Aluminum-based silicon carbide product, forming method thereof and electronic equipment

Abstract

The invention provides an aluminum-based silicon carbide product, a forming method thereof and electronic equipment. The forming method of the aluminum-based silicon carbide product comprises the following steps that aluminum alloy powder and silicon carbide powder are mixed to form a mixture, so that at least part of silicon carbide particles are embedded into an aluminum alloy matrix; smelting the mixture to obtain slurry; and carrying out extrusion casting molding on the slurry to obtain the aluminum-based silicon carbide product. According to the technical scheme, a complex structure can be formed, and the aluminum-based silicon carbide product can have the excellent mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of material forming, and in particular to an aluminum-based silicon carbide product and a forming method thereof, and electronic equipment. Background Art

[0002] Aluminum-based silicon carbide is a metal-based composite material with excellent physical properties such as low density, high strength, high stiffness, high thermal conductivity, and small thermal expansion coefficient. It is a good material for making structural parts for electronic devices such as AR (Augmented Reality) and VR (Virtual Reality) glasses that have high demands for lightweight and miniaturization. It can also meet the performance requirements of structural parts that carry precision optical instruments.

[0003] In the related art, aluminum-based silicon carbide products are usually made by pressureless infiltration or stirring casting process, or powder metallurgy process. In electronic devices such as AR (Augmented Reality) and VR (Virtual Reality) glasses, in order to meet the needs of miniaturization, the wall thickness of the structural parts is relatively thin and the structure is relatively complex. Although more complex structures can be formed by pressureless infiltration or stirring casting process, their mechanical properties are reduced due to the limitations of the forming method. The powder metallurgy process can ensure its excellent mechanical properties, but it cannot form more complex structures at one time, and complex configurations can only be cut out by CNC machining. Moreover, since aluminum-based silicon carbide is hard and brittle, diamond tools are required for cutting, which makes the processing difficult and the production yield low. Summary of the invention

[0004] The main purpose of the present invention is to provide an aluminum-based silicon carbide product and a molding method thereof, and an electronic device, aiming to be able to mold complex structures and enable the aluminum-based silicon carbide product to have excellent mechanical properties.

[0005] To achieve the above object, the present invention provides a method for forming an aluminum-based silicon carbide product, comprising the following steps:

[0006] mixing aluminum alloy powder and silicon carbide powder to form a mixture so that at least a portion of the silicon carbide particles are embedded in the aluminum alloy matrix;

[0007] melting the mixture to obtain a slurry;

[0008] The slurry is squeeze-cast to obtain aluminum-based silicon carbide.

[0009] In one embodiment of the present application, the aluminum alloy powder is a 4-series aluminum alloy or a 6-series aluminum alloy;

[0010] And / or, the particle size of the aluminum alloy powder is 50 μm to 200 μm.

[0011] In one embodiment of the present application, the particle size of the silicon carbide particles is 2-8 μm, and the volume percentage of the silicon carbide powder is 8%-20%.

[0012] In one embodiment of the present application, the step of mixing aluminum alloy powder and silicon carbide powder to form a mixture comprises:

[0013] Aluminum alloy powder, silicon carbide powder and copper powder are mixed to form a mixture.

[0014] In one embodiment of the present application, the mass ratio of the copper powder in the mixture is 3% to 6%.

[0015] In one embodiment of the present application, the step of mixing aluminum alloy powder and silicon carbide powder to form a mixture comprises:

[0016] The aluminum alloy powder and silicon carbide powder are ball-milled and mixed to form a mixture.

[0017] In one embodiment of the present application, the step of ball-milling the aluminum alloy powder and the silicon carbide powder to form a mixture comprises:

[0018] Aluminum alloy powder and silicon carbide powder are placed in a ball mill with ceramic balls as grinding balls to mix and form a mixture, wherein the diameter of the ceramic balls is 5mm to 300mm, and the mass ratio of the ceramic balls to the mixture is 0.8 to 1.2.

[0019] In one embodiment of the present application, the step of mixing the aluminum alloy powder and the silicon carbide powder in a ball mill using ceramic balls as grinding balls comprises:

[0020] Ceramic balls of different diameters were added to the ball mill;

[0021] The aluminum alloy powder and the silicon carbide powder are placed in a ball mill for mixing to form a mixture.

