Metallized ceramic multilayer composite material and preparation method and application thereof

Abstract

The invention discloses a metalized ceramic multilayer composite material and a preparation method and application thereof, and belongs to the technical field of metalized ceramic materials. The composite material comprises n aluminum alloy material layers and m aluminum-based silicon carbide composite material layers which are sequentially and alternately arranged, n is equal to m or n is equal to m + 1, and m is larger than or equal to 1. The composite material realizes interface metallurgical bonding of the aluminum alloy material layer and the aluminum-based silicon carbide composite material layer, has the characteristics of light weight and high performance, and can meet the requirements of electronic equipment shells on light weight, high rigidity, high strength, high heat conductivity and appearance. The preparation method comprises the steps that according to the preset layer number, the aluminum alloy materials and the aluminum-based silicon carbide composite materials which are alternately placed in a stacked mode are subjected to hot rolling compounding, and then diffusion annealing, second-time hot rolling, intermediate annealing, cold rolling, solution treatment, stretch straightening treatment and aging treatment are conducted; the method solves or improves the problems that the rolling machining difficulty of the low-volume-fraction aluminum-based silicon carbide composite material is large, the yield is low, and the surface quality is difficult to control.

Description

Technical Field

[0001] The present invention relates to the technical field of metallized ceramic materials, and in particular, to a metallized ceramic multi-layer composite material, a preparation method thereof, and an application thereof. Background Art

[0002] The existing metal bottom shell materials mainly use aluminum alloys, magnesium alloys, titanium alloys, stainless steels, etc. Among them, although aluminum alloy materials can meet the requirements of lightweight and anodic oxidation appearance, they have low strength, low elastic modulus, and insufficient stiffness; stainless steel materials have a high density and cannot meet the weight reduction requirements; titanium alloy materials have problems such as high density, poor heat conduction, low modulus, poor anodic appearance effect, and high cost; magnesium alloys have problems such as low strength; although composite materials such as aluminum matrix silicon carbide have excellent comprehensive properties, they have problems such as poor anodic effect, difficult surface quality control, high production difficulty, and high cost.

[0003] Therefore, these materials currently cannot meet the advantages of high strength, high stiffness, high heat conduction, lightweight, ultra-thin, and beautiful anodic appearance at the same time, and thus it is difficult to meet the actual requirements of the comprehensive performance of materials for 3C products (collectively referring to computers, communications, and consumer electronics).

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a metallized ceramic multi-layer composite material, a preparation method thereof, and an application thereof, so as to solve or improve at least one of the above technical problems.

[0006] The present invention can be implemented as follows: In a first aspect, the present invention provides a metallized ceramic multi-layer composite material, which includes n layers of aluminum alloy material layers and m layers of aluminum matrix silicon carbide composite material layers, and the aluminum alloy material layers and the aluminum matrix silicon carbide composite material layers are alternately arranged in sequence, where n = m or n = m + 1, and m ≥ 1; The thickness ratio of a single-layer aluminum alloy material layer to a single-layer aluminum matrix silicon carbide composite material layer is 1:1 to 1:5; the total thickness of the metallized ceramic multi-layer composite material ≤ 2.0 mm; The aluminum matrix silicon carbide composite material in the aluminum matrix silicon carbide composite material layer is obtained by compounding silicon carbide particles with an Al-Mg-Si-Cu alloy, and the volume percentage of silicon carbide particles in the aluminum matrix silicon carbide composite material is 15% - 30%.

[0007] In an optional embodiment, the metallized ceramic multi-layer composite material has a two-layer structure, and the metallized ceramic multi-layer composite material is composed of an aluminum matrix silicon carbide composite material layer and an aluminum alloy material layer disposed on any one side surface of the aluminum matrix silicon carbide composite material layer.

[0008] In an alternative embodiment, the metallized ceramic multi-layer composite material has a three-layer structure and is composed of an aluminum matrix silicon carbide composite material layer and aluminum alloy material layers disposed on both surface sides of the aluminum matrix silicon carbide composite material layer.

[0009] In an alternative embodiment, the metallized ceramic multi-layer composite material has at least one of the following characteristics: Characteristic 1: The thickness ratio of a single-layer aluminum alloy material layer to a single-layer aluminum matrix silicon carbide composite material layer is 1:1 to 1:3; Characteristic 2: The total thickness of the metallized ceramic multi-layer composite material ≤ 1.5 mm; Characteristic 3: The D 50 of the silicon carbide particles is 3 μm to 10 μm.

[0010] In a second aspect, the present invention provides a method for preparing a metallized ceramic multi-layer composite material according to any one of the foregoing embodiments, including the following steps: hot-rolling and laminating alternately stacked aluminum alloy materials and aluminum matrix silicon carbide composite materials according to a preset number of layers, followed by diffusion annealing, second hot-rolling, intermediate annealing, cold-rolling, solution treatment, straightening, stretching treatment, and aging treatment.

[0011] In an alternative embodiment, before hot-rolling and laminating, it further includes: pre-treating the aluminum alloy material and the aluminum matrix silicon carbide composite material; wherein, the pre-treatment includes at least one of surface texturing treatment, laser drilling, ultrasonic cleaning, and mechanical bonding.

[0012] In an alternative embodiment, the hot-rolling and laminating includes at least one of the following characteristics: Characteristic 4: The heating temperature of the hot-rolling and laminating is 450 °C to 520 °C; Characteristic 5: The heating and holding time of the hot-rolling and laminating is 15 min to 30 min; Characteristic 6: The form of the hot-rolling and laminating is single-pass large-deformation rolling, wherein the single-pass rolling deformation amount is 30% to 40%.

[0013] In an alternative embodiment, the diffusion annealing includes at least one of the following characteristics: Characteristic 7: The temperature of the diffusion annealing is 360 °C to 420 °C; Characteristic 8: The time of the diffusion annealing is 0.5 h to 2 h; Characteristic 9: The form of the diffusion annealing is press-plate diffusion annealing.

[0014] In an alternative embodiment, surface sanding treatment is further included between the diffusion annealing and the second hot-rolling.

[0015] In an alternative embodiment, the second hot rolling includes at least one of the following features: Feature 10: The heating temperature of the second hot rolling is 450°C to 500°C; Feature 11: The heating and holding time of the second hot rolling is 10 min to 20 min; Feature 12: The second hot rolling method is multi-pass rolling with small deformation, where the deformation per pass is 10% to 15%.

[0016] In an alternative embodiment, the intermediate annealing includes at least one of the following features: Feature 13: The temperature of the intermediate annealing is 350°C to 400°C; Feature 14: The time of the intermediate annealing is 0.5 h to 1 h.

[0017] In an alternative embodiment, the deformation per pass during cold rolling is 5% to 10%.

[0018] In an alternative embodiment, trimming is also included between cold rolling and solution treatment, and the trimming amount on each side is ≤ 6 mm.

[0019] In an alternative embodiment, the solution treatment includes at least one of the following features: Feature 15: The temperature of the solution treatment is 480°C to 530°C; Feature 16: The time of the solution treatment is 5 min to 30 min.

[0020] In an alternative embodiment, the stretching treatment includes at least one of the following features: Feature 17: The stretching deformation ratio of the stretching treatment is 0.8% to 1.5%; Feature 18: The flatness after the stretching treatment is ≤ 0.5 mm.

[0021] In an alternative embodiment, the aging treatment includes at least one of the following features: Feature 19: The temperature of the aging treatment is 170°C to 180°C; Feature 20: The time of the aging treatment is 4 h to 16 h.

[0022] In a third aspect, the present invention provides an application of a metallized ceramic multi-layer composite material according to any one of the foregoing embodiments, and the metallized ceramic multi-layer composite material is used to prepare a housing.

[0023] In a fourth aspect, the present invention provides a housing, and the raw materials for preparing the housing include the metallized ceramic multi-layer composite material according to any one of the foregoing embodiments.

[0024] In an alternative embodiment, the housing is a housing of an electronic device.

[0025] In an alternative embodiment, the housing is the housing of a 3C product.

[0026] In an alternative embodiment, the housing is the outer housing of a mobile terminal product.

[0027] In an alternative embodiment, the mobile terminal product includes at least one of a laptop computer, a tablet computer, and a mobile phone.

