Lightweight automobile brake disc and preparation method thereof

Abstract

The present application relates to a lightweight automobile brake disc and a preparation method thereof. The lightweight automobile brake disc disc cap is made of a first aluminum-based material with good machinability, and the disc body is made of a second aluminum-based material with good wear resistance and heat resistance. By controlling the alloy element content of the aluminum alloy matrix in the first aluminum-based material to be ≤ the alloy element content of the aluminum alloy matrix in the second aluminum-based material, the sintering shrinkage rates of the above two materials in the preparation process using a powder metallurgy method are matched, and no defects such as cracking occur during the preparation process. At the same time, the thermal expansion coefficients of the above two materials under the service conditions of the automobile brake disc are also matched, so that the disc cap and the disc body are metallurgically connected only in the circumferential direction, so as to obtain a higher interface bonding strength, and at the same time meet the friction, wear, fatigue resistance and other braking performance requirements required by traditional automobile brake discs in the friction braking process.

Description

Technical Field

[0001] The invention relates to the technical field of brake discs, in particular to a lightweight automobile brake disc. Background Art

[0002] Lightweighting is one of the most effective means to achieve energy conservation and consumption reduction for automobiles and other transportation vehicles. Using high-performance light metal materials instead of steel materials in key moving parts such as engines and brake discs of transportation equipment can not only reduce the weight of the entire vehicle and reduce the momentum of high-speed moving parts of transportation equipment, but also significantly improve the dynamic performance of transportation equipment while reducing energy consumption.

[0003] Silicon carbide particle reinforced aluminum-based composites have low density, high specific strength and specific stiffness, high thermal conductivity, and excellent wear resistance and corrosion resistance. They have broad application prospects in the field of lightweight structural parts. The use of silicon carbide particle reinforced aluminum-based composites to replace traditional brake disc materials has also become the main research direction for lightweight transportation vehicles.

[0004] Most existing lightweight automobile brake discs use disc caps made of aluminum alloy to achieve lightweight, while the disc body is still made of cast iron with good wear resistance, which requires the disc body and the disc cap to be able to move radially relative to each other to minimize the thermal tension generated in the disc body during each braking process. The radial degree of freedom is generated by the fit clearance, which is generated by machining and inserted connecting elements, which leads to high manufacturing costs. In addition, the inserted connecting elements are subject to large torque during braking and are prone to deformation and fracture, affecting driving safety.

[0005] CN111442039A discloses a lightweight, wear-resistant aluminum-based powder metallurgy composite automobile brake disc, wherein the disc body is made of an aluminum-based structural material, and the friction surface is made of a wear-resistant aluminum-based composite material. The friction surface and the disc body are made of lightweight materials of different materials to further reduce the weight, thereby reducing energy consumption while meeting the friction performance requirements. However, the disc body of the automobile brake disc is actually composed of a disc cap and a support structure extending radially outward from the disc cap to between the two friction surfaces, and the contact area between the friction surface and the disc body is increased to improve the connection strength between the disc body and the friction surface. The existence of the support structure undoubtedly increases the manufacturing cost and the complexity of the preparation process.

[0006] Technical issues

[0007] The invention solves the problem of how to connect the disc body and the disc cap to meet the working requirements of the brake disc while meeting their respective processing needs and working requirements.

[0008] Technical Solutions

[0009] Based on this, it is necessary to provide a new lightweight automobile brake disc in which the disc body and the disc cap are metallurgically connected in the circumferential direction, which can save the manufacturing cost of the supporting structure and simplify the preparation process.

[0010] A lightweight automobile brake disc comprises a disc cap and a disc body, wherein the disc cap and the disc body are metallurgically connected in a circumferential direction, the disc cap is made of a first aluminum-based material, and the disc body is made of a second aluminum-based material, the first aluminum-based material is composed of a ceramic reinforcement phase with a volume content of 0 to 30% and an aluminum alloy matrix as the balance, the second aluminum-based material is composed of a ceramic reinforcement phase with a volume content of 30 to 70% and an aluminum alloy matrix as the balance, and the alloy element content of the aluminum alloy matrix in the first aluminum-based material is ≤ the alloy element content of the aluminum alloy matrix in the second aluminum-based material; wherein, when the alloy element content of the aluminum alloy matrix in the first aluminum-based material is equal to the alloy element content of the aluminum alloy matrix in the second aluminum-based material, the volume contents of the ceramic reinforcement phase in the first aluminum-based material and the second aluminum-based material are not equal.

[0011] In one embodiment, the aluminum alloy matrix is ​​a second series or sixth series aluminum alloy.

[0012] In one embodiment, the second series aluminum alloy is an Al-Cu-Mg series alloy or an Al-Cu-Mg-Si series alloy; the sixth series aluminum alloy is an Al-Mg-Si series alloy.

