Sealing ring and preparation method thereof, sealing structure and intelligent dismounting system

Abstract

The invention discloses a sealing ring and a preparation method thereof, a sealing structure and an intelligent dismounting system, and relates to the technical field of sealing, the sealing ring comprises an outer layer, a middle layer, an inner layer and a shape memory alloy wire mesh, and the middle layer is arranged on at least one side of the outer layer; the inner layer is arranged on the side, away from the outer layer, of the middle layer. The shape memory alloy wire mesh is pre-embedded between the middle layer and the inner layer, and the shape memory alloy wire mesh can be activated under external stimulation to generate phase change. The sealing ring provided by the invention aims to solve the technical problems of interface adhesion, disassembly damage and high maintenance cost caused by aging of the sealing ring in the hydrogen fuel cell.

Description

Technical Field

[0001] This application relates to the field of sealing technology, and in particular to a sealing ring and its preparation method, sealing structure and intelligent disassembly system. Background Technology

[0002] Hydrogen fuel cell stacks typically employ a multi-layered, series-connected single-cell structure, with each cell separated and insulated by elastic sealing rings. Currently, commercially available sealing rings mostly use single polymer materials such as silicone rubber and fluororubber. Under long-term high-temperature (60-90℃), high-humidity (relative humidity >90%), and acidic (pH=3-5) conditions, these materials are prone to chemical aging and physical creep. Chemically, fluororubber shows main chain breakage, and silicone rubber shows side chain oxidation; Fourier transform infrared spectroscopy reveals a reduction in CF bonds and Si-O-Si breakage. Physically, according to ISO 815 standards, the compression set exceeds 30%. Furthermore, aging products easily form interfacial chemical bonds with stainless steel or titanium alloy bipolar plates, leading to a significant increase in disassembly force, reaching 200%-300%.

[0003] Existing improvement solutions mostly focus on a single dimension, such as material modification or surface coating, making it difficult to simultaneously address both anti-adhesion and sealing reliability. Disassembly relies on mechanical prying, which easily causes plastic deformation of the bipolar plate sealing groove, resulting in a damage rate exceeding 20%. At the same time, there is a lack of effective preventive maintenance methods, and a single stack disassembly often takes more than 4 hours, resulting in low maintenance efficiency and high costs.

[0004] Therefore, developing a hydrogen fuel cell sealing system that is anti-aging, anti-adhesion, easy to disassemble, and structurally reliable has become a key issue in improving stack life and maintenance efficiency. Summary of the Invention

[0005] This application provides a sealing ring and its preparation method, sealing structure and intelligent disassembly system, aiming to solve the technical problems of interface adhesion, disassembly damage and high maintenance costs caused by sealing ring aging in hydrogen fuel cells.

[0006] In a first aspect, this application provides a sealing ring, which, according to an embodiment of this application, comprises: Outer layer; An intermediate layer is disposed on at least one side of the outer layer; The inner layer is located on the side of the intermediate layer away from the outer layer; A shape memory alloy wire mesh is embedded between the intermediate layer and the inner layer, and the shape memory alloy wire mesh can be activated and undergo a phase transition under external stimulation.

[0007] This application effectively solves the problem of interfacial adhesion and disassembly difficulties caused by the aging of sealing rings through its multi-layered structure and the synergistic design of the built-in shape memory alloy mesh. Specifically, the outer layer of the sealing ring can suppress the exponential growth of interfacial adhesion force; the middle layer of the sealing ring has high thermal conductivity, which can homogenize the temperature field and alleviate the thermo-mechanical coupling damage caused by the combined effect of local temperature rise and shear force; the inner layer of the sealing ring provides excellent elastic recovery force, ensuring long-term sealing reliability; and the shape memory alloy mesh pre-embedded between the middle layer and the inner layer can be activated under external thermal stimulation, undergoing an austenitic phase transformation and producing precise strain contraction. This contraction behavior can actively break the interfacial adhesion between the sealing ring and the mating parts from the inside, forming a controllable separation gap, thereby significantly reducing disassembly resistance, achieving non-destructive and efficient disassembly, and effectively avoiding damage to related components.

[0008] In some embodiments, the shape memory alloy wire mesh is embedded at a distance of 0.04-0.06 mm from the bottom surface of the intermediate layer. Embedding the shape memory alloy wire mesh at this specific location (0.04-0.06 mm from the bottom surface of the intermediate layer) allows the shrinkage force generated when the wire mesh undergoes an austenitic phase transformation upon heating to be more effectively transmitted outward through the intermediate layer. This preferentially induces separation in the interface region most prone to adhesion, while simultaneously avoiding any impact on the sealing performance of the inner layer.

[0009] In some embodiments, the shape memory alloy wire mesh comprises a grid woven from nickel-titanium alloy wires. The grid-like shape memory alloy wire mesh woven from nickel-titanium alloy wires can be precisely activated under external thermal stimulation, undergoing an austenitic phase transformation, thereby producing uniform and controllable strain contraction. This contraction behavior effectively breaks the interfacial adhesion between the sealing ring and the mating component from the inside, forming a separation gap, significantly reducing disassembly resistance, and achieving non-destructive separation. Simultaneously, its grid morphology ensures a strong bond with the sealing ring substrate and uniform stress distribution.

[0010] In some embodiments, the diameter of the nickel-titanium alloy wire is 0.09-0.11 mm. This diameter range provides sufficient phase change shrinkage force while ensuring the flexibility of the wire mesh and its bonding strength with the polymer matrix, and it is easy to weave into a mesh structure.

[0011] In some embodiments, the mesh shape includes a rhombus. The rhombus mesh structure ensures that the shape memory alloy wire mesh undergoes uniform radial shrinkage when heated, while the structure is evenly distributed within the sealing ring, preventing stress concentration and ensuring a strong bond with the polymer matrix.

[0012] In some embodiments, the outer layer is thinner than the inner layer. This "thin outer layer, thick inner layer" structure achieves anti-sticking through the thin outer layer, while the thick inner layer ensures sealing and support.

[0013] In some embodiments, the thickness ratio of the outer layer, the intermediate layer, and the inner layer is (0.5-1.5):(0.8-1.2):(2.5-3.5), preferably (0.8-1.2):(0.9-1.1):(2.8-3.2). Limiting the thickness ratio of the outer, intermediate, and inner layers within this range ensures that the outer layer provides anti-stick properties and the intermediate layer provides thermal conductivity, while also ensuring that the inner layer has sufficient thickness to provide stable sealing elasticity and support, and that the shape memory alloy wire mesh is embedded at the optimal point of action.

[0014] In some embodiments, the surface energy of the outer layer is less than or equal to 18 mN / m, and the contact angle is greater than or equal to 130°. This ultra-low surface energy and non-wetting property can effectively suppress the formation of intermolecular forces between the outer layer of the sealing ring and the surface of the mating component, thereby significantly weakening or even blocking interfacial chemical bonding and physical adsorption. This fundamentally prevents the strong adhesion problem between the sealing ring and the contact interface caused by long-term aging, providing anti-stick protection for subsequent maintenance and disassembly.

[0015] In some embodiments, the outer layer comprises a composite material of polytetrafluoroethylene and fluorinated nanoparticles. This composite material can significantly reduce the surface interfacial energy and effectively inhibit the formation of chemical bonds between the sealing ring and the mating surface, thereby preventing interfacial adhesion problems caused by material aging during long-term use and providing a material basis for achieving non-destructive disassembly.

[0016] In some embodiments, the thermal conductivity of the intermediate layer is 1.2-1.5 W / m·K. Limiting the thermal conductivity of the intermediate layer to this range improves the thermal management capability of the sealing ring, enabling rapid and uniform heat conduction during operation, effectively preventing excessively high local temperatures, thereby slowing down the thermal aging process of the material and reducing the risk of sealing ring deformation or damage due to thermal stress concentration, ensuring the long-term stability and reliability of the sealing interface under high-temperature conditions.

[0017] In some embodiments, the intermediate layer comprises a composite material of graphene and silicone rubber. The high thermal conductivity of graphene improves the overall thermal conductivity of the sealing ring, homogenizes the temperature field, and thus reduces the risk of material aging or damage due to thermal stress concentration.

[0018] In some embodiments, the inner layer has an elastic recovery force greater than 90% at 70% compression. This greater than 90% elastic recovery force ensures that the sealing ring maintains excellent resilience under long-term high-compression conditions, effectively resisting permanent deformation. This provides a stable and reliable sealing pressure throughout its service life, preventing a decline in interface sealing performance due to plastic failure of the sealing ring.

