A mine-used power device heat dissipation device and a preparation method thereof

Abstract

The application discloses a mine-used power device heat dissipation device and a preparation method thereof. The method comprises the following steps: mixing coarse particles, fine particles, boron-silicon fine powder and paraffin wax to obtain material W1; granulating the material W1 to obtain material W2; cold-pressing the material W2 to obtain a blank P1; sintering the blank P1 to obtain a preform P2; performing punching treatment on the preform P2 to obtain a preform P3; performing near-forming aluminum alloy impregnation on the preform P3, so that the preform P3 is impregnated with aluminum alloy, an aluminum-silicon carbide substrate is formed, an outer aluminum alloy layer for processing a heat dissipation tooth plate is formed on the surface of the aluminum-silicon carbide substrate, and an aluminum-silicon carbide composite material blank P4 with the outer aluminum alloy layer is obtained; processing the outer aluminum alloy layer into the heat dissipation tooth plate, and processing a cooling structure in the aluminum-silicon carbide substrate to obtain the mine-used power device heat dissipation device. The application can significantly improve the heat dissipation capacity of the mine-used power device, ensure the stable and efficient operation of the mine-used power device, and further ensure the safety production of the coal mine.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of heat dissipation devices, and particularly relates to a mine-used power device heat dissipation device and a preparation method thereof. BACKGROUND

[0002] In a mine-used variable frequency device (for example, a mine-used explosion-proof frequency converter), frequent opening and closing cause a large amount of heat to be generated by power devices, and the heat cannot be timely conducted and dissipated to a cooling medium and air, which is easy to cause accumulation and damage the power devices due to excessively high temperature. The material of a traditional mine-used heat dissipation device is aluminum alloy, the thermal conductivity of which is only 140-150 W / mK, the strength of which is 230-250 MPa, and the thermal expansion coefficient of which reaches 20-30 ppm / K. The heat dissipation efficiency is low, and mechanical stress is easy to be generated in a thermal alternating environment, which reduces the stable and efficient operation life of the power devices. Methane is a flammable gas commonly existing in a coal mine, and if a key device is overheated and fails, the methane is easy to explode, which causes loss of equipment and personnel. Therefore, stable and efficient operation of all power devices is a guarantee for safety production of a coal mine. In order to prevent the power devices from being overheated and failing, a reasonable heat dissipation device needs to be designed. SUMMARY

[0003] In order to solve the problems in the prior art, the purpose of the present application is to provide a mine-used power device heat dissipation device and a preparation method thereof, which can significantly improve the heat dissipation capacity of the mine-used power device, ensure stable and efficient operation of the mine-used power device, and further guarantee safety production of a coal mine.

[0004] The technical scheme adopted by the present application is as follows:

[0005] A preparation method of a mine-used power device heat dissipation device, comprising the following processes:

[0006] Coarse particles, fine particles, borosilicate fine powder and paraffin are mixed to obtain material W1, wherein the particle size of the coarse particles is greater than that of the fine particles, and the coarse particles and the fine particles both adopt silicon carbide powder;

[0007] The material W1 is granulated to obtain material W2;

[0008] The material W2 is cold-pressed to obtain a blank P1;

[0009] The blank P1 is sintered to obtain a preform P2;

[0010] A punching process is performed on the preform P2 to process assembly holes, and a preform P3 is obtained;

[0011] The preform P3 is subjected to near-net-shape infiltration of aluminum alloy, so that the aluminum alloy is infiltrated into the preform P3, an aluminum silicon carbide substrate is formed, and an outer aluminum alloy layer for processing the heat dissipation tooth plate is formed on the surface of the aluminum silicon carbide substrate, thereby obtaining an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy layer;

[0012] The outer aluminum alloy layer is processed into a heat dissipation tooth plate, and a cooling structure is processed in the aluminum silicon carbide substrate, thereby obtaining the mine power device heat dissipation device.

[0013] Preferably, the particle size of the coarse particles is 70-150 μm, the particle size of the fine particles is 15-30 μm, the particle size of the borosilicon fine powder is 7-10 nm, and the mass ratio of the coarse particles, the fine particles, and the borosilicon fine powder is (6-9):(1-4):(0.5-1), and the mass of the paraffin accounts for 7%-9% of the total mass of the coarse particles, the fine particles, and the borosilicon fine powder.

[0014] Preferably, when the coarse particles, the fine particles, the borosilicon fine powder, and the paraffin are mixed, the mixing temperature is 90-110 ℃, and the mixing time is 1-2 h.

[0015] Preferably, the material W2 is passed through a 60-mesh sieve, and the undersize is cold-pressed to obtain the blank P1.