[0022] In one embodiment of the present application, the step of smelting the mixed material to obtain the slurry further includes:

[0023] The mixed material is remelted and ultrasonically treated to obtain a slurry.

[0024] In one embodiment of the present application, in the step of remelting the mixed material and performing ultrasonic treatment to obtain the slurry, the ultrasonic treatment time is controlled to be 1 min to 5 min, and the ultrasonic frequency is controlled to be 23 kHz to 30 kHz.

[0025] In one embodiment of the present application, the step of mixing aluminum alloy powder and silicon carbide powder to form a mixture comprises:

[0026] mixing aluminum alloy powder and silicon carbide powder in an inert gas environment to form a mixture;

[0027] And / or, the step of smelting to obtain slurry comprises:

[0028] The mixed material is placed in a vacuum or inert gas environment and smelted to obtain a slurry.

[0029] The present application also provides an aluminum-based silicon carbide product, wherein the aluminum-based silicon carbide product is produced by the molding method of the aluminum-based silicon carbide product as described in any of the above embodiments, and the molding method of the aluminum-based silicon carbide product comprises the following steps:

[0030] mixing aluminum alloy powder and silicon carbide powder to form a mixture so that at least a portion of the silicon carbide particles are embedded in the aluminum alloy matrix;

[0031] melting the mixture to obtain a slurry;

[0032] The slurry is extruded and cast to obtain an aluminum-based silicon carbide product.

[0033] The present application also proposes an electronic device, wherein the electronic device comprises the aluminum-based silicon carbide product as described in the above embodiment.

[0034] The technical solution of the present invention is to perform a mixing process on silicon carbide powder and aluminum alloy powder so that at least part of the silicon carbide particles are embedded in the aluminum alloy matrix during the mixing process, and a mixture is obtained after sufficient mixing; with such an arrangement, when the mixture is smelted, the aluminum alloy can be coated on the silicon carbide particles embedded therein, reducing the aggregation of the silicon carbide particles, so that the silicon carbide is evenly distributed in the slurry, and the bonding strength between the silicon carbide particles and the aluminum alloy matrix is ​​improved; the slurry after smelting is subjected to an extrusion casting process, during which the slurry can be injected into a mold cavity of a corresponding structure according to the structure of the desired silicon carbide product, and the desired structure can be obtained after the slurry is filled, and a more complex structure can be formed; in addition, the slurry is filled under pressure and solidified under high pressure, and the structure is dense and uniform, the internal defects of the aluminum-based silicon carbide product are reduced, the grains have a higher bonding strength, the strength and rigidity of the aluminum-based silicon carbide product are improved, and the aluminum-based silicon carbide has good mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0036] Figure 1 It is a flow chart of the first embodiment of the molding method of the aluminum-based silicon carbide product of the present invention;

[0037] Figure 2 This is a flow chart of a second embodiment of a method for forming an aluminum-based silicon carbide product according to the present invention;

[0038] Figure 3 It is a flow chart of a third embodiment of the molding method of an aluminum-based silicon carbide product of the present invention;

[0039] Figure 4 It is a flow chart of a fourth embodiment of the molding method of an aluminum-based silicon carbide product of the present invention;

[0040] Figure 5 It is a flow chart of a fifth embodiment of the molding method of an aluminum-based silicon carbide product of the present invention;

[0041] Figure 6 It is a flow chart of a sixth embodiment of the molding method of an aluminum-based silicon carbide product of the present invention;

[0042] Figure 7 This is a flow chart of the seventh embodiment of the molding method of aluminum-based silicon carbide products of the present invention.

[0043] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] Based on the technical problem raised by the background technology, the present invention proposes a molding method of an aluminum-based silicon carbide product, aiming to obtain aluminum-based silicon carbide with excellent mechanical properties and easy processing.

[0049] The molding method of the aluminum-based silicon carbide product proposed by the present invention will be described in the following specific embodiments:

[0050] like Figure 1 FIG. 1 is a first embodiment of a method for forming an aluminum-based silicon carbide product according to the present invention. In this embodiment, the method for forming an aluminum-based silicon carbide product comprises the following steps:

[0051] Step S10, mixing aluminum alloy powder and silicon carbide powder to form a mixture, so that at least part of the silicon carbide particles are embedded in the aluminum alloy matrix.

