Manufacturing method of bus duct shell and bus duct shell

Abstract

The application discloses a manufacturing method of a bus duct shell and the bus duct shell, and comprises the following steps: preparing an aluminum-based composite powder of a main shell, laser selective melting additive manufacturing of the main shell, preparing an aluminum-based composite blank of a connecting plate, atomic-level combination of the main shell and the connecting plate, construction of a surface micro-nano heat dissipation structure, supercritical fluid and magnetic field synergistic treatment, preparation of a protective layer, and temperature balance regulation. Through advanced technologies such as laser additive manufacturing, the method improves the precision, mechanical properties and heat conduction performance of the main shell, realizes atomic-level combination of the main shell and the connecting plate, improves the heat dissipation and protection performance, reduces residual stress, and ensures long-term reliable use of the shell.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bus ducts, and particularly relates to a bus duct shell manufacturing method and a bus duct shell. BACKGROUND

[0002] At present, as a key equipment for power transmission, the structural stability, heat conduction balance and advanced manufacturing process of the shell of the bus duct directly affect the power transmission efficiency and safety. The existing bus duct shell is mostly prepared by traditional casting or stamping process, the main shell and the connecting plate are often connected by welding or bolts, and the following problems exist:

[0003] The aluminum alloy shell prepared by the traditional casting process is prone to have defects such as pores and shrinkage holes in the inside, which leads to insufficient structural strength, and it is difficult to realize high-precision forming of a complex internal mounting cavity, so that the close assembly requirement of the bus duct assembly cannot be met;

[0004] The connection between the main shell and the connecting plate is mostly physical splicing or conventional welding, the interface bonding strength is low, the thermal resistance is prone to be too large, the temperature balance of the two main shells is difficult to realize, and long-term use is prone to cause safety hazards due to local overheating;

[0005] The surface treatment of the shell mostly adopts simple spraying or oxidation process, the protective layer has weak bonding force with the base body, the high and low temperature resistance and corrosion resistance are limited, and there is a lack of targeted heat dissipation structure design, so that the heat dissipation efficiency is low;

[0006] During the manufacturing process, the microstructure of the material is not accurately controlled, the residual stress of the shell is unevenly distributed, deformation is prone to occur, and the dimensional stability is affected; meanwhile, there is a lack of directional optimization and calibration means for the heat conduction performance, so that the temperature balance accuracy cannot be guaranteed. SUMMARY

[0007] The purpose of the application is to provide a bus duct shell manufacturing method and a bus duct shell to solve the problems in the background art.

[0008] Therefore, the application provides a bus duct shell manufacturing method, which comprises the following steps:

[0009] S1: main shell aluminum-based gradient composite powder customization preparation, taking an aviation-grade aluminum alloy powder as a base material, mixing a nano-sized heat conduction enhancement phase, performing ultrasonic airflow crushing and plasma activation modification, and obtaining a main shell composite powder;

[0010] S2: main shell laser selective melting additive manufacturing, using multi-beam collaborative laser selective melting to print the main shell composite powder obtained in S1 into two oppositely arranged main shell rough castings, dynamically adjusting laser parameters during printing, and forming a high-precision mounting cavity;

[0011] S3: The aluminum-based bionic composite blank is prepared, the internal passage is designed by imitating the vein heat conduction structure, the composite nanometer carbon tube heat conduction layer and the porous aluminum alloy support layer are prepared, and the prefabricated blank is prepared through vacuum hot pressing solidification;

[0012] S4: The main shell and the connecting plate are combined and formed in a cross-scale interface, and the heterogeneous interface is combined at the atomic level through laser-assisted hot isostatic pressing;

[0013] S5: The surface of the shell is constructed by bionic micro-nano heat dissipation structure, the micro-nano convex array is processed by femtosecond laser, and the plasma activation treatment is combined;

[0014] S6: The shell is treated by supercritical fluid and magnetic field, so that the internal stress homogenization and precipitated phase optimization are realized;

[0015] S7: The shell gradient multi-functional protective layer is prepared, and the high-temperature-resistant and high-thermal-conductivity protective system is formed;

[0016] S8: The shell temperature uniformity intelligent regulation ensures that the temperature difference between the two main shells is controlled within a preset range.