[0016] Preferably, the pressure of the cold-pressing is 8-12 MPa, and the pressure holding time is 15-25 s.

[0017] Preferably, when the blank P1 is sintered, the sintering temperature is 1000-1100 ℃, and the sintering time is 30-50 min.

[0018] The specific process of heating during sintering includes:

[0019] From room temperature to 200 ℃, 1-2 h; from 200 ℃ to 400 ℃, 2-3 h; at 400 ℃, 1-2 h; from 400 ℃ to 600 ℃, 60-100 min; at 600 ℃, 2-3 h; from 600 ℃ to the sintering temperature, 30 min-1 h.

[0020] Preferably, the aluminum alloy material is ZL102 series.

[0021] When the preform P3 is subjected to near-net-shape infiltration of aluminum alloy, the infiltration temperature is 695-715 ℃, the infiltration pressure is 3-6 MPa, and the pressure holding time is 10-25 min.

[0022] Preferably, the heat dissipation tooth plate adopts a parallel tooth plate or a star point tooth plate.

[0023] After the outer aluminum alloy layer is processed into a heat dissipation tooth plate, the surface of the heat dissipation tooth plate is subjected to oxidation and blackening treatment.

[0024] Preferably, the cooling structure inside the aluminum silicon carbide substrate comprises a cooling cavity arranged inside the aluminum silicon carbide substrate, and a copper pipe arranged along the cooling cavity.

[0025] The cooling cavity is an S-shaped cavity or a Z-shaped cavity.

[0026] The application also provides a mine power device heat dissipation device prepared by the preparation method.

[0027] The application has the following advantages:

[0028] In the application, the porous silicon carbide ceramic (i.e., the preform P2) is processed from coarse particles, fine particles and borosilicon fine powder. The coarse particles and the fine particles are particle graded in a certain proportion, and then the borosilicon fine powder in different proportions is added. After high-temperature sintering, a binary strengthening bonding phase of silicon oxide-boron oxide is formed between the coarse particles and the fine particles, and a porous silicon carbide ceramic with adjustable bulk density and strength is obtained. The preform P2 is perforated to process assembly holes, which reduces the processing amount and processing difficulty of the final product structure and solves the manufacturing cost. When the preform P3 is near-net-shape infiltrated with aluminum alloy, the aluminum alloy is infiltrated into the preform P3 to form an aluminum silicon carbide substrate. The aluminum silicon carbide substrate formed has a large increase in thermal conductivity, strength and thermal stability compared with the traditional cast aluminum substrate. Therefore, the application can timely transfer the heat generated by the operation of the power device to the heat dissipation teeth, and reduce the mechanical stress between the power device and the heat dissipation substrate, greatly improving the efficiency and stability of the operation of the high-power device. When the preform P3 is near-net-shape infiltrated with aluminum alloy, an outer aluminum alloy layer for processing the heat dissipation tooth plate is formed on the surface of the aluminum silicon carbide substrate. Therefore, the heat dissipation tooth plate of the application is almost an integral structure with the aluminum silicon carbide substrate, so the thermal stress between the heat dissipation tooth plate and the aluminum silicon carbide substrate is small, which ensures the stable and efficient operation life of the mine power device heat dissipation device. The preform P3 is near-net-shape infiltrated with aluminum alloy, so the processing allowance is reduced and the processing cost is reduced. The aluminum silicon carbide substrate is processed with a cooling structure inside, so the cooling structure can further effectively improve the heat dissipation capacity of the mine power device heat dissipation device, and ensure that the power device will not fail due to overheating. In summary, the application can significantly improve the heat dissipation capacity of the mine power device, ensure the stable and efficient operation of the mine power device, and thus ensure the safe production of coal mines.

[0029] Further, the heat dissipation tooth plate adopts parallel tooth plate or star point tooth plate, which increases the contact of tooth surface and air and improves the heat dissipation efficiency. The surface of the heat dissipation tooth plate is subjected to oxidation and blackening treatment, so that on the basis of increasing the contact surface of the heat dissipation tooth and air, the heat dissipation and radiation heat dissipation double-enhanced heat dissipation mechanism is formed by using the heat radiation mode, which greatly improves the heat dissipation efficiency and timely dissipates the heat generated by the power device to the air.

