Powder metallurgy brake disc and production process thereof

Abstract

The invention relates to the technical field of powder metallurgy, in particular to a powder metallurgy brake disc and a production process thereof.The powder metallurgy brake disc comprises a first disc body, a second disc body and an assembly seat, and a heat dissipation ring groove is formed between the first disc body and the assembly seat; the brake disc has the beneficial effects that a traditional production process for preparing the brake disc through powder metallurgy is changed, firstly, auxiliary components such as a lubricating agent, a binding agent and a sintering aid are added into powder and evenly mixed to prepare particles with the size ranging from 50 micrometers to 100 micrometers, then pressing is carried out, and the brake disc is manufactured. According to the brake disc, the powder fluidity, formability and sintering performance can be improved, the first disc body, the second disc body and the assembly base can be integrally pressed and formed through cooperation with special molds of the upper mold and the lower mold, then sintering and post-processing are conducted, the strength of the brake disc is improved, and meanwhile the production efficiency of the brake disc is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of powder metallurgy, and in particular relates to a powder metallurgy brake disc and a production process thereof. Background Art

[0002] Powder metallurgy brake discs are high-performance brake components manufactured through powder metallurgy processes and are widely used in vehicles such as automobiles, motorcycles, trains, and industrial machinery. This type of brake disc has excellent wear resistance, high temperature resistance, and good braking performance, and can effectively improve the safety and reliability of the vehicle. In the prior art, the manufacturing process of powder metallurgy brake discs generally uses metal powder for cold pressing and then high-temperature firing, and finally surface treatment. However, the result is a semi-finished brake disc that needs to be assembled with heat dissipation components or cut and drilled to produce heat dissipation grooves or heat dissipation holes. Subsequent processing is more troublesome and difficult to process.

[0003] A Chinese patent document with an existing publication number of CN113983090A proposes a powder metallurgy brake disc, which proposes that a brake disc body includes a first brake disc and a second brake disc, a mounting surface is provided at the center of the first brake disc, a center hole is provided at the middle of the mounting surface, the mounting surface is connected to the first brake disc, and there is a small hole between the mounting surface and the first brake disc. A hollow is opened at the center of the first brake disc, the outer side of the first brake disc is the first brake surface, and a heat dissipation hole is provided at a position corresponding to the hollow on the first brake surface. A plurality of groups of copper tubes are penetrated at the edge circumference of the first brake surface, a plurality of connecting blocks are welded in a ring shape on the inner side of the first brake surface, and a second brake disc is welded on the other side of the connecting block. The heat dissipation performance of the brake disc is improved by means of a small hole at the center of the second brake disc. However, dividing the brake disc into the first brake disc and the second brake disc and then welding them will reduce the overall strength of the brake disc.

[0004] Therefore, the present invention proposes a powder metallurgy brake disc and a production process thereof, which solves the problem in the prior art that dividing the brake disc into a first brake disc and a second brake disc and then welding them will reduce the overall strength of the brake disc. The production process of the traditional powder metallurgy brake disc is improved by adding a certain proportion of lubricant and binder to improve the powder fluidity, formability and sintering properties, and the brake disc is sintered into an integral part with a mold of a special shape, which improves the strength of the brake disc while also improving the production efficiency of the brake disc. Summary of the invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a powder metallurgy brake disc and a production process thereof to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a powder metallurgy brake disc, comprising a powder metallurgy brake disc, the powder metallurgy brake disc comprising a disc body one, a disc body two and an assembly seat, a heat dissipation ring groove is arranged between the disc body one and the assembly seat, heat discharge grooves and heat dissipation columns are evenly distributed between the disc body one and the disc body two, the heat discharge grooves and the heat dissipation columns are distributed at intervals, a reinforcement ring is arranged on the side of the assembly seat close to the disc body one, and arc grooves are arranged on both sides of the heat dissipation column.