[0019] In some embodiments, the inner layer comprises a composite material of carbon fiber and hydrogenated nitrile butadiene rubber. The use of this composite material enhances the mechanical strength and creep resistance of the inner layer material, allowing it to maintain an elastic recovery force exceeding 90% even under high compression ratios (approximately 70%). This ensures that the sealing ring maintains stable and reliable sealing contact stress under long-term harsh operating conditions, effectively overcoming the problems of permanent compression deformation and sealing failure caused by physical creep in traditional single rubber materials.

[0020] Secondly, this application provides a method for preparing the sealing ring described above, comprising: Three polymer compositions are provided for forming an outer layer, a middle layer, and an inner layer, respectively. The three polymer compositions are fed into a three-layer co-extrusion device, and the sealing ring is integrally formed by a co-extrusion die, wherein the dimensional tolerance of the co-extrusion is controlled within ±0.05mm.

[0021] The sealing ring preparation method provided in this application feeds three polymer compositions used to form the outer layer, middle layer and inner layer into a three-layer co-extrusion device and integrally forms them using a co-extrusion die. This process realizes the manufacturing of a gradient anti-stick sealing ring and controls the dimensional tolerance of the co-extrusion within ±0.05mm, ensuring the accuracy and consistency of the sealing ring structure dimensions, and providing manufacturing assurance for subsequent mating with mating parts and reliable sealing.

[0022] In some embodiments, the outer surface of the molded sealing ring is further subjected to plasma grafting modification treatment. Plasma grafting modification treatment of the outer surface of the molded sealing ring can introduce fluorine-containing active groups into the outer PTFE surface, enhance the bonding strength of the fluorinated silica nanoparticles through chemical bonding, prevent the particles from falling off during use, and further reduce the surface energy to 15-18 mN / m and increase the contact angle to ≥130°, significantly enhancing the durability and stability of the anti-sticking effect.

[0023] Thirdly, this application provides a sealing structure, including: Sealing groove; A sealing ring is disposed within the sealing groove, and the sealing ring includes the sealing ring described above.

[0024] The sealing structure provided in this application, by setting the aforementioned sealing ring in the sealing groove, can solve the problem of uncontrolled interface adhesion between the traditional sealing ring and the metal groove, reduce the disassembly force, and avoid thermal-mechanical coupling damage during the disassembly process. When this sealing structure is applied to fuel cells, it can improve the reusability of bipolar plates and effectively extend the service life of the sealing ring.

[0025] In some embodiments, the bottom of the sealing groove is provided with a micro-protrusion array. This micro-protrusion array reduces the actual contact area between the sealing ring and the sealing groove to 42.7% compared to a traditional flat groove, thereby reducing interfacial adhesion and providing a structural basis for storing grease to form a boundary lubrication film. Ultimately, it reduces the interfacial friction coefficient to 0.08, achieving effective control of disassembly force and efficient separation of the sealing structure.

[0026] In some embodiments, the sidewalls of the sealing groove are provided with a progressive tilt angle of 3°-5°. This structure can form an effective disassembly guide step during disassembly, matching the wedge-shaped guide angle of the disassembly tool, thereby avoiding lateral stress, achieving smooth separation, and preventing plastic deformation of the bipolar plate sealing groove.

[0027] In some embodiments, a disassembly guide step is provided at the end of the groove opening of the sealing groove. This guide step can cooperate with the wedge-shaped guide mechanism of the disassembly tool to provide a precise guide path and initial separation force during the disassembly process, effectively guiding the tool head smoothly into the sealing gap, thereby avoiding lateral stress and preventing plastic deformation of the sealing groove due to tool deflection.

[0028] In some embodiments, the inner surface of the sealing groove is provided with a micron-level texture. This micron-level texture can store grease to form a stable boundary lubrication film, thereby significantly reducing the coefficient of friction to 0.08, effectively reducing the sliding resistance and interfacial shear strength between the sealing ring and the groove wall, and providing an effective drag reduction effect for disassembly operations.

[0029] In some embodiments, the micro-protrusions in the micro-protrusion array have a height of 50-200 μm and a spacing of 300-500 μm. This size range of micro-protrusions significantly reduces the actual contact area between the sealing ring and the sealing groove to 42.7% of that of a conventional planar structure, thereby reducing interfacial adhesion. Simultaneously, this structure results in a more uniform distribution of contact stress, avoiding localized stress concentrations and guiding the interfacial separation process during disassembly, thus synergistically reducing disassembly resistance and the risk of damage.

[0030] In some embodiments, the micron-scale texture is honeycomb-shaped with a depth of 20-50 μm. This texture can store grease to form a stable boundary lubrication film, significantly reducing the interfacial friction coefficient to 0.08. At the same time, its honeycomb morphology and 20-50 μm depth design work together to effectively promote lubricant retention and stress dispersion, thereby significantly reducing frictional resistance and interfacial shear strength during disassembly.

[0031] Fourthly, this application provides an intelligent disassembly system for disassembling the aforementioned sealing structure, the intelligent disassembly system comprising: Control unit; A triggering device, communicatively connected to the control unit, is used to activate the shape memory alloy wire mesh in response to the instructions of the control unit; The separation device, which is communicatively connected to the control unit, is used to apply a mechanical separation action to the sealing structure after the shape memory alloy wire mesh is activated.

[0032] The intelligent disassembly system provided in this application embodiment triggers a device that responds to a control unit command by generating hot air or heating it with electricity to activate the shape memory alloy wire mesh, causing it to undergo an austenitic phase transformation and shrink, creating an initial separation gap between the sealing ring and the sealing groove wall. Subsequently, under the command of the control unit, the separation device applies a mechanical separation action to the sealing structure with precisely controlled speed and force, achieving a smooth disassembly through thermo-mechanical coupling, ultimately significantly reducing the disassembly force to below 60N and effectively avoiding damage to the components.

[0033] In some embodiments, the separation device includes a gripper assembly for clamping, a drive unit for driving the gripper assembly, and a guide unit for engaging with a guide step of the sealing groove. The gripper assembly reliably grips the edge of the sealing groove, the drive unit provides smooth linear separation force, and the guide unit, through precise engagement with the pre-set guide step of the sealing groove, ensures that the disassembly force is always transmitted along a precise axial direction, effectively decomposing and avoiding lateral stress. Thus, while achieving efficient separation, it prevents scratching of the sealing groove due to uneven force loading.

[0034] In some embodiments, the control unit employs a PID control algorithm. By using a PID control algorithm and closed-loop control through thermo-coupling, the temperature during disassembly is stabilized at 80℃±2℃ and the speed is controlled at 5mm / s. This allows for the regulation of the shape memory alloy wire mesh's triggered shrinkage and interface softening processes, ensuring a stable disassembly force that does not exceed 60N, effectively preventing component damage caused by overheating or sudden stress changes.

[0035] In some embodiments, the separation device further includes a heating component integrated into the gripper assembly. This heating component can assist in heating the sealing ring interface after the initial gap is triggered by the shape memory alloy wire mesh. By further increasing the interface temperature and stabilizing it within an optimized range of 80℃±2℃, the aged sealing ring material is effectively softened, significantly reducing its adhesion strength and interfacial shear stress with the groove wall. This, combined with the mechanical shrinkage behavior of the SMA, forms a thermo-mechanical coupling synergy, ensuring that the disassembly force is further reduced to below 60N, achieving efficient and non-destructive separation operation.

[0036] In some embodiments, the guide portion is a wedge-shaped structure. This wedge-shaped structure can form a geometric match and mechanical guidance with the progressive tilt angle of the sealing groove sidewall and the disassembly guide step at the end. During the disassembly process, it automatically and smoothly converts the axial linear motion applied by the tool into the radial component force required to detach the sealing ring from the groove wall, thereby effectively guiding the direction of the disassembly force, avoiding stress concentration and lateral scraping, and is a key mechanical guarantee for achieving non-destructive disassembly.

[0037] In some embodiments, the separation device further includes a force feedback system. The force feedback system in the separation device can monitor and control the disassembly process in real time. Specifically, the system has a built-in pressure sensor that can provide real-time feedback on the clamping force during disassembly. When the disassembly force exceeds the limit, it immediately triggers an audible and visual alarm and stops the operation, thereby effectively avoiding plastic deformation of the bipolar plate or damage to the sealing ring due to overload, ensuring the safety, controllability, and non-destructive nature of the disassembly operation.