[0030] Further, the cooling cavity in the cooling structure of the aluminum silicon carbide substrate adopts S-shaped cavity or Z-shaped cavity, and the copper pipe arranged along the cooling cavity ensures the contact surface between the copper pipe and the aluminum silicon carbide substrate. The copper pipe has excellent heat conduction performance, forms the internal heat conduction and dissipation mechanism of the aluminum silicon carbide substrate, and increases the heat conduction and dissipation efficiency of the power device. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1(a) is a front view of the preform P3 in the embodiment of the present application; Fig. 1(b) is a left view of the preform P3 in the embodiment of the present application;

[0032] Fig. 2(a) is a front view of the near-net forming die structure adopted in the embodiment of the present application; Fig. 2(b) is a schematic view of the A-A cross section in Fig. 2(a);

[0033] Fig. 3(a) is a front view of the heat dissipation device (the heat dissipation tooth plate adopts parallel tooth plate) of the mining power device in the embodiment of the present application; Fig. 3(b) is a top view of Fig. 3(a);

[0034] Fig. 4(a) is a front view of the heat dissipation device (the heat dissipation tooth plate adopts star point tooth plate) of the mining power device in the embodiment of the present application; Fig. 4(b) is a top view of Fig. 4(a);

[0035] Figure 5 It is a schematic view of the cooling cavity structure in the aluminum silicon carbide substrate of the present application.

[0036] In the figure, 1 is the preform P3, 1-1 is the assembly hole, 2 is the near-net forming die, 3 is the aluminum silicon carbide substrate, 3-1 is the cooling cavity, 4-1 is the parallel tooth plate, and 4-2 is the star point tooth plate. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be further described in detail below with reference to the drawings and embodiments.

[0038] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0039] The preparation method of the mine power device heat dissipation device comprises the following steps:

[0040] Step (1), the coarse particles, fine particles, boron-silicon fine powder and paraffin are placed into a heated mixer for mixing, the mixing temperature is 90-110 DEG C, the mixing time is 1-2h, and material W1 is obtained; wherein, the coarse particles and fine particles are both silicon carbide powder, the purity of the silicon carbide powder is ≥98%, and the purity of the paraffin is ≥99.9%. The particle size range of the coarse particles is 70-150 μm, the particle size range of the fine particles is 15-30 μm, the particle size range of the boron-silicon fine powder is 7-10 nm, and the mass ratio of the coarse particles, fine particles and boron-silicon fine powder is (6-9):(1-4):(0.5-1), and the mass of the paraffin accounts for 7%-9% of the total mass of the mixed powder of the coarse particles, fine particles and boron-silicon fine powder;

[0041] Step (2), the material W1 obtained in step (1) is placed into a swing granulating sieve for granulation, and material W2 is obtained; wherein the rotating speed of the swing granulating sieve is 100 r / min, and the mesh number of the sieve is 60;

[0042] Step (3), the material W2 obtained in step (2) is placed into a cold pressing mold, and cold pressing forming is carried out under the condition that the pressure is 8-12 MPa and the pressure holding time is 15-25 s, and a blank P1 is obtained;

[0043] Step (4), the blank P1 obtained in step (3) is placed into a high-temperature atmosphere sintering furnace for sintering, and a preform P2 is obtained; wherein the sintering temperature is 1000-1100 DEG C, and the sintering time is 30-50 min;

[0044] The specific process of heating during sintering comprises:

[0045] Ramp from room temperature to 200℃, 1-2h; Ramp from 200℃ to 400℃, 2-3h; Keep at 400℃ for 1-2h; Ramp from 400℃ to 600℃, 60-100min; Keep at 600℃ for 2-3h; Ramp from 600℃ to sintering temperature, 30min-1h, then keep at sintering temperature to obtain the preform P2, the volume fraction of the preform P2 is 65%-70%, and the three-point bending strength is 3-6MPa;

[0046] Step (5), taking the preform P2 obtained in step (4), using a laser puncher to punch, as shown in Figures 1(a) and 1(b), to obtain a preform P3;

[0047] Step (6), taking the preform P3 obtained in step (5), placing it into a near-net-shape infiltration mold, as shown in Figures 2(a) and 2(b), and placing the near-net-shape infiltration mold into an infiltration furnace to perform near-net-shape infiltration of aluminum alloy on the preform P3, so that the preform P3 is infiltrated with aluminum alloy inside to form an aluminum silicon carbide substrate, and an outer aluminum alloy layer for processing a heat dissipation tooth plate is formed on the surface of the aluminum silicon carbide substrate, to obtain an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy layer; the aluminum alloy material can be ZL102 series, the volume ratio of the silicon carbide ceramic (i.e. the preform P3) to the aluminum alloy is (6-8):(2-4), a near-net-shape infiltration mold is used, the upper part of the step is the aluminum silicon carbide substrate, the lower part of the step is the aluminum alloy casting, the infiltration temperature is 695-715℃, the infiltration pressure is 3-6MPa, and the pressure maintaining time is 10-25min;