[0052] Specifically, aluminum alloy powder and silicon carbide powder are mixed, wherein the diameter of the aluminum alloy matrix particles is larger than the diameter of the silicon carbide particles. Ball milling, stirring or rolling mixing can be used to provide impact or extrusion force to the powder particles, so that part of the silicon carbide particles are embedded in the aluminum alloy matrix. It can be understood that compared with the traditional method of only mixing silicon carbide powder and aluminum alloy powder, only part of the silicon carbide particles need to be embedded in the aluminum alloy matrix, which can improve the mechanical properties of the final aluminum-based silicon carbide to a certain extent. It can be understood that the diameter of the aluminum alloy matrix particles needs to be larger than the diameter of the silicon carbide particles, so that the silicon carbide particles can be embedded in the aluminum alloy matrix under impact or extrusion without breaking the aluminum alloy matrix.

[0053] Step S30, melting the mixed material to obtain slurry.

[0054] It can be understood that in the mixture obtained by mixing silicon carbide powder and aluminum alloy powder, the silicon carbide powder and the aluminum alloy powder can be mixed and at least part of the silicon carbide particles are embedded in the aluminum alloy matrix; in this step, the mixture is subjected to high-temperature remelting treatment, and the temperature can be increased from room temperature at a heating rate of 10°C / min to 20°C / min, so that the remelting temperature reaches 650°C to 700°C. At this time, the aluminum alloy matrix is ​​melted, and the silicon carbide particles form a semi-solid state. Since at least part of the silicon carbide particles are embedded in the aluminum alloy matrix, at this time, the molten aluminum alloy can be coated on the silicon carbide particles embedded therein, avoiding the floating and aggregation of silicon carbide, making the silicon carbide evenly distributed in the molten slurry, and improving the bonding strength between the silicon carbide particles and the aluminum alloy matrix.

[0055] Step S50, extrusion casting the slurry to obtain an aluminum-based silicon carbide product.

[0056] Specifically, in this embodiment, the molten slurry is extrusion cast, and the molten slurry is injected into a preheated metal mold cavity for extrusion casting. During this process, the slurry fills the mold under pressure. After the molten slurry is filled, the pressure is maintained to solidify the slurry under the high pressure state of the mold cavity. Then, the aluminum-based silicon carbide product can be obtained by demolding. Since the slurry is always under pressure during the solidification and molding process, the molded aluminum-based silicon carbide product has a dense and uniform structure, which reduces the internal defects of the aluminum-based silicon carbide, and has a higher bonding strength between the grains, thereby improving the strength and stiffness of the aluminum-based silicon carbide, so that the aluminum-based silicon carbide has good mechanical properties. In addition, the metal mold cavity can be prefabricated into the required product style to directly cast to form an aluminum-based silicon carbide product, or the aluminum-based silicon carbide billet can be cast to form a final product through cutting, milling, grinding and other processing.

[0057] Usually, according to the melting points of aluminum alloy and silicon carbide, the pouring temperature in squeeze casting is controlled at 680℃~750℃, the mold temperature is 400~600℃, and the casting pressure is 8~15MPa. In addition, according to the specific product structure of the casting, the pressure can be maintained for 1~5 minutes after the molten slurry is filled into the mold to ensure the stability of the internal structure of the product.

[0058] Therefore, it can be understood that the technical solution of the present invention is to mix silicon carbide powder and aluminum alloy powder so that at least part of the silicon carbide particles are embedded in the aluminum alloy matrix during the mixing process, and a mixture is obtained after sufficient mixing; with such an arrangement, when the mixture is melted, the aluminum alloy can be coated on the silicon carbide particles embedded therein, reducing the aggregation of silicon carbide particles, so that silicon carbide is evenly distributed in the slurry, and the bonding strength between the silicon carbide particles and the aluminum alloy matrix is ​​improved; the slurry after melting is subjected to extrusion casting treatment, during which the slurry can be injected into the mold cavity of the corresponding structure according to the structure of the desired silicon carbide product, and the desired structure can be obtained after the slurry is filled, and a more complex structure can be formed; in addition, the slurry is filled under pressure and high-pressure solidification occurs, the structure is dense and uniform, the internal defects of the aluminum-based silicon carbide product are reduced, the grains have a higher bonding strength, the strength and rigidity of the aluminum-based silicon carbide product are improved, and the aluminum-based silicon carbide has good mechanical properties.