[0038] In some embodiments, the force feedback system includes a pressure sensor. When the disassembly force detected in real time exceeds 60N, the control unit triggers an alarm. The force feedback system monitors the disassembly force in real time through a built-in pressure sensor. When the disassembly force exceeds the 60N threshold, the control unit immediately triggers an audible and visual alarm, thereby forcibly interrupting the disassembly process. This active protection mechanism effectively prevents tearing of the sealing ring or plastic deformation of the sealing groove caused by uncontrolled disassembly force, keeping the disassembly process within a safe force range and ensuring the reliable implementation of non-destructive disassembly operations.

[0039] Compared with the prior art, the beneficial effects of this application are as follows: 1. Through a triple innovation system, the system achieves layered synergy of anti-sticking, heat conduction and sealing functions through material gradient design (outer layer anti-sticking, middle layer heat conduction, inner layer sealing), significantly reduces interface friction through structural biomimetic optimization (micro-protrusion array, progressive sidewall, laser texture), and achieves non-destructive separation through intelligent active intervention (shape memory alloy triggered shrinkage). This reduces disassembly force by 72% compared to traditional solutions, effectively avoids bipolar plate deformation and damage, extends the sealing ring life to more than 8,000 hours, and is fully compatible with existing fuel cell stack assembly processes. The modification cost is less than 5%, and a comprehensive leap forward has been achieved in the reliability, durability and maintainability of hydrogen fuel cell sealing structures.

[0040] 2. Regarding disassembly force, after 1000 hours, it decreased significantly from 198N in the traditional solution to 54N, a reduction of 72.7%; the bipolar plate reuse rate increased from 78% to 95%, an increase of 21.8%; the sealing ring lifespan increased from 3000 hours to 8000 hours, an increase of 166%; the single maintenance time was shortened from 240 minutes to 35 minutes, a reduction of 85.4%; and the interfacial shear strength decreased from 0.8 MPa to 0.2 MPa, a reduction of 75%. These data clearly demonstrate that this application effectively solves the problems of interfacial adhesion and disassembly damage to the sealing ring, achieving a significant reduction in maintenance costs and time.

[0041] 3. In terms of economic benefits, the maintenance cost of a single fuel cell stack is reduced by 62%, from 5,200 yuan to 1,980 yuan. The production line transformation cost is only 15,000 yuan per line, while the traditional solution requires 80,000 yuan. It is also compatible with existing fuel cell stack assembly processes, and the transformation cost is less than 5%. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A schematic diagram of the cross-sectional structure of the sealing ring provided in this application.

[0044] Figure 2 This is a front view of the structure of the sealing groove provided in this application.

[0045] Figure 3 The structural diagram of the micro-protrusion array of the sealing groove provided in this application is as follows: (a) top view; (b) cross-sectional view of the micro-protrusion.

[0046] Figure 4 A structural diagram of the micron-scale texture of the sealing groove provided in this application.

[0047] Figure 5 A diagram illustrating the composition of the intelligent disassembly system provided in this application.

[0048] Reference numerals: sealing ring 100, outer layer 110, middle layer 120, inner layer 130, shape memory alloy wire mesh 140, sealing groove 200, micro-protrusion array 210, micro-protrusion 211, progressive tilt angle 220, guide step 230, micron-level texture 240, intelligent disassembly system 300, control unit 310, separation device 320, gripper assembly 321, guide part 322, heating assembly 323, force feedback system 324, bipolar plate 330. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0050] Hydrogen fuel cell stacks typically employ a multi-layer series structure, with individual cells separated by elastic sealing rings for airtight isolation. Currently, commercially available sealing rings are primarily made of single materials such as silicone rubber and fluororubber. However, these sealing rings are prone to various degradation phenomena under long-term operating conditions of high temperature (60-90℃), high humidity (relative humidity >90%), and acidic environment (pH 3-5). In terms of chemical aging, the main chain of fluororubber breaks down, and the side chains of silicone rubber oxidize. Fourier transform infrared spectroscopy reveals a reduction in CF bonds and Si-O-Si breakage. In terms of physical creep, according to ISO 815 standard testing, the compression set exceeds 30%. Regarding interfacial adhesion, aging products form chemical bonds with stainless steel or titanium alloy bipolar plates, leading to a significant increase in disassembly force, reaching 200%-300%.

[0051] Currently, existing improvement solutions have many limitations, often focusing on a single dimension, such as material modification or surface coating, failing to simultaneously ensure both anti-sticking and sealing reliability. During disassembly, relying on mechanical prying can easily cause plastic deformation of the bipolar plate sealing groove, with a damage rate exceeding 20%. Furthermore, existing technologies lack effective preventative maintenance methods, with each fuel cell stack disassembly taking more than 4 hours, resulting in low efficiency and high maintenance costs.

[0052] Therefore, there is an urgent need for a hydrogen fuel cell sealing structure and disassembly solution that can comprehensively address key issues such as uncontrolled interfacial adhesion, thermo-mechanical coupling damage, and high maintenance costs.

[0053] In view of this, this application provides a sealing ring and its preparation method, sealing structure and intelligent disassembly system, aiming to solve the technical problems of interface adhesion, disassembly damage and high maintenance costs caused by sealing ring aging in hydrogen fuel cells.

[0054] Firstly, this application provides a sealing ring 100, with reference to... Figure 1 As shown, the sealing ring 100 includes: Outer layer 110; An intermediate layer 120 is disposed on at least one side of the outer layer 110; The inner layer 130 is disposed on the side of the intermediate layer 120 away from the outer layer 110; A shape memory alloy mesh 140 is embedded between the intermediate layer 120 and the inner layer 130, and the shape memory alloy mesh 140 can be activated and undergo a phase change under external stimulation.

[0055] This application effectively solves the problem of interfacial adhesion and disassembly difficulties caused by the aging of sealing rings through its multi-layered structure and the synergistic design of the built-in shape memory alloy (SMA) mesh. Specifically, the outer layer of the sealing ring can suppress the exponential growth of interfacial adhesion force; the middle layer of the sealing ring has high thermal conductivity, which can homogenize the temperature field and alleviate the thermo-mechanical coupling damage caused by the combined effect of local temperature rise and shear force; the inner layer of the sealing ring provides excellent elastic recovery force, ensuring long-term sealing reliability; and the shape memory alloy mesh pre-embedded between the middle layer and the inner layer can be activated under external thermal stimulation, undergoing an austenitic phase transformation and producing precise strain contraction. This contraction behavior can actively break the interfacial adhesion between the sealing ring and the mating parts from the inside, forming a controllable separation gap, thereby significantly reducing disassembly resistance, achieving non-destructive and efficient disassembly, and effectively avoiding damage to related components.

[0056] It should be explained that "shape memory alloy (SMA)" refers to a shape memory alloy material that, after being plastically deformed at low temperatures, can completely recover its original high-temperature shape when heated to a certain critical temperature (called the "austenite phase transformation start temperature").

[0057] In conjunction with the first aspect, in some embodiments provided in this application, the shape memory alloy wire mesh 140 is embedded at a distance of 0.04-0.06 mm from the bottom surface of the intermediate layer 120. Embedding the shape memory alloy wire mesh at this specific location (0.04-0.06 mm from the bottom surface of the intermediate layer) ensures that when the shape memory alloy wire mesh undergoes an austenitic phase transformation upon heating, the resulting shrinkage force is more effectively transmitted outward through the intermediate layer. This preferentially induces separation in the interface region most prone to adhesion, while simultaneously avoiding any impact on the sealing performance of the inner layer.

[0058] In conjunction with the first aspect, in some embodiments provided in this application, the shape memory alloy wire mesh 140 comprises a mesh woven from nickel-titanium alloy wire. The mesh-like shape memory alloy wire mesh woven from nickel-titanium alloy wire can be activated under external stimulation such as 60°C hot air or electric heating, triggering an austenitic phase transformation and generating a 1.0% strain contraction, thereby forming a disassembly gap of approximately 0.2 mm. This contraction behavior can actively break the interfacial adhesion between the sealing ring and the mating parts from the inside, significantly reducing disassembly resistance and achieving non-destructive separation. Simultaneously, its mesh structure ensures a strong bond with the sealing ring substrate and uniform strain distribution.

[0059] Preferably, the nickel-titanium alloy is Ni 50.8 Ti alloy, the Ni 50.8 The austenitic phase transformation temperature of Ti alloys is 55-65℃.

