Nanometer multilayer structure enhanced metal valve sealing ring and preparation method

Abstract

The invention discloses a nanometer multilayer structure enhanced metal valve sealing ring and a preparation method, the nanometer multilayer structure enhanced metal valve sealing ring comprises nanometer multilayer layers and a functional layer, a base body ring is provided with an attaching layer, and at least two nanometer multilayer layers are arranged between the attaching layer and the functional layer. The nano multilayer comprises soft metal sub-layers and two-dimensional material sub-layers, the soft metal sub-layers and the two-dimensional material sub-layers are alternately overlapped, the soft metal sub-layers are in contact with the fitting layer, and the two-dimensional material sub-layers are in contact with the functional layer. A nano-multilayer structure is arranged between a bonding layer and a functional layer, and the nano-multilayer structure forces cracks in expansion to deflect, branch or be stopped when penetrating through each layer of interface through an interface stress field and a crack deflection effect, so that a large amount of energy is consumed. Therefore, the hardness and the toughness of the plating layer are synchronously improved while good sealing performance of soft metal is maintained, and the wear resistance and the damage resistance are remarkably enhanced. The nano multilayer layered structure can effectively scatter and absorb internal stress generated by thermal mismatch, and macroscopic spalling caused by stress concentration is prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sealing rings, in particular to a nano-multilayer structure reinforced metal valve sealing ring and a preparation method. BACKGROUND

[0002] The soft metal plating layer (such as silver) of the metal valve sealing ring has the inherent disadvantages of poor wear resistance, easy scratching, and easy penetration in corrosive media while providing excellent sealing performance. The traditional single material plating layer structure often cannot balance the "softness" required for sealing performance and the "hardness" required for durability. The existing technology usually adds hard particles to the soft metal plating layer to form a composite material, but this often leads to a decrease in the toughness of the plating layer and easy cracking under stress. Another way is to increase the thickness of the plating layer to compensate for wear, but this will increase the risk of peeling and the effect of preventing medium penetration is limited. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provide a nano-multilayer structure reinforced metal valve sealing ring and a preparation method.

[0004] The purpose of the present application is achieved by the following technical solutions: A nano-multilayer structure reinforced metal valve sealing ring, comprising a base ring, a bonding layer, a nano-multilayer, and a functional layer, the base ring is provided with the bonding layer, and at least two layers of the nano-multilayer are provided between the bonding layer and the functional layer.

[0005] Further, the nano-multilayer comprises a soft metal sublayer and a two-dimensional material sublayer, the soft metal sublayer and the two-dimensional material sublayer are alternately and superimposed, the soft metal sublayer is in contact with the bonding layer, and the two-dimensional material sublayer is in contact with the functional layer.

[0006] Further, the thickness of the bonding layer is 1-5 microns, the single layer thickness of the soft metal sublayer is 50-200 nanometers, the single layer thickness of the two-dimensional material sublayer is 5-20 nanometers, and the thickness of the functional layer is 5-50 microns.

[0007] Further, the material of the base ring is stainless steel or nickel-based alloy, the material of the bonding layer is copper, molybdenum, or tantalum, the material of the soft metal sublayer is gold, silver, or copper, the material of the two-dimensional material sublayer is boron nitride or graphene oxide, and the material of the functional layer is gold, silver, or copper.

[0008] A preparation method of a metal valve sealing ring, the nano-multilayer structure reinforced metal valve sealing ring is manufactured, and the preparation method comprises the following steps: S1: manufacturing the base ring by precision machining, and pretreating the surface of the base ring; S2: placing the activated substrate ring in a PVD device, and performing vacuumizing operation on the PVD device; S3: depositing the adhesion layer on the substrate ring by physical vapor deposition; S4: depositing a soft metal sub-layer on the adhesion layer by physical vapor deposition, and depositing a two-dimensional material sub-layer on the soft metal sub-layer, and alternately stacking the soft metal sub-layer and the two-dimensional material sub-layer at least twice; S5: taking out the substrate ring from the PVD device after the substrate ring is cooled in the PVD device; S6: placing the substrate ring in an electroplating tank, and depositing the functional layer on the two-dimensional material sub-layer by the electroplating tank; S7: taking out the substrate ring from the electroplating tank, and then obtaining a metal valve sealing ring by sequentially performing cleaning, drying and heat treatment.