[0017] In the application, in step S1, the mixed nanoscale thermal conductivity enhancement phase is designed according to the radial function gradient, and the main shell composite powder with particle size gradient distribution and surface activity is prepared; the aviation grade aluminum alloy powder is 7075 aluminum alloy, the nanoscale thermal conductivity enhancement phase is aluminum nitride and silicon carbide, the particle size is 80-100nm, the gradient proportion is mixed from inside to outside in the radial direction, the ultrasonic airflow crushing pressure is 1.2MPa, the particle size distribution deviation of the crushed powder is ≤10%, the plasma activation is carried out in the mixed gas of argon and hydrogen with a volume ratio of 9:1, the power is 800W, the activation time is 15min, and the powder surface hydroxyl density is improved by more than 40%.

[0018] In the application, in step S2, the multi-beam collaborative laser selective melting adopts 3 beams of wavelength 1064nm fiber laser, the single-beam power is 500W, the spot diameter is 35μm, the scanning speed is 1500-2000mm / s, the layer thickness is 20-30μm, the powder laying density is ≥98%, the real-time molten pool monitoring adopts high-speed camera, when the molten pool temperature fluctuation exceeds ±5℃, the laser power is automatically compensated by 5%-8%, the cavity size tolerance is controlled within ±0.01mm, and the surface roughness Ra is ≤0.6μm.

[0019] In the present application, further embodiments are, in step S3, the super-thin aluminum alloy foil is used as the base material, and the nanometer carbon tube heat conduction layer and the porous aluminum alloy support layer are alternately compounded; the super-thin aluminum alloy foil is 1050 pure aluminum, the length-diameter ratio of the carbon tube in the nanometer carbon tube heat conduction layer is greater than or equal to 1000, the dispersion concentration is 5%, the coating thickness is 10 microns, the porous aluminum alloy support layer is 3A21 aluminum alloy, the vacuum heat pressing curing temperature is 200 DEG C, the pressure is 8 MPa, the vacuum degree is less than or equal to 10-3 Pa, the holding time is 60 min, and the preform heat conduction coefficient is greater than or equal to 220 W / (m*K).

[0020] In the present application, further embodiments are, in step S4, the two main shell rough blanks are fixed on the magneto-rheological precision clamp, and the nanometer metal solder paste is pre-placed in the connection plate preform and the main shell connection area; the positioning precision of the magneto-rheological precision clamp is ±0.003 mm, and the clamping force is steplessly adjusted through the magnetic field intensity; the nanometer metal solder paste is a tin, silver and copper alloy, the coating thickness is 5-8 microns, the laser-assisted hot isostatic pressing temperature is 500 DEG C, the pressure is 20 MPa, the laser preheating power is 300 W, the interface bonding strength is greater than or equal to 220 MPa, and the diffusion layer thickness is greater than or equal to 8 microns.

[0021] In the present application, further embodiments are, in step S5, the periodic micro-nano convex array is processed by referring to the scale structure of butterfly wings; the femtosecond laser wavelength is 800 nm, the pulse width is 30 fs, the micro-nano convex array processed is a hexagon, the plasma activation adopts a mixed plasma of oxygen and argon, the volume ratio is 1:3, the power is 300 W, the processing time is 5 min, the surface contact angle is reduced to below 30 DEG, and the heat dissipation area is improved by 50%.

[0022] In the present application, further embodiments are, in step S6, the shell processed in S5 is placed in a supercritical medium, and a composite treatment is performed by synchronously applying an alternating magnetic field; the supercritical medium is a mixed fluid of carbon dioxide and ethanol, the volume ratio is 8:2, the temperature is 180 DEG C, the pressure is 25 MPa, the alternating magnetic field strength is 0.8 T, the frequency is 50 Hz, and the processing time is 90 min; the medium flow rate is 0.8 m / s, the pulse type pressure regulation is adopted, the residual stress of the shell after processing is less than or equal to 25 MPa, and the size stability is improved by 30%.

