Integrated folding forming method of heat pipe wick and multi-scale structure thereof

Abstract

The application belongs to the technical field of heat pipe and particularly relates to a heat pipe wick integrated folding forming method and a multi-scale structure thereof. The application comprises the following steps: S1, silk screen pretreatment; S2, multi-layer positioning and preliminary fixation; S3, precise mold folding forming; S4, composite support layer; S5, winding and positioning; S6, overall sintering forming; S7, post-processing; the structure of the application comprises an integrated folding capillary framework: after the multi-layer high-mesh metal screen is stacked, the folding structure with continuous and regular wave shape is formed along the axial direction of the heat pipe through mold pressing. The framework itself has extremely high capillary pumping capacity; the support layer: closely adhered to the wave peak side of the integrated folding capillary framework, composed of one or several low-mesh metal screens. The application realizes the integration of the capillary material as the flow channel wall surface through structure reconstruction, significantly improves the capillary performance and anti-dryout capacity of the wick, and can greatly improve the heat transfer limit and reliability of the heat pipe.

Description

Technical Field

[0001] This invention belongs to the field of heat pipe technology, specifically relating to an integrated folding and forming method for a heat pipe wick and its multi-scale structure. Background Technology

[0002] Heat pipes are highly efficient heat transfer elements that rely on the phase change of the internal working fluid for heat transfer. They possess extremely high thermal conductivity and excellent isothermal properties, and have a wide range of applications in aerospace thermal control, advanced nuclear energy systems, chemical and metallurgical fields. The performance of a heat pipe is constrained by the trade-off between the capillary drive capability of the internal wick and the resistance to fluid reflux. Traditional single-structure wicks (such as channel, sintered, and wire mesh wicks) all have significant drawbacks: channel wicks have low fluid reflux resistance but limited capillary force; sintered wicks have strong capillary force but poor permeability, high reflux resistance, and complex processing technology with uncontrollable and unstable structures; wire mesh wicks are simple to prepare, have controllable dimensions, and strong capillary capability, but single-mesh wire mesh has poor permeability and low liquid storage capacity, making it prone to localized drying due to uneven liquid distribution.

[0003] To overcome the shortcomings of single-layer wicking structures, composite wicking technology has become a key development focus. However, existing mainstream composite solutions, whether using "layering wire meshes of different mesh sizes" or "filling prefabricated channels with wire mesh or sintered powder," all follow a design approach of "first forming capillary structures and flow channels separately, and then physically combining them." This approach has led to a fundamental technical contradiction that has remained unresolved for a long time: (1) Inherent interface problem: There must be a physical or mechanical interface between the capillary structure (wire mesh / sintered powder) and the flow channel (channel / gap). This interface not only introduces additional thermal resistance and flow resistance, but is also prone to degradation or separation under thermal cycling stress, becoming a weak point for performance degradation.

[0004] (2) Failure risk: The exchange of liquid between the reflux channel and the capillary structure depends on the capillary connection at the interface. Once the interface connection is not smooth (such as local separation or blockage), flow or heat transfer dead zones are easily formed, resulting in uneven liquid distribution and causing local drying. Moreover, this type of structure relies on a few main reflux channels and has poor resistance to drying.

[0005] (3) The contradiction between process and structure: In order to pursue performance, more complex precision machining (such as micro-channels) and fine assembly are often required, but this also reduces process reliability and structural consistency, and increases costs. Summary of the Invention

[0006] The technical problem solved by this invention is to provide an integrated folding and forming method for heat pipe wicks and its multi-scale structure. By reconstructing the structure, the capillary material is integrated as the wall of the flow channel, significantly improving the capillary performance and anti-drying ability of the wick, thereby fundamentally solving the above-mentioned technical problems.

[0007] The technical solution adopted in this invention is as follows: An integrated folding forming method for a heat pipe wick includes the following steps: S1. Wire mesh pretreatment; S2. Multi-layer positioning and initial fixing; S3. Precision mold folding and forming; S4. Composite support layer; S5. Rolling and positioning; S6. Overall sintering and forming; S7. Post-processing.

[0008] In step S1, according to the heat pipe size design, the required number of high-mesh and low-mesh wire mesh layers are cut out respectively, and then cleaned, degreased and dried.