[0028] The beneficial effects of the present invention include: The present invention creatively composes an aluminum alloy material layer on at least one surface of an aluminum matrix silicon carbide composite material layer made of a specific material, while controlling the thickness ratio of a single-layer aluminum alloy material layer to a single-layer aluminum matrix silicon carbide composite material layer, and controlling the total thickness of the metallized ceramic multi-layer composite material, effectively avoiding problems such as unstable process, difficult rolling, and easy edge cracking when anodizing the aluminum matrix silicon carbide composite material layer as the appearance surface. Moreover, the present invention solves or improves the problems of difficult rolling processing, low yield rate, and difficult surface quality control of aluminum matrix silicon carbide composite materials (especially low-volume fraction aluminum matrix silicon carbide composite materials) through a specific preparation method, realizes the interfacial metallurgical bonding of the aluminum alloy material layer and the aluminum matrix silicon carbide composite material layer, and finally obtains a layered composite material with excellent comprehensive performance, controllable thickness accuracy of each layer, and controllable surface quality, which can meet the requirements of electronic device housings for lightweight, high stiffness, high strength, high thermal conductivity, and appearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 Digital microscope image of the composite interface of the metallized ceramic multi-layer composite material prepared in Example 1; Figure 2 For Figure 1 Enlarged view of a partial area in; Figure 3 Panoramic digital microscope image of the composite interface of the metallized ceramic multi-layer composite material prepared in Example 2; Figure 4 For Figure 3 Enlarged view of a partial area in; Figure 5 Panoramic digital microscope image of the composite interface of the metallized ceramic multi-layer composite material prepared in Example 3; Figure 6 is Figure 5 an enlarged view of a partial area in Figure 7 is Figure 1 a metallographic microscope image of the aluminum matrix silicon carbide composite layer in at a magnification of 500X; Figure 8 is Figure 1 a scanning electron microscope image of the aluminum matrix silicon carbide composite layer in at a magnification of 500X. Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For reagents or instruments whose manufacturers are not specified, they are all conventional products that can be obtained through commercial purchase.

[0032] The following specifically describes the metallized ceramic multi-layer composite material provided by the present invention, its preparation method, and applications.

[0033] The present invention provides a metallized ceramic multi-layer composite material, which includes n layers of aluminum alloy material layers and m layers of aluminum matrix silicon carbide composite layers. The aluminum alloy material layers and the aluminum matrix silicon carbide composite layers are alternately arranged in sequence, where n = m or n = m + 1, and m ≥ 1.

[0034] That is to say, the number of layers of the aluminum alloy material layer is equal to or more than the number of layers of the aluminum matrix silicon carbide composite layer. In other words, in the metallized ceramic multi-layer composite material, at least one outermost layer on one side is an aluminum alloy material layer. The aluminum matrix silicon carbide composite layer can be used as a support plate or a reinforcing plate to improve the stiffness of the metallized ceramic multi-layer composite material; the outermost aluminum alloy material layer can be subjected to anodizing treatment for appearance, avoiding problems such as unstable process, difficult rolling, and easy occurrence of edge cracks when the aluminum matrix silicon carbide composite layer is used as the appearance surface for anodizing treatment.

[0035] As an example, m can take values of 1, 2, 3, 4, 5 or more, and can be specifically set according to actual needs.

[0036] In some optional implementation manners, the metallized ceramic multi-layer composite material has a two-layer structure. At this time, n = m = 1, and the metallized ceramic multi-layer composite material is composed of an aluminum matrix silicon carbide composite layer and an aluminum alloy material layer disposed on any one side surface of the aluminum matrix silicon carbide composite layer. Specifically, it can be understood that in the upward direction, the layer structure of the metallized ceramic multi-layer composite material is: aluminum alloy material layer - aluminum matrix silicon carbide composite layer, or aluminum matrix silicon carbide composite layer - aluminum alloy material layer.

[0037] In other optional embodiments, the metallized ceramic multilayer composite material is a three-layer structure, in which case m=1, n=m+1=2, and the metallized ceramic multilayer composite material is composed of an aluminum-based silicon carbide composite material layer and an aluminum alloy material layer arranged on the surface of both sides of the aluminum-based silicon carbide composite material layer. Specifically, it can be understood that, from bottom to top, the layer structure of the metallized ceramic multilayer composite material is: aluminum alloy material layer-aluminum-based silicon carbide composite material layer-aluminum alloy material layer. It should be emphasized that the production of aluminum-based silicon carbide composite material layers into sheets or plates with a thickness of less than 1 mm requires extremely complex processes, and the process flow is long, the cost is high, and there is a problem that the appearance cannot be anodized. The present invention can improve problems such as edge cracking of the plate during rolling, improve the yield rate, and reduce material costs by arranging aluminum alloy material layers on both sides of the aluminum-based silicon carbide composite material layer; and this sandwich structure can make the temperature of the metallized ceramic multilayer composite material not easy to lose, and avoid excessive cooling.

[0038] In the present invention, the thickness ratio of a single-layer aluminum alloy material layer to a single-layer aluminum-based silicon carbide composite material layer can be 1:1 to 1:5, such as 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, etc., or other values ​​within the range of 1:1 to 1:5. In some typical embodiments, the thickness ratio of a single-layer aluminum alloy material layer to a single-layer aluminum-based silicon carbide composite material layer can be 1:1 to 1:3.

[0039] In the present invention, the total thickness of the metallized ceramic multilayer composite material is ≤2mm, such as 2mm, 1.8mm, 1.5mm, 1.2mm, 1.0mm, 0.8mm, 0.6mm, 0.4mm or 0.2mm, etc., and can also be other values ​​within the range of >0 and ≤2mm. In some typical embodiments, the total thickness of the metallized ceramic multilayer composite material is ≤1.5mm; in some more typical embodiments, the total thickness of the metallized ceramic multilayer composite material is 0.3mm~1.2mm. For example, when the metallized ceramic multilayer composite material is used as or used to prepare a metal shell of a laptop computer, the total thickness of the metallized ceramic multilayer composite material is preferably set to 0.6mm~1.2mm; when the metallized ceramic multilayer composite material is used as or used to prepare a metal shell of a tablet computer, the total thickness of the metallized ceramic multilayer composite material is preferably set to 0.3mm~0.8mm.

[0040] As an example, taking the metallized ceramic multi-layer composite material as a two-layer structure with a total thickness of 0.6 mm, the thickness of a single-layer aluminum alloy material layer and a single-layer aluminum matrix silicon carbide composite material layer can both be 0.3 mm, or the thickness of the single-layer aluminum alloy material layer and the single-layer aluminum matrix silicon carbide composite material layer are 0.2 mm and 0.4 mm respectively, or the thickness of the single-layer aluminum alloy material layer and the single-layer aluminum matrix silicon carbide composite material layer are 0.15 mm and 0.45 mm respectively.

[0041] As an example, taking the metallized ceramic multi-layer composite material as a three-layer structure with a total thickness of 0.8 mm, the thickness of a single-layer aluminum alloy material layer and a single-layer aluminum matrix silicon carbide composite material layer are 0.2 mm and 0.4 mm respectively. Taking the metallized ceramic multi-layer composite material as a three-layer structure with a total thickness of 1.0 mm, the thickness of a single-layer aluminum alloy material layer and a single-layer aluminum matrix silicon carbide composite material layer are 0.2 mm and 0.6 mm respectively. Taking the metallized ceramic multi-layer composite material as a three-layer structure with a total thickness of 0.6 mm, the thickness of a single-layer aluminum alloy material layer and a single-layer aluminum matrix silicon carbide composite material layer are 0.15 mm and 0.3 mm respectively.

[0042] In the present invention, the aluminum matrix silicon carbide composite material in the aluminum matrix silicon carbide composite material layer is obtained by compounding silicon carbide particles with an Al-Mg-Si-Cu alloy. Among them, the silicon carbide particles play the role of a reinforcing phase, and the Al-Mg-Si-Cu alloy plays the role of a matrix.

[0043] The volume percentage of the above silicon carbide particles in the aluminum matrix silicon carbide composite material can be 15% - 30%, such as 15%, 20%, 25% or 30%, etc., or other values within the range of 15% - 30%. In other words, the volume percentage of the Al-Mg-Si-Cu alloy in the aluminum matrix silicon carbide composite material can be 70% - 85%.