[0013] In one embodiment, the Al-Cu-Mg alloy is Al-4Cu-0.8Mg, the Al-Cu-Mg-Si alloy is Al-2Cu-0.5Mg-0.7Si-0.5Mn, and the Al-Mg-Si alloy is Al-0.6Mg-0.9Si or Al-1Mg-0.7Si-0.25Cu.

[0014] In one embodiment, the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement particles or ceramic reinforcement fibers; when the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement particles, the average particle size of the ceramic reinforcement particles in the first aluminum-based material is 10μm to 40μm; when the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement fibers, the aspect ratio of the ceramic reinforcement fibers in the first aluminum-based material is 5 to 10, and the diameter of the ceramic reinforcement fibers is ≤50μm.

[0015] In one embodiment, the ceramic reinforcement phase in the second aluminum-based material is ceramic reinforcement particles, and the average particle size of the ceramic reinforcement particles in the second aluminum-based material is 45 μm to 100 μm, and more preferably 45 μm to 75 μm.

[0016] In one embodiment, the ceramic reinforcement phase is selected from at least one of carbides, nitrides, oxides, silicides and borides.

[0017] In one of the embodiments, the disk cap includes a cap body and a brim, the disk body includes a friction portion and a connecting portion, and the axial outer side wall of the brim is metallurgically connected to the axial inner side wall of the connecting portion in the circumferential direction.

[0018] In one embodiment, a plurality of protrusions or receiving openings are provided on the axial outer side wall of the brim along the circumferential direction, and correspondingly, a plurality of receiving openings or protrusions are provided on the axial inner side wall of the connecting portion along the circumferential direction; when the brim is metallurgically connected to the connecting portion, the protrusions are arranged in the receiving openings.

[0019] In one embodiment, the length direction of the protrusion is parallel to or at an angle to the radial direction of the brake disc.

[0020] The provision of the protruding portion can increase the contact area between the brim and the connecting portion, thereby further increasing the interface bonding strength between the disk cap and the disk body.

[0021] In one embodiment, a plurality of protrusions are provided on the axial outer side wall of the brim along the circumferential direction, and a corresponding receiving opening is provided on the axial inner side wall of the connecting portion along the circumferential direction. The length direction of the protrusion is set at an angle of 5° to 10° with the radial direction of the brake disc. The protrusion slightly deviates from the radial direction and extends outward, which can alleviate deformation and further improve the interface bonding strength between the disc cap and the disc body.

[0022] Furthermore, the circumferential width of each protrusion gradually shrinks or expands along the extension direction (ie, the length direction thereof), or the circumferential width of each protrusion first shrinks, then expands, and then shrinks along the extension direction.

[0023] In one embodiment, the axial thickness of the protruding portion is the same as the axial depth of the accommodating opening and is less than or equal to the axial thickness of the friction portion.

[0024] In addition, the present application also provides a method for preparing the above-mentioned lightweight automobile brake disc, the specific scheme is as follows:

[0025] A method for preparing a lightweight automobile brake disc comprises the following steps:

[0026] Providing the first aluminum-based material and the second aluminum-based material;

[0027] The first aluminum-based material and the second aluminum-based material are pre-pressed separately, or one of them is pre-pressed and the other is filled with powder; then they are pressed together, sintered and hot-pressed to obtain the lightweight automobile brake disc.

[0028] In one of the embodiments, the pre-pressing pressure is 30MPa-70MPa; the combined pressing pressure is 200MPa-400MPa, and more preferably 200MPa-300MPa.

[0029] In one embodiment, the sintering conditions are: heating to 570°C to 640°C at a heating rate of 5°C / min to 10°C / min, and keeping warm for 0.5 to 2 hours, more preferably 580°C to 600°C, and keeping warm for 0.5 to 2 hours.

[0030] In one embodiment, the temperature of the hot pressing shaping is 530° C. to 570° C., and the pressure is 200 MPa to 300 MPa.

[0031] Beneficial Effects

[0032] The above-mentioned lightweight automobile brake disc, the disc cap is made of a first aluminum-based material composed of a ceramic reinforcement phase with a volume content of 0 to 30% and an aluminum alloy matrix as the balance, and the disc body is made of a second aluminum-based material composed of a ceramic reinforcement phase with a volume content of 30% to 70% and an aluminum alloy matrix as the balance, by controlling the alloy element content of the aluminum alloy matrix in the first aluminum-based material ≤ the alloy element content of the aluminum alloy matrix in the second aluminum-based material; and at the same time controlling the alloy element content of the aluminum alloy matrix in the first aluminum-based material = the alloy element content of the aluminum alloy matrix in the second aluminum-based material, the volume content of the ceramic reinforcement phase in the first aluminum-based material and the second aluminum-based material are not equal; so that the sintering shrinkage rates of the above-mentioned first aluminum-based material and the second aluminum-based material in the process of preparation by a powder metallurgy method are matched, and no defects such as cracking occur during the preparation process, and at the same time, the thermal expansion coefficients of the above-mentioned first aluminum-based material and the second aluminum-based material under the service conditions of the automobile brake disc are also matched, so that the disc cap and the disc body are metallurgically connected only in the circumferential direction, and a higher interface bonding strength can be obtained.