[0007] The present invention also proposes a powder metallurgy brake disc production process, comprising the following steps: step one: uniformly mix various metal powders and additives according to a proportion, granulate the mixed powder by a spray drying method to prepare a granular material, the size of the granular material is between 50 microns and 100 microns; the specific ratio of various powders is: 4% graphite, 6% copper powder, 3% nickel powder, 3% molybdenum powder, 2% tungsten powder, 0.5% zinc stearate, 0.3% polyvinyl alcohol, 0.2% phenolic resin, 1% sintering aid, and the rest is iron; step two: design a special mold for the brake disc according to the size and shape of the required brake disc, load the prepared mixed particles into the mold, and cold press mold under high pressure to obtain a preliminary shape of the brake disc blank, the pressure is 800MPa, and the pressing time is 20 seconds; step three: perform a sintering treatment, pre-burn the cold pressed blank at a relatively low temperature to remove residual organic matter and preliminarily Densification, the pre-sintering temperature is set between 300°C and 600°C, the pre-sintering time is 3 hours, the pre-sintered green body should be naturally cooled to below 100°C at room temperature, and then the pre-sintered green body is finally sintered in a high-temperature furnace to diffuse and bond the powder particles to form a dense metal matrix. The final sintering temperature is usually between 1100°C and 1300°C, and the sintering time is 1.5 hours. Finally, the metal matrix is ​​taken out and naturally cooled to 850°C to 950°C at room temperature; Step 4: Post-treatment, first quenching and then tempering heat treatment process, the quenching temperature is 1200°C to 1300°C, after quenching for 5 minutes, quickly immersed in oil medium and quickly cooled to room temperature, and then tempered, the tempering temperature is 350°C to 500°C, and naturally cooled to room temperature after keeping warm for 1 hour; Finally, the brake disc is cleaned and fine-ground according to production needs to ensure dimensional accuracy and surface finish.

[0008] Preferably, the brake disc-specific mold in step two includes an upper mold and a lower mold, a guide column is fixedly installed on the lower surface of the upper mold, a guide hole matched with the guide column is provided on the upper surface of the lower mold, a first sealing platform is fixedly installed on the middle part of the lower surface of the upper mold, a second sealing platform is fixedly installed on the middle part of the lower surface of the first sealing platform, a molding tube is fixedly installed on the middle part of the lower surface of the second sealing platform, a molding column is fixedly installed inside the molding tube, and the depth of the molding tube is matched with the depth of the heat dissipation ring groove.

[0009] Preferably, an upper sealing ring is fixedly installed on the upper inner wall of the lower mold, a mold base is fixedly installed on the bottom of the inner wall of the lower mold, a sealing bottom plate is fixedly installed below the mold base by bolts, and a bottom sealing ring is fixedly installed on the upper surface of the mold base.

[0010] Preferably, a combined molded single-cavity plate is evenly distributed between the mold base and the upper sealing ring, a spacer block is fixedly installed on the inner middle part of the combined molded single-cavity plate, and both sides of the spacer block are provided with demolding circular protrusions adapted to the arc groove, the position of the spacer block is adapted to the position of the heat dissipation column, a sliding block is fixedly installed on the outer surface of the combined molded single-cavity plate, the inner side wall of the lower mold is provided with a limit strip adapted to the sliding block, and the side wall of the combined molded single-cavity plate is provided with a square hole adapted to the limit strip.

[0011] Preferably, a side sealing rubber block is fixedly installed on one side wall of the combined molded single-cavity plate, a card slot adapted to the side sealing rubber block is provided on the other side wall of the combined molded single-cavity plate, a bottom limiting elastic block is movably installed on the bottom of the combined molded single-cavity plate, and a card slot adapted to the bottom limiting elastic block is provided on the upper surface of the bottom sealing ring.

[0012] Preferably, a molding cavity is provided on the inner side of the bottom sealing ring, an adjustment disk is rotatably installed between the inner wall of the lower mold and the outer wall of the bottom sealing ring, a gear ring is fixedly installed on the outer surface of the adjustment disk, a gear is provided on one side of the upper surface of the mold base, and the side surface of the gear is meshed with the side surface of the gear ring.

[0013] Preferably, a locking sealing ring is clamped and installed above the upper sealing ring, and a locking block adapted to the sliding block is fixedly installed on the lower surface of the locking sealing ring.

[0014] Preferably, a demoulding push block is provided on the bottom inner wall of the mold base, a fixing ring is fixedly installed below the demoulding push block, a wedge block 1 is fixedly installed on the lower surface of the fixing ring, and a wedge block 2 is provided on one side of the wedge block 1.

[0015] Preferably, a threaded rod is rotatably installed on one side surface of the wedge block 2, the outer surface of the threaded rod is threadedly connected to the side wall of the mold base, the upper surface of the sealing bottom plate is provided with a limiting slide groove adapted to the wedge block 2, and a reset telescopic spring sleeve rod is fixedly installed between the upper surface of the fixing ring and the top of the inner surface of the mold base.