[0023] In the application, in step S7, the nanoceramic transition layer is grown by atomic layer deposition technology, and then the graphene reinforced polyimide outer layer is prepared by electrophoretic deposition; the nanoceramic transition layer deposited by atomic layer deposition is zirconium oxide, the deposition temperature is 200 DEG C, the precursor is tetrabutyl zirconium and ozone, the cycle number is 160 times, the graphene content in the graphene reinforced polyimide outer layer prepared by electrophoretic deposition is 10%, the electrophoretic voltage is 100V, the deposition time is 8min, the coating thickness is 40um, and the coating does not crack after-50 DEG C to 200 DEG C cold and hot impact cycle is greater than or equal to 50 times.

[0024] In the application, in step S8, the local heat conduction weak area of the connecting plate is subjected to laser shock peening by combined detection of infrared thermal imaging and a heat flow meter; the infrared thermal imaging resolution is 1920x1536, the temperature measurement accuracy is ±0.3 DEG C, the heat flow meter detection accuracy is ±2%, the laser shock peening adopts Q-switched laser with a wavelength of 1064nm, a power density of 5GW / cm², a spot diameter of 1mm, and 3 times of impact.

[0025] A bus duct shell is manufactured by a manufacturing method of a bus duct shell, and the bus duct shell comprises:

[0026] Main shells arranged oppositely, and the main shells are internally used for mounting bus duct assemblies;

[0027] A connecting plate integrally arranged at the middle part between the two main shells and used for balancing the temperature uniformity of the two main shells.

[0028] The application has the following beneficial effects:

[0029] The near-net forming of the main shell is realized by laser selective melting additive manufacturing (S2), and the parameters are dynamically adjusted in cooperation with real-time molten pool monitoring, so that a high-precision mounting cavity can be accurately formed, and the defects of traditional casting can be avoided; at the same time, the gradient composite (S1) of the aviation-grade aluminum alloy base material and the nano-enhanced phase can significantly improve the mechanical properties and heat conduction basis of the main shell.

[0030] The atomic-level combination (S4) of the main shell and the connecting plate is realized by laser-assisted hot isostatic pressing, the interface bonding strength is improved, and the interface thermal resistance is greatly reduced; the temperature difference between the two main shells can be controlled within a preset range by combining the bionic structure (S3) of the connecting plate and the intelligent temperature balancing (S8), and the temperature imbalance problem of the traditional connection mode is solved.

[0031] The bionic micro-nano heat dissipation structure (S5) on the surface of the shell is processed by femtosecond laser and plasma activation, so that the heat dissipation area is improved; the gradient multifunctional protective layer (S7) can ensure the high and low temperature resistance and corrosion resistance, and does not affect the heat conduction efficiency, so that the protection and heat dissipation are coordinated.

[0032] The supercritical fluid and the magnetic field cooperative treatment (S6) can control the residual stress of the shell to be below 25 MPa, improve the dimensional stability, and avoid the stress concentration problem of the traditional heat treatment; the whole process precisely regulates the microstructure of the material, and further guarantees the long-term use reliability of the shell. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a structural schematic diagram of a bus duct shell of the application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0035] In the description of the present application, it should be noted that the terms used herein are only for describing the specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. The technologies, methods and devices known to those skilled in the art may not be discussed in detail, but should be considered as part of the authorized description. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values.

[0036] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, and are not intended to describe a specific order or sequence. It should be understood that the data used in this way can be exchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second" and the like are generally of a kind, and are not limited to the number of objects, for example, the first object can be one or more. In addition, the specification and claims "and / or" indicate at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are a "or" relationship.

[0037] It should be noted that in the description of the present application, the terms of orientation such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship are generally based on the orientation or position relationship, only for the convenience of describing the present application and simplifying the description, without making the opposite statement, these orientation terms do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the present application; the orientation terms "inner, outer" refer to the inner and outer relative to the contour of each component.

[0038] It should be noted that in the present application, the terms "include", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but can also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method can be performed in an order different from the described order, and various steps can also be added, omitted or combined. In addition, the features described with reference to certain examples can be combined in other examples.

