09-2018 high load test and the Jaso C 419-2006 torsional failure test, indicating that the brake disc's structural strength and friction and wear performance meet the requirements for a brake disc.

[0063] Example 2

[0064] The three-layer integrated brake disc was prepared using steps S110 to S170. The friction material consisted of 55% ceramic particles by mass and the remainder of 2324 aluminum alloy. The structural material consisted of 10% ceramic particles by mass and the remainder of 2A16 aluminum alloy. The depth of the recess was 10 mm, the thickness of the annular spacer was 1.0 mm, and the outer diameter of the annular spacer was 15 mm smaller than the outer diameter of the connecting part. The pressure of the pre-pressing punch was 5 kPa, the pressure of the mold closing was 250 MPa, the holding pressure was 8 s, and the sintering temperature was 650 °C.

[0065] Observation revealed that the three-layer integrated brake disc prepared in Example 2 exhibited uniform and consistent interfaces, and its dimensional accuracy met the requirements. Bench tests were conducted on the three-layer integrated brake disc prepared in Example 2, and it successfully completed and passed two bench tests: T / CAAMTB 09-2018 high load and Jaso C 419-2006 torsional failure. This indicates that the brake disc's structural strength and friction and wear performance meet the requirements for a brake disc.

[0066] Example 3

[0067] The three-layer integrated brake disc is prepared using steps S110 to S170. The friction material consists of 50% ceramic particles by mass and the remainder is 2324 aluminum alloy. The structural material consists of 12% ceramic particles by mass and the remainder is 2324 aluminum alloy. The depth of the recess is 5 mm, the thickness of the annular spacer is 0.5 mm, and the outer diameter of the annular spacer is 12 mm smaller than the outer diameter of the connecting part. The pressure of the pre-pressing punch is 2 kPa, the pressure of the mold closing is 200 MPa, the holding pressure is 12 s, and the sintering temperature is 600℃.

[0068] Observation revealed that the three-layer integrated brake disc prepared in Example 3 exhibited a uniform interface and met the required dimensional accuracy. Bench tests were conducted on the three-layer integrated brake disc prepared in Example 3, and it successfully completed and passed two bench tests: T / CAAMTB 09-2018 high load and Jaso C 419-2006 torsional failure. This indicates that the brake disc's structural strength and friction and wear performance meet the requirements for a brake disc.

[0069] Comparative Example 1

[0070] Comparative Example 1 is basically the same as Example 3, except that the step of pressing down the pre-pressing punch in S160 is omitted in Comparative Example 1.

[0071] Observation revealed that the three-layer integrated brake disc prepared in Comparative Example 1 had an irregular shape at the interface, with no consistency at all.

[0072] Comparative Example 2

[0073] Comparative Example 2 is basically the same as Example 3, except that Comparative Example 3 does not use annular spacers for blocking.

[0074] Observations showed that the interface position of the three-layer integrated brake disc prepared in Comparative Example 2 fluctuated significantly.

[0075] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for manufacturing a three-layer integrated brake disc, the three-layer integrated brake disc comprising an annular disc body and a disc cap, the disc cap comprising an end, a sidewall extending axially along the end, and a connecting portion extending radially along the sidewall, the annular disc body being connected to the connecting portion, the side of the disc cap protruding relative to the disc body being an outer surface, and the opposite side of the outer surface being an inner surface, characterized in that... The method for manufacturing the three-layer integrated brake disc includes the following steps: providing a brake disc mold, the brake disc mold including an upper mold, a lower mold and a female mold arranged coaxially, after the mold is closed, the upper mold and the lower mold surround the female mold to form a mold cavity, the pressing surface of the lower mold is adapted to the outer surface, and the pressing surface of the upper mold is adapted to the inner surface; providing an annular spacer, the outer diameter of the annular spacer being ≤ the outer diameter of the connecting part; the thickness of the annular spacer being 0.5mm~1.0mm; providing friction material and structural material; providing a pre-pressing punch, the pressing surface of the pre-pressing punch being adapted to the inner surface, and having a notch adapted to the annular spacer; placing the annular spacer coaxially in the mold cavity, dividing the mold cavity into a disc body mold cavity and a disc cap mold cavity, laying the structural material in the disc cap mold cavity, and laying the friction material and structural material in the disc body mold cavity to obtain a disc with a central layer of structural material. The disc structure has friction material on both sides of the structural material. The pre-pressing punch presses down, pressing out a surface roughly the same as the inner surface. The pre-pressing punch and the annular spacer are then removed, the mold is closed, and the disc is demolded to obtain a green blank. The green blank is sintered and cooled in a protective gas atmosphere to obtain a three-layer integrated brake disc. The specific steps for laying the friction material and structural material in the disc mold cavity to obtain a disc structure with structural material in the middle and friction material on both sides are as follows: After laying the friction material in the disc mold cavity, a first mating surface with regular pits or grooves is pressed out. After laying the structural material on the first mating surface, a second mating surface with mirror symmetry to the first mating surface is pressed out. After laying the friction material on the second mating surface, a disc structure with structural material in the middle and friction material on both sides is obtained. The pressure of the pre-pressing punch is 1.5 kPa to 5 kPa.

2. The method for preparing a three-layer integrated brake disc according to claim 1, characterized in that, The depth of the pit or groove is 5mm to 10mm.

3. The method for preparing a three-layer integrated brake disc according to claim 1 or 2, characterized in that, The outer diameter of the annular partition is 10mm to 15mm smaller than the outer diameter of the connecting part.

4. The method for preparing a three-layer integrated brake disc according to claim 1 or 2, characterized in that, The pressure of the mold clamping is 180MPa~250MPa, and the pressure is held for 8~15s.

5. The method for preparing a three-layer integrated brake disc according to claim 1 or 2, characterized in that, The sintering temperature is 560℃~650℃.

6. The method for preparing a three-layer integrated brake disc according to claim 1 or 2, characterized in that, During the sintering process, the green blank is placed with the side corresponding to the outer surface facing upwards.

7. The method for preparing a three-layer integrated brake disc according to claim 1 or 2, characterized in that, The cooling conditions are: cooling with the furnace to below 300°C.