[0059] In some embodiments of the present application, the aluminum alloy powder is a 4-series aluminum alloy or a 6-series aluminum alloy.

[0060] In this embodiment, the 4 series aluminum alloy is an aluminum alloy with silicon as the main alloying element, with high silicon content, low melting point and good melt fluidity, so that the remelted mixed slurry has good fluidity, and the finally obtained aluminum-based silicon carbide has high wear resistance and high temperature resistance; the alloy components of the 6 series aluminum alloy are magnesium and silicon, which have good mechanical properties and the melt has good fluidity, so that the remelted mixed slurry has good fluidity and is convenient for extrusion molding.

[0061] In some embodiments of the present application, the particle size of the aluminum alloy powder is 50 μm to 200 μm.

[0062] In this embodiment, aluminum alloy powder with a particle size of 50 μm to 200 μm is used as the matrix material, so that the aluminum alloy matrix has a relatively large volume to avoid being crushed by silicon carbide particles during ball milling and unable to be embedded by silicon carbide particles. Among them, the particle size of the aluminum alloy matrix particles can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 120μm, 140μm, 160μm, 180μm, 200μm or any value between 50μm and 200μm, which can be determined by the diameter of the selected silicon carbide particles and the volume ratio of each component, or by selecting silicon carbide powder that meets the specifications based on the particle size of the selected aluminum alloy powder and the volume ratio of each component; in addition, it can be understood that the diameters of the aluminum alloy particles in the aluminum alloy powder can be different, so that a certain proportion of the aluminum alloy matrix particles in the aluminum alloy powder used are within the required size range, while another part of the aluminum alloy matrix particles can be outside the size range, so that the overall aluminum alloy volume meets the material volume ratio, or the average particle size of the aluminum alloy fraction is within the required size range.

[0063] In some embodiments of the present application, the particle size of the silicon carbide particles is 2 μm to 8 μm, and the volume percentage is 8% to 20%.

[0064] In this embodiment, silicon carbide particles with a particle size of 2 μm to 8 μm are used, and the volume ratio of silicon carbide particles in the total material particles is 8% to 20%, so that the silicon carbide particles can be evenly and densely distributed in the mixture. In addition, when the particle size of the aluminum alloy powder used is 50 μm to 200 μm, sufficient silicon carbide particles can be embedded in the aluminum alloy matrix particles, so that the final aluminum-based silicon carbide has higher strength and rigidity, and thus has good mechanical properties.

[0065] In some embodiments of the present application, before the step of smelting the mixed material to obtain the slurry, the method further includes:

[0066] A mixed material sample is extracted, and if the proportion of silicon carbide particles embedded in the aluminum alloy matrix in the sample reaches a preset range, the next step is performed.

[0067] It can be understood that in order to ensure that the mechanical properties of the final aluminum-based silicon carbide meet the use requirements, it is necessary to ensure that the content of silicon carbide particles embedded in the aluminum alloy matrix in the mixture meets a certain proportion; in this embodiment, before the mixture is remelted, the mixture is sampled and tested, and the content of silicon carbide particles embedded in the aluminum alloy matrix in the mixture is judged by judging the ratio of silicon carbide particles embedded in the aluminum alloy matrix in the sample to the total amount of the sample. When the proportion of silicon carbide particles embedded in the aluminum alloy matrix in the sample reaches a preset range, the mixture can be considered to have reached the preset mixing standard, and the mixture can be remelted; if the proportion of silicon carbide particles embedded in the aluminum alloy matrix in the sample does not reach the preset range, it is necessary to continue mixing until the proportion of silicon carbide particles embedded in the aluminum alloy matrix in the proposed sample reaches the preset range.