[0039] The embodiment provides a manufacturing method of a bus duct shell, comprising the following steps:

[0040] S1: aluminum-based gradient composite powder of main shell 1 is prepared, aluminum alloy powder of aviation level is used as base material, nano-sized heat conduction reinforcing phase is mixed according to radial function gradient design, main shell 1 composite powder with particle size gradient distribution and surface activity is prepared through supersonic airflow crushing and plasma activation modification.

[0041] This step can make the main shell 1 obtain adaptive mechanical properties and thermal conductivity properties at different radial positions by mixing the base material and the reinforcing phase according to the radial gradient design, the supersonic airflow crushing can ensure that the powder particle size distribution is uniform, and the plasma activation modification can improve the powder surface activity, which lays a foundation for good combination in subsequent forming.

[0042] S2: The main shell 1 is laser selective melting additive manufacturing, and the composite powder obtained in S1 is printed into two main shell 1 rough castings arranged in opposite directions by multi-beam collaborative laser selective melting. During the printing process, the laser parameters are dynamically adjusted through real-time monitoring of the molten pool, so that a high-precision bus duct assembly mounting cavity is formed inside the rough casting. Compared with single-beam, multi-beam collaborative laser selective melting can improve the forming efficiency, and real-time molten pool monitoring and dynamic adjustment of laser parameters can avoid forming defects, ensure the quality of the rough casting, and the formation of the high-precision mounting cavity can meet the needs of the tight assembly of the bus duct assembly.

[0043] S3: The aluminum-based bionic composite blank of the connecting plate 2 is prepared, the internal passage is designed by imitating the vein heat transfer structure, the ultra-thin aluminum alloy foil is used as the base material, the nano-carbon tube heat conduction layer and the porous aluminum alloy support layer are alternately compounded, and the connecting plate 2 preform is prepared by vacuum hot pressing curing. The internal passage design of the vein heat transfer structure can optimize the heat transfer path and improve the heat conduction efficiency. The alternately compounded structure can consider the heat conduction and structural support performance, and the vacuum hot pressing curing can reduce the internal porosity of the preform and ensure the structural density.

[0044] S4: The main shell 1 and the connecting plate 2 are combined into a cross-scale interface, the two main shell 1 rough castings are fixed in the magnetorheological precision clamp, the nano-metal solder paste is pre-placed in the connecting area between the connecting plate 2 preform and the main shell 1, and the heterogeneous interface is combined at the atomic level by laser-assisted hot isostatic pressing. The magnetorheological precision clamp can accurately fix the main shell 1 rough casting, the nano-metal solder paste can promote the interface combination, and the laser-assisted hot isostatic pressing can make the heterogeneous interface reach the atomic level combination, greatly improving the connection strength and reducing the interface thermal resistance.

[0045] S5: The surface of the shell is constructed with a bionic micro-nano heat dissipation structure, referring to the scale structure of butterfly wings, a periodic micro-nano convex array is processed on the outer surface of the shell by femtosecond laser, and the surface heat dissipation efficiency is improved by plasma activation treatment. The bionic design of the scale structure of butterfly wings can increase the surface heat dissipation area of the shell, femtosecond laser processing can ensure the precision of the micro-nano convex array, and plasma activation treatment can further improve the surface heat dissipation capacity.

[0046] S6: The shell is treated by supercritical fluid and magnetic field, the shell treated in S5 is placed in a supercritical medium, and an alternating magnetic field is applied simultaneously for composite treatment, so as to realize internal stress homogenization and optimization of precipitated phase. The supercritical medium can uniformly act on each part of the shell, the alternating magnetic field can affect the movement of atoms inside the material, and the synergistic effect of the two can effectively eliminate residual stress, optimize the distribution of precipitated phase, and improve the size stability and mechanical properties of the shell.

[0047] S7: Shell gradient multifunctional protective layer preparation, atomic layer deposition technology is used to grow nanoceramic transition layer, and then graphene reinforced polyimide outer layer is prepared through electrophoretic deposition, forming a high-temperature-resistant and high-thermal-conductivity protective system. The nanoceramic transition layer prepared by atomic layer deposition can enhance the bonding force of the protective layer and the shell, and the graphene reinforced polyimide outer layer can endow the protective layer with high-temperature-resistant and high-thermal-conductivity performance, realizing the dual functions of protection and heat conduction.