[0009] Ensure that the high-mesh wire mesh is tightly adhered to the inner wall of the heat pipe shell after folding, and ensure that the low-mesh wire mesh is tightly adhered to the high-mesh folded wire mesh.

[0010] In step S2, multiple layers of high-mesh-count wire mesh are precisely aligned and stacked, and micro-spot welding technology is used to perform multi-point positioning welding in non-critical functional areas to prevent interlayer misalignment caused by subsequent processing; the same treatment is performed on low-mesh-count wire mesh.

[0011] In step S3, the positioned multi-layer high-mesh wire mesh is placed in a specially made waveform mold. By controlling the pressure and holding time, the wire mesh is pressed into an integrated folded capillary skeleton with a preset waveform, pitch and peak height.

[0012] In step S4, a low-mesh support layer wire mesh is bonded to the crest side surface of the folded capillary skeleton, and spot welding is used to initially fix it along the bonding line to form a liquid-absorbing core preform.

[0013] In step S5, the liquid absorbent core preform is rolled up and installed into the heat pipe housing with the support layer facing inward. With the assistance of a mandrel or clamp, it is ensured that the trough of the folded skeleton is in good contact with the pipe wall or is slightly compressed, and all return main channels are unobstructed along the axial direction, forming a heat pipe assembly.

[0014] The support layer faces inward, the low-mesh wire mesh faces inward, and the folded wire mesh troughs face outward.

[0015] In step S6, the heat pipe assembly is placed in a vacuum or atmosphere sintering furnace for overall sintering.

[0016] The sintering process employs a gradient heating sintering process, where multiple layers of high-mesh wire mesh are fully diffused and bonded together to form a robust folded skeleton. The troughs of the folded skeleton and the inner wall of the heat pipe form a metallurgical bond at the contact point, and the bond between the peaks of the folded skeleton and the support layer is strengthened.

[0017] In step S7, the sintered heat pipe assembly undergoes post-processing such as cleaning and drying to complete the preparation of the liquid wick.

[0018] A multi-scale structure for a heat pipe wick includes an integrated folded capillary skeleton: composed of multiple layers of high-mesh metal wire mesh, which are then pressed along the heat pipe axis using a mold to form a folded structure with continuous, regular waveforms. This skeleton itself possesses extremely high capillary suction capacity; a support layer: tightly fitted to the crest side of the integrated folded capillary skeleton, consisting of one or more layers of low-mesh metal wire mesh.

[0019] The integrated folded capillary skeleton naturally forms a series of axially extending liquid reflux main channels with triangular or rectangular cross-sections between the inner wall of the heat pipe shell and the support layer.

[0020] The troughs of the integrated folded capillary skeleton are in close contact or bonded to the inner wall of the heat pipe, and its peaks are in close contact with the support layer.

[0021] The beneficial effects of this invention are: (1) The present invention provides an integrated folding forming method for heat pipe wicking core, which changes the design mindset of simply splicing and combining the functional units in the existing composite wicking core design, and provides a new method for generating wicking core structure. By performing specific spatial transformation on a single capillary material to reconstruct its structure, a capillary driving structure and a liquid return channel are generated in one step, rather than being physically combined, thereby achieving seamless physical integration and essential functional synergy between the two.

[0022] (2) The integrated folding forming method of the heat pipe wick provided by the present invention has the advantages of process reliability and design freedom: the precision mold folding forming process ensures the high consistency of the integrated core structure. By adjusting parameters such as folding waveform, pitch, and number of layers, the cross-sectional area of ​​the return channel, the thickness and porosity of the capillary skeleton can be precisely controlled, thereby providing a flexible design space for matching different working fluids, working temperatures and heat flux densities.

[0023] (3) The present invention provides a multi-scale structure of heat pipe wick with excellent capillary-permeability performance: it fundamentally changes the path of capillary performance optimization, and completely eliminates the unfavorable interface in the traditional composite structure by making the capillary material itself form the flow channel wall. Through structural reconstruction, it realizes the synergistic improvement of capillary force and permeability, so that the capillary performance of the wick is greatly improved.

