Preparation Method of Brake Disc with Inner and Outer Ring Structures

Abstract

This application relates to a preparation method of a brake disc with an inner and outer ring structure. Through the design of a positioning system, the terminal controller can obtain the diameter of the sintered blank in real time through a laser rangefinder, and then accurately move the positioning devices in three different directions to the position of 1 / 2 of the diameter from the axis of the female mold according to this diameter. Finally, control the pushing device to push the sintered blank against these three positioning devices, which can ensure that the sintered blank is coaxially arranged with the female mold, so as to ensure that during the subsequent shaping process, even if the material flows, it flows uniformly relative to the axis. Furthermore, it is ensured that by removing the machining allowance left on the bottom surface of the shaped blank subsequently, a brake disc with an inner and outer ring structure with a consistent interface can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of brake discs, and particularly to a preparation method for a brake disc with an inner and outer ring structure. Background Art

[0002] Ceramic-reinforced aluminum matrix composites have a low density, high specific strength and specific stiffness, high thermal conductivity, and excellent wear resistance and corrosion resistance, and have broad application prospects in the field of lightweight structural components. Specifically applied to brake discs, since the disc body needs to have properties such as high temperature resistance and wear resistance, and the disc cap needs to have relatively high mechanical properties, therefore, the disc body is usually prepared from an aluminum matrix composite reinforced with a high volume fraction of ceramics, and the disc cap is usually prepared from an aluminum matrix composite reinforced with a low volume fraction of ceramics to meet their respective performance requirements. Such a disc is also known as a brake disc with an inner and outer ring structure.

[0003] When preparing a brake disc with an inner and outer ring structure by powder metallurgy process, usually a blank with an inner and outer ring structure is first prepared through forming and sintering processes, then a disc cap is prepared through a sizing process, and finally a brake disc with the required dimensions is obtained through machining. Although the position of the inner and outer ring interface is fixed during the forming and sintering processes, during the subsequent sizing and machining processes, the uncontrolled material flow and the variation of machining allowance will cause fluctuations in the interface position, thereby affecting the performance of the inner and outer rings respectively, and ultimately leading to the failure of the brake disc.

[0004] Therefore, there is an urgent need to find a preparation method that can achieve the interface consistency of the brake disc with an inner and outer ring structure. Summary of the Invention

[0005] Based on this, it is necessary to provide a preparation method for a brake disc with an inner and outer ring structure. This method ensures that the sintered blank and the female die are coaxially arranged through a positioning system, so as to ensure that during the subsequent sizing process, even if the material flows, it flows uniformly relative to the axis, and further ensures that by removing the machining allowance left on the bottom surface of the sized blank, a brake disc with an inner and outer ring structure with consistent interfaces can be obtained.

[0006] A preparation method for a brake disc with an inner and outer ring structure includes the following steps:

[0007] Provide a sintered blank of a brake disc with an inner and outer ring structure;

[0008] Provide a sizing die, the sizing die includes an upper die, a lower die and a female die. After closing the die, the upper die and the lower die enclose the female die to form a closed cavity;

[0009] Provide a positioning system, the positioning system includes a terminal controller, and a pushing device, a laser rangefinder, a first positioning device, a second positioning device and a third positioning device respectively signal-connected to the terminal controller;

[0010] After the laser rangefinder measures the diameter of the sintered blank, it sends the measurement result to the terminal controller. Based on the received diameter data, the terminal controller controls the first positioning device, the second positioning device, and the third positioning device to move to a position that is 1 / 2 of the diameter away from the axis of the female mold. After the pushing device pushes the sintered blank until it abuts against the first positioning device, the second positioning device, and the third positioning device, the terminal controller controls the pushing device, the first positioning device, the second positioning device, and the third positioning device to return to their original positions;

[0011] After closing the shaping die, perform shaping pressing and then demoulding to obtain a shaped blank with machining allowance left on the bottom surface;

[0012] Machine the machining allowance on the bottom surface of the shaped blank to remove it, thereby obtaining the inner and outer ring structure brake disc.

[0013] In one embodiment, after the pushing device pushes the sintered blank until it abuts against the first positioning device, the second positioning device, and the third positioning device, the contact points of the sintered blank with the first positioning device, the second positioning device, and the third positioning device form an isosceles right triangle in a plane.