[0048] S8: Shell temperature equalization intelligent control, through the joint detection of infrared thermal imaging and heat flow meter, the local heat conduction weak area of the connecting plate 2 is subjected to laser impact strengthening, so that the temperature difference between the two main shells 1 is controlled within the preset range. The joint detection of infrared thermal imaging and heat flow meter can accurately master the shell temperature distribution and heat flow situation, and the laser impact strengthening can improve the local heat conduction performance of the connecting plate 2, so as to ensure the temperature equalization of the two main shells 1.

[0049] In the present application, further embodiments are that in step S1, the aviation-grade aluminum alloy powder is 7075 aluminum alloy, which has high strength and can meet the structural strength requirements of the main shell 1; the nanoscale thermal conductivity enhancing phase is aluminum nitride and silicon carbide (particle size 80-100 nm), which have excellent thermal conductivity performance and can effectively improve the thermal conductivity of the main shell 1; the gradient proportion mixing from inside to outside in the radial direction can make the radial performance of the main shell 1 change in a gradient manner, adapting to the use requirements of different positions; the supersonic airflow crushing pressure is 1.2 MPa, which can crush the powder to a suitable particle size and ensure uniform particle size distribution; the particle size distribution deviation of the crushed powder is ≤10%, ensuring stable powder performance; the plasma activation is carried out in a mixed gas of argon and hydrogen (volume ratio 9:1), which can provide a suitable environment for activation; the power is 800 W, and the activation time is 15 min, which can effectively improve the surface activity of the powder; the surface hydroxyl density of the powder is increased by more than 40%, enhancing the reaction activity and bonding capacity of the powder.

[0050] In the present application, further embodiments are that in step S2, the multi-beam collaborative laser selective melting adopts 3 beams of fiber laser with wavelength 1064 nm, which has concentrated energy and is suitable for material melting; the single-beam power is 500 W, the spot diameter is 35 μm, the scanning speed is 1500-2000 mm / s, the layer thickness is 20-30 μm, and the powder laying density is ≥98%, which can ensure the forming efficiency and quality; the real-time molten pool monitoring adopts high-speed photography, which can capture the molten pool state in real time; when the molten pool temperature fluctuation exceeds ±5℃, the laser power is automatically compensated by 5%-8%, which can timely adjust the forming conditions to avoid defects; the installation cavity size tolerance is controlled within ±0.01 mm, and the surface roughness Ra is ≤0.6 μm, which ensures that the installation cavity has very high precision and meets the installation requirements of the bus duct assembly.

[0051] In the present application, further embodiments are that in step S3, the ultra-thin aluminum alloy foil is 1050 pure aluminum, which has good ductility and thermal conductivity, and is suitable as a substrate; the carbon nanotube thermal conduction layer has a length-diameter ratio of carbon tubes of 1000 or more, and the large length-diameter ratio of carbon tubes can form more effective thermal conduction paths; the dispersion concentration is 5%, and the coating thickness is 10 microns, which can ensure the thermal conductivity while considering the coating quality; the porous aluminum alloy support layer is 3A21 aluminum alloy, which has good processing performance and strength, and can provide reliable support; the vacuum heat pressing curing temperature is 200℃, the pressure is 8MPa, the vacuum degree is less than or equal to 10-3Pa, and the holding time is 60min, which can make the layers tightly combined and reduce internal porosity; the preform thermal conductivity is greater than or equal to 220W / (m·K), which ensures that the connecting plate 2 has excellent thermal conductivity.

[0052] In the present application, further embodiments are that in step S4, the magnetic field precision clamp has a positioning accuracy of ±0.003mm, which can ensure the accurate butt joint of the main shell 1 and the connecting plate 2; the clamping force is steplessly adjusted by the magnetic field strength, which can flexibly adapt to different clamping requirements; the nano metal solder paste is a tin, silver and copper alloy, which has good welding performance and thermal conductivity; the coating thickness is 5-8 microns, which can ensure the welding effect; the laser-assisted hot isostatic pressing temperature is 500℃, the pressure is 20MPa, and the laser preheating power is 300W, which can promote the diffusion of interface atoms and achieve good bonding; the interface bonding strength is greater than or equal to 220MPa, and the diffusion layer thickness is greater than or equal to 8 microns, which ensures that the main shell 1 and the connecting plate 2 are connected firmly and the heat conduction is smooth.