[0060] In conjunction with the first aspect, in some embodiments provided in this application, the diameter of the nickel-titanium alloy wire is 0.09-0.11 mm. Limiting the diameter range of the nickel-titanium alloy wire ensures sufficient phase change shrinkage force while maintaining the flexibility of the wire mesh and its bonding strength with the polymer matrix, and facilitates weaving into a mesh structure.

[0061] In conjunction with the first aspect, in some embodiments provided in this application, the shape of the mesh includes a rhombus shape. The rhombus mesh structure ensures that the shape memory alloy wire mesh undergoes uniform radial shrinkage when heated, while the structure is evenly distributed within the sealing ring, preventing stress concentration and ensuring a strong bond with the polymer matrix.

[0062] Furthermore, the rhomboid mesh size is 2mm × 2mm. This 2mm × 2mm rhomboid mesh design is a comprehensive optimization based on factors such as mechanical transmission efficiency, thermal activation uniformity, and compatibility with the overall structure of the sealing ring. It is one of the key structural parameters for achieving the core functions of shape memory alloy wire mesh: "high-efficiency actuation, uniform response, and synergy with the substrate." Specifically: 1. Optimal Mechanical Synergy: This mesh size ensures a sufficiently dense and uniformly distributed distribution of contractile force application points when the shape memory alloy is activated. If the mesh size is too large (e.g., >3mm), the application points will be too sparse, potentially causing excessive local deformation of the sealing ring during disassembly instead of overall coordinated contraction, affecting the separation effect. If the mesh size is too small (e.g., <1mm), the mesh rigidity will be too strong, potentially restricting the elasticity of the sealing ring body, thus affecting its sealing performance and increasing processing difficulty and cost. A 2mm×2mm mesh size ensures sufficient application point density while guaranteeing good synergy between the mesh and the polymer matrix in deformation.

[0063] 2. Thermal activation uniformity and response speed: This mesh size ensures that the triggering heat (such as 60°C hot air) can be quickly and evenly transferred to each alloy wire, realizing synchronous phase change of the SMA mesh. This avoids local inactivation or activation delay caused by untimely heat transfer, thereby ensuring that the sealing ring can produce instantaneous and consistent radial contraction (approximately 0.2mm gap), creating optimal conditions for subsequent mechanical disassembly.

[0064] 3. Perfect Match with Thickness Ratio: The total thickness of the three layers of the sealing ring provided in this application is approximately 1mm. The 2mm×2mm mesh size forms an optimal match with the cross-sectional size of the sealing ring, allowing each mesh cell to effectively cover and act on the corresponding sealing ring area. This avoids insufficient "leverage effect" due to excessively large mesh cells, and also prevents "over-constraint" due to excessively small mesh cells, ensuring that the contraction force is efficiently converted into interface separation.

[0065] In conjunction with the first aspect, in some embodiments provided in this application, the thickness of the outer layer 110 is less than the thickness of the inner layer 130. This "thin outer layer, thick inner layer" structure achieves anti-sticking through the thin outer layer, while the thick inner layer ensures sealing and support.

[0066] In conjunction with the first aspect, in some embodiments provided in this application, the thickness ratio of the outer layer 110, the intermediate layer 120, and the inner layer 130 is (0.5-1.5): (0.8-1.2): (2.5-3.5). Limiting the thickness ratio of the outer layer 110, the intermediate layer 120, and the inner layer 130 to the above range ensures that the outer layer has sufficient thickness to provide stable sealing elasticity and support, while guaranteeing the anti-sticking function of the outer layer and the thermal conductivity function of the intermediate layer, and simultaneously ensuring that the shape memory alloy wire mesh is embedded at the optimal point of action. Furthermore, the thickness ratio of the outer layer 110, the intermediate layer 120, and the inner layer 130 can preferably be (0.8-1.2): (0.9-1.1): (2.8-3.2).

[0067] The specific value of the thickness ratio of the outer layer 110, the middle layer 120 and the inner layer 130 needs to vary from stack to stack, and is determined comprehensively based on the actual size and specifications of different electric stacks and the magnitude of the fastening force. According to a specific embodiment of this application, the thickness ratio of the outer layer 110, the middle layer 120 and the inner layer 130 is 1:1:3.

[0068] In conjunction with the first aspect, in some embodiments provided in this application, the surface energy of the outer layer 110 is less than or equal to 18 mN / m, and the contact angle is greater than or equal to 130°. This ultra-low surface energy and non-wetting property can effectively suppress the formation of intermolecular forces between the outer layer of the sealing ring and the surface of the mating component, thereby significantly weakening or even blocking interfacial chemical bonding and physical adsorption, fundamentally preventing the strong adhesion problem between the sealing ring and the contact interface caused by long-term aging, and providing anti-stick protection for subsequent maintenance and disassembly.

[0069] In conjunction with the first aspect, in some embodiments provided in this application, the outer layer 110 comprises a composite material of polytetrafluoroethylene (PTFE) and fluorinated nanoparticles. This composite material can significantly reduce the surface interfacial energy and effectively inhibit the formation of chemical bonds between the sealing ring and the mating surface, thereby preventing interfacial adhesion problems caused by material aging during long-term use, and providing a material basis for achieving non-destructive disassembly.

[0070] It should be noted that there is no specific limitation on the type of fluorinated nanoparticles; they can be flexibly selected according to the actual situation. In a specific embodiment of the present invention, the fluorinated nanoparticles are fluorinated silica nanoparticles. The selection of fluorinated silica nanoparticles is mainly based on the following key effects: 1. Superior anti-stick properties and low surface energy: Fluorinated silica particles are rich in stable CF bonds, which are among the lowest surface energy known chemical bonds. When combined with PTFE, they work synergistically with PTFE's excellent anti-stick properties, reducing the overall surface energy of the composite material to ≤18mN / m and the contact angle to ≥130°. This significantly inhibits chemical bonding and physical adsorption with the metal bipolar plate surface, preventing interfacial adhesion at its source.

[0071] 2. Excellent wear resistance and durability: Silica (SiO2) itself has high hardness and good mechanical strength. It exists in a "hard core" form, significantly improving the scratch resistance and wear resistance of the PTFE outer layer surface. This avoids the problem of pure PTFE or soft coatings being easily worn during assembly and long-term operation, ensuring the durability of the anti-stick effect.

[0072] 3. Nanoscale effect and interfacial bonding: Nanoscale particles have a huge specific surface area. After surface fluorination modification, their compatibility and bonding force with the PTFE matrix are enhanced. This effectively prevents particle shedding and agglomeration, ensuring the structural uniformity and long-term stability of the composite material, and maintaining the low surface energy characteristics throughout its service life.

[0073] Thus, fluorinated silica nanoparticles achieve a perfect combination of "hard core reinforcement" and "fluorine shell anti-sticking". They not only give the outer layer of the sealing ring a durable and ultimate anti-sticking property, but also significantly improve its mechanical durability, making them a key material choice for solving the problem of sealing ring aging and adhesion.

[0074] Furthermore, based on the total mass of the PTFE and fluorinated silica nanoparticle composite material, the fluorinated silica nanoparticles account for 10% of the mass. Limiting the content of fluorinated silica nanoparticles fully utilizes their ultra-low surface energy and reinforcing properties to achieve excellent anti-sticking and durability effects, while also ensuring the processability of the sealing ring during manufacturing and its structural reliability during long-term use. Specifically: 1. Achieving optimal surface properties and anti-sticking effect: A 10% addition is sufficient to form a dense, low-surface-energy nanoscale protective layer within the PTFE matrix. When the sealing ring contacts the metal bipolar plate, these surface-enriched fluorinated silica particles effectively block direct contact between the PTFE matrix and the metal surface, minimizing interfacial chemical bonding and physical adsorption, thus fundamentally solving the adhesion problem. Too low a content will result in insufficient protective effect; too high a content may lead to difficulties in subsequent processing.

[0075] 2. Ensuring good processability and structural integrity: In co-extrusion processes, the rheological properties of the material are crucial. An addition of 10% significantly improves material properties without excessively increasing the viscosity of the polymer melt, ensuring the stability of the co-extrusion process and molding accuracy (tolerance ±0.05mm). Excessive content leads to poor melt flowability, making processing difficult and potentially causing product deformation or defects due to increased internal stress.