[0014] In one embodiment, the specific process of the shaping pressing is as follows: Under the protective pressure, lower the upper die for displacement control.

[0015] In one embodiment, the protective pressure is 150 MPa to 250 MPa.

[0016] In one embodiment, the bottom surface of the shaped blank has a machining allowance of 0.5 mm to 2 mm.

[0017] In one embodiment, the material of the shaping die is H13, and the hardness of the shaping die is 45 HRC to 50 HRC.

[0018] In one embodiment, in the shaping die, after closing the die, the unilateral clearance between the upper die and the female die is 0.15 mm to 0.2 mm, and the unilateral clearance between the lower die and the female die is 0.15 mm to 0.2 mm.

[0019] In one embodiment, the sintered blank of the inner and outer ring structure brake disc is prepared by the following method:

[0020] Provide high volume fraction ceramic reinforced aluminum matrix composite raw material powder;

[0021] Provide low volume fraction ceramic reinforced aluminum matrix composite raw material powder;

[0022] Provided is a forming die with a forming cavity, the forming cavity including an inner ring cavity adapted to the shape of the inner ring of the inner and outer ring structure brake disc and an outer ring cavity adapted to the shape of the outer ring of the inner and outer ring structure brake disc;

[0023] Fill the raw material powder of the high volume fraction ceramic reinforced aluminum matrix composite into the outer ring cavity, fill the raw material powder of the low volume fraction ceramic reinforced aluminum matrix composite into the inner ring cavity, and perform combined pressing to obtain a formed blank of the inner and outer ring structure brake disc;

[0024] Sinter the formed blank in a protective gas atmosphere to obtain a sintered blank of the inner and outer ring structure brake disc.

[0025] In one embodiment, the combined pressing adopts a two-way pressing method, the pressure of the two-way pressing is controlled within the range of the set value ±5 MPa, and the set value of the pressure of the two-way pressing is 150 MPa to 220 MPa.

[0026] In one embodiment, the temperature of the sintering is controlled within the range of the set value ±5 °C, and the set value of the temperature of the sintering is 560 °C to 630 °C.

[0027] For the above preparation method of the inner and outer ring structure brake disc, through the design of the positioning system, the terminal controller can obtain the diameter of the sintered blank in real time through the laser rangefinder, and then accurately move the positioning devices in three different directions to the position of 1 / 2 of the diameter from the axis of the female die according to this diameter. Finally, control the pushing device to push the sintered blank to abut against these three positioning devices, so as to ensure that the sintered blank is coaxially arranged with the female die, thereby ensuring that during the subsequent shaping process, even if the material flows, it flows uniformly relative to the axis. Furthermore, by removing the machining allowance left on the bottom surface of the shaped blank, an inner and outer ring structure brake disc with a consistent interface can be obtained. Detailed implementation mode

[0028] For the convenience of understanding the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present invention more thorough and comprehensive.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0030] The preparation method of the inner and outer ring structure brake disc of an embodiment includes the following steps S110 to S160:

[0031] S110. Provide the sintered blank of the inner and outer ring structure brake disc.

[0032] In this embodiment, the sintered blank of the inner and outer ring structure brake disc is prepared by the following method S1101 to S1104:

[0033] S1101. Provide the high-volume fraction ceramic-reinforced aluminum matrix composite raw material powder and the low-volume fraction ceramic-reinforced aluminum matrix composite raw material powder.

[0034] In this embodiment, the high-volume fraction ceramic-reinforced aluminum matrix composite raw material powder is composed of 30% - 70% by volume of ceramic reinforcing phase and the balance of aluminum alloy matrix. The low-volume fraction ceramic-reinforced aluminum matrix composite raw material powder is composed of 0 - 30% by volume of ceramic reinforcing phase and the balance of aluminum alloy matrix. The volume contents of the ceramic reinforcing phases in the high-volume fraction ceramic-reinforced aluminum matrix composite raw material powder and the low-volume fraction ceramic-reinforced aluminum matrix composite raw material powder are not both 30% at the same time.