[0053] In the present application, further embodiments are that in step S5, the femtosecond laser wavelength is 800nm, and the pulse width is 30fs, which can accurately process the micro-nano structure; the processed micro-nano convex array is hexagonal, which has good stability and can effectively increase the heat dissipation area; the plasma activation uses a mixed plasma of oxygen and argon (volume ratio 1:3), which can effectively activate the surface; the power is 300W, and the processing time is 5min, which can achieve good activation effect; the surface contact angle is reduced to below 30°, which improves the surface wettability and is beneficial to heat dissipation; the heat dissipation area is increased by 50%, which significantly enhances the heat dissipation efficiency of the shell.

[0054] In the present application, further embodiments are, in step S6, the supercritical medium is a carbon dioxide and ethanol mixed fluid (volume ratio 8:2), the mixed fluid has good permeability and mass transfer; the temperature is 180 DEG C, the pressure is 25 MPa, the alternating magnetic field intensity is 0.8T, the frequency is 50Hz, and the processing time is 90min, and the combination of these parameters can effectively realize stress homogenization and precipitated phase optimization; the medium flow rate is 0.8m / s, and pulse pressure regulation is used to enhance the interaction between the medium and the shell; the residual stress of the shell after treatment is less than or equal to 25MPa, and the dimensional stability is improved by 30%, so that the shell is not easy to deform during use and has stable performance.

[0055] In the present application, further embodiments are, in step S7, the atomic layer deposition nanoceramic transition layer is zirconium oxide, which has good high temperature resistance and chemical stability; the deposition temperature is 200 DEG C, the precursor is tetrabutyl zirconium and ozone, and the cycle number is 160 times, which can form a uniform and dense transition layer; the graphene content in the graphene reinforced polyimide outer layer deposited by electrophoresis is 10%, and the graphene can improve the thermal conductivity of the outer layer; the electrophoretic voltage is 100V, the deposition time is 8min, and the coating thickness is 40um, which can ensure the quality of the outer layer; no cracking occurs after-50 DEG C to 200 DEG C cold and hot impact cycle is greater than or equal to 50 times, which indicates that the protective layer has excellent high and low temperature impact resistance.

[0056] In the present application, further embodiments are, in step S8, the infrared thermal imaging resolution is 1920x1536, the temperature measurement accuracy is ±0.3 DEG C, the temperature distribution of the shell can be accurately captured; the detection accuracy of the heat flow meter is ±2%, which can accurately measure the heat flow; the laser shock peening uses a Q-switched laser with a wavelength of 1064nm, a power density of 5GW / cm², a spot diameter of 1mm, and an impact number of 3, which can effectively improve the local thermal conductivity and ensure that the temperature difference between the two main shells is controlled within the ideal range.

[0057] The present embodiment also provides a bus duct shell made by the above bus duct shell manufacturing method, which comprises: main shells 1 arranged oppositely, and the inside of the main shells 1 is used for mounting a bus duct assembly; the main shells 1 are made by the above manufacturing method, have the advantages of high structural strength, high precision and good thermal conductivity, and can provide stable and reliable mounting space for the bus duct assembly; and further comprises a connecting plate 2 integrally formed in the middle between the two main shells 1, which is used for balancing the temperature of the two main shells 1.

[0058] The connecting plate 2 is connected with the main shells 1 by the integral forming mode, has high bonding strength, and has excellent thermal conductivity itself, which can effectively balance the temperature of the two main shells 1 and ensure the safety and stability of the overall operation of the bus duct.

[0059] The manufacturing method of the bus duct shell and the bus duct shell manufactured by the method have many beneficial effects. In terms of structural performance, through advanced forming and connecting process, the main shell 1 and the connecting plate 2 are combined firmly, the overall structural strength is high, the main shell 1 installation cavity has high precision, and the assembly requirements of the bus duct assembly can be met.