[0068] Preferably, when the proportion of silicon carbide embedded in the aluminum alloy matrix in the sample reaches 60% or more, it can be ensured that the mechanical properties of the final formed aluminum-based silicon carbide meet the use requirements. At this time, the elastic modulus of the aluminum-based silicon carbide is 80-90GPa, the thermal conductivity is 130-150W / (m·K), the tensile strength is 350-450MPa, and the elongation is ≥2%.

[0069] like Figure 2 FIG. 2 is a second embodiment of the molding method of aluminum-based silicon carbide products of the present invention. Compared with the first embodiment, the step of mixing aluminum alloy powder and silicon carbide powder to form a mixture comprises:

[0070] Step S11, mixing aluminum alloy powder, silicon carbide powder and copper powder to form a mixture.

[0071] In the present embodiment, copper is also added to the aluminum-based silicon carbide, and the copper powder is evenly mixed with the aluminum alloy powder and the silicon carbide powder to obtain a mixture. With such an arrangement, when the mixture is melted, the copper in the molten state can improve the fluidity of the slurry, which is beneficial to evenly mix the raw materials. In addition, during the extrusion casting process, the slurry encounters little resistance when flowing, and can evenly fill the mold cavity, thereby reducing internal defects of the product and easily obtaining a casting with a complete shape and a clear outline, which is beneficial to improving the forming rate of products with complex structures, thin walls, small corners, and the like.

[0072] In some embodiments of the present application, the mass ratio of the copper powder is 3% to 6%.

[0073] In this embodiment, the mass percentage of copper powder added to the mixture is 3% to 6%, which can be 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6% or any value between 3% and 6%. The required mass of copper powder can be added according to the mass ratio of silicon carbide and aluminum alloy in the mixture, so that the mass ratio of the added copper powder is not less than 3%, so that the added copper powder can play a more obvious role in improving the fluidity of the molten slurry, and the mass ratio of the added copper powder does not exceed 6%, so as to avoid excessive addition of copper powder and affect the mechanical properties of aluminum-based silicon carbide. Of course, it should be noted that powders of other elements can also be added to the mixture to improve the fluidity of the slurry and the mechanical properties of the product. At this time, the copper powder can be appropriately increased or decreased so that when the mass ratio of the copper powder exceeds the range of 3% to 6%, the slurry after the mixture is melted and the final molded product can also have similar effects as when the mass ratio of the copper powder is within the above range.

[0074] like Figure 3 FIG. 1 is a third embodiment of the molding method of an aluminum-based silicon carbide product according to the present invention. Compared with the first embodiment, the step of mixing aluminum alloy powder and silicon carbide powder to form a mixture comprises:

[0075] Step S13, ball-milling the aluminum alloy powder and the silicon carbide powder to form a mixture.

[0076] In this embodiment, the aluminum alloy powder and silicon carbide powder are mixed in a preset volume ratio and placed in a ball mill to be mixed with the grinding balls in the ball mill. The grinding balls can be ceramic balls, steel balls, etc. At this time, during the mixing process, the grinding balls will impact the abrasives, so that the silicon carbide particles are embedded in the aluminum alloy matrix, so that the silicon carbide particles and the aluminum alloy matrix are better combined, and the two can be fully mixed to avoid the aggregation of powder particles of the same material.

[0077] like Figure 4 FIG. 4 is a fourth embodiment of the method for forming an aluminum-based silicon carbide product according to the present invention. Compared with the first embodiment, the step of ball-milling the aluminum alloy powder and the silicon carbide powder to form a mixture comprises:

[0078] Step S131, placing aluminum alloy powder and silicon carbide powder in a ball mill using ceramic balls as grinding balls to mix and form a mixture, wherein the diameter of the ceramic balls is 5 mm to 300 mm, and the mass ratio of the ceramic balls to the mixture is 0.8 to 1.2.

[0079] In this embodiment, ceramic balls are used as grinding balls. Compared with traditional metal grinding balls, ceramic balls have higher hardness and lower wear when impacting the mixture. Ceramic balls also have the advantages of corrosion resistance, etc. Therefore, using ceramic balls can reduce abrasive consumption and environmental pollution.