[0076] 3. Maintaining the mechanical properties of the matrix and avoiding stress concentration: PTFE itself has relatively low mechanical strength. 10% fluorinated silica nanoparticles can act as dispersion reinforcement, improving the hardness, wear resistance, and creep resistance of the outer layer. However, if the filler content is too high (e.g., exceeding 15%), the nanoparticles are prone to agglomeration in the matrix, forming stress concentration points, which can become crack initiation points, reducing the toughness of the material and the tear resistance of the sealing ring.

[0077] In conjunction with the first aspect, in some embodiments provided in this application, the thermal conductivity of the intermediate layer 120 is 1.2-1.5 W / m·K. Limiting the thermal conductivity of the intermediate layer to this range improves the thermal management capability of the sealing ring, enabling rapid and uniform heat conduction during operation, effectively preventing excessively high local temperatures, thereby slowing down the thermal aging process of the material and reducing the risk of deformation or damage to the sealing ring due to thermal stress concentration, ensuring the long-term stability and reliability of the sealing interface under high-temperature conditions.

[0078] In conjunction with the first aspect, in some embodiments provided in this application, the intermediate layer 120 comprises a composite material of graphene oxide and silicone rubber. The high thermal conductivity of graphene improves the overall thermal conductivity of the sealing ring, which can homogenize the temperature field and thus reduce the risk of material aging or damage due to thermal stress concentration.

[0079] Furthermore, based on the total mass of the graphene oxide and silicone rubber composite material, the mass percentage of graphene oxide is 1.2%. Limiting the graphene oxide content allows for the formation of a continuous and efficient three-dimensional thermally conductive network within the silicone rubber matrix, significantly increasing the thermal conductivity of the composite material to 1.2-1.5 W / m·K. If the content is too low, an effective thermal conduction pathway cannot be formed, resulting in limited thermal conductivity enhancement; if the content is too high, agglomeration between the layers is likely to occur, which not only degrades the mechanical properties of the sealing ring (e.g., excessive hardness, decreased elasticity) but may also reduce sealing reliability due to interface defects. Therefore, a 1.2% proportion is the key to achieving a balance between excellent thermal conductivity and good mechanical properties, ensuring that the sealing ring can quickly and evenly dissipate heat during operation, avoiding localized overheating.

[0080] In conjunction with the first aspect, in some embodiments provided in this application, the inner layer 130 has an elastic recovery force greater than 90% at a 70% compression rate. This greater than 90% elastic recovery force at a 70% compression rate ensures that the sealing ring maintains excellent resilience under long-term high-compression conditions, effectively resisting permanent deformation. This provides a stable and reliable sealing pressure throughout its service life, preventing a decline in interface sealing performance due to plastic failure of the sealing ring.

[0081] In conjunction with the first aspect, in some embodiments provided in this application, the inner layer 130 comprises a composite material of carbon fiber and hydrogenated nitrile butadiene rubber (HNBR). The use of this carbon fiber composite material enhances the mechanical strength and creep resistance of the inner layer material, enabling it to maintain an elastic recovery force exceeding 90% while retaining a high compression ratio (approximately 70%). This ensures that the sealing ring maintains stable and reliable sealing contact stress under long-term harsh operating conditions, effectively overcoming the problems of permanent compression deformation and sealing failure caused by physical creep in traditional single rubber materials.

[0082] Furthermore, based on the total mass of the carbon fiber and HNBR composite material, the carbon fiber accounts for 2% of the mass. Limiting the carbon fiber mass percentage within this range is based on a comprehensive consideration of the "percolation threshold" principle and processing feasibility. This content is close to the critical point for forming a reinforcing network in the hydrogenated nitrile butadiene rubber (HNBR) matrix, maximizing the utilization of the high modulus and creep resistance of carbon fibers, significantly improving the mechanical strength of the composite material and suppressing its plastic deformation under long-term compression. Simultaneously, the 2% addition ensures good dispersion of carbon fibers in the matrix, avoiding agglomeration due to excessive content, which would affect the cohesive strength and sealing integrity of the sealing ring. This formulation allows the inner layer to maintain over 90% elastic recovery force even under 70% high compression, providing a durable and stable contact pressure at the sealing interface.

[0083] Furthermore, the aspect ratio of the carbon fiber is 50:1. Limiting the aspect ratio of the carbon fiber follows the core mechanism of short-fiber reinforced elastomer composites. This aspect ratio ensures that the fibers have sufficient length to effectively bear and transfer stress from the soft rubber matrix through the "shear hysteresis" effect, thereby fully exerting their reinforcing effect and greatly improving the material's tensile and compressive strength. On the other hand, this aspect ratio also ensures that the fibers have suitable flowability, allowing them to be smoothly oriented and distributed during the three-layer co-extrusion process, preventing entanglement due to an excessively large aspect ratio, which could affect molding quality or damage the precision extrusion die. Therefore, an aspect ratio of 50:1 is the optimal choice for achieving high strength, high resilience, and good processability in the material.

[0084] Secondly, this application provides a method for preparing the sealing ring 100 described above. According to an embodiment of this application, the preparation method includes: Three polymer compositions are provided for forming an outer layer, a middle layer, and an inner layer, respectively. The three polymer compositions are fed into a three-layer co-extrusion device, and the sealing ring is integrally formed by a co-extrusion die, wherein the dimensional tolerance of the co-extrusion is controlled within ±0.05mm.

[0085] The sealing ring preparation method provided in this application feeds three polymer compositions used to form the outer layer, middle layer and inner layer into a three-layer co-extrusion device and integrally forms them using a co-extrusion die. This process realizes the manufacturing of a gradient anti-stick sealing ring and controls the dimensional tolerance of the co-extrusion within ±0.05mm, ensuring the accuracy and consistency of the sealing ring structure dimensions, and providing manufacturing assurance for subsequent mating with mating parts and reliable sealing.

[0086] In conjunction with the second aspect, in some embodiments provided in this application, the preparation method further includes plasma grafting modification treatment of the outer surface of the formed sealing ring. Plasma grafting modification treatment of the outer surface of the formed sealing ring can introduce fluorine-containing active groups onto the outer PTFE surface, enhancing the bonding strength of the fluorinated silica nanoparticles through chemical bonding, preventing particle detachment during use, and further reducing the surface energy to 15-18 mN / m and increasing the contact angle to ≥130°, significantly enhancing the durability and stability of the anti-sticking effect.

[0087] Thirdly, this application provides a sealing structure, the sealing structure comprising: Sealing groove 200; A sealing ring 100 is disposed within the sealing groove 200, and the sealing ring 100 includes the sealing ring 100 described above.

[0088] The sealing structure provided in this application embodiment, by setting the aforementioned sealing ring 100 in the sealing groove 200, can suppress the formation of interfacial chemical bonds due to the low surface energy characteristics of the outer layer material of the sealing ring 100. When disassembly is required, the pre-embedded shape memory alloy wire mesh 140 shrinks due to thermal phase transformation, actively breaking the adhesive interface between the sealing ring 100 and the groove wall from the inside and generating a separation gap, thereby transforming direct mechanical peeling into active desorption from the inside out, fundamentally avoiding uncontrolled disassembly force and structural damage caused by strong adhesion.

[0089] In conjunction with the third aspect, in some embodiments provided in this application, reference is made to Figures 2-3 As shown, the bottom of the sealing groove 200 is provided with a micro-protrusion array 210. This structure transforms the continuous surface contact between the sealing ring 100 and the bottom of the sealing groove 200 into discrete point contact, reducing the actual contact area to 42.7% compared to a traditional planar groove, thereby reducing the effective bonding interface during the aging process. At the same time, the gaps between the micro-protrusions 211 provide stress release space in the initial stage of disassembly, allowing interface peeling to start locally and gradually expand, thus significantly reducing the initial peeling resistance and overall disassembly force.

[0090] Optionally, the bottom of the sealing groove 200 is provided with a periodic array of micro-protrusions 210. This periodic structure reduces the contact area between the sealing ring 100 and the bottom of the groove to 42.7% of that in a traditional planar design, significantly reducing interfacial adhesion. Furthermore, the periodic arrangement ensures a uniform distribution of contact stress, avoiding creep or damage to the sealing ring caused by localized stress concentration.

[0091] In conjunction with the third aspect, in some embodiments provided in this application, reference is made to Figure 3 As shown, in the micro-protrusion array 210, the height of the micro-protrusions 211 is 50-200 μm, and the spacing is 300-500 μm. This size range of micro-protrusions 211 significantly reduces the actual contact area between the sealing ring 100 and the sealing groove 200 to 42.7% of that of a traditional planar structure, thereby reducing interfacial adhesion. Simultaneously, this structure makes the contact stress distribution more uniform, avoids localized stress concentration, and guides the interface separation process during disassembly, thus synergistically reducing disassembly resistance and damage risk.