[0044] It should be noted that at present, aluminum matrix silicon carbide composites can be roughly divided into low volume fraction systems (the volume percentage of SiC component is 15% - 30%), medium volume fraction systems (the volume percentage of SiC component is 35% - 55%), and high volume fraction systems (the volume percentage of SiC component > 55% and ≤ 75%) according to the proportion of SiC components (volume percentage). For the present invention, neither the medium volume fraction system nor the high volume fraction system is applicable. The reasons are as follows: If the volume percentage of the SiC component in the aluminum matrix silicon carbide composite is less than 15%, the elastic modulus of the aluminum matrix silicon carbide composite will be relatively low, and it cannot play a role in improving the stiffness of the metallized ceramic multi-layer composite. If the volume percentage of the SiC component in the aluminum matrix silicon carbide composite is higher than 30%, since silicon carbide is a hard and brittle ceramic particle, it will cause the metallized ceramic multi-layer composite to be more brittle and hard, with low elongation and extremely poor plasticity, and the rolling difficulty is relatively large (such as problems like cracks or fractures are likely to occur during the rolling process), which is not suitable for the development and preparation of sheet products. The present invention specifically adopts an aluminum matrix silicon carbide composite of the low volume fraction system, which can not only effectively avoid the above problems, but also has the advantages of being thin, light, high thermal conductivity, high strength, etc. Compared with traditional aluminum-magnesium alloys, it has a higher specific stiffness and the thickness can be reduced by half; compared with steel-aluminum composites, it is lighter in weight, with a weight reduction of more than 50%; compared with titanium alloys, it has a higher specific stiffness, is lighter and has good thermal conductivity, and can make the metallized ceramic multi-layer composite applicable to the shell (especially the outer shell of mobile terminal products).

[0045] In some alternative embodiments, the above-mentioned aluminum matrix silicon carbide composite of the low volume fraction system has the advantages of high strength (> 300 MPa), high stiffness (elastic modulus > 70 GPa), high thermal conductivity (thermal conductivity > 120 W / (m·K)), lightweight (density < 3 g / cm 3 ) and so on.

[0046] The D of the silicon carbide particles 50 can be 3 μm - 10 μm, such as 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm, etc., or other values within the range of 3 μm - 10 μm.

[0047] It should be noted that if the D of the silicon carbide particles 50 is too small (such as < 3 μm), it is easy to be difficult to disperse evenly during the preparation process, and in the powder metallurgy method, it is easy to cause uneven regions in the sintered aluminum matrix silicon carbide composite, reducing the overall performance of the material. If the D of the silicon carbide particles 50Too large (e.g., >10 μm), the specific surface area of the particles is smaller, and the dispersibility is better, but the interfacial bonding between the silicon carbide particles and the aluminum matrix is poor. For example, due to the large size of the silicon carbide particles, the interfacial region may become the starting point of cracks. Especially when subjected to external forces, large particles are prone to initiate crack propagation, resulting in an increase in the brittleness of the material and a decrease in toughness. In addition, the size of the silicon carbide particles also affects the density of the aluminum matrix silicon carbide composite material. If the silicon carbide particles are too small, they may not be able to effectively fill the voids between large particles due to agglomeration, resulting in an increase in porosity; while if the silicon carbide particles are too large, it may be difficult to effectively arrange them during the pressing process, causing large voids in the material, which will also affect the density and mechanical properties of the material.

[0048] In some alternative embodiments, taking the metalized ceramic multi-layer composite material with a three-layer structure as an example, the density of the metalized ceramic multi-layer composite material < 3 g / cm 3 , the flexural stiffness / elastic modulus > 80 GPa, the strength > 300 MPa, the thermal conductivity > 160 W / (m·K), and the appearance can be anodized, bent / stamped, etc.

[0049] In some alternative embodiments, the width of the metalized ceramic multi-layer composite material can be ≤ 300 mm, and the length can be ≤ 600 mm. This size can meet the requirements of most current 3C electronic products and other mobile terminals. Of course, in other embodiments, the width and / or length of the metalized ceramic multi-layer composite material can also be set to other values according to actual needs.

[0050] Correspondingly, the present invention also provides a preparation method for the above-mentioned metalized ceramic multi-layer composite material, which may include the following steps: hot-rolling and laminating the alternately stacked aluminum alloy material and the aluminum matrix silicon carbide composite material according to a preset number of layers, followed by diffusion annealing, secondary hot-rolling, intermediate annealing, cold rolling, solution treatment, straightening, stretching treatment, and aging treatment.

[0051] In some alternative embodiments, before hot-rolling and laminating, it further includes: pre-treating the aluminum alloy material and the aluminum matrix silicon carbide composite material. The above-mentioned aluminum alloy material can be a coil, and the aluminum matrix silicon carbide composite material can be a sheet or a plate.

[0052] Exemplarily, the thickness of the aluminum alloy material can be 0.4 mm to 2.5 mm, and the width can be 50 mm to 300 mm; the thickness of the aluminum matrix silicon carbide composite material can be 0.4 mm to 4.2 mm, the width can be 50 mm to 300 mm, and the length can be 100 mm to 300 mm.

[0053] The pre-treatment may include at least one of surface texturing treatment, laser drilling, ultrasonic cleaning, and mechanical bonding.

[0054] Exemplarily, the aluminum matrix silicon carbide composite material can be subjected to double-sided 45° oblique surface texturing with a 150-mesh abrasive belt. The texturing removal thickness can be 0.1 mm, and the surface roughness of the aluminum matrix silicon carbide composite material after texturing can be 2 μm to 6 μm, ensuring uniform stress on the aluminum matrix silicon carbide composite material during the texturing process. Exemplarily, the aluminum alloy coil can be subjected to single-sided texturing, and the texturing direction can be along the length direction of the coil. The texturing removal thickness can be 0.05 mm, and the surface roughness of the aluminum alloy coil after texturing can be 1.5 μm to 4 μm, ensuring uniform stress on the aluminum alloy coil during the texturing process. Through surface texturing treatment, the oxide scale, oil stain, and dust on the surfaces of the aluminum alloy material and the aluminum matrix silicon carbide composite material can be polished off, keeping their surfaces clean.

[0055] Exemplarily, laser drilling can be carried out in the following manner: After positioning the aluminum alloy material (such as a plate) and the aluminum matrix silicon carbide composite material (such as a plate), laser cutting is used to process riveting holes. Specifically: Round holes are cut at both ends in the length direction, and the round holes are located in the middle position corresponding to the width direction at each end. The diameter of the round hole can be 3.2 mm, for example, and the shortest distance from the round hole to the edge of the plate in the length direction can be 5 mm. By using the method of laser drilling, batch drilling can be achieved, with high efficiency, and it is beneficial to keep the positions of the corresponding holes in the upper and lower layers consistent.

[0056] Exemplarily, ultrasonic cleaning can be carried out in the following manner: Ultrasonic water washing for 2 minutes to remove surface dirt completely to make the bonding surface clean, and then drying treatment after water washing is sufficient.

[0057] Exemplarily, mechanical bonding can be carried out in the following manner: Rivets are used to achieve mechanical bonding of each layer of materials, ensuring that each layer of materials is aligned and there is no dislocation.

[0058] In some alternative embodiments, the heating temperature for hot rolling composite can be 450°C to 520°C, such as 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, or 520°C, etc., or other values within the range of 450°C to 520°C.

[0059] If the temperature of hot rolling composite is lower than 450°C, it is likely to cause problems such as increased deformation resistance, poor plastic flow ability, insufficient interfacial bonding after rolling, and edge cracking during the rolling process of the laminated material; if the temperature of hot rolling composite is higher than 520°C, an oxide layer is likely to be generated on the surface of the laminated material, thereby affecting the bonding effect between layers.

[0060] The heating and holding time for hot rolling composite can be 15 minutes to 30 minutes, such as 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes, or 30 minutes, etc., or other values within the range of 15 minutes to 30 minutes.

[0061] The form of hot rolling composite is single-pass rolling with a large deformation amount. Among them, the deformation amount of single-pass rolling is 30% - 40%, such as 30%, 35% or 40%, etc. If the deformation amount of single-pass rolling is greater than 40%, it is easy to cause serious edge cracking.

[0062] The rolls for hot rolling composite are preferably flat rolls, and the flatness and size of the roll gap are adjusted well before rolling.

[0063] The above hot rolling composite process utilizes the powerful pressure of the rolling mill and the rolls, and through a large enough rolling deformation amount, intense plastic deformation occurs at the interface between the aluminum alloy material layer and the aluminum matrix silicon carbide composite material layer, so that they are bonded together. In other words, during the rolling process, the surface of the metal to be bonded ruptures, and then the two fresh metals come into contact with each other and form a good bond.