[0048] Step (7), taking the aluminum silicon carbide composite material blank P4 with an outer aluminum alloy layer obtained in step (6), machining the inner cavity of the aluminum silicon carbide composite material substrate into a cooling cavity as shown in Figure 3(a) and 3(b), to obtain a material W5; the cooling cavity can be an S-shaped cavity or a Z-shaped cavity; Figure 5

[0049] Step (8), taking the material W5 obtained in step (7), machining the outer aluminum alloy layer into a heat dissipation tooth plate, and performing oxidation and blackening treatment on the surface of the heat dissipation tooth plate, to obtain a material W6; the blackening liquid used for the oxidation and blackening treatment is Q / YS.205 (Yishun brand), the temperature is 75-90℃, and the time is 9-15min;

[0050] Step (9), taking the material W6 obtained in step (8), arranging a red copper pipe along the inner cavity structure, to obtain a mining power device heat dissipation device of the present application, wherein the red copper pipe can be filled with cooling water for cooling.

[0051] ​The thickness of the aluminum silicon carbide substrate is 5-8mm, and the thickness of the outer aluminum alloy layer (i.e. the height of the heat dissipation tooth plate) is 11-16mm. The heat dissipation tooth plate adopts parallel tooth plate (as shown in Figures 3(a) and 3(b)) or star point tooth plate (as shown in Figures 4(a) and 4(b)). The surface of the heat dissipation tooth plate is subjected to blackening oxidation treatment.

[0052] In the above scheme of the present application, the pre-punching processed silicon carbide porous ceramic (i.e. the preform P3) reduces the processing amount and difficulty of the final product structure, and solves the manufacturing cost. The structure is shown in Figures 1(a) and 1(b).

[0053] The aluminum silicon carbide composite material with a thickness of 5-8mm and an outer aluminum alloy layer thickness of 11-16mm is integrally formed, and the final product structure is adopted. The infiltration mold structure shown in Figures 2(a) and 2(b) is used for the integrated near forming of the aluminum silicon carbide composite material, thereby reducing the processing cost.

[0054] The aluminum silicon carbide substrate replaces the traditional cast aluminum substrate, and the heat conduction efficiency is improved by 20%, the strength is improved by 30%, and the thermal stability is improved by 65%. The heat generated by the power device is transmitted to the heat dissipation tooth in time, and the mechanical stress between the power device and the heat dissipation substrate is reduced, thereby greatly improving the efficiency and stability of the operation of the high-power device.

[0055] The cooling cavity in the aluminum silicon carbide heat dissipation substrate is machined into an "S" shape or a "Z" shape, and a red copper pipe is laid in the cooling cavity, and cooling water flows in the red copper pipe. The "S" shape or "Z" shape structure increases the contact surface between the red copper pipe and the substrate. The red copper pipe has excellent heat conduction performance, forms an internal heat conduction and dissipation mechanism, and increases the heat conduction and dissipation efficiency of the power device.

[0056] The heat dissipation teeth are distributed in a star point shape or in parallel, which increases the contact between the tooth surface and the air and improves the heat dissipation efficiency.

[0057] The oxidation blackening treatment can utilize thermal radiation to form a medium heat dissipation + radiation heat dissipation double-enhanced heat dissipation mechanism on the basis of increasing the contact surface between the heat dissipation teeth and the air, thereby greatly improving the heat dissipation efficiency and dissipating the heat generated by the power device to the air in time.

[0058] As can be seen from the above scheme, the mine power device heat dissipation device includes a pre-punching processed silicon carbide porous ceramic; an aluminum silicon carbide substrate with a thickness of 5-8mm and an outer aluminum alloy layer with a thickness of 11-16mm is integrally formed; the density of the aluminum silicon carbide substrate is greater than 99.5%, the thermal expansion coefficient is less than 8ppm / ℃, the thermal conductivity is greater than 190W / mK, and the bending strength is greater than 310MPa.

[0059] The measurement of the above parameters is based on the following: the data of density (porosity), pore size distribution, three-point bending strength, thermal conductivity and thermal expansion coefficient are obtained according to “Ceramic Green Body Apparent Porosity and Bulk Density Test Method (QB / T 1642-2012)”, “Porous Ceramic Pore Diameter Test Method (GB / T 1967-1996)”, “Stress-Strain Test Method (GB / T 38978-2020)”, “Flash Method for Measuring Thermal Diffusivity or Thermal Conductivity (GBT 22588-2008)”, and “Solid Material Linear Expansion System Test Method (GJB 332A-2004)”.