[0035] Among them, the ceramic reinforcing phase is selected from at least one of carbides (such as TiC, SiC, B4C, etc.), nitrides (such as Si3N4), oxides (such as Al2O3), silicides (such as Ti5Si3), and borides (such as TiB, TiB2, etc.).

[0036] The aluminum alloy matrix is a second-series or sixth-series aluminum alloy. Among them, the second-series aluminum alloy is an aluminum alloy with copper as the main alloying element, including Al-Cu-Mg series alloys, Al-Cu-Mg-Si series alloys, etc.; the sixth-series aluminum alloy is an aluminum alloy with magnesium and silicon as the main alloying elements and Mg2Si phase as the strengthening phase, including Al-Mg-Si series alloys, etc.

[0037] Furthermore, the Al-Mg-Si series alloy is Al-1Mg-0.7Si-0.25Cu (that is, this alloy is mainly composed of 1% by mass of Mg, 0.7% by mass of Si, 0.25% by mass of Cu, and the balance of Al) or Al-0.6Mg-0.9Si (that is, this alloy is mainly composed of 0.6% by mass of Mg, 0.9% by mass of Si, and the balance of Al). The Al-Cu-Mg series alloy is Al-4Cu-0.8Mg (that is, this alloy is mainly composed of 4% by mass of Cu, 0.8% by mass of Mg, and the balance of Al). The Al-Cu-Mg-Si series alloy is Al-2Cu-0.5Mg-0.7Si-0.5Mn (that is, this alloy is mainly composed of 2% by mass of Cu, 0.5% by mass of Mg, 0.7% by mass of Si, 0.5% by mass of Mn, and the balance of Al).

[0038] S1102. Provide a forming die.

[0039] It can be understood that after the forming die is closed, a forming cavity can be formed. The forming cavity includes an inner ring cavity and an outer ring cavity. The inner ring cavity is adapted to the inner ring shape of the inner and outer ring structure brake disc and is used for forming the inner ring structure; the outer ring cavity is adapted to the outer ring shape of the inner and outer ring structure brake disc and is used for forming the outer ring structure.

[0040] S1103. Fill the above-mentioned high-volume fraction ceramic-reinforced aluminum matrix composite raw material powder into the outer ring cavity, fill the above-mentioned low-volume fraction ceramic-reinforced aluminum matrix composite raw material powder into the inner ring cavity, and perform combined pressing to obtain a formed blank of the inner and outer ring structure brake disc.

[0041] In this embodiment, the combined pressing adopts a two-way pressing method, that is, the upper die of the forming die presses down and the lower die presses up simultaneously.

[0042] Furthermore, the pressure of the two-way pressing is controlled within the range of the set value ±5 MPa. Among them, the set value of the pressure of the two-way pressing is 150 MPa to 220 MPa.

[0043] S1104. Sinter the above-mentioned formed blank in a protective gas atmosphere to obtain a sintered blank of the inner and outer ring structure brake disc.

[0044] In this embodiment, the sintering temperature is controlled within the range of the set value ±5 °C. Among them, the set value of the sintering temperature is 560 °C to 630 °C.

[0045] By controlling the pressure of the two-way pressing to fluctuate within the range of the set value ±5 MPa and controlling the sintering temperature to fluctuate within the range of the set value ±5 °C, the consistency of the density of the formed blank and the consistency of the sintering shrinkage rate of each batch can be ensured, so as to ensure the consistency of the interface and the consistency of the size of the sintered blank of the inner and outer ring structure brake disc produced in each batch.

[0046] S120. Provide a sizing die.

[0047] In this embodiment, the sizing die includes an upper die, a lower die and a female die. After closing the die, the upper die and the lower die enclose the female die to form a closed die cavity, and the closed die cavity is adapted to the shape of the brake disc to be prepared.

[0048] Furthermore, the material of the sizing die is H13 (hot work die steel), and the hardness is 45 HRC to 50 HRC to avoid deformation of the die during the sizing pressing process.

[0049] After closing the die, the unilateral gap between the upper die and the female die is 0.15 mm to 0.2 mm, and the unilateral gap between the lower die and the female die is 0.15 mm to 0.2 mm to avoid flash during the sizing pressing process, resulting in material loss.

[0050] S130. Provide a positioning system.