[0024] (4) The multi-scale structure of the heat pipe wick provided by the present invention has excellent anti-drying capability based on dual redundancy: the distributed return main channel is derived from the same folded skeleton and interconnected to form a dual redundancy liquid network of "macro-channel parallel transport + micro-skeleton capillary interconnection adjustment"; when one or more channels are partially blocked due to manufacturing defects, foreign object blockage, steam blockage, etc., the liquid can be quickly replenished from the adjacent unobstructed channel to the downstream of the blocked area through the wire mesh pores of the skeleton, thereby maintaining the effective wetting of the evaporation section and greatly reducing the risk of heat pipe failure due to local dryness; this self-regulation and anti-drying capability cannot be achieved by any other composite structure obtained by splicing, and significantly improves the operational reliability of the heat pipe under non-ideal working conditions.

[0025] (5) The multi-scale structure of the heat pipe wick provided by the present invention has excellent thermal response and isothermal properties: the integrated folded skeleton provides a huge capillary inner surface area that is directly connected to the reflux channel, so that any local hot spot generated in the evaporation section can be quickly cooled by the powerful radial capillary force from the nearest reflux main channel, which reduces the hot spot temperature of the evaporation section, greatly improves the temperature uniformity, and suppresses the occurrence of local boiling and instability.

[0026] (6) The present invention provides a multi-scale structure of heat pipe wick. Applying the above-mentioned wick to the heat pipe can significantly improve the capillary heat transfer limit, reliability, resistance to local drying and long-term working stability of the heat pipe. It is particularly suitable for occasions with extremely demanding requirements for reliability and heat flux density, such as advanced nuclear energy systems, aerospace active thermal control, and heat dissipation of ultra-high power density electronic devices. Attached Figure Description

[0027] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in describing the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments recorded in the present invention. Those skilled in the art can derive other drawings from the following drawings without any creative effort.

[0028] Figure 1 A flowchart of an integrated folding and forming method for a heat pipe liquid wick provided by the present invention; Figure 2 A schematic diagram of a multi-scale structure of a heat pipe wick provided by the present invention; Figure 3 A schematic diagram of a multi-scale structure of a heat pipe wick after assembly inside a heat pipe, as provided by the present invention. Explanation of reference numerals in the attached figures: 1-Integrated folded capillary skeleton, 2-Support layer, 3-Heat pipe shell, 4-Main liquid reflux channel. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0030] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., refer to the orientation or positional relationship shown in the accompanying drawings, and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] like Figure 1 As shown, the present invention provides an integrated folding and forming method for a heat pipe wick, comprising the following steps: S1. Wire mesh pretreatment: According to the heat pipe size design, cut the required number of high mesh and low mesh wire mesh layers respectively, and clean, degrease and dry them. S2. Multi-layer positioning and initial fixing: Precisely align and stack multiple layers of high-mesh-count wire mesh, and use micro-spot welding technology to perform multi-point positioning welding in non-critical functional areas to prevent interlayer misalignment caused by subsequent processing; perform the same treatment on low-mesh-count wire mesh. S3. Precision mold folding and forming: The positioned multi-layer high-mesh wire mesh is placed in a specially made waveform mold. By controlling parameters such as pressure and holding time, the wire mesh is pressed into an integrated folded capillary skeleton with a preset waveform (such as serrated shape), pitch and peak height. S4. Composite support layer: The low mesh support layer wire mesh is bonded to the crest side surface of the folded capillary skeleton, and spot welding is used to initially fix it along the bonding line to form the liquid absorption core preform. S5. Rolling and Positioning: Roll the absorbent core preform with the support layer facing inward and insert it into the heat pipe housing. With the aid of a mandrel or clamp, ensure that the troughs of the folded skeleton make good contact with the pipe wall or are slightly compressed, and that all return main channels are unobstructed along the axial direction, forming the heat pipe assembly; S6. Integral Sintering: The heat pipe assembly is placed in a vacuum or atmosphere sintering furnace for integral sintering. Sintering process parameters need precise control to achieve: a) full diffusion and bonding between multiple layers of high-mesh wire mesh, forming a robust folded skeleton; b) metallurgical bonding between the troughs of the folded skeleton and the inner wall of the heat pipe at the contact points; c) strengthened bonding between the peaks of the folded skeleton and the support layer. A gradient heating sintering process is preferred to balance bonding strength and porosity maintenance.

[0033] S7. Post-processing: Cleaning, drying and other post-processing are performed on the sintered heat pipe assembly to complete the preparation of the liquid wick.