[0016] Compared with the prior art, the present invention has the following beneficial effects: By changing the traditional powder metallurgy production process for preparing brake discs, firstly, auxiliary ingredients such as lubricants, binders and sintering aids are added to the powder and evenly mixed to prepare particles with a size between 50 microns and 100 microns, and then pressed. This can not only improve the fluidity, formability and sintering performance of the powder, but also cooperate with special molds for the upper mold and the lower mold, so that the disc body one, the disc body two, and the assembly seat can be pressed into one piece and then sintered and post-processed. While improving the strength of the brake disc, the production efficiency of the brake disc is also improved, and the problem that the brake disc is divided into the first brake disc and the second brake disc and then welded in the prior art will reduce the overall strength of the brake disc is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall top view of the powder metallurgy brake disc of the present invention; Figure 2 It is a schematic diagram of the overall structure of the powder metallurgy brake disc of the present invention when viewed from above; Figure 3 It is a schematic diagram of the overall cross-sectional structure of the powder metallurgy brake disc of the present invention; Figure 4 It is a schematic diagram of the exploded structure of the powder metallurgy brake disc of the present invention; Figure 5 It is a schematic diagram of the overall structure of the upper mold and the lower mold of the present invention; Figure 6 It is a schematic diagram of the overall structure of the upper mold and the lower mold of the present invention when viewed from bottom; Figure 7 It is a schematic diagram of the overall top view of the lower mold of the present invention; Figure 8 It is a schematic diagram of the installation structure of the locking sealing ring of the present invention; Fig. 9 It is a schematic diagram of the structure of the combined molded single-cavity plate after dispersion of the present invention; Fig.10 It is a schematic diagram of the structure comparing the dispersed and aggregated states of the combined molded single-cavity plate of the present invention; Fig.11 This is a schematic diagram of the internal structure of the mold base of the present invention when viewed from above; Fig.12 This is a schematic diagram of the structure of the combined molding single cavity plate of the present invention; Fig.13 It is a schematic cross-sectional structure diagram of the upper mold and the lower mold in the pressed state of the present invention; Fig.14 The figure is a schematic diagram of the production process of the powder metallurgy brake disc of the present invention.

[0018] In the figure: 1. Powder metallurgy brake disc; 11. Disc body 1; 12. Disc body 2; 13. Assembly seat; 2. Heat dissipation ring groove; 21. Heat dissipation groove; 22. Heat dissipation column; 221. Arc groove; 3. Reinforcement ring; 4. Upper mold; 41. First sealing platform; 42. Second sealing platform; 43. Forming tube; 431. Forming column; 5. Lower mold; 51. Mold base; 511. Sealing bottom plate; 512. Bottom sealing ring; 52. Upper sealing ring; 53. Locking sealing ring; 531, locking block; 54, combined molding single cavity plate; 541, spacer block; 5411, demoulding circular protrusion; 542, sliding block; 543, side sealing rubber block; 544, bottom limiting elastic block; 55, molding cavity; 56, demoulding push block; 561, fixing ring; 562, wedge block one; 563, wedge block two; 564, threaded rod; 565, reset telescopic spring sleeve rod; 57, adjusting plate; 571, gear ring; 572, gear. DETAILED DESCRIPTION