[0092] The shape of the micro-protrusion 211 is not particularly limited, and those skilled in the art can choose it flexibly as needed. In this application, reference is made to... Figure 3 As shown, the micro-protrusion 211 adopts a trapezoidal design, with a contact base plane size of 100μm×100μm with the bottom of the groove. The trapezoidal sidewalls have a 75° inclination angle, and the top plane has a small surface area due to the slope contraction effect. The overall height is 150μm.

[0093] In conjunction with the third aspect, in some embodiments provided in this application, reference is made to Figure 2 As shown, the sidewall of the sealing groove 200 is provided with a progressive tilt angle 220 of 3°-5°. This tilt angle structure can guide the wedge-shaped head of the disassembly tool to be smoothly inserted and accurately centered during the disassembly process. By converting part of the vertical separation force into a lateral component force, it effectively decomposes and reduces the disassembly resistance, while avoiding rigid collision between the tool and the groove wall, thereby significantly reducing lateral stress and preventing plastic deformation or damage to the edge of the sealing groove 200.

[0094] It should be explained that "progressive tilt angle" refers to the fact that the sidewall of the sealing groove 200 is not designed vertically, but rather forms a slope with a gradually changing angle from the groove opening to the bottom. In this application, it specifically refers to the sidewall of the sealing groove 200 forming a slope with an angle that gradually increases from 3° to 5° from the groove opening to the bottom. This gradual design can provide a gradually increasing guiding effect during disassembly, ensuring that the separation process is smooth and controllable.

[0095] In conjunction with the third aspect, in some embodiments provided in this application, reference is made to Figure 2 As shown, a disassembly guide step 230 is provided at the end of the groove opening of the sealing groove 200. This guide step 230 can match and smoothly receive the wedge-shaped guide head of the disassembly tool, achieving effective centering in the initial stage of disassembly, converting the separation force applied by the tool into smooth traction along the disassembly direction, thereby avoiding lateral stress and stress concentration, and thus preventing plastic deformation and damage to the sealing groove 200 caused by prying.

[0096] It should be explained that "the end of the groove of the sealing groove 200" refers to the edge of the opening where the sealing ring is prepared to be installed or eventually removed.

[0097] Preferably, a 0.2mm disassembly guide step 230 is formed at the end of the groove opening of the sealing groove 200. The technical advantage of forming a 0.2mm disassembly guide step 230 at the end of the groove opening of the sealing groove 200 is that the height of the step is optimized to precisely match the wedge-shaped guide head of the disassembly tool, providing a smooth guide path in the initial stage of disassembly, effectively converting the axial separation force into a radial component force, and avoiding plastic deformation of the edge of the sealing groove 200 caused by stress concentration.

[0098] In conjunction with the third aspect, in some embodiments provided in this application, reference is made to Figure 2 and Figure 4 As shown, the inner surface of the sealing groove 200 is provided with a micron-level texture 240. This micron-level texture 240 can store grease to form a boundary lubrication film, reducing the coefficient of friction to 0.08, thereby reducing frictional resistance and interfacial shear strength during disassembly.

[0099] It should be explained that "micron-level texture" refers to tiny, regular patterns or textures "etched" on the metal surface of the sealing groove 200 using an extremely fine laser. Simply put, it is a micro-oil storage structure etched onto a metal surface using a laser, utilizing a lubricating oil film to make disassembly easier and less damaging to parts. In this application, it refers to regular micron-level patterns formed on the metal surface of the sealing groove 200 by picosecond laser processing, specifically an array of hexagonal honeycomb-like pits with a depth of 20-50 μm. These microstructures can store lubricating media, forming a stable boundary lubricating film at the interface.

[0100] In conjunction with the third aspect, in some embodiments provided in this application, reference is made to Figure 4 As shown, the micron-scale texture 240 is honeycomb-shaped with a depth of 20-50 μm. This texture can serve as a micro-oil reservoir, effectively capturing and storing grease, and continuously forming a stable boundary lubrication film during disassembly. Its 20-50 μm depth design ensures sufficient lubricant storage to maintain long-term lubrication while avoiding stress concentration that may be caused by excessive texture depth, thereby significantly reducing the interfacial friction coefficient to 0.08, which in turn reduces frictional resistance and interfacial shear strength during disassembly.

[0101] It should be explained that "depth" refers to the vertical sinking distance of each honeycomb pit. In other words, it refers to the maximum vertical distance from the original surface to the bottom of each honeycomb pit. This depth range is optimized to ensure sufficient lubricant storage capacity while avoiding stress concentration problems that may be caused by excessive texture.

[0102] In conjunction with the third aspect, in some embodiments provided in this application, the processing method of the sealing groove 200 combines five-axis precision milling (Ra≤0.4μm) and picosecond laser micro-nano processing. The technical advantage of combining five-axis precision milling and picosecond laser micro-nano processing is that five-axis precision milling can ensure the macroscopic dimensional accuracy of the sealing groove 200 (Ra≤0.4μm), while picosecond laser micro-nano processing forms a high-quality micron-level texture 240 on the inner surface of the groove through a "cold working" mechanism. The combination of these two processes achieves full-scale precision control from macro to micro, ensuring the overall performance of the sealing structure.

[0103] It should be noted that "five-axis precision milling" refers to the coordinated movement of a cutting tool (or machining platform) in five directions (three linear axes X, Y, and Z and two rotary axes A and C), ensuring that the tool tip always approaches and cuts the complex surface of the workpiece at the optimal angle without requiring multiple reclampings. In this application, the high-speed rotation of the tool continuously removes material, thereby machining the macroscopic structure of the sealing groove 200 with complex three-dimensional contours and minute features (such as the progressive tilt angle 220 and the micro-protrusion array 210 in this case) in a single, high-precision operation.

[0104] It should be noted that "picosecond laser micro-nano fabrication" refers to the use of lasers with extremely short durations (picoseconds, or 10^6 seconds). -12 An ultrafast laser pulse (seconds) is applied to the material surface. When the laser energy is absorbed by the material in an extremely short time, the surface electrons do not have time to diffuse the energy to the surrounding area through thermal conduction. Instead, they directly undergo a Coulomb explosion or vaporization, thus achieving precise removal of the material through a "cold working" method. This mechanism minimizes the thermal impact on the surrounding material, avoiding thermal damage such as melting and resolidification, and microcracks, thereby enabling high-precision, high-quality micron / nanoscale structural processing of materials such as metals.

[0105] In conjunction with the third aspect, in some embodiments provided in this application, the sealing structure is applied to a hydrogen fuel cell. Specifically, by assembling the sealing ring 100 into the sealing groove 200 of the bipolar plate 330, stable sealing, heat conduction, and anti-aging are achieved during stack operation by utilizing its material gradient.

[0106] Fourthly, this application provides an intelligent disassembly system 300 for disassembling the aforementioned sealing structure, with reference to... Figure 5 As shown, the intelligent disassembly system 300 includes: Control unit 310; A triggering device, communicatively connected to the control unit 310, is used to activate the shape memory alloy mesh 140 in response to the instructions of the control unit 310. The separation device 320 is communicatively connected to the control unit 310 and is used to apply a mechanical separation action to the sealing structure after the shape memory alloy wire mesh 140 is activated.

[0107] The intelligent disassembly system 300 provided in this application embodiment triggers the device in response to the command of the control unit 310. It activates the shape memory alloy wire mesh 140 by generating hot air or heating it with electricity, causing it to undergo austenitic phase transformation and shrink, creating an initial separation gap between the sealing ring 100 and the wall of the sealing groove 200. Subsequently, under the command of the control unit 310, the separation device 320 applies a mechanical separation action to the sealing structure with precisely controlled speed and force, realizing a smooth disassembly with thermal-mechanical coupling. Ultimately, the disassembly force is greatly reduced to below 60N, and damage to the components is effectively avoided.

[0108] In conjunction with the fourth aspect, in some embodiments provided in this application, the control unit 310 employs a PID control algorithm. By using a PID control algorithm and implementing closed-loop control through thermo-coupling, the temperature during the disassembly process is stabilized at 80℃±2℃ and the speed is controlled at 5mm / s. This allows for the regulation of the triggered shrinkage and interface softening process of the shape memory alloy wire mesh 140, ensuring a stable disassembly force that does not exceed 60N, effectively preventing component damage caused by overheating or sudden stress changes.