[0060] In terms of heat conduction and temperature balance, the heat conduction performance of the shell is improved, and the intelligent regulation and control of the temperature balance can effectively ensure the temperature balance of the two main shells 1.

[0061] In terms of heat dissipation and protection, the bionic micro-nano heat dissipation structure enhances the heat dissipation efficiency, and the gradient multifunctional protective layer endows the shell with good high and low temperature resistance and corrosion resistance, while not affecting the heat conduction.

[0062] In terms of stability, the supercritical fluid and magnetic field synergistic treatment reduces the residual stress of the shell, improves the dimensional stability, and ensures the long-term stable performance of the shell.

[0063] The above describes the embodiments of the present application, and in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other, the present application is not limited to the above specific embodiments, the above specific embodiments are only illustrative, but not limited, and the person skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the protection scope of the claims, all of which belong to the protection of the present application.

Claims

1. A method of manufacturing a busway housing, comprising: The method comprises the following steps: ​ S1: Customized preparation of aluminum-based gradient composite powder for the main shell, using aviation-grade aluminum alloy powder as the base material, mixing nano-sized thermal conductivity enhancing phase, and performing ultrasonic airflow crushing and plasma activation modification to obtain the main shell composite powder; S2: Laser selective melting additive manufacturing of the main shell, using multi-beam collaborative laser selective melting to print the composite powder obtained in S1 into two oppositely arranged main shell rough castings, dynamically adjusting the laser parameters during printing to form a high-precision mounting cavity; S3: Preparation of aluminum-based bionic composite blank for the connecting plate, simulating the internal passage of the vein heat transport structure, and compounding the nano-carbon tube thermal conductivity layer and the porous aluminum alloy support layer, and then performing vacuum hot pressing solidification to obtain a precast blank; S4: Cross-scale interface bonding of the main shell and the connecting plate, realizing atomic-level bonding of the heterogeneous interface through laser-assisted hot isostatic pressing; S5: Construction of bionic micro-nano heat dissipation structure on the surface of the shell, using femtosecond laser processing of micro-nano protrusion arrays combined with plasma activation treatment; S6: Synergistic treatment of the shell with supercritical fluid and magnetic field to realize internal stress homogenization and precipitated phase optimization; S7: Preparation of gradient multi-functional protective layer for the shell to form a high-temperature-resistant and high-thermal-conductivity protective system; S8: Intelligent regulation and control of the temperature uniformity of the shell to ensure that the temperature difference between the two main shells is controlled within a preset range.

2. The manufacturing method of the bus duct housing according to claim 1, wherein In step S1, the nano-sized thermal conductivity enhancing phase is mixed according to the radial functional gradient to obtain the main shell composite powder with a particle size gradient distribution and surface activity; the aviation-grade aluminum alloy powder is 7075 aluminum alloy, the nano-sized thermal conductivity enhancing phase is aluminum nitride and silicon carbide with a particle size of 80-100 nm, and the gradient proportion is mixed from the inside to the outside in the radial direction; the ultrasonic airflow crushing pressure is 1.2 MPa, the powder particle size distribution deviation after crushing is ≤10%, the plasma activation is performed in a mixed gas of argon and hydrogen with a volume ratio of 9:1, the power is 800 W, the activation time is 15 min, and the powder surface hydroxyl density is increased by more than 40%.

3. The manufacturing method of the bus duct housing according to claim 1, wherein In step S2, the multi-beam collaborative laser selective melting uses 3 beams of fiber lasers with a wavelength of 1064 nm, a single-beam power of 500 W, a spot diameter of 35 μm, a scanning speed of 1500-2000 mm / s, a layer thickness of 20-30 μm, and a powder laying density of ≥98%; real-time molten pool monitoring is performed using a high-speed camera, when the molten pool temperature fluctuation exceeds ±5℃, the laser power is automatically compensated by 5%-8%, the cavity size tolerance is controlled within ±0.01 mm, and the surface roughness Ra is ≤0.6 μm.