[0034] Example 1 S1 Wire Mesh Pretreatment: Based on the dimensions of the heat pipe shell 3, cut 400-mesh wire mesh into strips of a certain length and width. The length is slightly shorter than the pipe length, and the width is calculated to ensure that it fits tightly against the inner wall of the heat pipe shell 3 after folding. Cut 40-mesh wire mesh into strips of the same length, with the width calculated to ensure that it fits tightly against the larger mesh folded wire mesh 1. After cutting, ultrasonically clean the 40-mesh and 400-mesh wire meshes to remove grease and other impurities, and then dry them.

[0035] S2 - Multi-layer positioning and preliminary fixing: Four layers of 400-mesh wire mesh are precisely aligned and stacked, and a precision spot welding machine is used to perform preliminary spot welding to fix the center and edges of the wire mesh.

[0036] S3 - Precision Mold Folding: The positioned 400-mesh wire mesh is placed into a special V-shaped tooth mold and pressed under a certain pressure to form a stable and regular sawtooth (V-shaped) folding structure. The folding pitch (distance from one peak to the next peak) is 1.5mm, and the folding height (vertical distance from trough to peak) is 0.8mm.

[0037] S4-Composite support layer: Lay a 40-mesh wire mesh flat on the workbench, attach the crest of the folded wire mesh to the 40-mesh wire mesh, and use a spot welding machine to spot weld the attached surfaces to achieve initial fixation and form a liquid-absorbing core prefabricated part.

[0038] S5 - Rolling and Positioning: The aforementioned absorbent core preform is tightly rolled onto the mandrel with the 40-mesh wire mesh facing inward (towards the central axis of the heat pipe shell 3) and the folded wire mesh troughs facing outward (towards the inner wall of the heat pipe shell 3). The mandrel and the preform rolled onto it are then inserted into the heat pipe shell 3. The mandrel is then removed, allowing the preform to naturally unfold due to its elasticity, with its troughs forming line contact with the inner wall of the heat pipe shell 3. At this point, the integrated folded capillary skeleton 1, the support layer 2, and the main liquid return channel 4 have been initially formed.

[0039] S6 - Integral Sintering: The assembled heat pipe assembly is placed in a vacuum sintering furnace and vacuum sintered using a specific heating program. At high temperature, four layers of 400-mesh wire mesh are sintered to form a robust integrated folded capillary skeleton 1. The integrated folded capillary skeleton 1 is firmly bonded to the inner wall of the heat pipe shell 3 at the contact points, and the contact points between the integrated folded capillary skeleton 1 and the support layer 2 are further strengthened, achieving overall bonding. After vacuum sintering, a stable integrated folded capillary skeleton 1, support layer 2, and liquid return main channel 4 are formed, thus creating a multi-scale structure of a heat pipe wick.

[0040] S7 - Post-processing: Remove the sintered heat pipe assembly and perform necessary cleaning (such as acid washing) to obtain a heat pipe fitting with a high-performance folded wire mesh wick, which can be used for subsequent filling and heat pipe manufacturing.

[0041] Based on the above methods, such as Figure 2 and Figure 3 As shown, this invention provides a multi-scale structure for a heat pipe wick, comprising an integrated folded capillary skeleton 1: composed of multiple layers (typically 3-8 layers) of high-mesh (typically ≥400 mesh) wire mesh, which are then pressed along the heat pipe axis using a mold to form a folded structure with continuous, regular waveforms (such as sawtooth, sinusoidal, or trapezoidal waves). This skeleton itself possesses extremely high capillary suction capacity. A support layer 2: closely fitted to the crest side (i.e., the side facing the vapor chamber) of the integrated folded capillary skeleton, is composed of one or more layers of low-mesh (typically ≤100 mesh) wire mesh. The support layer 2 provides rigid support for the integrated folded capillary skeleton 1, maintaining its waveform stability. Its large porosity also provides a smooth path for vapor escape and circumferential diffusion of the liquid, preventing vapor from blocking the liquid return channel and helping to stabilize the vapor-liquid interface.

[0042] The troughs of the integrated folded capillary skeleton 1 are in close contact or bonded to the inner wall of the heat pipe shell 3, while its peaks are in close contact with the support layer 2. Thus, each periodic waveform unit of the integrated folded capillary skeleton 1, together with the inner wall of the heat pipe shell 3 and the support layer 2, encloses multiple axially penetrating main liquid return channels 4 with triangular or rectangular cross-sections. These channels are naturally formed after the structure is folded, and are numerous (usually no fewer than 12), uniformly or non-uniformly distributed along the inner circumference of the heat pipe, forming a parallel distributed liquid transport network. Even if a local channel is blocked, it does not affect the overall liquid transport function of the wick.