[0109] In conjunction with the fourth aspect, in some embodiments provided in this application, the separation device 320 includes a gripper assembly 321 for clamping, a drive unit for driving the gripper assembly 321, and a guide part 322 for engaging with the guide step 230 of the sealing groove 200. The gripper assembly 321 is responsible for reliably clamping the edge of the sealing groove 200, the drive unit provides smooth linear separation power, and the guide part 322, through precise engagement with the pre-set guide step 230 of the sealing groove 200, ensures that the disassembly force is always transmitted along a precise axial direction, effectively decomposing and avoiding lateral stress, thereby achieving efficient separation while preventing scratches on the sealing groove 200 caused by uneven force loading. Furthermore, the gripper assembly 321 is a hydraulically driven gripper.

[0110] In conjunction with the fourth aspect, in some embodiments provided in this application, the separation device 320 further includes a heating component 323 integrated on the gripper assembly 321. This heating component 323 can provide auxiliary heating to the sealing ring interface after the shape memory alloy wire mesh 140 triggers the generation of the initial gap. By further increasing the interface temperature and stabilizing it within an optimized range of 80℃±2℃, it effectively softens the aged sealing ring material, significantly reducing its adhesion strength and interfacial shear stress with the groove wall. This, combined with the mechanical contraction behavior of the SMA, forms a thermo-mechanical coupling synergy, jointly ensuring that the disassembly force is further reduced to below 60N, achieving efficient and non-destructive separation operation. Furthermore, the heating component 323 is a PTC heating element.

[0111] In conjunction with the fourth aspect, in some embodiments provided in this application, the guide portion 322 is a wedge-shaped structure. This wedge-shaped structure can geometrically match and mechanically guide the progressive tilt angle 220 of the sidewall of the sealing groove 200 and the disassembly guide step 230 at its end. During disassembly, it automatically and smoothly converts the axial linear motion applied by the tool into the radial component force required to detach the sealing ring from the groove wall, thereby effectively guiding the direction of the disassembly force and avoiding stress concentration and lateral scraping. This is a key mechanical guarantee for achieving non-destructive disassembly. Furthermore, the wedge-shaped structure is a V-shaped wedge block (angle 10°), which cooperates with the guide step 230 of the sealing groove 200 to avoid lateral stress.

[0112] In conjunction with the fourth aspect, in some embodiments provided in this application, the separation device 320 further includes a force feedback system 324. The force feedback system 324 provided in the separation device 320 can monitor and control the disassembly process in real time. Specifically, the system has a built-in pressure sensor that can provide real-time feedback on the clamping force during disassembly. When the disassembly force exceeds the limit, it immediately triggers an audible and visual alarm and stops the operation, thereby effectively avoiding plastic deformation of the bipolar plate or damage to the sealing ring due to overload, ensuring the safety, controllability, and non-destructive nature of the disassembly operation.

[0113] In conjunction with the fourth aspect, in some embodiments provided in this application, the force feedback system 324 includes a pressure sensor. When the disassembly force detected in real time exceeds 60 N, the control unit 310 triggers an alarm. The force feedback system 324 monitors the disassembly force in real time through its built-in pressure sensor. When the detected disassembly force exceeds the 60 N threshold, the control unit 310 immediately triggers an audible and visual alarm, thereby forcibly interrupting the disassembly process. This active protection mechanism can effectively prevent the sealing ring from tearing or the sealing groove 200 from plastic deformation due to uncontrolled disassembly force, keeping the disassembly process within a safe force range and ensuring the reliable implementation of non-destructive disassembly operations. Furthermore, the pressure sensor has a range of 0-200 N, and triggers an audible and visual alarm when the limit is exceeded.

[0114] According to an embodiment of this application, the intelligent disassembly system 300 has an active intervention mechanism, wherein the shape memory alloy wire mesh 140 can generate a radial displacement of 0.8 mm after triggering contraction, and this displacement has been verified by finite element simulation. The system adopts a thermo-coupling control strategy to precisely control the temperature during the disassembly process at 80℃±2℃, and executes the disassembly action at a constant speed of 5 mm / s. The entire process uses PID closed-loop control to ensure stability. In terms of the design of the special tool, its wedge-shaped guide angle is precisely matched with the inclination angle of the side wall of the sealing groove 200, and the angle tolerance is controlled within ±0.5°; at the same time, the tool integrates a real-time feedback system of force-temperature-displacement three parameters, and all data are displayed in real time on the HMI interface.

[0115] Furthermore, the intelligent disassembly system provided in this application embodiment has the following workflow: Before disassembly, a command is sent through the BMS system to start the hot air generator (temperature 60℃, flow rate 5L / min) for 30 seconds, causing the SMA mesh to shrink and create a gap of 0.1–0.3mm between the sealing ring 100 and the groove wall; then the separation device 320 clamps the edge of the sealing groove 200, and the PTC heating element integrated in its head (power 50W, heats up to 80℃ in 3 seconds) contacts the sealing ring area to further soften the interface; the hydraulically driven gripper smoothly separates the bipolar plate 330 at a speed of 5mm / s, and the disassembly force is controlled within ≤60N throughout the process; the tool is equipped with a V-shaped wedge block (angle 10°) as a guide mechanism, which cooperates with the guide step 230 of the sealing groove 200 to eliminate lateral stress, and has a built-in pressure sensor with a range of 0-200N to form a force feedback system 324, which immediately triggers an audible and visual alarm when the disassembly force exceeds the limit, thereby realizing a controllable and non-destructive disassembly operation.

[0116] Furthermore, when the sealing structure provided in this embodiment is applied to a hydrogen fuel cell, by assembling the sealing ring into the sealing groove 200 of the bipolar plate 330, stable sealing, heat conduction, and anti-aging are achieved during stack operation using its material gradient. When maintenance is required, the intelligent disassembly system triggers the phase change contraction of the SMA wire mesh pre-embedded in the sealing ring through BMS commands, generating an initial separation gap. Combined with the separation device 320 with thermal assistance and force feedback functions, force is applied along the progressive tilt angle 220 and guide step 230 of the sealing groove 200 to achieve non-destructive and stable separation of the bipolar plate 330 with a disassembly force of ≤60N. This significantly improves the maintainability and service life of the stack while ensuring its operational reliability.

[0117] The technical solutions provided in this application will be described in detail below with reference to the embodiments.

[0118] Examples 1-5 Embodiments 1-5 of this application provide a sealing ring, which includes an outer layer, a middle layer, an inner layer, and a shape memory alloy mesh. The middle layer is disposed on at least one side of the outer layer; the inner layer is disposed on the side of the middle layer away from the outer layer; the shape memory alloy mesh is embedded between the middle layer and the inner layer, and the shape memory alloy mesh can be activated and undergo a phase transition under external stimulation, and its parameters are shown in Table 1. Table 1

[0119] The sealing rings provided in Examples 1-5 can be obtained by the following methods: In terms of manufacturing process, a three-layer co-extrusion molding is adopted. The specific process parameters are: outer layer extrusion temperature 280℃, middle layer 180℃, inner layer 160℃, extrusion speed 2-5m / min, die pressure 8-12MPa, tolerance controlled within ±0.05mm. After molding, argon plasma treatment is performed with a treatment power of 200W and a treatment time of 30s, finally obtaining a composite sealing ring with gradient function.

[0120] Examples 6-8 Examples 6-8 provide a sealing groove, the parameters of which are shown in Table 2: Table 2

[0121] The sealing grooves provided in Examples 6-8 can be obtained by the following methods: In terms of processing methods, five-axis precision milling and picosecond laser micro-nano machining are combined. The parameters for five-axis precision milling are set as follows: diamond-coated tool, spindle speed 8000 rpm, feed rate 500 mm / min, Ra≤0.4μm. The parameters for picosecond laser micro-nano machining are set as follows: laser wavelength 1064nm, average power 20W, scanning speed 500mm / s, and performed in a nitrogen-protected environment, ultimately obtaining a sealing groove.

[0122] Examples 9-23 Examples 9-23 provide a sealing structure assembled from the sealing rings of Examples 1-5 and the sealing grooves of Examples 6-8, as shown in Table 3: Table 3

[0123] Example 24 Example 24 provides a sealing structure, wherein the sealing ring is that of Example 1, the sealing groove is a conventional planar groove design, without micro-protrusion array, without progressive tilt angle, and without micron-level texture.