[0051] In this embodiment, the positioning system includes a terminal controller, and a pushing device, a laser rangefinder, a first positioning device, a second positioning device, and a third positioning device that are respectively connected to the terminal controller in a signal connection manner.

[0052] It should be noted that since the terminal controller can receive the data measured by the laser rangefinder through existing software programs, and send commands to the pushing device, the first positioning device, the second positioning device, and the third positioning device according to this data to realize the displacement control of the above devices, the software program will not be elaborated here.

[0053] S140. After the laser rangefinder measures the diameter of the sintered blank and sends it to the terminal controller, the terminal controller controls the first positioning device, the second positioning device, and the third positioning device to move to a position 1 / 2 diameter away from the axis of the female die. After the pushing device pushes the sintered blank until it abuts against the first positioning device, the second positioning device, and the third positioning device, the terminal controller controls the pushing device, the first positioning device, the second positioning device, and the third positioning device to return to their original positions.

[0054] In this embodiment, after the pushing device pushes the sintered blank until it abuts against the first positioning device, the second positioning device, and the third positioning device, the contact points of the first positioning device, the second positioning device, and the third positioning device with the sintered blank form an isosceles right triangle in a plane, so that the pushing device can quickly push the sintered blank to a position coaxial with the female die.

[0055] It can be understood that since the outer diameter of the sintered blank is smaller than the inner diameter of the female die, after the sintered blank enters the female die, there will be a certain margin of movement, resulting in an unfixed position of the blank in the female die. The positioning system designed in this application can adjust the moving distance of the positioning device in real time according to the diameter of the sintered blank, and then push the sintered blank until it abuts against the positioning device through the pushing device, so as to quickly realize the positioning of the sintered blank, providing the possibility for continuous production.

[0056] S150. After closing the shaping die, perform shaping pressing and demoulding to obtain a shaped blank with a machining allowance left on the bottom surface.

[0057] In this embodiment, the process of shaping pressing is specifically: under the protection pressure, the upper die is pressed down for displacement control. Among them, the protection pressure is 150 MPa to 250 MPa.

[0058] Furthermore, a machining allowance of 0.5 mm to 2 mm is left on the bottom surface of the shaped blank.

[0059] It can be understood that during the shaping pressing process, the inner ring material needs to flow to fill the cavity of the disc cap. Inevitably, the interface between the inner and outer rings will gradually tilt towards the direction close to the axis due to the flow of the inner ring material. At this time, by adopting the one-way pressing method of controlling the displacement by the downward pressure of the upper die and protecting with pressure, the surface of the sintered blank in contact with the upper die is mainly shaped and densified, so as to ensure that the interface position of the inner and outer rings close to the upper die changes very little or does not change. Then, by setting the machining allowance at the bottom surface, the inclined interface of the inner and outer rings close to the lower die can be removed by machining and removing the machining allowance subsequently, thereby ensuring the consistency of the interface position.

[0060] S160. Machine and remove the machining allowance on the bottom surface of the shaped blank to obtain the inner and outer ring structure brake disc.

[0061] In this embodiment, during the shaping process, through displacement control, the consistency of the thickness of the shaped blank is ensured. Therefore, the machining allowance for each time is a fixed value, and further, the consistency of the interface position of all batches of products is ensured.

[0062] The following are specific embodiments

[0063] Embodiment 1

[0064] For the inner and outer ring structure brake disc to be prepared, the designed distance between the inner and outer ring interfaces from the axis of the disc is 215 mm.

[0065] Prepared by the method as in steps S110 - S160 to obtain the inner and outer ring structure brake disc.

[0066] Measure its interface position, and it is found that the interface position is within the range of 214.5 mm to 215 mm from the axis of the disc, and the interface position fluctuation is not obvious.

[0067] Comparative Example 1

[0068] Comparative Example 1 is basically the same as Embodiment 1. The difference is that in Comparative Example 1, the pressure fluctuation range of the two-way pressing exceeds the set value of ±5 MPa, and the sintering temperature also exceeds the set value of ±5 °C.

[0069] It is found that for the prepared inner and outer ring structure brake disc, its interface position is within the range of 212 mm to 215 mm from the axis of the disc, and the interface position fluctuation is obvious.