[0033] At the same time, the disc cap is made of a first aluminum-based material composed of 0-30% by volume of a ceramic reinforcement phase and the remainder of an aluminum alloy matrix. It has high strength and good machinability, avoiding the problem of difficult forming caused by the use of high-volume ceramic-reinforced aluminum-based composite materials. The disc body is made of a second aluminum-based material composed of 30% to 70% by volume of a ceramic reinforcement phase and the remainder of an aluminum alloy matrix. It has good wear resistance and heat resistance, and can meet the friction, wear, fatigue resistance and other braking performance requirements required by traditional automobile brake discs during friction braking.

[0034] In addition, compared with the automobile brake disc structure in which the disc cap and the disc body are axially connected, the lightweight automobile brake disc of the present application eliminates the preparation of the supporting structure between the friction surfaces. The disc cap and the disc body are both made of aluminum-based composite materials with aluminum alloy as the matrix. They are light in weight and do not need to set pressure for the disc cap and the disc body separately during pressing. This can simplify equipment design, save preparation costs, and simplify the preparation process. At the same time, it avoids the formation of steps at the interface joint due to different pressures during the pressing process, which affects the formation of the brake disc. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of a lightweight automobile brake disc according to one embodiment;

[0036] Figure 2 for Figure 1 Cross-sectional view of a medium-lightweight automotive brake disc;

[0037] Figure 3 for Figure 1 Schematic diagram of the exploded structure of a medium-lightweight automobile brake disc;

[0038] Figure 4 It is a structural schematic diagram of a lightweight automobile brake disc according to another embodiment;

[0039] Figure 5 for Figure 4 Cross-sectional view of a medium-lightweight automotive brake disc;

[0040] Figure 6 for Figure 4 Schematic diagram of the exploded structure of a medium and lightweight automobile brake disc.

[0041] Embodiments of the present invention

[0042] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are provided. 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 of the present invention more thorough and comprehensive.

[0043] It should be noted that the “axial direction” used in this article refers to the direction parallel to the central axis of rotation of the brake disc, the “radial direction” refers to the direction perpendicular to the central axis of rotation of the brake disc, and the “circumferential direction” refers to the circumferential direction of the disc body.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. 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.

[0045] See also Figure 1 to Figure 3, provides an embodiment of a lightweight automobile brake disc 10, including a disc cap 110 and a disc body 120. The disc cap 110 includes a cap body 112 and a cap brim 114, and the disc body 120 includes a friction portion 122 and a connecting portion 124. The axial outer side wall of the cap brim 114 and the axial inner side wall of the connecting portion 124 are metallurgically connected in the circumferential direction, thereby realizing the metallurgical connection between the disc cap 110 and the disc body 120 in the circumferential direction.

[0046] Specifically, the axial outer side wall of the brim 114 is provided with a plurality of protrusions 1142 uniformly distributed in the circumferential direction, and the protrusions 1142 extend outward, and the length direction of the protrusions 1142 is set at an angle of (5° to 10°) with the radial direction of the brake disc, and the connecting portion 124 is provided with an accommodating port 1242 matching the protrusions 1142, each protrusion 1142 is tightly accommodated in the corresponding accommodating port 1242, and the axial side wall of each accommodating port 1242 is metallurgically connected to the axial side wall of the corresponding protrusion 1142, thereby realizing the metallurgical connection between the axial outer side wall of the brim 114 and the axial inner side wall of the connecting portion 124 in the circumferential direction.

[0047] The protrusion 1142 can increase the contact area between the brim 114 and the connecting portion 124, thereby increasing the interface bonding strength between the brim 114 and the connecting portion 124, thereby enabling the disk cap 110 and the disk body 120 to obtain a higher interface bonding strength by metallurgical connection only in the circumferential direction.

[0048] In this embodiment, the protrusion 1142 deviates from the radial direction and extends outward, which can alleviate deformation to a certain extent and extend the service life of the brake disc.

[0049] In this embodiment, the circumferential width of each protrusion 1142 gradually shrinks along the extension direction (ie, the length direction thereof) to form an arc shape or a sawtooth shape.