4. The manufacturing method of the bus duct housing according to claim 1, wherein In step S3, the super-thin aluminum alloy foil is used as the base material, and the nano-carbon tube thermal conductivity layer and the porous aluminum alloy support layer are alternately compounded; the super-thin aluminum alloy foil is 1050 pure aluminum, the nano-carbon tube thermal conductivity layer has a carbon tube aspect ratio of ≥1000 and a dispersion concentration of 5%, and the coating thickness is 10 μm; the porous aluminum alloy support layer is 3A21 aluminum alloy, the vacuum hot pressing solidification temperature is 200℃, the pressure is 8 MPa, the vacuum degree is ≤10⁻³ Pa, the holding time is 60 min, and the precast blank has a thermal conductivity of ≥220 W / (m・K).

5. The manufacturing method of the bus duct housing according to claim 1, wherein In step S4, the two main shell blanks are fixed to a magneto-rheological precision clamp, and nano-metal solder paste is pre-placed at the connecting plate preform and the main shell connecting area; the positioning precision of the magneto-rheological precision clamp is ±0.003 mm, and the clamping force is steplessly adjusted through the magnetic field strength; the nano-metal solder paste is a tin, silver and copper alloy, the coating thickness is 5-8 μm, the laser-assisted hot isostatic pressing temperature is 500℃, the pressure is 20 MPa, the laser preheating power is 300 W, the interface bonding strength is ≥220 MPa, and the diffusion layer thickness is ≥8 μm.

6. The manufacturing method of the bus duct housing according to claim 1, wherein In step S5, a periodic micro-nano convex array is processed by referring to the structure of a butterfly wing scale; the femtosecond laser wavelength is 800 nm, the pulse width is 30 fs, the micro-nano convex array processed is a hexagon, the plasma activation adopts a mixed oxygen and argon plasma with a volume ratio of 1:3, the power is 300 W, the processing time is 5 min, the surface contact angle is reduced to below 30°, and the heat dissipation area is increased by 50%.

7. The method of manufacturing a busway housing of claim 1, wherein, In step S6, the shell processed in S5 is placed in a supercritical medium, and a composite treatment is performed by synchronously applying an alternating magnetic field; the supercritical medium is a mixed fluid of carbon dioxide and ethanol with a volume ratio of 8:2, a temperature of 180℃, a pressure of 25 MPa, an alternating magnetic field strength of 0.8 T, a frequency of 50 Hz, and a processing time of 90 min; the medium flow rate is 0.8 m / s, pulse pressure regulation is adopted, the residual stress of the shell after processing is ≤25 MPa, and the size stability is increased by 30%.

8. The manufacturing method of the bus duct housing according to claim 1, wherein In step S7, a nano-ceramic transition layer is grown by atomic layer deposition technology, and a graphene-reinforced polyimide outer layer is prepared by electrophoretic deposition; the nano-ceramic transition layer deposited by atomic layer deposition is zirconium oxide, the deposition temperature is 200℃, the precursor is tetrabutyl zirconium and ozone, the cycle number is 160 times, the graphene content in the graphene-reinforced polyimide outer layer deposited by electrophoretic deposition is 10%, the electrophoretic voltage is 100 V, the deposition time is 8 min, the coating thickness is 40 μm, and there is no cracking after -50℃ to 200℃ cold and hot impact cycles ≥50 times.

9. The manufacturing method of the bus duct housing according to claim 1, wherein In step S8, laser shock peening is performed on the local heat conduction weak area of the connecting plate through joint detection of infrared thermal imaging and a heat flow meter; the infrared thermal imaging resolution is 1920×1536, the temperature measurement accuracy is ±0.3℃, the heat flow meter detection accuracy is ±2%, the laser shock peening adopts a Q-switched laser with a wavelength of 1064 nm, a power density of 5 GW / cm², a spot diameter of 1 mm, and 3 impact times.

10. A busway housing characterized by, The bus duct shell is manufactured by the manufacturing method of any one of claims 1-9, and the bus duct shell comprises: main shells arranged oppositely, the inside of the main shells being used for mounting a bus duct assembly; a connecting plate integrally formed in the middle between the two main shells and used for balancing the temperature uniformity of the two main shells.

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