[0019] In order to make the purpose and technical solution of the present invention clearly and completely described, and the advantages more clearly understood, the embodiments of the present invention are further described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, not all of them, and are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] For example, see Figures 1 to 14The present invention provides a technical solution: a powder metallurgy brake disc, comprising a powder metallurgy brake disc 1, the powder metallurgy brake disc 1 comprising a disc body 11, a disc body 2 and an assembly seat 13, a heat dissipation ring groove 2 is arranged between the disc body 11 and the assembly seat 13, heat discharge grooves 21 and heat dissipation columns 22 are evenly distributed between the disc body 11 and the disc body 2, the heat discharge grooves 21 and the heat dissipation columns 22 are spaced apart, a reinforcement ring 3 is arranged on one side of the assembly seat 13 close to the disc body 11, and arc grooves 221 are arranged on both sides of the heat dissipation column 22; in this embodiment, the disc body 11, the disc body 2 12 and the assembly seat 13 are an integrated brake disc, compared with the traditional brake disc, the disc body 11 and the disc body 2 12 are connected by bolts, and the integrated design reduces the disc body 11, the disc body 2 1 2, reduces the risk caused by loose bolts or connection failure, makes the overall structure more solid, can better withstand high loads and impact forces, and improves the stability and safety of the vehicle during driving. The design of the heat dissipation ring groove 2 increases the heat dissipation area, so that more heat can be dissipated through surface conduction and radiation. The ring groove structure can guide the air to flow along a specific path to accelerate the dissipation of heat, especially when driving at high speeds. The airflow through the ring groove can take away more heat. When the brake disc rubs, the heat is dissipated in time to avoid local heat accumulation. The heat dissipation column 22 not only connects the disc body 11 and the disc body 2 12 tightly into one, but is also evenly distributed between the disc body 11 and the disc body 2 12. The heat dissipation column 22 separates the heat discharge groove 21. Further expanding the heat dissipation area ensures unimpeded air circulation and improves heat dissipation efficiency. The heat discharge groove 21 not only provides an additional heat dissipation path, but also optimizes the air exchange between the inside and outside of the brake disc, promotes the rapid dissipation of heat, and allows heat to be more evenly distributed throughout the structure to avoid local overheating. The arc groove 221 not only optimizes the thermal conductivity of the heat dissipation column 22, but also facilitates demolding. The cross-section of the assembly seat 13 is trapezoidal.

[0021] For example 2, please refer to Figures 1 to 14On the basis of Example 1, this example further proposes a powder metallurgy brake disc production process, comprising the following steps: Step 1: uniformly mix various metal powders and additives according to a proportion, granulate the mixed powder by a spray drying method, and prepare a granular material, the size of the granular material is between 50 microns and 100 microns; the specific ratio of various powders is: 4% graphite, 6% copper powder, 3% nickel powder, 3% molybdenum powder, 2% tungsten powder, 0.5% zinc stearate, 0.3% polyvinyl alcohol, 0.2% phenolic resin, 1% sintering aid, and the rest is iron; Step 2: design a special brake disc mold according to the size and shape of the required brake disc, load the prepared mixed particles into the mold, and cold press mold under high pressure to obtain a preliminary shape of the brake disc blank, the pressure is 800 MPa, the pressing time is 20 seconds; Step 3: Sintering treatment, pre-sintering the cold pressed green body at a relatively low temperature to remove residual organic matter and preliminarily densify, the pre-sintering temperature is set between 300°C and 600°C, the pre-sintering time is 3 hours, the pre-sintered green body should be naturally cooled down to below 100°C at room temperature, and then the pre-sintered green body is finally sintered in a high-temperature furnace to diffuse and bond the powder particles to form a dense metal matrix, the final sintering temperature is usually between 1100°C and 1300°C, and the sintering time is 1.5 hours, finally take out the metal matrix and naturally cool it to 850°C to 950°C at room temperature; Step 4: Post-treatment, first quench and then perform tempering heat treatment process, the quenching temperature is 1200°C to 1300°C, quench for 5 minutes and quickly immerse in oil medium to quickly cool to room temperature, then temper, the tempering temperature is 350°C to 500°C, keep warm for 1 hour and naturally cool to room temperature; finally, according to production requirements, the brake disc is cleaned and finely ground to ensure dimensional accuracy and surface finish; in this embodiment, compared with the traditional raw material ratio for the preparation of powder brake discs, this The powder brake disc production process proposed in the embodiment firstly mixes the powder evenly to prepare particles with a size between 50 microns and 100 microns, and then presses the powder, which can not only improve the powder fluidity, formability and sintering performance, but also add auxiliary ingredients such as lubricants, binders and sintering aids. The particles of 50 microns to 100 microns are in a relatively ideal range, which will not easily agglomerate because of being too fine, nor will they cause uneven filling because of being too large. Within this particle size range, the friction between the particles is moderate, which reduces the possibility of mutual adhesion, allowing the powder to flow more smoothly and controllable. Uniform filling of particle distribution helps to achieve more uniform mold filling, reduces local density differences, and thus improves the dimensional accuracy and shape integrity of the final product, making it easier to perform cold pressing. Adding lubricants can reduce the friction coefficient. For example, graphite and zinc stearate can form a thin protective film on the surface of the particles, reducing the friction coefficient between particles, further improving the fluidity of the powder, and effectively preventing the powder from adhering to the inner wall of the mold to ensure smooth demolding. Adding binders can improve the bonding force between particles. For example, polyvinyl alcohol (PVA) and phenolic resin can provide temporary adhesion between powder particles, enhance the integrity of the powder during the pressing process, prevent looseness or stratification, and improve the strength of the green body. After pressing, the green body containing the binder has higher mechanical strength, which is convenient for subsequent handling and processing, and reduces the risk of damage. Adding sintering aids, such as magnesium oxide and aluminum oxide, can reduce the sintering temperature by promoting the formation of liquid phase or changing the grain boundary behavior, reducing energy consumption and shortening the production cycle. It can also promote densification. For example, glass powder and boric acid can promote the contact and bonding between powder particles, improve the density of the material, and thus enhance the mechanical properties of the finished product. .