[0060] Embodiment 1

[0061] The preparation method of the mining power device heat dissipation device includes the following steps:

[0062] (1) Put the coarse particles, fine particles, boron-silicon fine powder and paraffin into a heated mixer for mixing, the mixing temperature is 90°C, and the mixing time is 1h, to obtain material W1; wherein, the coarse particles and fine particles are both silicon carbide powder, the purity of the silicon carbide powder is 99%, the purity of the paraffin is 99.98%, the particle size range of the coarse particles is 70-150μm, the particle size range of the fine particles is 15-30μm, the particle size range of the boron-silicon fine powder is 7-10nm, the mass ratio of the coarse particles: fine particles: boron-silicon fine powder is 9:1:0.5, and the mass fraction of the paraffin in the mixed powder is 9%;

[0063] (2) Take the material W1 obtained in step (1) and put it into a swing granulating sieve, the rotation speed is 100r / min, and the sieve mesh number is 60, to obtain material W2;

[0064] (3) Take the material W2 obtained in step (2) and put it into a cold pressing mold, and cold press form under the condition of a pressure of 8MPa for 15s, to obtain a green body P1;

[0065] (4) Take the green body P1 obtained in step (3) and put it into a high-temperature atmosphere sintering furnace for sintering, to obtain a preform P2; wherein, the sintering temperature is 1000°C, and the sintering time is 30min;

[0066] The specific process of heating during sintering includes:

[0067] From room temperature to 200°C, it takes 1h; from 200°C to 400°C, it takes 2h; keep at 400°C for 1h; from 400°C to 600°C, it takes 60min; keep at 600°C for 2h; from 600°C to the sintering temperature, it takes 30min, then keep at the sintering temperature, to obtain the preform P2, the volume fraction of the preform P2 is 65%, and the three-point bending strength is 3MPa;

[0068] (5) Take the preform P2 obtained in step (4) and use a laser drilling machine to drill holes. The structure is shown in Figure 1(a) and Figure 1(b), and the preform P3 is obtained.

[0069] (6) Take the preform P3 obtained in step (5) and place it into the near-forming impregnation mold. The structure of the near-forming impregnation mold is shown in Figure 2(a) and Figure 2(b). Place the near-forming impregnation mold into the impregnation furnace and impregnate the preform P3 with aluminum alloy in a near-forming manner, so that aluminum alloy is impregnated into the interior of the preform P3 to form an aluminum silicon carbide substrate. An outer aluminum alloy layer for processing heat dissipation tooth plates is formed on the surface of the aluminum silicon carbide substrate to obtain an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy. The aluminum alloy material is ZL102 series, the impregnation temperature is 695℃, the impregnation pressure is 3MPa, and the holding time is 10min to obtain an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy.

[0070] (7) Take the aluminum-silicon carbide composite material blank P4 with aluminum alloy coating obtained in step (6), and machine the inner cavity of the aluminum-silicon carbide composite material substrate as follows. Figure 5 The cooling chamber structure shown yields material W5;

[0071] (8) Take the material W5 obtained in step (7), machine one side of the outer aluminum alloy layer into the structure shown in Figure 3(a) and 3(b), and perform oxidation blackening treatment on the surface of the heat dissipation tooth plate. The blackening liquid used for oxidation blackening treatment is Q / YS.205 (Yishun brand), the temperature is 75℃, and the time is 9min, to obtain material W6;

[0072] (9) Take the material W6 obtained in step (8) and arrange the copper tubes along the inner cavity structure to obtain the heat dissipation device for power devices in coal mines in this embodiment.

[0073] In this embodiment, the thickness of the integrally molded aluminum silicon carbide substrate is 5 mm, and the thickness of the outer aluminum alloy layer is 11 mm; the density of the aluminum silicon carbide substrate is 99.6%, and the thermal conductivity is 195 W / m. K, flexural strength 315MPa, coefficient of thermal expansion 7.8×10 -6 / K; The heat dissipation tooth plate has a straight structure; the surface of the tooth plate is oxidized and blackened. Under the same working environment conditions, after a period of time, compared with the traditional heat dissipation device that uses a solid die-cast aluminum alloy substrate and has a parallel structure with no surface treatment, the temperature of the mining power device assembled by the heat dissipation device of this embodiment is reduced by 2 times, and the temperature of the heat dissipation tooth plate is reduced by 1.5 times.

[0074] Example 2

[0075] The preparation method of the heat dissipation device for mining power devices in this embodiment includes the following steps:

[0076] (1) Coarse particles, fine particles, borosilicate powder and paraffin wax are placed in a heated mixer for mixing. The mixing temperature is 100℃ and the mixing time is 1.5h to obtain material W1. Among them, coarse particles and fine particles are both silicon carbide powder with a purity of 99% and a paraffin wax purity of 99.98%. The particle size range of coarse particles is 70-150μm, the particle size range of fine particles is 15-30μm, the particle size range of borosilicate powder is 7-10nm, the mass ratio of coarse particles: fine particles: borosilicate powder is 8:2:0.8, and the mass fraction of paraffin wax in the mixed powder is 8%.