[0043] Based on the multi-scale structure of the heat pipe wick described above, when the heat pipe is working, on a macroscopic scale, the liquid is axially transported within the main return channel 4 with extremely low resistance; on a microscopic scale, through the strong capillary force generated by the micropores of the integrated folded capillary skeleton 1 itself, the liquid is continuously transported from the heat pipe condensation section to the evaporation section via the main channel, and then drawn into the skeleton through the main channel, spreading and distributing radially and circumferentially along the mesh, so that the entire wick can be completely wetted by the working fluid.

[0044] Example 2 This invention provides a multi-scale structure for a heat pipe wick. The heat pipe shell 3 is a 316 stainless steel tube with an outer diameter of 20 mm, a wall thickness of 2 mm, and a length of 1500 mm. The integrated folded capillary skeleton 1 is composed of four layers of 400-mesh (0.032 mm aperture) 304 stainless steel plain weave wire mesh, with a single layer thickness of approximately 0.056 mm. Considering the 0.01 mm interlayer spacing between the wire meshes, the total thickness is approximately 0.254 mm. After folding, a sawtooth (V-shaped) waveform is formed, with a folding pitch P = 1.5 mm and a folding height H = 0.8 mm. The support layer 2 uses one layer of 40-mesh (0.475 mm aperture) stainless steel plain weave wire mesh, with a thickness of approximately 0.32 mm. The liquid reflux main channel 4 is formed by an integrated folded capillary skeleton 1, a support layer 2, and the inner wall of the heat pipe shell 3. Its cross-section is approximately an isosceles triangle with a base (contacting the pipe wall) of about 1.5 mm and a height of about 0.8 mm. There are approximately 67 such channels distributed along the circumference.

[0045] To further illustrate the superiority of the present invention, the performance of the liquid absorption core obtained in this embodiment is calculated, analyzed and compared.

[0046] For stainless steel-sodium high-temperature heat pipes, when starting from room temperature under freezing conditions, their heat transfer performance is mainly limited by the viscosity limit and the velocity of sound at low temperatures, and by the carry-over limit, boiling limit, and capillary limit at normal operating temperatures, with the capillary limit being the key factor. The capillary force provided by the heat pipe wick is the driving force for the circulation of the working fluid inside the heat pipe; when the heat pipe is operating normally, its value... It should be greater than the steam flow pressure drop. Liquid reflux pressure drop and gravitational pressure drop The sum of the vapor pressure drop, the liquid return pressure drop, and the gravitational pressure drop is sufficient. However, when the reflux pressure drop is too large, the capillary force cannot drive the liquid to completely return to the heat pipe evaporator section, resulting in insufficient reflux flow in the heat pipe evaporator section, causing localized drying and a sudden temperature rise, which is the capillary limit. At this point, the capillary force equals the sum of the vapor flow pressure drop, the liquid reflux pressure drop, and the gravitational pressure drop, i.e., ... (1) Through certain assumptions and a series of derivations, the formula for calculating the capillary limit of a heat pipe can be obtained as follows: (2) In the formula The equivalent flow coefficient of the absorbent core is equal to the permeability. With circulation area The accumulation of, For the working fluid density, The latent heat of phase transition of the working fluid, For the surface tension of the working fluid, The effective capillary pore size of the liquid suction core, It is the acceleration due to gravity. The diameter of the steam chamber. The total length of the heat pipe, For the heat pipe tilt angle, The viscosity of the working fluid. This is the effective length of the heat pipe.

[0047] Various wicking structures are applied to the heat pipe shell 3 in this embodiment, and the heat pipe operates under horizontal conditions. At this time, without gravity assistance, the corresponding capillary limit values ​​can be calculated, as shown in Table 1.

[0048] Table 1 Theoretical capillary limits for different wicking structures As can be seen, the multi-scale structure of the heat pipe wick provided in this embodiment can significantly improve the heat transfer performance of the heat pipe.