[0022] For example 3, please refer to Figures 1 to 14On the basis of the second embodiment, the present embodiment further proposes that the brake disc special mold of step 2 includes an upper mold 4 and a lower mold 5, a guide column is fixedly installed on the lower surface of the upper mold 4, a guide hole matched with the guide column is arranged on the upper surface of the lower mold 5, a first sealing platform 41 is fixedly installed on the middle part of the lower surface of the upper mold 4, a second sealing platform 42 is fixedly installed on the middle part of the lower surface of the first sealing platform 41, a molding tube 43 is fixedly installed on the middle part of the lower surface of the second sealing platform 42, a molding column 431 is fixedly installed inside the molding tube 43, and the depth of the molding tube 43 is the same as that of the heat dissipation ring groove 2 The depth is adapted, an upper sealing ring 52 is fixedly installed on the upper inner wall of the lower mold 5, a mold base 51 is fixedly installed on the bottom of the inner wall of the lower mold 5, a sealing bottom plate 511 is fixedly installed below the mold base 51 by bolts, a bottom sealing ring 512 is fixedly installed on the upper surface of the mold base 51, and a combined molded single cavity plate 54 is evenly distributed between the mold base 51 and the upper sealing ring 52. A spacer block 541 is fixedly installed on the inner middle of the combined molded single cavity plate 54, and both sides of the spacer block 541 are provided with demoulding circular protrusions 5411 adapted to the arc groove 221. The position is adapted to the position of the heat dissipation column 22, a sliding block 542 is fixedly installed on the outer surface of the combined single-cavity plate 54, and a limiting strip adapted to the sliding block 542 is provided on the inner wall of the lower mold 5, and a square hole adapted to the limiting strip is opened on the side wall of the combined single-cavity plate 54, and a side sealing rubber block 543 is fixedly installed on one side wall of the combined single-cavity plate 54, and a card groove adapted to the side sealing rubber block 543 is provided on the other side wall of the combined single-cavity plate 54, and a bottom limiting elastic block 544 is movably installed on the bottom of the combined single-cavity plate 54, and the upper surface of the bottom sealing ring 512 is provided There is a card slot matched with the bottom limiting elastic block 544, a molding cavity 55 is arranged on the inner side of the bottom sealing ring 512, an adjusting disk 57 is rotatably installed between the inner side wall of the lower mold 5 and the outer side wall of the bottom sealing ring 512, a gear ring 571 is fixedly installed on the outer surface of the adjusting disk 57, a gear 572 is arranged on one side of the upper surface of the mold base 51, the side surface of the gear 572 and the side surface of the gear ring 571 are meshed with each other, a locking sealing ring 53 is clamped and installed above the upper sealing ring 52, and a locking block 531 matched with the sliding block 542 is fixedly installed on the lower surface of the locking sealing ring 53;In this embodiment, the upper mold 4 and the lower mold 5 form a complete brake disc special mold. The rotating gear 572 can drive the gear ring 571 to rotate, and then drive the adjusting disk 57 to rotate a certain angle, so that the sliding block 542 moves synchronously inward under the cooperation of the limiting bar until the bottom limiting elastic block 544 pops out and snaps into the outer groove above the bottom sealing ring 512. At this time, the side sealing rubber block 543 is clamped in turn to make the combined single-cavity plates 54 bite each other to form a sealing ring, and then the locking sealing ring 53 is clamped above the upper sealing ring 52, and the locking block 531 is clamped into the inner inclined surface of the sliding block 542 in turn to lock the sealing ring formed by the mutual bite of the combined single-cavity plates 54, and then the mixed particles prepared in step 1 are evenly filled into the molding cavity 55 and the combined single-cavity plates 54 forms the internal space of the sealing ring, ensuring that the spacer block 541 is completely covered, and finally the upper mold 4 and the lower mold 5 are stamped and molded together. At this time, the particles will be squeezed into the internal space of the sealing ring formed by the molding cavity 55 and the combined molding single cavity plate 54 for flow, mutual extrusion and interlocking. After the upper mold 4 is pulled out, the position of the molding tube 43 will form a heat dissipation ring groove 2, and then the reverse rotation gear 572 will make the adjustment disk 57 rotate in the opposite direction. At this time, the spacer block 541 is withdrawn, and the position of the spacer block 541 forms a heat discharge groove 21. The demoulding circular protrusion 5411 shapes the arc groove 221, which is also convenient for demoulding. Through the design of the upper mold 4 and the lower mold 5, the disc body 11, the disc body 2 12, and the assembly seat 13 can be pressed and molded as a whole, which improves the strength of the brake disc and the production efficiency of the brake disc. ;