[0064] In some alternative embodiments, the temperature of diffusion annealing can be 360°C - 420°C, such as 360°C, 370°C, 380°C, 390°C, 400°C, 410°C or 420°C, etc., or other values within the range of 360°C - 420°C.

[0065] The time of diffusion annealing can be 0.5h - 2h, such as 0.5h, 1h, 1.5h or 2h, etc., or other values within the range of 0.5h - 2h.

[0066] The form of diffusion annealing can adopt press plate diffusion annealing.

[0067] For the above press plate diffusion annealing, on the one hand, it can further promote the metallurgical bond of the bonding surface through the diffusion process and strengthen the bonding force between layers; on the other hand, it can achieve press calibration of the plate shape to ensure better flatness, which is beneficial to the subsequent surface sanding treatment. The flatness after press calibration is preferably controlled to be ≤0.5mm. It should be noted that although hot rolling composite can make the laminated composite material form a good interface bond, subsequent reasonable diffusion annealing treatment is still required to obtain a good metallurgical bond at the interface. Through diffusion annealing, the interface atoms can diffuse, and on the premise of not generating a relatively thick intermetallic compound, the bonding strength of the laminated composite plate can be improved.

[0068] In some alternative embodiments, surface sanding treatment is also included between diffusion annealing and the second hot rolling. Exemplarily, a 400-mesh sand belt can be used for sanding treatment to remove the dirt and defects on the upper and lower surfaces of the material completely and ensure uniform sanding.

[0069] In some alternative embodiments, the heating temperature of the second hot rolling can be 450°C - 500°C, such as 450°C, 460°C, 470°C, 480°C, 490°C or 500°C, etc., or other values within the range of 450°C - 500°C.

[0070] The heating and holding time for the second hot rolling can be 10 min to 20 min, such as 10 min, 12 min, 15 min, 18 min, or 20 min, etc., or other values within the range of 10 min to 20 min.

[0071] The second hot rolling method can be multi-pass rolling with small deformation amounts. Among them, the deformation amount per pass is 10% to 15%, such as 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, or 15%, etc.

[0072] By adopting multi-pass rolling with small deformation amounts, it is beneficial to control the thickness uniformity and avoid edge cracking at the edges. Exemplarily, the thickness of the laminated composite material after the second hot rolling can be 0.5 mm ± 0.05 mm to 1.2 mm ± 0.05 mm, and the edge crack length ≤ 5 mm.

[0073] In some alternative embodiments, the temperature of the intermediate annealing can be 350 °C to 400 °C, such as 350 °C, 360 °C, 370 °C, 380 °C, 390 °C, or 400 °C, etc., or other values within the range of 350 °C to 400 °C.

[0074] The time for the intermediate annealing can be 0.5 h to 1 h, such as 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h, or 1 h, etc., or other values within the range of 0.5 h to 1 h.

[0075] Through the intermediate annealing, the stress can be removed, which is beneficial to eliminating work hardening and preparing for the subsequent cold rolling.

[0076] In some alternative embodiments, the deformation amount per pass during the cold rolling can be 5% to 10%, such as 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%, etc., or other values within the range of 5% to 10%.

[0077] Exemplarily, a four-high or six-high rolling mill with higher precision can be used for cold rolling, and the roll roughness ≤ 0.45 μm, which is beneficial to controlling the rolling thickness precision, uniformity, and the surface quality of the sheet. In some alternative ways, through the above cold rolling, different rolling thicknesses within the range of 0.2 mm to 0.9 mm can be achieved, and the edge crack length can be controlled ≤ 5 mm.

[0078] In some alternative embodiments, trimming is also included between the cold rolling and the solution treatment. The trimming mainly removes the micro-cracks at the edges. Exemplarily, the unilateral trimming amount can ≤ 6 mm.

[0079] In some alternative embodiments, the solution treatment temperature can be 480°C to 530°C, such as 480°C, 490°C, 500°C, 510°C, 520°C or 530°C, etc., or other values within the range of 480°C to 530°C.

[0080] The solution treatment time can be 5 min to 30 min, such as 5 min, 10 min, 15 min, 20 min, 25 min or 30 min, etc., or other values within the range of 5 min to 30 min.

[0081] The cooling method for solution treatment can adopt water cooling.

[0082] In some alternative embodiments, a high-precision 25-roll straightening machine can be used for precision straightening.

[0083] In some alternative embodiments, the tensile deformation ratio of the stretching treatment can be 0.8% to 1.5%, such as 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5%, etc., or other values within the range of 0.8% to 1.5%.

[0084] The flatness after stretching treatment is ≤ 0.5 mm.

[0085] In some alternative embodiments, the aging treatment temperature can be 170°C to 180°C, such as 170°C, 172°C, 175°C, 178°C or 180°C, etc., or other values within the range of 170°C to 180.

[0086] The aging treatment time can be 4 h to 16 h, such as 4 h, 8 h, 10 h, 12 h, 14 h or 16 h, etc., or other values within the range of 4 h to 16 h.

[0087] The cooling method for aging treatment can adopt air cooling.

[0088] After aging treatment, the product can be slit. For example, the head and tail can be cut off and slit according to size requirements.

[0089] It should be noted that the production difficulties of the metallized ceramic multi-layer composite material provided by the present invention include: (1) the interfacial composite of different materials; (2) the co-deformation and co-thermal treatment of different materials; (3) the control of the thickness accuracy and uniformity of each composite layer material. Among them, the difficulty of interfacial composite mainly lies in that an oxide film is easily formed on the material surface, hindering the interfacial composite. The difficulties of co-deformation and co-thermal treatment mainly lie in the large performance differences between two materials, namely aluminum and aluminum matrix silicon carbide, such as deformation resistance, linear expansion coefficient, elongation rate, etc. The present invention realizes the metallurgical bond between layered materials by controlling the influence of oxidation problems on the bonding strength. The present invention realizes the co-deformation and co-thermal treatment of different materials by exploring the balance point of the processing deformation and heat treatment process parameters between aluminum and aluminum matrix silicon carbide. The present invention realizes the thickness accuracy, thickness uniformity and flatness of the composite interface by combining the control of the thickness size of raw materials, the control of heating and rolling process conditions, and the control of the deformation ratio between layers.

[0090] Continuing from the above, the present invention realizes good interfacial metallurgical bond of dissimilar plates through specific processing means (such as rolling composite, diffusion annealing, second hot rolling, intermediate annealing, etc.). Moreover, through multiple cumulative rollings, the present invention breaks through the limiting conditions such as poor ductility of the equipment and materials themselves, enables the plate to obtain a large reduction, so as to achieve good metallurgical bond between layers, and no delamination and other problems will occur after tensile or bending tests until fracture.

[0091] In addition, the present invention also provides the application of the above-mentioned metallized ceramic multi-layer composite material. For example, the metallized ceramic multi-layer composite material can be used to prepare a housing, especially an outer housing.

[0092] Correspondingly, the present invention also provides a housing, and the preparation raw materials of the housing include the above-mentioned metallized ceramic multi-layer composite material. The housing can have the characteristics of ultra-thin (≤2 mm, preferably ≤1.5 mm, further preferably 0.3 mm - 1.2 mm), lightweight, etc.

[0093] In some alternative embodiments, the housing is a housing of an electronic device. For example, it can be a housing of 3C products, and further can be an outer housing of a mobile terminal product. Among them, the mobile terminal product can include at least one of a laptop computer, a tablet computer and a mobile phone.

[0094] The features and properties of the present invention will be further described in detail below in conjunction with embodiments.

[0095] Example 1 This example provides a metallized ceramic multi-layer composite material, and its preparation method includes: S1: Material preparation (all directly purchased from commercially available products).

[0096] Aluminum alloy material: Coil, 1 coil, 6R01 aluminum alloy, with a thickness of about 0.65 mm and a width of 250 mm ± 0.1 mm; Aluminum matrix silicon carbide composite material: Plate, 1 piece; Low volume fraction system, the volume percentage of SiC component is 17.5% (the D of silicon carbide particles is 5 μm - 10 μm), correspondingly, the volume percentage of Al-Mg-Si-Cu alloy is 82.5%; The thickness is about 1.3 mm, the width is 250 mm ± 0.1 mm, and the length is 200 mm ± 0.1 mm. 50 For (the D of silicon carbide particles is 5 μm - 10 μm), correspondingly, the volume percentage of Al-Mg-Si-Cu alloy is 82.5%; The thickness is about 1.3 mm, the width is 250 mm ± 0.1 mm, and the length is 200 mm ± 0.1 mm.