[0080] In addition, in order to better impact-mix the silicon carbide particles and the aluminum alloy matrix particles, a diameter of 5 mm to 300 mm is used, wherein uniform ceramic balls of the same diameter can be added, or ceramic balls of different diameters can be added and mixed at the same time as in the following embodiment; the content of ceramic balls is roughly equal to that of the mixture, which can be slightly lower than the mixture or slightly higher than the mixture, so that the mass ratio of ceramic balls to the mixture is 0.8 to 1.2, so that during the mixing process, when the ceramic balls and the mixture are evenly mixed, the silicon carbide particles and the aluminum alloy matrix particles at various positions can be impacted by the ceramic balls, so that the silicon carbide particles can be evenly embedded in the aluminum alloy matrix, so that the material distribution in the mixture is even.

[0081] like Figure 5 FIG. 5 is a fifth embodiment of the molding method of an aluminum-based silicon carbide product of the present invention. Compared with the fourth embodiment, the mixing step is refined in this embodiment. The step of mixing the aluminum alloy powder and the silicon carbide powder in a ball mill using ceramic balls as grinding balls to form a mixture includes:

[0082] Step S1311, adding ceramic balls of different diameters into the ball mill;

[0083] Step S1313, placing the aluminum alloy powder and the silicon carbide powder in a ball mill for mixing to form a mixture.

[0084] In this embodiment, aluminum alloy powder, silicon carbide powder and ceramic balls of different diameters are placed in a ball mill for mixing. It can be understood that for ceramic balls with larger diameters, the impact force generated is also larger, so that a larger impact force can be applied to the silicon carbide particles and the aluminum alloy matrix particles during the mixing process, so that the silicon carbide particles can be better embedded in the aluminum alloy matrix; but when the diameter of the ceramic ball is larger, there will be a gap between two adjacent ceramic balls, resulting in some silicon carbide particles and aluminum alloy particles cannot be impacted; at this time, ceramic balls with smaller diameters can be used to fill the gap to impact the silicon carbide particles and aluminum alloy particles in the gap, so that most of the silicon carbide particles and aluminum alloy particles can be impacted and embedded, thereby improving the mixing effect.

[0085] like Figure 6 FIG. 6 is a sixth embodiment of the molding method of aluminum-based silicon carbide products according to the present invention. Compared with the first embodiment, the step of remelting the mixed material further includes:

[0086] Step S31, smelting the mixed material to obtain slurry.

[0087] In this embodiment, in order to enhance the uniformity of silicon carbide dispersion, ultrasonic treatment may be performed during the remelting process. That is, during the remelting process, when the mixture forms a molten composite material slurry, ultrasonic waves are applied to the slurry, and the flow of the composite material slurry is strengthened by using acoustic vibrations, so that silicon carbide can be more evenly distributed in the slurry, thereby making the internal grains of the product after extrusion casting uniform and the mechanical properties stable.

[0088] In one embodiment of the present application, in the step of remelting the mixed material and performing ultrasonic treatment to obtain the slurry, the ultrasonic treatment time is controlled to be 1 min to 5 min, and the ultrasonic frequency is controlled to be 23 kHz to 30 kHz.

[0089] In this embodiment, the ultrasonic treatment time during the remelting process of the mixed material is controlled to be 1min~5min, and the ultrasonic frequency is 23kHZ~30kHZ, that is, the composite material slurry is subjected to ultrasonic treatment for a short time to avoid the ultrasonic frequency being too high and the time being too long to destroy the mixed structure of the silicon carbide and aluminum alloy matrix in the slurry.

[0090] like Figure 7 FIG. 1 is a seventh embodiment of the method for forming an aluminum-based silicon carbide product according to the present invention. Compared with the first embodiment, the step of mixing aluminum alloy powder and silicon carbide powder to form a mixture comprises:

[0091] Step S15, mixing the aluminum alloy powder and the silicon carbide powder in an inert gas environment to form a mixture.

[0092] In this embodiment, when aluminum alloy powder and silicon carbide powder are mixed, an inert gas such as nitrogen, argon, etc. is appropriately introduced into the mixing environment to avoid the presence of oxygen in the mixing environment that may cause oxidation of the aluminum alloy, thereby ensuring the safety of the ball milling process.

[0093] Reference Figure 7 In some embodiments of the present application, the step of smelting to obtain slurry includes:

[0094] Step S33, placing the mixed material in a vacuum or inert gas environment for smelting to obtain slurry.