[0077] (2) Take the material W1 obtained in step (1) and put it into a gyratory granulation sieve. The rotation speed is 100 r / min and the sieve mesh number is 60 to obtain material W2.

[0078] (3) Take the material W2 obtained in step (2), put it into the cold press mold, hold it under pressure of 10MPa for 20s, and cold press it to obtain the blank P1.

[0079] (4) Take the preform P1 obtained in step (3) and place it in a high-temperature atmosphere sintering furnace for sintering to obtain the preform P2; wherein the sintering temperature is 1050℃ and the sintering time is 40min.

[0080] The specific heating process during sintering includes:

[0081] The process involved heating from room temperature to 200℃ in 1.5 hours; heating from 200℃ to 400℃ in 2.5 hours; holding at 400℃ for 1.5 hours; heating from 400℃ to 600℃ in 80 minutes; holding at 600℃ for 2.5 hours; and heating from 600℃ to the sintering temperature in 45 minutes, followed by holding at the sintering temperature to obtain preform P2. Preform P2 had a volume fraction of 68% and a three-point flexural strength of 4.5 MPa.

[0082] (5) Take the preform P2 obtained in step (4) and use a laser drilling machine to drill holes. The structure is shown in Figure 1(a) and Figure 1(b), and the preform P3 is obtained.

[0083] (6) Take the preform P3 obtained in step (5) and place it into the near-forming impregnation mold. The structure of the near-forming impregnation mold is shown in Figure 2(a) and Figure 2(b). Place the near-forming impregnation mold into the impregnation furnace and impregnate the preform P3 with aluminum alloy in a near-forming manner, so that aluminum alloy is impregnated into the interior of the preform P3 to form an aluminum silicon carbide substrate. An outer aluminum alloy layer for processing heat dissipation tooth plates is formed on the surface of the aluminum silicon carbide substrate, and an aluminum alloy blank P4 with an outer aluminum alloy is obtained. The aluminum alloy material is ZL102 series, the impregnation temperature is 700℃, the impregnation pressure is 5MPa, and the holding time is 15min. The aluminum silicon carbide blank P4 with an outer aluminum alloy is obtained.

[0084] (7) Take the aluminum-silicon carbide composite material blank P4 with aluminum alloy coating obtained in step (6), and machine the inner cavity of the aluminum-silicon carbide composite substrate as follows. Figure 5 The cooling chamber structure shown yields material W5;

[0085] (8) Take the material W5 obtained in step (7), machine one side of the outer aluminum alloy layer into the structure shown in Figure 4(a) and Figure 4(b), and perform oxidation blackening treatment on the surface of the heat dissipation tooth plate. The blackening liquid used for oxidation blackening treatment is Q / YS.205 (Yishun brand), the temperature is 80℃, and the time is 12min, to obtain material W6;

[0086] (9) Take the material W6 obtained in step (8), arrange the copper tubes along the inner cavity structure, and obtain the heat dissipation device for mining power devices in this embodiment.

[0087] In this embodiment, the thickness of the integrally molded aluminum silicon carbide substrate is 7 mm, and the thickness of the outer aluminum alloy layer is 14 mm; the density of the aluminum silicon carbide substrate is 99.7%, and the thermal conductivity is 200 W / m. K, flexural strength 330MPa, coefficient of thermal expansion 7.5×10 -6 / K; The heat dissipation tooth plate has a star-shaped structure; the surface of the tooth plate is oxidized and blackened. Under the same working environment conditions, after a period of time, compared with the traditional heat dissipation device that uses a solid die-cast aluminum alloy substrate and has a parallel structure with no surface treatment, the temperature of the mining power device assembled by the heat dissipation device of this embodiment is reduced by 3 times, and the temperature of the heat dissipation tooth plate is reduced by 2 times.

[0088] Example 3

[0089] The preparation method of the heat dissipation device for mining power devices in this embodiment includes the following steps:

[0090] (1) Coarse particles, fine particles, borosilicate powder and paraffin wax are placed in a heated mixer for mixing. The mixing temperature is 110℃ and the mixing time is 2h to obtain material W1. Among them, coarse particles and fine particles are both silicon carbide powder with a purity of 99% and a paraffin wax purity of 99.98%. The particle size range of coarse particles is 70-150μm, the particle size range of fine particles is 15-30μm, the particle size range of borosilicate powder is 7-10nm, the mass ratio of coarse particles: fine particles: borosilicate powder is 6:4:1, and the mass fraction of paraffin wax in the mixed powder is 7%.