[0050] It is understandable that in other embodiments, the circumferential width of each protrusion 1142 can also be gradually expanded along the extension direction, so that a mutually engaging structure is formed between the brim 114 and the connecting portion 124, further increasing the connection strength between the disk cap 110 and the disk body 120.

[0051] Furthermore, the axial thickness of the protrusion 1142 is the same as the axial depth of the receiving opening 1242, and is less than or equal to the axial thickness of the friction portion 122. When the axial thickness of the protrusion 1142 is less than the axial thickness of the friction portion 122, it is beneficial to heat dissipation and chip removal of the friction portion 122.

[0052] The above-mentioned lightweight automobile brake disc 10, the disc cap 110 is made of a first aluminum-based material, and the disc body 120 is made of a second aluminum-based material. The specific preparation method includes the following steps S110 to S130:

[0053] S110, providing a first aluminum-based material and a second aluminum-based material.

[0054] Among them, the first aluminum-based material is composed of a ceramic reinforcement phase with a volume content of 0 to 30% and an aluminum alloy matrix as the balance, the second aluminum-based material is composed of a ceramic reinforcement phase with a volume content of 30% to 70% and an aluminum alloy matrix as the balance, and the alloy element content of the aluminum alloy matrix in the first aluminum-based material is ≤ the alloy element content of the aluminum alloy matrix in the second aluminum-based material; wherein, when the alloy element content of the aluminum alloy matrix in the first aluminum-based material = the alloy element content of the aluminum alloy matrix in the second aluminum-based material, the volume contents of the ceramic reinforcement phase in the first aluminum-based material and the second aluminum-based material are not equal.

[0055] It should be noted that the above alloy element contents are relative to the aluminum alloy matrix and refer to the mass content.

[0056] Furthermore, 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 alloy, Al-Cu-Mg-Si alloy, 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 alloy, etc.

[0057] Furthermore, the Al-Mg-Si alloy is Al-1Mg-0.7Si-0.25Cu (i.e., the 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 (i.e., the alloy is mainly composed of 0.6% by mass of Mg and 0.9% by mass of Si and the balance of Al). The Al-Cu-Mg alloy is Al-4Cu-0.8Mg (i.e., the 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 alloy is Al-2Cu-0.5Mg-0.7Si-0.5Mn (i.e., the 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).

[0058] It should be noted that the aluminum alloy matrix in the first aluminum-based material and the aluminum alloy matrix in the second aluminum-based material can be of the same series or of different series, as long as the alloy element content of the aluminum alloy matrix in the first aluminum-based material is ≤ the alloy element content of the aluminum alloy matrix in the second aluminum-based material; and at the same time, when the alloy element content of the aluminum alloy matrix in the first aluminum-based material is controlled to be equal to the alloy element content of the aluminum alloy matrix in the second aluminum-based material, the volume content of the ceramic reinforcement phase in the first aluminum-based material and the second aluminum-based material are not equal.

[0059] Furthermore, the ceramic reinforcement phase in the first aluminum-based material can be ceramic reinforcement particles or ceramic reinforcement fibers. When the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement particles, the average particle size of the ceramic reinforcement particles is 10 μm to 40 μm. When the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement fibers, the aspect ratio of the ceramic reinforcement fibers is 5 to 10, and the diameter thereof is ≤50 μm.

[0060] The ceramic reinforcement phase in the second aluminum-based material may be ceramic reinforcement particles, and the average particle size of the ceramic reinforcement particles is 45 μm to 100 μm, and more preferably the average particle size is 45 μm to 75 μm.

[0061] Furthermore, 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.).

[0062] It should be noted that the ceramic reinforcement phase in the first aluminum-based material and the ceramic reinforcement phase in the second aluminum-based material may be the same or different.

[0063] S120, placing the first aluminum-based material in a disk cap mold for pre-pressing to obtain a disk cap pre-pressed blank; at the same time, placing the second aluminum-based material in a disk body mold for pre-pressing to obtain a disk body pre-pressed blank;

[0064] Alternatively, the first aluminum-based material is placed in a tray cap mold for pre-pressing, and then the second aluminum-based material is filled into the tray body mold accordingly;

[0065] The pre-pressing pressure in step S120 is 30 MPa to 70 MPa.

[0066] S130, and then perform pressing, sintering and hot pressing shaping to obtain a lightweight automobile brake disc.

[0067] The combined pressing pressure is 200MPa to 400MPa. The sintering conditions are: heating to 570℃ to 640℃ at a heating rate of 5℃ / min to 10℃ / min, and keeping the temperature for 0.5 to 2 hours. The hot pressing shaping temperature is 530℃ to 570℃, and the pressure is 200MPa to 300MPa.