[0097] S2: Surface texturing treatment.

[0098] The aluminum alloy coil is textured on one side, and the texturing direction is along the length direction of the coil. After texturing, the thickness is 0.6 mm, and the surface roughness Ra after texturing is 2 μm - 4 μm. The texturing force on the whole coil is uniform; The aluminum matrix silicon carbide composite material is textured on both sides at a 45° oblique angle with a 150 - mesh abrasive belt. After texturing, the thickness is 1.2 mm, and the surface roughness Ra after texturing is 3 μm - 5 μm. The texturing force on the whole plate is uniform.

[0099] S3: Aluminum plate cutting.

[0100] The aluminum alloy coil after surface texturing treatment is cut into plates with a thickness of 0.6 mm, a width of 250 mm ± 0.1 mm, and a length of 200 mm ± 0.1 mm, 2 pieces.

[0101] S4: Laser drilling.

[0102] After positioning the above 2 pieces of aluminum alloy plates and 1 piece of aluminum matrix silicon carbide composite plate on the laser cutting platform, laser cutting is used to process riveting holes. Specifically: Round holes are cut at both ends in the length direction, and the round holes are located in the middle position of the corresponding width direction at each end. The diameter of the round hole is 3.2 mm, and the shortest distance from the round hole to the edge of the plate in the length direction end is 5 mm.

[0103] S5: Ultrasonic cleaning.

[0104] Ultrasonic water washing for 2 min, and then drying until there is no water stain residue; S6: Mechanical bonding.

[0105] Align the 3 plates in the order of aluminum alloy plate, aluminum matrix silicon carbide composite plate, and aluminum alloy plate from bottom to top, and then use rivets to mechanically bond the 3 plates.

[0106] S7: Hot rolling composite.

[0107] The heating temperature for hot rolling composite is 520 °C, the heating and holding time for hot rolling composite is 20 min, the form of hot rolling composite is single-pass large deformation rolling, the single-pass rolling deformation is 30%, the rolls are flat rolls, and the roll gap flatness and size are adjusted well before rolling; cross rolling is carried out with a width of 250 mm, and three plates (with thicknesses of 0.6 mm, 1.2 mm, and 0.6 mm respectively) are hot rolled and combined to a total thickness of 1.6 mm (with a tolerance of 0 mm to 0.1 mm).

[0108] S8: Diffusion annealing.

[0109] A pressing and straightening tooling is used to carry out pressing plate diffusion annealing on the rolled and combined material to obtain a laminated intermediate composite material; the temperature for pressing and straightening diffusion annealing is 400 °C, the time is 2 h, and the flatness after pressing and straightening is 0.3 mm.

[0110] S9: Surface sanding treatment.

[0111] The laminated intermediate composite material is sanded with a 400-mesh sand belt, and the thickness of the laminated intermediate composite material after sanding treatment is controlled at 1.55 mm (with a tolerance of 0 mm to 0.1 mm).

[0112] S10: Second hot rolling.

[0113] The heating temperature for the second hot rolling is 500 °C, and the heating and holding time for the second hot rolling is 15 min; multi-pass small deformation rolling is adopted, the single-pass deformation is 10%, and the edge crack length ≤ 5 mm; the thickness of the laminated intermediate composite material after the second hot rolling is 1.0 mm ± 0.05 mm, that is, the thickness of the laminated intermediate composite material after the second hot rolling is 1.0 mm ± 0.05 mm, the width is 255 mm ± 0.1 mm, and the length is 450 mm ± 0.1 mm.

[0114] S11: Intermediate annealing.

[0115] The temperature for intermediate annealing is 400 °C, and the time is 1 h.

[0116] S12: Cold rolling.

[0117] Cold rolling is carried out with a four-high rolling mill with higher precision, and the surface roughness of the rolls is 0.4 μm to 0.45 μm; cold rolling is carried out until the thickness of the laminated intermediate composite material is 0.6 mm ± 0.05 mm; during cold rolling, the single-pass deformation is controlled at 5%, and the edge crack length ≤ 3 mm; the thickness of the laminated intermediate composite material after cold rolling is 0.6 mm ± 0.03 mm, the width is 255 mm ± 0.1 mm, and the length is 750 mm ± 0.1 mm.

[0118] S13: Edge trimming.

[0119] Remove the microcracks on the edges and ensure straight cutting; the unilateral edge cutting amount is 5 mm.

[0120] S14: Solution treatment.

[0121] The temperature of the solution treatment is 520 °C, the time is 30 min, and water cooling is used.

[0122] S15: Straightening.

[0123] The material after solution treatment is precisely straightened by a high-precision 25-roll straightening machine.

[0124] S16: Tensile treatment.

[0125] The straightened laminated intermediate composite material is subjected to tensile straightening treatment, the tensile deformation ratio is 1.0%, the head and tail tensile clamping length is 15 mm, and finally a laminated intermediate composite material with a flatness of 0.4 mm is obtained.

[0126] S17: Aging treatment.

[0127] The temperature of the aging treatment is 175 °C, the time is 16 h, and air cooling is used.

[0128] S18: Finished product slitting.

[0129] The head, tail and clamping ends of the laminated intermediate composite material after aging treatment are removed and slit into 2 pieces of metallized ceramic multi-layer composite material finished products. The total thickness of each metallized ceramic multi-layer composite material finished product is 0.6 mm ± 0.03 mm, the width is 245 mm ± 0.1 mm, and the length is 360 mm ± 0.1 mm.

[0130] That is, the metallized ceramic multi-layer composite material finished product has a three-layer structure, which is, from bottom to top, an aluminum alloy material layer of about 0.15 mm, an aluminum matrix silicon carbide composite material layer of about 0.3 mm, and an aluminum alloy material layer of about 0.15 mm; the thickness ratio of each layer is about 1:2:1.

[0131] Example 2 This example provides a metallized ceramic multi-layer composite material, and its preparation method includes: S1: Material preparation (all directly purchased from commercially available products).

[0132] Aluminum alloy material: Coil, 1 roll, 6061 aluminum alloy, thickness about 1.25 mm, width 250 mm ± 0.1 mm; Aluminum matrix silicon carbide composite material: Plate, 1 piece; low-volume fraction system, the volume percentage of SiC component is 15% (the D of silicon carbide particles 50The size is 3μm to 5μm,), correspondingly, the volume percentage of the Al-Mg-Si-Cu alloy is 85%; the thickness is about 1.3mm, the width is 250mm ± 0.1mm, and the length is 200mm ± 0.1mm.

[0133] S2: Surface texturing treatment.

[0134] The aluminum alloy coil is textured on one side, and the texturing direction is along the length direction of the coil. After texturing, the thickness is 1.2mm, and the surface roughness Ra after texturing is 1.5μm to 2μm. The force on the entire coil during texturing is uniform; The aluminum matrix silicon carbide composite material is textured on both sides at an angle of 45° with 150-mesh abrasive belts. After texturing, the thickness is 1.2mm, and the surface roughness Ra after texturing is 2μm to 3μm. The force on the entire plate during texturing is uniform.

[0135] S3: Aluminum plate slitting.

[0136] The aluminum alloy coil after surface texturing treatment is slit into plates with a thickness of 1.2mm, a width of 250mm ± 0.1mm, and a length of 200mm ± 0.1mm, 1 piece.

[0137] S4: Laser drilling.

[0138] After positioning the above 1 piece of aluminum alloy plate and 1 piece of aluminum matrix silicon carbide composite plate on the laser cutting platform, laser cutting is used to process riveting holes. Specifically: round holes are cut at both ends in the length direction, and the round holes are located in the middle position of the corresponding width direction at each end. The diameter of the round hole is 3.2mm, and the shortest distance from the round hole to the edge of the plate in the length direction is 5mm.

[0139] S5: Ultrasonic cleaning.

[0140] Ultrasonic water washing for 2min, and after washing, it is dried until there is no water stain residue; S6: Mechanical bonding.

[0141] Align the aluminum alloy plate and the aluminum matrix silicon carbide composite plate, and then use rivets to mechanically bond the two plates.

[0142] S7: Hot rolling composite.