[0091] (2) Take the material W1 obtained in step (1) and put it into a gyratory granulation sieve. The rotation speed is 100 r / min and the sieve mesh number is 60 to obtain material W2.

[0092] (3) Take the material W2 obtained in step (2), put it into the cold press mold, hold it under pressure of 12MPa for 25s, and perform cold pressing to obtain the blank P1;

[0093] (4) Take the preform P1 obtained in step (3) and place it in a high-temperature atmosphere sintering furnace for sintering to obtain preform P2; wherein the sintering temperature is 1100℃ and the sintering time is 50min.

[0094] The specific heating process during sintering includes:

[0095] The process involved heating from room temperature to 200℃ in 2 hours; heating from 200℃ to 400℃ in 3 hours; holding at 400℃ for 2 hours; heating from 400℃ to 600℃ in 100 minutes; holding at 600℃ for 3 hours; and heating from 600℃ to the sintering temperature in 1 hour, followed by holding at the sintering temperature to obtain preform P2. Preform P2 has a volume fraction of 70% and a three-point flexural strength of 6 MPa.

[0096] (5) Take the preform P2 obtained in step (4) and use a laser drilling machine to drill holes. The structure is shown in Figure 1(a) and Figure 1(b), and the preform P3 is obtained.

[0097] (6) Take the preform P3 obtained in step (5) and place it into the near-forming impregnation mold. The structure of the near-forming impregnation mold is shown in Figure 2(a) and Figure 2(b). Place the near-forming impregnation mold into the impregnation furnace and impregnate the preform P3 with aluminum alloy in a near-forming manner, so that aluminum alloy is impregnated into the interior of the preform P3 to form an aluminum silicon carbide substrate. An outer aluminum alloy layer for processing heat dissipation tooth plates is formed on the surface of the aluminum silicon carbide substrate to obtain an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy. The aluminum alloy material is ZL102 series, the impregnation temperature is 715℃, the impregnation pressure is 6MPa, and the holding time is 25min to obtain an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy.

[0098] (7) Take the aluminum-silicon carbide composite material blank P4 with aluminum alloy coating obtained in step (6), and machine the inner cavity of the aluminum-silicon carbide composite material substrate as follows. Figure 5 The cooling chamber structure shown yields material W5;

[0099] (8) Take the material W5 obtained in step (7), machine one side of the outer aluminum alloy layer into the structure shown in Figure 4(a) and Figure 4(b), and perform oxidation blackening treatment on the surface of the heat dissipation tooth plate. The blackening liquid used for oxidation blackening treatment is Q / YS.205 (Yishun brand), the temperature is 90℃, and the time is 15min, to obtain material W6;

[0100] (9) Take the material W6 obtained in step (8) and arrange the copper tubes along the inner cavity structure to obtain the heat dissipation device for mining power devices in this embodiment.

[0101] In this embodiment, the thickness of the integrally molded aluminum silicon carbide substrate is 8 mm, and the thickness of the outer aluminum alloy layer is 16 mm; the density of the aluminum silicon carbide substrate is 99.8%, and the thermal conductivity is 215 W / m. K, flexural strength 350MPa, coefficient of thermal expansion 7×10 -6 / K; The heat dissipation tooth plate has a star-shaped structure; the surface of the tooth plate is oxidized and blackened. Under the same working environment conditions, after a period of time, compared with the traditional heat dissipation device that uses a solid die-cast aluminum alloy substrate and has a parallel structure with no surface treatment, the temperature of the mining power device assembled by the heat dissipation device in this embodiment is reduced by 4 times, and the temperature of the heat dissipation tooth plate is reduced by 3 times.

[0102] Table 1 compares the time / temperature parameters of the heat dissipation device for mining power devices prepared in Example 3 of the present invention with those of the traditional aluminum alloy heat dissipation device for mining.

[0103] Table 1

[0104]

[0105] As can be seen from Table 1, under the same working environment conditions, after a period of time, compared with the traditional heat dissipation device that uses a solid die-cast aluminum alloy substrate and has parallel structure and untreated surface heat dissipation teeth, the temperature of the mining power device assembled by the heat dissipation device of the present invention is reduced by 2-4 times, and the temperature of the heat dissipation tooth plate is reduced by 2-3 times.