[0124] Comparative Example 1 Comparative Example 1 provides a sealing structure in which the sealing ring is similar to that of Example 1, except that it does not contain shape memory alloy wire mesh, and the sealing groove is that of Example 6.

[0125] Comparative Example 2 Comparative Example 2 provides a sealing structure, which is a conventional solution. This conventional sealing structure consists of a sealing ring made of a single material and a sealing groove of a conventional structure, specifically: 1. Sealing ring: Materials: Commercially available fluororubber (FKM) or liquid silicone rubber (LSR) are used for compression molding. This is a sealing material that has been widely used in the field of hydrogen fuel cells for a long time.

[0126] Structure: It is a homogeneous single-layer structure without functional gradient design and without any internal reinforcing fibers or shape memory alloy mesh.

[0127] Key performance characteristics: Its compressive settling rate (tested according to ISO 815 standard) is typically greater than 30%, and its surface energy is approximately 28-35 mN / m.

[0128] 2. Sealing groove: Structure: It is manufactured by conventional milling on a bipolar plate.

[0129] The bottom of the groove is a smooth flat surface with no micro-protrusions in the array design.

[0130] Sidewalls: These are vertical sidewalls (i.e., with an inclination angle of 0°) or simple inclined planes without a specific angle, and do not have a gradual change from the opening to the bottom of the groove.

[0131] Surface: The inner surface of the tank is a raw machined surface (roughness Ra is about 0.8-1.6μm) without any micron-level texturing treatment.

[0132] Groove: No dedicated disassembly guide steps.

[0133] 3. The preparation method of this traditional sealing structure is as follows: 1) Sealing ring preparation: A single-material compression molding process is used. Fluororubber or silicone rubber compound is placed in a mold and vulcanized under specific temperature (e.g., 170-180℃) and pressure (e.g., 10-15MPa). After demolding and trimming, the finished sealing ring is obtained. This process cannot achieve multi-layer composite structures, and dimensional tolerances are typically controlled within ±0.1mm.

[0134] 2) Sealing groove preparation: The sealing groove is prepared using a conventional three-axis CNC milling machine. The bipolar plate graphite or metal blank is milled using a standard milling cutter to directly form the macroscopic contour of the sealing groove, without including subsequent micro-nano processing steps.

[0135] Performance testing The sealing structures assembled in Examples 9-24 and Comparative Examples 1-2 were applied to hydrogen fuel cells, and performance tests were performed on the sealing structures assembled in Examples 9-24 and Comparative Examples 1-2, respectively. The performance test methods and steps are as follows: Disassembly force (1000h) test: The sealed structure was assembled in a test device simulating fuel cell operating conditions and operated continuously for 1000 hours in an environment of 85℃ and 95% relative humidity. Then, it was disassembled using a universal testing machine at a speed of 5mm / min, and the maximum disassembly force value was recorded.

[0136] Bipolar plate reuse rate: After disassembly, the geometric changes of the sealing groove are detected by a three-dimensional profilometer, and the percentage of bipolar plates that have not undergone plastic deformation (deformation amount ≤10μm) is calculated out of the total number of tests.

[0137] Sealing ring life: The time required for the sealing ring to reach a compression permanent deformation rate of 30% is tested through accelerated aging tests at 120℃. The life under actual operating temperature is calculated based on the Arrhenius formula.

[0138] Single maintenance time: The time required from the start of the disassembly operation to the complete separation of the sealed structure, including the shape memory alloy activation time (30s) and mechanical separation time.

[0139] Interfacial shear strength: The interfacial shear strength between the sealing ring and the bipolar plate was tested using a shear testing machine at a speed of 1 mm / min, and the average value of 5 tests was taken.

[0140] The specific test results are shown in Table 4: Table 4

[0141] As shown in Table 4, the optimal parameter combination (as in Examples 15 and 16) uses high-performance sealing rings (Examples 2 or 3) and sealing grooves (Example 7), exhibiting the lowest disassembly force (50-51N), the highest bipolar plate reusability (97%), the longest sealing ring life (8500-8600h), the shortest maintenance time (30-31min), and the lowest interfacial shear strength (0.18MPa).

[0142] Suboptimal parameter combinations (such as Examples 9, 10, 11, 19, 20, and 21): These use superior sealing rings but have slightly inferior sealing grooves (Examples 6 or 8), resulting in performance that is slightly lower than the optimal combination, but still excellent.

[0143] Non-optimal parameter combinations (Examples 12, 13, 17, 18, 22, 23): Due to deviations in sealing ring parameters (such as in Examples 4 and 5), the performance is significantly reduced, but still better than the comparative examples.

[0144] Traditional sealing groove combination (Example 24): Although a superior sealing ring is used, the sealing groove is a traditional design and its performance is poor, only slightly better than Comparative Example 1.

[0145] Comparative Example 1: Without shape memory alloy wire mesh, the disassembly force is higher (145N), the lifespan is shorter (4200h), and the maintenance time is longer (85min).

[0146] Comparative Example 2: Its single-material sealing ring is prone to severe aging and creep under long-term harsh working conditions. Furthermore, its smooth, vertical sealing groove structure forms a large area of ​​tight contact with the sealing ring, leading to a sharp increase in interfacial adhesion. Disassembly can only be performed by mechanical prying, which easily causes tearing of the sealing ring and plastic damage to the bipolar plate sealing groove. Therefore, its performance is the worst, with a disassembly force as high as 198N, a lifespan of only 3000 hours, and a maintenance time of 240 minutes.

[0147] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0148] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0149] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A seal ring, characterized by, The application relates to a sealing ring, which comprises: an outer layer; an intermediate layer arranged on at least one side of the outer layer; an inner layer arranged on a side of the intermediate layer away from the outer layer; and a shape memory alloy wire mesh embedded between the intermediate layer and the inner layer, and the shape memory alloy wire mesh can be activated and undergoes phase change under external stimulation. The shape memory alloy wire mesh is embedded at a position 0.04-0.06 mm away from the bottom surface of the intermediate layer; and / or The shape memory alloy wire mesh comprises a grid woven by nickel-titanium alloy wires; and / or The wire diameter of the shape memory alloy wire mesh is 0.09-0.11 mm; and / or The grid shape of the shape memory alloy wire mesh comprises a rhombus.

2. The seal ring of claim 1, wherein The thickness of the outer layer is smaller than the thickness of the inner layer; and / or The thickness ratio of the outer layer, the intermediate layer and the inner layer is (0.5-1.5):(0.8-1.2):(2.5-3.5), preferably (0.8-1.2):(0.9-1.1):(2.8-3.2); and / or The surface energy of the outer layer is smaller than or equal to 18 mN / m, and the contact angle is greater than or equal to 130 degrees; and / or The outer layer comprises a composite material of polytetrafluoroethylene and fluorinated nanoparticles; and / or 3. The seal ring of claim 1 or 2, wherein The thermal conductivity of the intermediate layer is 1.2-1.5 W / m*K; and / or The intermediate layer comprises a composite material of graphene and silicone rubber; and / or The elastic recovery force of the inner layer under a 70% compression rate is greater than 90%; and / or The inner layer comprises a composite material of carbon fibers and hydrogenated nitrile rubber. The application further relates to a preparation method of the sealing ring. The application further relates to a sealing groove. The application further relates to a smart disassembly system. The application further relates to a control unit, a trigger device and a separation device.

4. A method of producing the seal ring as claimed in claim 2, characterized in that The control unit adopts a PID control algorithm; and / or ​ ​ 5. The production method according to claim 4, wherein ​ 6. A seal structure, characterized by, ​ ​ ​ 7. The seal structure of claim 6, wherein ​ ​ ​ ​ 8. The seal structure of claim 6, wherein ​ ​ 9. An intelligent disassembly system for disassembling a sealed structure according to any one of claims 6-8, characterized in that, ​ ​ ​ ​ 10. The intelligent disassembly system of claim 9, wherein, ​ The separation device comprises a clamping jaw assembly for clamping, a driving part for driving the movement of the clamping jaw assembly, and a guide part for cooperating with the guide steps of the sealing groove; and / or, The separation device further comprises a heating assembly integrated on the clamping jaw assembly; and / or, The guide part is a wedge-shaped structure; and / or, The separation device further comprises a force feedback system; and / or, The force feedback system comprises a pressure sensor, and when the real-time detected disassembly force exceeds 60 N, the control unit triggers an alarm.

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