[0049] This embodiment provides an integrated folding and forming method for a heat pipe wick and its multi-scale structure, which has the following advantages: This method overturns the traditional composite process of "channel + filling" or simple superposition, realizing the integrated fusion of capillary material as the wall of the flow channel, fundamentally eliminating unfavorable interfaces. The resulting multi-scale wick structure not only achieves a synergistic improvement in capillary force and permeability, but also exhibits excellent resistance to localized drying and system robustness due to its unique "parallel macroscopic channels + interconnected microscopic skeleton" dual-redundant liquid network. This wick structure is stable and has excellent performance, which can significantly improve the heat transfer limit and reliability of the heat pipe, and has important application value in advanced nuclear energy, aerospace, and high-power electronic heat dissipation.

[0050] While those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention, the embodiments should be considered illustrative and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and therefore all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Furthermore, it should be understood that although the present invention is described according to embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for integrally folding and forming a heat pipe wick, characterized in that, Includes the following steps: S1. Wire mesh pretreatment; S2. Multi-layer positioning and initial fixing; S3. Precision mold folding and forming; S4. Composite support layer; S5. Rolling and positioning; S6. Overall sintering and forming; S7. Post-processing.

2. The integrated folding and forming method for the heat pipe wick according to claim 1, characterized in that, In step S1, according to the heat pipe size design, the required number of high-mesh and low-mesh wire mesh layers are cut out respectively, and then cleaned, degreased and dried; to ensure that the high-mesh wire mesh is tightly attached to the inner wall of the heat pipe shell after folding, and to ensure that the low-mesh wire mesh is tightly attached to the high-mesh folded wire mesh.

3. The integrated folding and forming method for the heat pipe wick according to claim 2, characterized in that, In step S2, multiple layers of high-mesh-count wire mesh are precisely aligned and stacked, and micro-spot welding technology is used to perform multi-point positioning welding in non-critical functional areas to prevent interlayer misalignment caused by subsequent processing; the same treatment is performed on low-mesh-count wire mesh.

4. The integrated folding and forming method for the heat pipe wick according to claim 3, characterized in that, In step S3, the positioned multi-layer high-mesh wire mesh is placed in a specially made waveform mold. By controlling the pressure and holding time, the wire mesh is pressed into an integrated folded capillary skeleton with a preset waveform, pitch and peak height.

5. The integrated folding and forming method for the heat pipe wick according to claim 4, characterized in that, In step S4, a low-mesh support layer wire mesh is bonded to the crest side surface of the folded capillary skeleton, and spot welding is used to initially fix it along the bonding line to form a liquid-absorbing core preform.

6. The integrated folding and forming method for the heat pipe wick according to claim 5, characterized in that, In step S5, the liquid absorbent core preform is rolled up and installed into the heat pipe shell with the support layer facing inward. With the assistance of a mandrel or clamp, it is ensured that the trough of the folded skeleton is in good contact with the pipe wall or is slightly compressed, and all return main channels are unobstructed along the axial direction to form a heat pipe assembly. The support layer faces inward, the low mesh count wire mesh faces inward, and the trough surface of the folded wire mesh faces outward.

7. The integrated folding and forming method for the heat pipe wick according to claim 6, characterized in that, In step S6, the heat pipe assembly is placed in a vacuum or atmosphere sintering furnace for overall sintering; the sintering adopts a gradient heating sintering process, in which multiple layers of high-mesh wire mesh are fully diffused and bonded to form a strong folded skeleton. The folded skeleton troughs and the inner wall of the heat pipe form a metallurgical bond at the contact point; the folded skeleton peaks and support layer are reinforced.

8. A multi-scale structure of a heat pipe wick prepared based on the method of claim 7, characterized in that, Including an integrated folded capillary skeleton: it is made of multiple layers of high-mesh metal wire mesh, which are then pressed into a folded structure with continuous and regular waveforms along the heat pipe axis by a mold; this skeleton itself has extremely high capillary suction capacity; Support layer: Closely attached to the crest side of the integrated folded capillary skeleton, consisting of one or more layers of low-mesh metal wire mesh.

9. The multi-scale structure of the heat pipe wick according to claim 8, characterized in that, The integrated folded capillary skeleton naturally forms a series of axially extending liquid reflux main channels with triangular or rectangular cross-sections between the inner wall of the heat pipe shell and the support layer.

10. The multi-scale structure of the heat pipe wick according to claim 9, characterized in that, The troughs of the integrated folded capillary skeleton are in close contact or bonded to the inner wall of the heat pipe, and its peaks are in close contact with the support layer.

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