[0143] The heating temperature for hot rolling composite is 450°C, the heating and holding time for hot rolling composite is 30min, the form of hot rolling composite is single-pass large deformation rolling, the single-pass rolling deformation amount is 33%, the rolling mill uses flat rolls, and the roll gap flatness and size are adjusted before rolling; cross rolling is carried out with a width of 250mm, and the two plates (with thicknesses of 1.2mm and 1.2mm respectively) are hot rolled and combined to a total thickness of 1.6mm (tolerance is 0mm to 0.1mm).

[0144] S8: Diffusion annealing.

[0145] Using a pressing and calibration tooling, the rolled and compounded material is subjected to pressing plate diffusion annealing to obtain a laminated intermediate composite material; the temperature of the pressing and calibration diffusion annealing is 360°C, the time is 1 h, and the flatness after pressing and calibration is 0.2 mm.

[0146] S9: Surface sanding treatment.

[0147] The laminated intermediate composite material is sanded using a 400-mesh sand belt, and the thickness of the laminated intermediate composite material after sanding treatment is controlled at 1.55 mm (the tolerance is 0 mm to 0.15 mm).

[0148] S10: Second hot rolling.

[0149] The heating temperature of the second hot rolling is 450°C, and the heating and holding time of the second hot rolling is 20 min; multi-pass rolling with small deformation is adopted, the single-pass deformation is controlled at 15%, and the edge crack length ≤ 5 mm; the thickness of the laminated intermediate composite material after the second hot rolling is 1.0 mm ± 0.05 mm, that is, the thickness of the laminated intermediate composite material after the second hot rolling is 1.0 mm ± 0.05 mm, the width is 255 mm ± 0.1 mm, and the length is 470 mm ± 0.1 mm.

[0150] S11: Intermediate annealing.

[0151] The temperature of the intermediate annealing is 350°C, and the time is 1 h.

[0152] S12: Cold rolling.

[0153] Cold rolling is carried out using a four-high rolling mill with high precision, and the surface roughness of the roll is 0.3 μm to 0.4 μm; cold rolling is carried out until the thickness of the laminated intermediate composite material is 0.6 mm ± 0.05 mm; during the cold rolling process, the single-pass deformation is controlled at 5%, and the edge crack length ≤ 3 mm; the thickness of the laminated intermediate composite material after cold rolling is 0.6 mm ± 0.05 mm, the width is 255 mm ± 0.1 mm, and the length is 780 mm ± 0.1 mm.

[0154] S13: Edge trimming.

[0155] The edge micro-cracks are removed to ensure straight cutting; the single-side edge trimming amount is 5 mm.

[0156] S14: Solution treatment.

[0157] The temperature of the solution treatment is 480°C, the time is 20 min, and water cooling is carried out.

[0158] S15: Straightening.

[0159] The material after solution treatment is precisely straightened using a high-precision 25-roll straightening machine.

[0160] S16: Stretching treatment.

[0161] The straightened laminated intermediate composite material is subjected to stretching and straightening treatment, with a stretching deformation ratio of 0.8%, a head and tail stretching clamping length of 15 mm, and finally a laminated intermediate composite material with a flatness of 0.5 mm is obtained.

[0162] S17: Aging treatment.

[0163] The temperature of the aging treatment is 170 °C, the time is 15 h, and it is air-cooled.

[0164] S18: Finished product slitting.

[0165] The head, tail, and clamping ends of the laminated intermediate composite material after aging treatment are cut off and slit to obtain a finished product of a metallized ceramic double-layer composite material with a total thickness of 0.6 mm ± 0.05 mm, a width of 245 mm ± 0.1 mm, and a length of 750 mm ± 0.1 mm. That is, the finished product of the metallized ceramic double-layer composite material has a two-layer structure, which is successively an aluminum alloy material layer of about 0.3 mm and an aluminum matrix silicon carbide composite material layer of about 0.3 mm from bottom to top; the thickness ratio of each layer is about 1:1.

[0166] Example 3 This example provides a metallized ceramic multi-layer composite material, and its preparation method includes: S1: Material preparation (all directly purchased from commercially available products).

[0167] Aluminum alloy material: Coil, 1 roll, 6R01 aluminum alloy, with a thickness of about 2.05 mm and a width of 220 mm ± 0.1 mm; Aluminum matrix silicon carbide composite material: Plate, 1 piece; low volume fraction system, the volume percentage of SiC component is 30% (the D of silicon carbide particles is 5 μm to 10 μm,), correspondingly, the volume percentage of Al-Mg-Si-Cu alloy is 70%; the thickness is about 4.1 mm, the width is 220 mm ± 0.1 mm, and the length is 200 mm ± 0.1 mm. 50

[0168] S2: Surface texturing treatment.

[0169] The aluminum alloy coil is textured on one side, and the texturing direction is along the length direction of the coil. After texturing, the thickness is 2.0 mm, and the surface roughness Ra after texturing is 2 μm to 4 μm, and the texturing force of the whole coil is uniform; The aluminum matrix silicon carbide composite material is textured on both sides at an angle of 45° with a 150-mesh abrasive belt. After texturing, the thickness is 4.0 mm, and the surface roughness Ra after texturing is 5 μm to 6 μm, and the texturing force of the whole plate is uniform.

[0170] S3: Aluminum sheet slitting.

[0171] Slit the aluminum alloy coil after surface texturing into a sheet with a thickness of 2.0 mm, a width of 220 mm ± 0.1 mm, and a length of 200 mm ± 0.1 mm, 1 piece.

[0172] S4: Laser drilling.

[0173] After positioning the above 1 piece of aluminum alloy sheet and 1 piece of aluminum matrix silicon carbide composite sheet on the laser cutting platform, use laser cutting to process riveting holes. Specifically: Cut round holes at both ends in the length direction. The round holes are located at the middle position in the corresponding width direction at each end. The diameter of the round holes is 3.2 mm, and the shortest distance from the round holes to the edge of the sheet in the length direction is 5 mm.

[0174] S5: Ultrasonic cleaning.

[0175] Ultrasonic water wash for 2 min, and dry after water wash until no water stain remains; S6: Mechanical bonding.

[0176] Align 1 piece of aluminum matrix silicon carbide composite sheet and the aluminum alloy sheet, and then use rivets to mechanically bond the two sheets.

[0177] S7: Hot rolling composite.

[0178] The heating temperature for hot rolling composite is 500 °C, the heating and holding time for hot rolling composite is 15 min, the form of hot rolling composite is single-pass large deformation rolling, the single-pass rolling deformation is 40%, the rolling rolls use flat rolls, and adjust the flatness and size of the roll gap before rolling; Cross-roll at a width of 220 mm, and hot roll composite the two sheets (with thicknesses of 2.0 mm and 4.0 mm respectively) to a total thickness of 3.6 mm (tolerance: 0 mm to 0.1 mm).

[0179] S8: Diffusion annealing.

[0180] Use a press calibration tooling to perform press plate diffusion annealing on the rolled composite material to obtain a laminated intermediate composite material; The temperature for press calibration diffusion annealing is 420 °C, the time is 1 h, and the flatness after press calibration is 0.5 mm.

[0181] S9: Surface sanding treatment.

[0182] Use a 400-mesh sanding belt to perform sanding treatment on the laminated intermediate composite material. After sanding treatment, the thickness of the laminated intermediate composite material is controlled at 3.55 mm (tolerance: 0 mm to 0.1 mm).

[0183] S10: Second hot rolling.

[0184] The heating temperature for the second hot rolling is 480 °C, and the heating and holding time for the second hot rolling is 10 min; multi-pass rolling with small deformation amounts is adopted, and the deformation amount per pass is controlled to be 12%, with the edge crack length ≤ 5 mm; after the second hot rolling, the thickness of the laminated intermediate composite material is 1.8 mm ± 0.05 mm, that is, after the second hot rolling, the thickness of the laminated intermediate composite material is 1.8 mm ± 0.05 mm, the width is 221 mm ± 0.1 mm, and the length is 650 mm ± 0.1 mm.

[0185] S11: Intermediate annealing.

[0186] The temperature for intermediate annealing is 350 °C and the time is 0.5 h.

[0187] S12: Cold rolling.

[0188] Cold rolling is carried out using a four-high rolling mill with relatively high precision, and the surface roughness of the rolls is 0.4 μm to 0.45 μm; cold rolling is performed until the thickness of the laminated intermediate composite material reaches 1.2 mm ± 0.05 mm; during cold rolling, the deformation amount per pass is controlled to be 10%, with the edge crack length ≤ 3 mm; after cold rolling, the thickness of the laminated intermediate composite material is 1.2 mm ± 0.05 mm, the width is 221 mm ± 0.1 mm, and the length is 930 mm ± 0.1 mm.