[0106] In summary, the fabrication method of the mining power device heat dissipation device of this invention reduces subsequent processing and saves costs. Simultaneously, the integral molding of the aluminum silicon carbide substrate and the aluminum alloy heat dissipation toothed plate eliminates the interfacial thermal resistance between the traditional substrate and heat dissipation toothed plate, improving conductivity and heat dissipation efficiency. It also significantly reduces the thermal stress caused by the large difference in thermal expansion coefficients between the aluminum alloy and aluminum silicon carbide, extending the device's service life. Furthermore, the substrate in contact with the power device uses an aluminum silicon carbide material substrate with higher thermal conductivity and better thermal stability, replacing the traditional die-cast aluminum alloy plate. The inner cavity of the aluminum silicon carbide substrate is processed into an "S" or "Z" shape, and copper pipes are laid along the inner cavity structure, with cooling water flowing inside the pipes to improve conductivity and heat dissipation efficiency. The toothed plate is distributed in a star-like pattern and its surface is oxidized and blackened, increasing the heat dissipation efficiency at the interface with air. This effectively solves the problem of thermal failure of high-power mining devices due to untimely conductivity and heat dissipation, providing a guarantee for efficient and stable mining production.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a heat dissipation device for mining power devices, characterized in that, The process includes the following: Coarse particles, fine particles, borosilicate powder and paraffin wax are mixed to obtain material W1, wherein the particle size of the coarse particles is larger than that of the fine particles, and both the coarse and fine particles are silicon carbide powder. The material W1 is granulated to obtain material W2; The material W2 is cold-pressed to obtain a preform P1; The preform P1 is sintered to obtain the preform P2; Drill holes in preform P2 to create assembly holes, and obtain preform P3; The preform P3 is subjected to near-forming impregnation with aluminum alloy, so that aluminum alloy is impregnated into the interior of the preform P3 to form an aluminum silicon carbide substrate, and an outer aluminum alloy layer for processing heat dissipation tooth plate is formed on the surface of the aluminum silicon carbide substrate to obtain an aluminum silicon carbide composite material blank P4 with an outer aluminum alloy. The outer aluminum alloy layer is processed into a heat dissipation toothed plate, and a cooling structure is processed inside the aluminum silicon carbide substrate to obtain the heat dissipation device for mining power devices. The coarse particles have a particle size of 70-150 μm, the fine particles have a particle size range of 15-30 μm, and the borosilicate powder has a particle size range of 7-10 nm. The mass ratio of coarse particles to fine particles to borosilicate powder is (6-9):(1-4):(0.5-1), and the mass of paraffin wax accounts for 7%-9% of the total mass of coarse particles, fine particles, and borosilicate powder. When sintering the preform P1, the sintering temperature is 1000-1100℃ and the sintering time is 30-50min. The specific heating process during sintering includes: raising the temperature from room temperature to 200℃ for 1-2 hours; raising the temperature from 200℃ to 400℃ for 2-3 hours; holding at 400℃ for 1-2 hours; raising the temperature from 400℃ to 600℃ for 60-100 minutes; holding at 600℃ for 2-3 hours; and raising the temperature from 600℃ to the sintering temperature for 30 minutes to 1 hour.

2. The method for preparing a heat dissipation device for mining power devices according to claim 1, characterized in that, When mixing coarse particles, fine particles, borosilicate powder and paraffin, the mixing temperature is 90-110℃ and the mixing time is 1-2 hours.

3. The method for preparing a heat dissipation device for mining power devices according to claim 1, characterized in that, Material W2 is passed through a 60-mesh sieve, and the material passing through the sieve is cold-pressed to obtain a preform P1.

4. The method for preparing a heat dissipation device for mining power devices according to claim 1, characterized in that, The pressure for cold pressing is 8-12 MPa, and the holding time is 15-25 seconds.

5. The method for preparing a heat dissipation device for mining power devices according to claim 1, characterized in that, The aluminum alloy material is ZL102 series; When near-forming aluminum alloy impregnation is performed on preform P3, the impregnation temperature is 695-715℃, the impregnation pressure is 3-6MPa, and the holding time is 10-25min.

6. The method for preparing a heat dissipation device for mining power devices according to claim 1, characterized in that, The heat dissipation fins can be made of parallel fins or star-shaped fins; After the outer aluminum alloy layer is processed into a heat dissipation tooth plate, the surface of the heat dissipation tooth plate is subjected to an oxidation and blackening treatment.

7. The method for preparing a heat dissipation device for mining power devices according to claim 1, characterized in that, The cooling structure inside the aluminum silicon carbide substrate includes a cooling cavity disposed inside the aluminum silicon carbide substrate, and copper pipes arranged along the direction of the cooling cavity. The cooling chamber is either an S-shaped chamber or a Z-shaped chamber.

8. A heat dissipation device for mining power devices, characterized in that, The heat dissipation device for mining power devices is prepared by the preparation method described in any one of claims 1-7.

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