[0068] The pressing pressure is preferably 200 MPa to 300 MPa. The sintering conditions are: heating to 580°C to 600°C at a heating rate of 5°C / min to 10°C / min, and keeping the temperature for 0.5 to 2 hours.

[0069] It should be noted that the above-mentioned lightweight automobile brake disc 10 can also be prepared by other methods, as long as the disc cap 110 and the disc body 120 can be metallurgically connected in the circumferential direction.

[0070] See also Figures 4 to 6 , another embodiment of a lightweight automobile brake disc 20 is provided, comprising a disc cap 210 and a disc body 220. The disc cap 210 comprises a cap body 212 and a cap brim 214, the disc body 220 comprises a friction portion 222 and a connecting portion 224, and the axial outer side wall of the cap brim 214 is metallurgically connected to the axial inner side wall of the connecting portion 224 in the circumferential direction, thereby realizing metallurgical connection between the disc cap 210 and the disc body 220 in the circumferential direction.

[0071] Further preferably, the axial outer side wall of the brim 214 is provided with a plurality of protrusions 2142 evenly distributed in the circumferential direction, the length direction of the protrusions 2142 is parallel to the radial direction of the brake disc (that is, the protrusions extend radially outward), and the connecting portion 224 is provided with an accommodating port 2242 matching the protrusions 2142, each protrusion 2142 is tightly accommodated in the corresponding accommodating port 2242, and the axial side wall of each accommodating port 2242 is metallurgically connected to the axial side wall of the corresponding protrusion 2142, thereby realizing the metallurgical connection between the axial outer side wall of the brim 214 and the axial inner side wall of the connecting portion 224 in the circumferential direction.

[0072] By providing a plurality of radially outwardly extending protrusions 2142 evenly distributed along the circumferential direction on the axial outer side wall of the brim 214 , the contact area between the brim 214 and the connecting portion 224 can be increased, thereby increasing the interface bonding strength between the brim 214 and the connecting portion 224 .

[0073] Furthermore, in the present embodiment, the circumferential width of each protrusion 2142 first contracts, then expands, and then contracts again along the extension direction, so that the brim 214 and the connecting portion 224 form a mutually engaging structure, further increasing the connection strength between the disk cap 210 and the disk body 220 .

[0074] Furthermore, the axial thickness of the protrusion 2142 is the same as the axial depth of the receiving opening 2242, and is less than or equal to the axial thickness of the friction portion 222. When the axial thickness of the protrusion 2142 is less than the axial thickness of the friction portion 222, it is beneficial to heat dissipation and chip removal of the friction portion 222.

[0075] The specific preparation method of the lightweight automobile brake disc 20 is the same as the above steps S110 to S130, and will not be further described here.

[0076] With respect to the lightweight automobile brake disc of the present application, examples and comparative examples are provided below to illustrate the influence of the volume content of the ceramic reinforcement phase in its composition ratio and the content of alloying elements in the aluminum alloy matrix on the finished product.

[0077] Embodiment 1:

[0078] In this embodiment, Figure 1-Figure 3 The structural form shown, wherein the first aluminum-based material is composed of Al-3Cu-0.8Mg, and the second aluminum-based material is composed of 30% volume content of silicon carbide particles and the remainder of Al-4Cu-0.8Mg; wherein the average particle size of the silicon carbide particles in the second aluminum-based material is 45μm.

[0079] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 200 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the brake disc structural strength and friction and wear performance meet the requirements of the brake disc.

[0080] Embodiment 2:

[0081] In this implementation, the Figure 1-Figure 3 The structural form shown, wherein the first aluminum-based material is composed of 5% volume content of silicon carbide particles and the remainder Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 35% volume content of silicon carbide particles and the remainder Al-4Cu-0.8Mg, wherein the average particle size of the silicon carbide particles in the first aluminum-based material is 10μm, and the average particle size of the silicon carbide particles in the second aluminum-based material is 50μm.

[0082] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 180 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the brake disc structural strength and friction and wear performance meet the requirements of the brake disc.

[0083] Embodiment 3:

[0084] This embodiment adopts Figure 2-Figure 4 The structure is in the form of, wherein the first aluminum-based material is composed of 10% by volume of silicon carbide reinforced fibers and the remainder is Al-2Cu-0.5Mg-0.7Si-0.5Mn, and the second aluminum-based material is composed of 40% by volume of silicon carbide reinforced particles and the remainder is Al-2Cu-0.5Mg-0.7Si-0.5Mn. The aspect ratio of the silicon carbide reinforced fibers in the first aluminum-based material is 5, and its diameter is ≤50μm; the average particle size of the silicon carbide reinforced particles in the second aluminum-based material is 50μm.

[0085] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 150 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the brake disc structural strength and friction and wear performance meet the requirements of the brake disc.