[0189] S13: Edge trimming.

[0190] The edge micro-cracks are removed to ensure straight cutting; the single-side edge trimming amount is 4 mm.

[0191] S14: Solution treatment.

[0192] The temperature for solution treatment is 530 °C, the time is 5 min, and water cooling is used.

[0193] S15: Straightening.

[0194] The material after solution treatment is precisely straightened using a high-precision 25-roll straightening machine.

[0195] S16: Tension treatment.

[0196] The straightened laminated intermediate composite material is subjected to tension straightening treatment, with a tensile deformation ratio of 1.5% and a head and tail tensile clamping length of 15 mm, and finally a laminated intermediate composite material with a flatness of 0.3 mm is obtained.

[0197] S17: Aging treatment.

[0198] The temperature for aging treatment is 175 °C, the time is 4 h, and air cooling is used.

[0199] S18: Finished product slitting.

[0200] After aging treatment, cut off the head, tail and clamping ends of the laminated intermediate composite material, and slit it to obtain a finished product of metallized ceramic multi-layer composite material with a total thickness of 1.2 mm ± 0.05 mm, a width of 213 mm ± 0.1 mm, and a length of 900 mm ± 0.1 mm.

[0201] That is, the finished product of the metallized ceramic multi-layer composite material has a two-layer structure, which is successively an aluminum alloy material layer of about 0.4 mm and an aluminum matrix silicon carbide composite material layer of about 0.8 mm from bottom to top; the thickness ratio of each layer is about 1:2.

[0202] Test Example 1 ①. Taking 2 finished products of metallized ceramic multi-layer composite materials with a three-layer structure prepared in Example 1 (defined as finished product 1 and finished product 2 respectively) as examples, randomly select 6 positions in each finished product of metallized ceramic multi-layer composite material, and measure the thickness of the first layer (aluminum alloy material layer), the second layer (aluminum matrix silicon carbide composite material layer) and the third layer (aluminum alloy material layer) corresponding to each position. The above 6 positions at least include the position at the center of the metallized ceramic multi-layer composite material and the positions close to 4 edges respectively, and the results are shown in Table 1.

[0203] ②. Taking 2 finished products of metallized ceramic multi-layer composite materials with a three-layer structure prepared in Example 1 (the same as above, defined as finished product 1 and finished product 2 respectively) as examples, randomly select a straight line (defined as straight line 1) on the bonding surface between the first layer and the second layer (defined as bonding surface 1) in each finished product of metallized ceramic multi-layer composite material, and randomly select a straight line (defined as straight line 2) on the bonding surface between the second layer and the third layer (defined as bonding surface 2). Fix thin wires at both ends of straight line 1 and tighten them, and measure the maximum deviation between straight line 1 and the thin wire, which is the flatness of bonding surface 1; fix thin wires at both ends of straight line 2 and tighten them, and measure the maximum deviation between straight line 2 and the thin wire, which is the flatness of bonding surface 2.

[0204] Table 1 Measured thickness of each layer of metallized ceramic multi-layer composite material and flatness of bonding surface

[0205] It can be seen from Table 1 that in the metallized ceramic multi-layer composite material prepared by the method provided by the present invention, the thickness uniformity of each layer is good, and the flatness of the bonding interface between layers is good.

[0206] ③. Taking the above sample 1 prepared in Example 1 as an example, observe its structure, and the panoramic digital microscope image of its composite interface is as Figure 1 shown, and the enlarged view of some areas is as Figure 2 shown.

[0207] Similarly, the metallized ceramic multi-layer composite materials prepared in Example 2 and Example 3 were subjected to structural observation. The panoramic digital microscope image of the composite interface corresponding to Example 2 is as shown in Figure 3 , and the enlarged view of some regions is as shown in Figure 4 ; the digital microscope of the composite interface corresponding to Example 3 is as shown in Figure 5 , and the enlarged view of some regions is as shown in Figure 6 .

[0208] It can be seen from Figures 1 to 6 that the thickness uniformity of each layer of the metallized ceramic multi-layer composite materials prepared in Examples 1 to 3 is good, and the flatness of the bonding interface between layers is good.

[0209] Furthermore, the metallographic microscope image and scanning electron microscope image of the aluminum matrix silicon carbide composite layer in the above sample 1 at a magnification of 500X are as shown in Figure 7 and Figure 8 respectively. Figure 7 The gray particles in Figure 8 are SiC particles, and the particles in Figure 7 and Figure 8 are all SiC particles. It can be seen from both Figure 7 Figure 8 that the particle size of SiC is about 5μm to 10μm.

[0210] Test Example 2 Taking 2 pieces of the finished metallized ceramic multi-layer composite materials with a three-layer structure prepared in Example 1 (same as Test Example 1, defined as finished product 1 and finished product 2 respectively) as an example, 2 pieces of samples were taken from each finished product to test the mechanical properties, bending stiffness, elastic modulus, thermal conductivity and density in the T6 state. Among them, the T6 state refers to the state after solution treatment and aging treatment, and the mechanical properties include tensile strength, yield strength and elongation. The tensile strength, yield strength and elongation were tested according to ASTM E8-2022; the bending stiffness was tested according to GB / T 5593-2015; the elastic modulus was tested according to GB / T 22315-2008, the thermal conductivity was tested according to ASTM E1461-13, and the density was tested according to GB / T 3850-2015. The results are shown in Table 2.

[0211] At the same time, a 6R01 aluminum alloy (this grade is equivalent to 6061 aluminum alloy - the difference is that the 6R01 raw material is smelted and prepared using recycled materials) material plate with a thickness of 0.6 mm was used as a control sample. 3 pieces of samples were taken from this plate and tested for the mechanical properties, bending stiffness, elastic modulus, thermal conductivity and density in the T6 state according to the same method as in Example 1. The solution treatment and aging treatment conditions of this plate were the same as those in Example 1. The test results are shown in Table 3.

[0212] Table 2 Test Results

[0213] Table 3 Test Results

[0214] As can be seen from Table 2 and Table 3: The finished product of the metalized ceramic multi-layer composite material prepared in Example 1 of the present invention is superior to the 6R01 aluminum alloy material plate in terms of mechanical properties (tensile strength, yield strength, elongation), bending stiffness, elastic modulus, etc.; the thermal conductivity is not much different from that of 6R01, and this thermal conductivity is already relatively high, which can meet the heat dissipation requirements of 3C products. That is to say, the metalized ceramic multi-layer composite material provided in Example 1 of the present invention can significantly improve the stiffness and strength compared with the 6R01 aluminum alloy on the premise of ensuring thermal conductivity and light weight.

[0215] Furthermore, the finished products of the metalized ceramic multi-layer composite materials prepared in Example 2 and Example 3 were respectively tested for T6 state mechanical properties, bending stiffness, elastic modulus, thermal conductivity coefficient and density according to the above method, and the results are shown in Table 4. The data results in Table 4 are the average values after testing 3 samples taken from each finished product.

[0216] Table 4 Test Results

[0217] Test Example 3 This test example sets 11 comparative examples, which are specifically as follows: The difference between Comparative Example 1 and Example 1 is that the aluminum matrix silicon carbide composite material in the aluminum matrix silicon carbide composite material layer is a medium volume fraction system, that is, the volume percentage of the SiC component is about 40%. This comparative example had serious edge cracking during the rolling process and the composite was not successful.

[0218] The difference between Comparative Example 2 and Example 1 is that the aluminum matrix silicon carbide composite material in the aluminum matrix silicon carbide composite material layer is a high volume fraction system, that is, the volume percentage of the SiC component is about 70%. This comparative example could not successfully prepare a composite plate according to the preparation method of the present application, and this high volume fraction system is suitable for the infiltration method or the squeeze casting method.

[0219] The difference between Comparative Example 3 and Example 1 is that the D50 of the SiC contained in the aluminum matrix silicon carbide composite material in the aluminum matrix silicon carbide composite material layer is 12 μm - 15 μm. The silicon carbide particles in this comparative example are too large, resulting in difficult effective arrangement during the pressing process, causing large pores inside the material and affecting the density of the material; during the subsequent heating process, the aluminum matrix silicon carbide foamed severely and could not be rolled and compounded.