[0023] Example 4, please refer to Figures 1 to 14 On the basis of the third embodiment, the present embodiment further proposes that a demoulding push block 56 is provided on the bottom inner wall of the mold base 51, a fixing ring 561 is fixedly installed below the demoulding push block 56, a wedge block 1 562 is fixedly installed on the lower surface of the fixing ring 561, a wedge block 2 563 is provided on one side of the wedge block 1 562, a threaded rod 564 is rotatably installed on one side surface of the wedge block 2 563, the outer surface of the threaded rod 564 is threadedly connected to the side wall of the mold base 51, and a threaded rod 564 is provided on the upper surface of the sealing bottom plate 511 to fit the wedge block 2 563. A reset telescopic spring sleeve rod 565 is fixedly installed between the upper surface of the fixed ring 561 and the top of the inner surface of the mold base 51; in this embodiment, the wedge block 2 563 can be slid in cooperation with the limiting slide groove on the upper surface of the sealing bottom plate 511 by rotating the threaded rod 564, and the wedge block 2 563 lifts the wedge block 1 562. At this time, the fixed ring 561 is lifted as a whole, so that the demoulding push block 56 is lifted, which is convenient for the powder metallurgy brake disc 1 to be demoulded as a whole from the bottom, thereby further improving the production efficiency of the brake disc.

[0024] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A powder metallurgy brake disc, comprising a powder metallurgy brake disc (1), wherein the powder metallurgy brake disc (1) comprises a disc body 1 (11), a disc body 2 (12) and an assembly seat (13), characterized in that: A heat dissipation ring groove (2) is provided between the disk body 1 (11) and the assembly seat (13), heat dissipation grooves (21) and heat dissipation columns (22) are evenly distributed between the disk body 1 (11) and the disk body 2 (12), the heat dissipation grooves (21) and the heat dissipation columns (22) are spaced apart, a reinforcement ring (3) is provided on one side of the assembly seat (13) close to the disk body 1 (11), and arc grooves (221) are provided on both sides of the heat dissipation columns (22).

2. A powder metallurgy brake disc production process, characterized in that: The method comprises the following steps: Step 1: uniformly mixing various metal powders and additives according to a proportion, granulating the mixed powders by a spray drying method, and preparing a granular material, wherein the size of the granular material is between 50 microns and 100 microns; the specific proportions of the various powders are: 4% graphite, 6% copper powder, 3% nickel powder, 3% molybdenum powder, 2% tungsten powder, 0.5% zinc stearate, 0.3% polyvinyl alcohol, 0.2% phenolic resin, 1% sintering aid, and the rest is iron; Step 2: Design a special mold for the brake disc according to the required size and shape of the brake disc, load the prepared mixed particles into the mold, and perform cold pressing under high pressure to obtain a preliminary shape of the brake disc blank. The pressure is 800 MPa and the pressing time is 20 seconds; Step 3: Sintering treatment, pre-sintering the cold pressed green body at a relatively low temperature to remove residual organic matter and preliminarily densify, the pre-sintering temperature is set between 300°C and 600°C, the pre-sintering time is 3 hours, the pre-sintered green body should be naturally cooled to below 100°C at room temperature, and then the pre-sintered green body is finally sintered in a high-temperature furnace to diffuse and bond the powder particles to form a dense metal matrix, the final sintering temperature is usually between 1100°C and 1300°C, the sintering time is 1.5 hours, and finally the metal matrix is ​​taken out and naturally cooled to 850°C to 950°C at room temperature; Step 4: Post-processing, first quenching and then tempering heat treatment process, the quenching temperature is 1200°C to 1300°C, after quenching for 5 minutes, quickly immerse in oil medium and quickly cool to room temperature, then temper, the tempering temperature is 350°C to 500°C, keep warm for 1 hour and then naturally cool to room temperature; finally, clean and fine-grind the brake disc according to production requirements to ensure dimensional accuracy and surface finish.