[0095] Similarly, during the melting process of the mixture, inert gases such as nitrogen and argon need to be continuously introduced, or the mixture needs to be placed in a vacuum environment to isolate the material from oxygen and prevent oxidation of the material.

[0096] In order to further understand the present invention, the molding method of the aluminum-based silicon carbide product provided by the present invention is specifically described below in conjunction with embodiments.

[0097] (1) Mixing

[0098] Select silicon carbide powder with a particle size of 5μm and aluminum alloy powder with a grade of 4A13 and an average particle size of 120μm, and mechanically mix them at a volume ratio of 1:9; pour the mixture into a ball mill, the ball milling medium is ceramic balls, the size content ratio is 200mm:80mm:5mm=1:2:3, and the ball-to-material mass ratio is 1:1. The speed is 120r / min, and the mixing time is 12 hours; during the ball milling process, argon gas is continuously introduced into the ball mill to ensure that the positive pressure in the chamber is between 0.01MPa and 0MPa.

[0099] (2) Sample testing

[0100] After the mixture is completed, samples are taken for inspection under a microscope. If some ceramic particles are not embedded in the aluminum alloy matrix, the mixing time can be appropriately extended by 1 to 5 hours to finally obtain a mixture.

[0101] (3) Melting mixture

[0102] The mixed material is placed in an induction melting furnace for remelting at a temperature of 680°C and a heating rate of 15°C / min. To prevent oxidation, the remelting process is carried out in a vacuum environment with a vacuum degree of about 10-3Pa.

[0103] In order to enhance the dispersion uniformity of silicon carbide particles, ultrasonic treatment with a frequency of 25 kHz was carried out for 3 min after the material was melted.

[0104] (4) Squeeze casting

[0105] The remelted slurry is injected into a metal mold with a mold temperature of 400°C for extrusion casting. The pouring temperature is 700°C and the casting pressure is 10MPa. After the molten slurry is filled into the mold, the pressure is maintained for 3 minutes. After the slurry is solidified and demolded, the aluminum-based silicon carbide product is obtained.

[0106] (5) Machining

[0107] The microstructure of the aluminum-based silicon carbide product after demoulding is CNC machined to finally form the product.

[0108] In view of the technical problems mentioned in the background technology, the present application also proposes an aluminum-based silicon carbide product, which is prepared by the molding method of the aluminum-based silicon carbide product as described above. The specific implementation of the molding method of the aluminum-based silicon carbide product refers to the above-mentioned embodiment. Since the aluminum-based silicon carbide product proposed in this embodiment adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by all the technical solutions of all the above-mentioned embodiments, which will not be repeated here one by one.

[0109] Compared with the related art, the aluminum-based silicon carbide product obtained by the molding method of the above-mentioned aluminum-based silicon carbide product has an elastic modulus of 80-90GPa, a thermal conductivity of 130-150W / (m·K), a tensile strength of 350-450MPa, an elongation of ≥2%, and has the characteristics of high strength, high stiffness, high thermal conductivity, and a low thermal expansion coefficient.

[0110] By adopting the molding method of the above-mentioned aluminum-based silicon carbide products, aluminum-based silicon carbide structural parts with complex structures and high mechanical properties can be directly produced. The structural parts have the characteristics of low density, high strength, high stiffness, high thermal conductivity and low thermal expansion coefficient; they can be used in electronic devices such as mobile phones, laptops, AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), smart watches, etc. that have a strong demand for lightweight and miniaturization, and can also be used in aerospace and other fields to produce lightweight, miniaturized, high structural strength and excellent mechanical properties. Complex structural parts, among which low-density and high-strength structural parts can reduce the weight of electronic equipment while ensuring that the structural parts have high performance and structural stability; and for structural parts such as optical machine brackets that are responsible for carrying precision optical instruments, the characteristics of high stiffness, high thermal conductivity and low thermal expansion coefficient can ensure the accuracy of the operation of optical devices.