[0220] The difference between Comparative Example 4 and Example 1 is that the temperature of hot rolling composite is 420 °C. In this comparative example, edge cracking was severe during the rolling process and effective mutual deformation between the Al alloy and the aluminum matrix composite could not be achieved, and the composite sheet was not successfully prepared.

[0221] The difference between Comparative Example 5 and Example 1 is that the temperature of hot rolling composite is 550 °C. In this comparative example, the heating temperature of hot rolling composite was too high and the material was overburned.

[0222] The difference between Comparative Example 6 and Example 1 is that the time of hot rolling composite is 10 min. In this comparative example, the composite between layers was not achieved.

[0223] The difference between Comparative Example 7 and Example 1 is that the single-pass rolling deformation amount during the hot rolling composite process is only 10%. In this comparative example, the composite between layers was not achieved.

[0224] The difference between Comparative Example 8 and Example 1 is that no diffusion annealing step was carried out during the hot rolling composite and the second hot rolling processes. In this comparative example, delamination occurred during the cold rolling process and metallurgical bonding was not achieved between the composite layers.

[0225] The difference between Comparative Example 9 and Example 1 is that the time of diffusion annealing is 1 h. In this comparative example, the diffusion annealing time was too long and a relatively thick intermetallic compound layer appeared, resulting in a delamination problem.

[0226] The difference between Comparative Example 10 and Example 1 is that the second hot rolling and intermediate annealing steps were not carried out. In this comparative example, cold rolling was directly carried out without hot rolling, and severe edge cracking was likely to occur during the cold rolling process.

[0227] The difference between Comparative Example 11 and Example 1 is that the single-pass deformation amount of the second hot rolling is 20%. In this comparative example, the deformation amount was too large, resulting in severe edge cracking and the composite sheet could not be successfully prepared.

[0228] It can be seen from the above comparative examples that if the preparation raw materials, preparation process or preparation conditions are not properly controlled, the comprehensive performance of the finished product will decline.

[0229] In summary, the present invention creatively composites an aluminum alloy material layer on at least one side of a low-volume aluminum-based silicon carbide composite material layer, thereby effectively avoiding the problems of unstable process, difficult rolling, and easy edge cracking when anodizing the aluminum-based silicon carbide composite material layer as an exterior surface. In addition, the present invention solves or improves the difficult problems of difficult rolling processing, low yield, and difficult surface quality control of low-volume aluminum-based silicon carbide composite materials through a specific preparation method, and realizes the interface metallurgical bonding of the aluminum alloy material layer and the aluminum-based silicon carbide composite material layer, and finally obtains a layered composite material with excellent comprehensive performance, controllable thickness accuracy of each layer, and controllable surface quality, which can meet the requirements of electronic equipment housings for lightweight, high stiffness, high strength, high thermal conductivity, and appearance.

[0230] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A metallized ceramic multi-layer composite material, characterized in that, The metallized ceramic multi-layer composite material includes n layers of aluminum alloy material layers and m layers of aluminum matrix silicon carbide composite material layers, and the aluminum alloy material layers and the aluminum matrix silicon carbide composite material layers are alternately arranged in sequence, where n = m or n = m + 1, and m ≥ 1; The thickness ratio of a single layer of the aluminum alloy material layer to a single layer of the aluminum matrix silicon carbide composite material layer is 1:1 to 1:5; the total thickness of the metallized ceramic multi-layer composite material ≤ 2.0 mm; The aluminum matrix silicon carbide composite material in the aluminum matrix silicon carbide composite material layer is obtained by compounding silicon carbide particles with an Al-Mg-Si-Cu alloy, and the volume percentage of silicon carbide particles in the aluminum matrix silicon carbide composite material is 15% - 30%.

2. The metallized ceramic multi-layer composite material according to claim 1, characterized in that The metallized ceramic multi-layer composite material has a two-layer structure, and the metallized ceramic multi-layer composite material is composed of an aluminum matrix silicon carbide composite material layer and an aluminum alloy material layer provided on any one side surface of the aluminum matrix silicon carbide composite material layer; Alternatively, the metallized ceramic multi-layer composite material has a three-layer structure, and the metallized ceramic multi-layer composite material is composed of an aluminum matrix silicon carbide composite material layer and aluminum alloy material layers provided on both side surfaces of the aluminum matrix silicon carbide composite material layer.

3. The metallized ceramic multi-layer composite material according to claim 1 or 2, characterized in that, The metallized ceramic multi-layer composite material has at least one of the following characteristics: Characteristic 1: The thickness ratio of a single layer of the aluminum alloy material layer to a single layer of the aluminum matrix silicon carbide composite material layer is 1:1 to 1:3; Characteristic 2: The total thickness of the metallized ceramic multi-layer composite material ≤ 1.5 mm; Feature 3: The D of the silicon carbide particles 50 is 3 μm to 10 μm.

4. A method for preparing a metallized ceramic multi-layer composite material according to any one of claims 1 to 3, characterized in that, It includes the following steps: According to the preset number of layers, hot-rolling and compounding the alternately stacked aluminum alloy material and aluminum matrix silicon carbide composite material, and then diffusion annealing, second hot-rolling, intermediate annealing, cold rolling, solution treatment, straightening, stretching treatment, and aging treatment.

5. The preparation method according to claim 4, wherein Before performing hot-rolling and compounding, it further includes: pre-treating the aluminum alloy material and the aluminum matrix silicon carbide composite material; wherein, the pre-treatment includes at least one of surface texturing treatment, laser drilling, ultrasonic cleaning, and mechanical bonding.

6. The preparation method according to claim 4, characterized in that The hot-rolling and compounding includes at least one of the following characteristics: Characteristic 4: The heating temperature of the hot-rolling and compounding is 450 °C - 520 °C; Characteristic 5: The heating and holding time of the hot-rolling and compounding is 15 min - 30 min; Characteristic 6: The form of the hot-rolling and compounding is single-pass large deformation rolling, where the single-pass rolling deformation amount is 30% - 40%; And / or, the diffusion annealing includes at least one of the following characteristics: Characteristic 7: The temperature of the diffusion annealing is 360 °C - 420 °C; Characteristic 8: The time of the diffusion annealing is 0.5 h - 2 h; Characteristic 9: The form of the diffusion annealing is press plate diffusion annealing; And / or, the second hot-rolling includes at least one of the following characteristics: Characteristic 10: The heating temperature of the second hot-rolling is 450 °C - 500 °C; Characteristic 11: The heating and holding time of the second hot-rolling is 10 min - 20 min; Characteristic 12: The second hot-rolling method is multi-pass small deformation rolling, where the single-pass deformation amount is 10% - 15%; And / or, the intermediate annealing includes at least one of the following characteristics: Characteristic 13: The temperature of the intermediate annealing is 350 °C - 400 °C; Feature 14: The time of intermediate annealing is 0.5 h to 1 h; And / or, the solution treatment includes at least one of the following features: Feature 15: The temperature of the solution treatment is 480°C to 530°C; Feature 16: The time of the solution treatment is 5 min to 30 min; And / or, the stretching treatment includes at least one of the following features: Feature 17: The stretching deformation ratio of the stretching treatment is 0.8% to 1.5%; Feature 18: The flatness after the stretching treatment is ≤ 0.5 mm; And / or, the aging treatment includes at least one of the following features: Feature 19: The temperature of the aging treatment is 170°C to 180°C; Feature 20: The time of the aging treatment is 4 h to 16 h.

7. The preparation method according to claim 6, characterized in that, Surface sanding treatment is also included between the diffusion annealing and the second hot rolling; And / or, the single-pass deformation amount during the cold rolling is 5% to 10%; And / or, edge trimming treatment is also included between the cold rolling and the solution treatment, and the unilateral edge trimming amount is ≤ 6 mm.

8. Use of a metallized ceramic multi-layer composite material according to any one of claims 1 to 3, characterized in that, The metallized ceramic multi-layer composite material is used for preparing a housing.

9. A housing, characterized in that, The preparation raw material of the housing includes the metallized ceramic multi-layer composite material described in any one of claims 1 to 3.

10. The housing according to claim 9, characterized in that, The housing is the housing of an electronic device.

11. The housing according to claim 10, wherein, The housing is the housing of a 3C product.

12. The housing according to claim 11, characterized in that, The housing is the outer housing of a mobile terminal product.

13. The housing according to claim 12, characterized in that, The mobile terminal product includes at least one of a laptop computer, a tablet computer, and a mobile phone.

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