[0086] Embodiment 4:

[0087] In this embodiment, the axial outer side wall of the brim and the axial inner side wall of the connecting portion are directly metallurgically connected in the circumferential direction (i.e., no protrusion and receiving opening are provided); wherein the first aluminum-based material is composed of 15% by volume of Si3N4 reinforcing fibers and the remainder of Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 50% by volume of Si3N4 reinforcing particles and the remainder of Al-2Cu-0.5Mg-0.7Si-0.5Mn. wherein the aspect ratio of the Si3N4 reinforcing fibers in the first aluminum-based material is 7, and its diameter is ≤50μm; the average particle size of the Si3N4 reinforcing particles in the second aluminum-based material is 55μm.

[0088] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 150 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the structural strength and friction and wear performance of the brake disc meet the requirements of the brake disc.

[0089] Embodiment 5:

[0090] This embodiment adopts Figure 2-Figure 4 The structure is in the form of, wherein the first aluminum-based material is composed of 20% by volume of Al2O3 reinforced fibers and the balance of Al-0.6Mg-0.9Si, and the second aluminum-based material is composed of 50% by volume of Al2O3 reinforced particles and the balance of Al-4Cu-0.8Mg. The aspect ratio of the Al2O3 reinforced fibers in the first aluminum-based material is 10, and its diameter is ≤50μm; the average particle size of the Al2O3 reinforced particles in the second aluminum-based material is 60μm.

[0091] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 150 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the structural strength and friction and wear performance of the brake disc meet the requirements of the brake disc.

[0092] Embodiment 6:

[0093] This embodiment adopts Figure 2-Figure 4 The first aluminum-based material is composed of 25% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 55% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu. The average particle size of the Al2O3 particles in the first aluminum-based material is 30μm, and the average particle size of the Al2O3 particles in the second aluminum-based material is 60μm.

[0094] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 150 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the structural strength and friction and wear performance of the brake disc meet the requirements of the brake disc.

[0095] Embodiment 7:

[0096] In this embodiment, the axial outer side wall of the brim and the axial inner side wall of the connecting portion are directly metallurgically connected in the circumferential direction (i.e., no protrusion and receiving opening are provided); wherein the first aluminum-based material is composed of 30% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 70% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu. The average particle size of the Al2O3 particles in the first aluminum-based material is 40 μm, and the average particle size of the Al2O3 particles in the second aluminum-based material is 100 μm.

[0097] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 150 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the structural strength and friction and wear performance of the brake disc meet the requirements of the brake disc.

[0098] Embodiment 8:

[0099] In this embodiment, Figure 2-Figure 4 The structure is in the form of, wherein the first aluminum-based material is composed of 30% by volume of Si3N4 reinforcing fibers and the balance of Al-0.6Mg-0.9Si, and the second aluminum-based material is composed of 30% by volume of Si3N4 reinforcing particles and the balance of Al-4Cu-0.8Mg. The aspect ratio of the Si3N4 reinforcing fibers in the first aluminum-based material is 7, and its diameter is ≤50μm; the average particle size of the Si3N4 reinforcing particles in the second aluminum-based material is 100μm.

[0100] By adopting the preparation method of steps S110-S130, it is found that the interface bonding strength between the disc cap and the disc body in the lightweight automobile brake disc is above 150 MPa. The lightweight automobile brake disc is subjected to bench testing, and completes and passes the two bench tests of T / CAAMTB09-2018 high load and Jaso C 419-2006 torsion failure, indicating that the structural strength and friction and wear performance of the brake disc meet the requirements of the brake disc.

[0101] Comparative Example 1:

[0102] In this comparative example, Figure 2-Figure 4 The structure is in the form of, wherein the first aluminum-based material is composed of 30% by volume of Si3N4 reinforcing fibers and the balance of Al-0.6Mg-0.9Si, and the second aluminum-based material is composed of 30% by volume of Si3N4 reinforcing particles and the balance of Al-0.6Mg-0.9Si. The aspect ratio of the Si3N4 reinforcing fibers in the first aluminum-based material is 7, and its diameter is ≤50μm; the average particle size of the Si3N4 reinforcing particles in the second aluminum-based material is 50μm.

[0103] Using the preparation method of steps S110-S130, it is found that after sintering, the shrinkage rate of the first aluminum-based material is greater than that of the second aluminum-based material, the two aluminum-based materials do not form an effective metallurgical bond, and cracks appear at the interface.

[0104] Comparative Example 2:

[0105] In this comparative example, Figure 1-Figure 3 The structural form shown, wherein the first aluminum-based material is composed of Al-3Cu-0.8Mg, and the second aluminum-based material is composed of 25% volume content of silicon carbide particles and the remainder of Al-4Cu-0.8Mg; wherein the average particle size of the silicon carbide particles in the second aluminum-based material is 45μm.