[0070] Comparative Example 2

[0071] Comparative Example 2 is basically the same as Embodiment 1. The difference is that in Comparative Example 2, the positioning system is not adopted, but the sintered blank is directly placed in the female die for die closing pressing only by visual observation.

[0072] It was found that for the prepared brake disc with an inner and outer ring structure, the position of the interface varies within the range of 210.5 mm to 215 mm from the axis of the disc, and the interface is irregular in shape and has no consistency at all.

Claims

1. A preparation method of a brake disc with an inner and outer ring structure, characterized in that, It includes the following steps: Provide a sintered blank of a brake disc with an inner and outer ring structure; Provide a sizing die, which includes an upper die, a lower die and a female die. After the die is closed, the upper die and the lower die enclose the female die to form a closed die cavity; Provide a positioning system, which includes a terminal controller, and a pushing device, a laser rangefinder, a first positioning device, a second positioning device and a third positioning device respectively signal-connected to the terminal controller; After the laser rangefinder measures the diameter of the sintered blank, it sends the measurement to the terminal controller. The terminal controller controls the first positioning device, the second positioning device and the third positioning device to move to a position 1 / 2 of the diameter away from the axis of the female die according to the received diameter data. After the pushing device pushes the sintered blank to abut against the first positioning device, the second positioning device and the third positioning device, the terminal controller controls the pushing device, the first positioning device, the second positioning device and the third positioning device to return to their original positions; After the sizing die is closed, perform sizing pressing and demoulding to obtain a sized blank with machining allowance left on the bottom surface. The specific process of the sizing pressing is as follows: Under the protection pressure, the upper die is pressed down for displacement control. The protection pressure is 150 MPa to 250 MPa, and the machining allowance left on the bottom surface of the sized blank is 0.5 mm to 2 mm.

2. The preparation method of the inner and outer ring structure brake disc according to claim 1, characterized in that, After the pushing device pushes the sintered blank to abut against the first positioning device, the second positioning device and the third positioning device, the contact points of the sintered blank with the first positioning device, the second positioning device and the third positioning device form an isosceles right triangle in a plane.

3. The preparation method of the inner and outer ring structure brake disc according to claim 1, characterized in that, The material of the sizing die is H13, and the hardness of the sizing die is 45 HRC to 50 HRC.

4. The preparation method of the inner and outer ring structure brake disc according to claim 1, characterized in that, In the sizing die, after the die is closed, the unilateral clearance between the upper die and the female die is 0.15 mm to 0.2 mm, and the unilateral clearance between the lower die and the female die is 0.15 mm to 0.2 mm.

5. The preparation method of the inner and outer ring structure brake disc according to any one of claims 1 to 4, characterized in that, The sintered blank of the brake disc with an inner and outer ring structure is prepared by the following method: Provide raw material powder of high-volume fraction ceramic-reinforced aluminum matrix composite; Provide raw material powder of low-volume fraction ceramic-reinforced aluminum matrix composite; Provide a forming die with a forming cavity, which includes an inner ring cavity adapted to the shape of the inner ring of the brake disc with an inner and outer ring structure and an outer ring cavity adapted to the shape of the outer ring of the brake disc with an inner and outer ring structure; Fill the raw material powder of high-volume fraction ceramic-reinforced aluminum matrix composite into the outer ring cavity, fill the raw material powder of low-volume fraction ceramic-reinforced aluminum matrix composite into the inner ring cavity, and perform combined pressing to obtain a formed blank of the brake disc with an inner and outer ring structure; Sinter the formed blank in a protective gas atmosphere to obtain the sintered blank of the brake disc with an inner and outer ring structure.

6. The preparation method of the inner and outer ring structure brake disc according to claim 5, characterized in that, The combined pressing adopts a two-way pressing method, and the pressure of the two-way pressing is controlled within the range of the set value ±5 MPa. The set value of the pressure of the two-way pressing is 150 MPa to 220 MPa.

7. The preparation method of the inner and outer ring structure brake disc according to claim 5, characterized in that, The temperature of the sintering is controlled within the range of the set value ±5 °C. The set value of the temperature of the sintering is 560 °C to 630 °C.