[0111] The present application also proposes an electronic device, which has an aluminum-based silicon carbide product as described in the aforementioned embodiment, wherein the electronic device can be a mobile phone, a laptop computer, AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), a smart watch, and other consumer electronic devices that have a strong demand for lightweight and miniaturization, and can also be an electronic device in the fields of aerospace and the like; the aluminum-based silicon carbide product can be a structural part in the electronic device, and the structural part obtained by the molding method of the above-mentioned aluminum-based silicon carbide product has the characteristics of low density, high strength, high stiffness, high thermal conductivity and low thermal expansion coefficient, which can reduce the weight of the electronic device while ensuring that the structural part has high performance and structural stability. When the structural part is a structural part such as an optical machine bracket that performs the task of carrying precision optical instruments, the use of the above-mentioned aluminum-based silicon carbide product can ensure the accuracy of the operation of the optical device.

[0112] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for forming an aluminum-based silicon carbide product, characterized in that: The steps include: mixing aluminum alloy powder and silicon carbide powder to form a mixture so that at least a portion of the silicon carbide particles are embedded in the aluminum alloy matrix; melting the mixture to obtain a slurry; The slurry is extruded and cast to obtain an aluminum-based silicon carbide product.

2. The method for forming an aluminum-based silicon carbide product according to claim 1, characterized in that: The aluminum alloy powder is a 4-series aluminum alloy or a 6-series aluminum alloy; And / or, the particle size of the aluminum alloy powder is 50 μm to 200 μm.

3. The method for forming an aluminum-based silicon carbide product according to claim 1, characterized in that: The particle size of the silicon carbide particles is 2-8 μm, and the volume percentage of the silicon carbide powder is 8%-20%.

4. The method for forming an aluminum-based silicon carbide product according to claim 1, characterized in that: The step of mixing the aluminum alloy powder and the silicon carbide powder to form a mixture comprises: Aluminum alloy powder, silicon carbide powder and copper powder are mixed to form a mixture.

5. The method for forming an aluminum-based silicon carbide product according to claim 4, characterized in that: The mass ratio of the copper powder in the mixed material is 3% to 6%.

6. The method for forming an aluminum-based silicon carbide product according to claim 1, characterized in that: The step of mixing the aluminum alloy powder and the silicon carbide powder to form a mixture comprises: The aluminum alloy powder and the silicon carbide powder are ball-milled to form a mixture.

7. The method for forming an aluminum-based silicon carbide product according to claim 6, characterized in that: The step of ball-milling the aluminum alloy powder and the silicon carbide powder to form a mixture comprises: Aluminum alloy powder and silicon carbide powder are placed in a ball mill with ceramic balls as grinding balls to mix and form a mixture, wherein the diameter of the ceramic balls is 5mm to 300mm, and the mass ratio of the ceramic balls to the mixture is 0.8 to 1.

2.

8. The method for forming an aluminum-based silicon carbide product according to claim 7, characterized in that: The step of mixing the aluminum alloy powder and the silicon carbide powder in a ball mill using ceramic balls as grinding balls comprises: Ceramic balls of different diameters were added to the ball mill; The aluminum alloy powder and the silicon carbide powder are placed in a ball mill for mixing to form a mixture.

9. The method for forming an aluminum-based silicon carbide product according to claim 1, characterized in that: The step of smelting the mixed material to obtain slurry also includes: The mixed material is remelted and ultrasonically treated to obtain a slurry.

10. The method for forming an aluminum-based silicon carbide product according to claim 9, characterized in that: In the step of remelting the mixed material and subjecting it to ultrasonic treatment to obtain the slurry, the ultrasonic treatment time is controlled to be 1 min to 5 min, and the ultrasonic frequency is controlled to be 23 kHz to 30 kHz.

11. The method for forming an aluminum-based silicon carbide product according to any one of claims 1 to 10, characterized in that: The step of mixing the aluminum alloy powder and the silicon carbide powder to form a mixture comprises: mixing aluminum alloy powder and silicon carbide powder in an inert gas environment to form a mixture; And / or, the step of smelting to obtain slurry comprises: The mixed material is placed in a vacuum or inert gas environment and smelted to obtain a slurry.

12. An aluminum-based silicon carbide product, characterized in that: The aluminum-based silicon carbide product is obtained by the molding method of the aluminum-based silicon carbide product as described in any one of claims 1 to 11.

13. An electronic device, characterized in that: The electronic device comprises the aluminum-based silicon carbide product as claimed in claim 12.

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