[0106] The preparation method of steps S110-S130 was adopted, and the braking performance bench test was carried out according to QC / T 564-2008. Because the ceramic content of the brake disc friction ring, i.e., the second aluminum-based material, was low and the temperature resistance did not meet the standard, obvious furrows appeared on the disc surface.

[0107] Comparative Example 3:

[0108] This comparative example adopts Figure 2-Figure 4 The structure is in the form of, wherein the first aluminum-based material is composed of 20% by volume of Al2O3 reinforced fibers and the balance of Al-4Cu-0.8Mg, and the second aluminum-based material is composed of 50% by volume of Al2O3 reinforced particles and the balance of Al-0.6Mg-0.9Si. The aspect ratio of the Al2O3 reinforced fibers in the first aluminum-based material is 10, and its diameter is ≤50μm; the average particle size of the Al2O3 reinforced particles in the second aluminum-based material is 45μm.

[0109] Using the preparation method of steps S110-S130, it is found that after sintering, the shrinkage rate of the first aluminum-based material is greater than that of the second aluminum-based material, the two aluminum-based materials do not form an effective metallurgical bond, and cracks appear at the interface.

[0110] Comparative Example 4:

[0111] In this comparative example, the axial outer wall of the brim and the axial inner wall of the connecting portion are directly metallurgically connected in the circumferential direction (i.e., no protrusion and receiving opening are provided); wherein the first aluminum-based material is composed of 30% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 75% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu. The average particle size of the Al2O3 particles in the first aluminum-based material is 40 μm, and the average particle size of the Al2O3 particles in the second aluminum-based material is 100 μm.

[0112] Using the preparation method of steps S110-S130, it was found that after sintering, the first aluminum-based material shrank and the second aluminum-based material expanded significantly. The two aluminum-based materials did not form an effective metallurgical bond, and cracks appeared at the interface.

[0113] Comparative Example 5:

[0114] This comparative example adopts Figure 2-Figure 4The first aluminum-based material is composed of 25% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 55% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu. The average particle size of the Al2O3 particles in the first aluminum-based material is 30μm, and the average particle size of the Al2O3 particles in the second aluminum-based material is 35μm.

[0115] Using the preparation method of steps S110-S130, it was found that after sintering, the shrinkage rate of the first aluminum-based material was greater than that of the second aluminum-based material, the two aluminum-based materials did not form an effective metallurgical bond in a partial circumferential area, and cracks appeared at the interface.

[0116] Comparative Example 6:

[0117] This comparative example adopts Figure 2-Figure 4 The first aluminum-based material is composed of 25% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu, and the second aluminum-based material is composed of 55% by volume of Al2O3 particles and the remainder of Al-1Mg-0.7Si-0.25Cu. The average particle size of the Al2O3 particles in the first aluminum-based material is 5μm, and the average particle size of the Al2O3 particles in the second aluminum-based material is 35μm.

[0118] The preparation method of steps S110-S130 was adopted, and the braking performance bench test was carried out according to QC / T 564-2008. Because the ceramic particles of the brake disc friction ring, i.e. the second aluminum-based material, were relatively fine and the wear resistance did not meet the standard, obvious furrows appeared on the disc surface.

[0119] Comparative Example 7:

[0120] This comparative example adopts Figure 2-Figure 4 The structure is in the form of, wherein the first aluminum-based material is composed of 20% by volume of Al2O3 reinforced fibers and the balance of Al-0.6Mg-0.9Si, and the second aluminum-based material is composed of 50% by volume of Al2O3 reinforced particles and the balance of Al-4Cu-0.8Mg. The aspect ratio of the Al2O3 reinforced fibers in the first aluminum-based material is 12, and its diameter is ≤50μm; the average particle size of the Al2O3 reinforced particles in the second aluminum-based material is 50μm.

[0121] When the preparation method of steps S110-S130 is adopted, since the fibers in the first aluminum-based material are too slender, the reinforcing phase fibers cannot be evenly dispersed in the aluminum-based composite material, which affects its mechanical properties and the interface structure with the second aluminum-based material, making it impossible to successfully prepare a lightweight brake disc.

[0122] By comparing the results of Examples 1-8 with Comparative Examples 1-7, it can be seen that when the same component is prepared using materials of different compositions, the interface bonding effect between the different materials needs to be fully considered. In the powder metallurgy process, the sintering stage determines the performance of the prepared components. When the sintering shrinkage of the two materials is significantly different, it will affect the interface bonding effect between the two materials. Adjusting the sintering shrinkage of powder metallurgy materials is closely related to factors such as the particle size of the raw material particles, the composition of the alloying elements, the powder forming pressure and the sintering temperature, as well as the process design. The difference in shrinkage is essentially the difference in the densification process of the material during the sintering process. The present application achieves a coordinated design of shrinkage by controlling the particle size, the content of the reinforcing phase and the content of the alloying elements, thereby ensuring that the interface of the two materials is well bonded, while each of them exerts its performance characteristics in different directions of structural strength and wear resistance.