3. A powder metallurgy brake disc production process according to claim 2, characterized in that: The brake disc-specific mold of step 2 comprises an upper mold (4) and a lower mold (5), wherein a guide column is fixedly mounted on the lower surface of the upper mold (4), and a guide hole matched with the guide column is arranged on the upper surface of the lower mold (5), a first sealing platform (41) is fixedly mounted on the middle part of the lower surface of the upper mold (4), a second sealing platform (42) is fixedly mounted on the middle part of the lower surface of the first sealing platform (41), a molding tube (43) is fixedly mounted on the middle part of the lower surface of the second sealing platform (42), a molding column (431) is fixedly mounted inside the molding tube (43), and the depth of the molding tube (43) is matched with the depth of the heat dissipation ring groove (2).

4. A powder metallurgy brake disc production process according to claim 3, characterized in that: An upper sealing ring (52) is fixedly mounted on the upper inner wall of the lower mold (5), a mold base (51) is fixedly mounted on the bottom of the inner wall of the lower mold (5), a sealing bottom plate (511) is fixedly mounted below the mold base (51) via bolts, and a bottom sealing ring (512) is fixedly mounted on the upper surface of the mold base (51).

5. The powder metallurgy brake disc production process according to claim 4, characterized in that: A combined molded single-cavity plate (54) is evenly distributed between the mold base (51) and the upper sealing ring (52); a spacer block (541) is fixedly mounted on the middle of the inner side of the combined molded single-cavity plate (54); both sides of the spacer block (541) are provided with demoulding circular protrusions (5411) that match the arc groove (221); the position of the spacer block (541) matches the position of the heat dissipation column (22); a sliding block (542) is fixedly mounted on the outer surface of the combined molded single-cavity plate (54); a limiting strip that matches the sliding block (542) is provided on the inner side wall of the lower mold (5); and a square hole that matches the limiting strip is opened on the side wall of the combined molded single-cavity plate (54).

6. A powder metallurgy brake disc production process according to claim 5, characterized in that: A side sealing rubber block (543) is fixedly mounted on one side wall of the combined molded single cavity plate (54), a slot matching the side sealing rubber block (543) is provided on the other side wall of the combined molded single cavity plate (54), a bottom limiting elastic block (544) is movably mounted on the bottom of the combined molded single cavity plate (54), and a slot matching the bottom limiting elastic block (544) is provided on the upper surface of the bottom sealing ring (512).

7. The powder metallurgy brake disc production process according to claim 4, characterized in that: A molding cavity (55) is provided on the inner side of the bottom sealing ring (512); an adjustment disk (57) is rotatably mounted between the inner side wall of the lower mold (5) and the outer side wall of the bottom sealing ring (512); a gear ring (571) is fixedly mounted on the outer side surface of the adjustment disk (57); a gear (572) is provided on one side of the upper surface of the mold base (51); and the side surface of the gear (572) meshes with the side surface of the gear ring (571).

8. The powder metallurgy brake disc production process according to claim 4, characterized in that: A locking sealing ring (53) is clamped and installed above the upper sealing ring (52), and a locking block (531) adapted to the sliding block (542) is fixedly installed on the lower surface of the locking sealing ring (53).

9. The powder metallurgy brake disc production process according to claim 4, characterized in that: A demoulding push block (56) is provided on the inner wall of the bottom of the mold base (51), a fixing ring (561) is fixedly installed below the demoulding push block (56), a wedge block 1 (562) is fixedly installed on the lower surface of the fixing ring (561), and a wedge block 2 (563) is provided on one side of the wedge block 1 (562).

10. The powder metallurgy brake disc production process according to claim 9, characterized in that: A threaded rod (564) is rotatably mounted on one side surface of the wedge block 2 (563); the outer surface of the threaded rod (564) is threadedly connected to the side wall of the mold base (51); the upper surface of the sealing bottom plate (511) is provided with a limiting sliding groove adapted to the wedge block 2 (563); and a reset telescopic spring sleeve rod (565) is fixedly mounted between the upper surface of the fixing ring (561) and the top of the inner surface of the mold base (51).

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