[0123] Finally, it should be noted that the lightweight automobile brake disc of the present application is not limited to the structure represented by the above-mentioned embodiments. The above-mentioned embodiments only express several embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several deformations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A lightweight automobile brake disc, characterized in that: The invention comprises a disk cap and a disk body, wherein the disk cap and the disk body are metallurgically connected in the circumferential direction, the disk cap is made of a first aluminum-based material, and the disk body is made of a second aluminum-based material, the first aluminum-based material is composed of a ceramic reinforcement phase with a volume content of 0 to 30% and an aluminum alloy matrix as the remainder, the second aluminum-based material is composed of a ceramic reinforcement phase with a volume content of 30 to 70% and an aluminum alloy matrix as the remainder, and the alloy element content of the aluminum alloy matrix in the first aluminum-based material is ≤ the alloy element content of the aluminum alloy matrix in the second aluminum-based material; wherein, when the alloy element content of the aluminum alloy matrix in the first aluminum-based material is equal to the alloy element content of the aluminum alloy matrix in the second aluminum-based material, the volume contents of the ceramic reinforcement phase in the first aluminum-based material and the second aluminum-based material are not equal; The alloy element content of the aluminum alloy matrix in the first aluminum-based material refers to the mass content of the alloy element in the first aluminum-based material relative to the aluminum alloy matrix; The alloy element content of the aluminum alloy matrix in the second aluminum-based material refers to the mass content of the alloy element in the second aluminum-based material relative to the aluminum alloy matrix.

2. The lightweight automobile brake disc according to claim 1, characterized in that: The aluminum alloy matrix is ​​a second series or sixth series aluminum alloy.

3. The lightweight automobile brake disc according to claim 2, characterized in that: The second series aluminum alloy is an Al-Cu-Mg series alloy or an Al-Cu-Mg-Si series alloy; the sixth series aluminum alloy is an Al-Mg-Si series alloy.

4. The lightweight automobile brake disc according to any one of claims 1 to 3, characterized in that: The ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement particles or ceramic reinforcement fibers; when the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement particles, the average particle size of the ceramic reinforcement particles in the first aluminum-based material is 10μm to 40μm; when the ceramic reinforcement phase in the first aluminum-based material is ceramic reinforcement fibers, the aspect ratio of the ceramic reinforcement fibers in the first aluminum-based material is 5 to 10, and the diameter of the ceramic reinforcement fibers is ≤50μm.

5. The lightweight automobile brake disc according to claim 4, characterized in that: The ceramic reinforcement phase in the second aluminum-based material is ceramic reinforcement particles, and the average particle size of the ceramic reinforcement particles in the second aluminum-based material is 45 μm to 100 μm.

6. The lightweight automobile brake disc according to claim 1, characterized in that: The disk cap comprises a cap body and a cap brim, the disk body comprises a friction portion and a connecting portion, and the axial outer side wall of the cap brim is metallurgically connected to the axial inner side wall of the connecting portion in the circumferential direction.

7. The lightweight automobile brake disc according to claim 6, characterized in that: The axial outer side wall of the brim is provided with a plurality of protrusions or receiving openings along the circumferential direction, and correspondingly, the axial inner side wall of the connecting part is provided with a plurality of receiving openings or protrusions along the circumferential direction; when the brim is metallurgically connected to the connecting part, the protrusions are arranged in the receiving openings.

8. The lightweight automobile brake disc according to claim 7, characterized in that: The length direction of the protrusion is parallel to or at an angle to the radial direction of the brake disc.

9. A method for preparing a lightweight automobile brake disc according to any one of claims 1 to 8, characterized in that: The following steps are involved: Providing the first aluminum-based material and the second aluminum-based material; The first aluminum-based material and the second aluminum-based material are pre-pressed separately, or one of them is pre-pressed and the other is filled with powder; then they are pressed together, sintered and hot-pressed to obtain the lightweight automobile brake disc.

10. The method for preparing a lightweight automobile brake disc according to claim 9, characterized in that: The pre-pressing pressure is 30MPa-70MPa; the combined pressing pressure is 200MPa-400MPa; The sintering conditions are: heating to 570°C to 640°C at a heating rate of 5°C / min to 10°C / min, and keeping the temperature for 0.5 to 2 hours; The temperature of the hot pressing shaping is 530° C. to 570° C., and the pressure is 200 MPa to 300 MPa.

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