[0009] Further, the substrate ring manufacturing includes the following steps: S11: manufacturing a sealing blank ring by using stainless steel or nickel-based alloy material; S12: forming a rough blank ring by removing most of the machining allowance after rough machining of the sealing blank ring; S13: annealing the rough blank ring to eliminate stress generated in the rough machining process; S14: performing semi-finishing on the rough blank ring after stress removal to obtain a semi-finished blank ring; S15: performing finishing on the semi-finished blank ring by using diamond or cubic boron nitride tool to obtain a finished blank ring with a surface roughness Ra≤0.8μm; S16: performing precise chamfering or passivation on the finished blank ring to obtain the substrate ring.

[0010] Further, the surface pretreatment of the substrate ring includes the following steps: S17: cleaning for 10-15 minutes at 40-50℃ by using high-purity acetone or isopropyl alcohol as solvent; S18: soaking in alkaline degreasing liquid for 10-15 minutes at a soaking temperature of 60-70℃; S19: first, cleaning in a deionized water tank at room temperature by vigorous shaking for 1-2 minutes, then ultrasonic cleaning in a deionized water tank at a temperature of 40-50℃ for 3-5 minutes, and finally rinsing in a deionized water tank at a temperature of 70-80℃ for 1-2 minutes; S110: baking the cleaned substrate ring in an oven at a temperature not higher than 80℃ for 10-15 minutes; S111: configuring an activation liquid; S112: Soak the dried substrate ring in the activation solution for 30 seconds to 2 minutes for activation; S113: Take out the activated substrate ring and then quickly rinse it with flowing deionized water.

[0011] Further, the soft metal sublayer is deposited by magnetron sputtering or electron beam evaporation, and the two-dimensional material sublayer is deposited by magnetron sputtering. When the target material of the two-dimensional material sublayer is boron nitride, boron nitride is deposited by introducing nitrogen gas. When the target material of the two-dimensional material sublayer is graphene oxide, graphene oxide is deposited by introducing a mixture of oxygen and argon.

[0012] Further, the substrate ring is subjected to pulse electrochemical plating or direct current plating in the electroplating tank.

[0013] Further, the heat treatment includes the following steps: S71: Place the metal valve sealing ring in a vacuum furnace and heat it for 2-4 hours, with the temperature in the vacuum furnace controlled at 190-230°C. S72: Heat the metal valve sealing ring in the vacuum furnace to 250-400°C and keep it for 1-3 hours. S73: Finally, keep it at 150-300°C for 1-2 hours.

[0014] The beneficial effects of the present application are: 1) In the present technology, nanometer multilayers are arranged between the adhesion layer and the functional layer. The nanometer multilayer structure forces the expanding crack to deflect, branch or be stopped when passing through each layer interface through the interface stress field and crack deflection effect, consuming a large amount of energy. This makes the plating layer maintain good sealing of the soft metal while the hardness and toughness are simultaneously improved, and the wear resistance and damage resistance are significantly enhanced. The layered structure of the nanometer multilayer can effectively scatter and absorb the internal stress generated by thermal mismatch, prevent macroscopic peeling caused by stress concentration, and greatly improve the stability of the plating layer under thermal cycle working conditions.

[0015] 2) In the present technology, by adjusting the material combination, thickness ratio and cycle number of the soft metal sublayer and the two-dimensional material sublayer, the mechanical properties and protective properties of the final plating layer can be accurately controlled to meet the specific needs of different harsh working conditions.

[0016] 3) In the present technology, the soft metal sublayer and the two-dimensional material sublayer are both provided with multiple layers, so that the nanometer multilayer forms a tortuous structure, which can greatly prolong the diffusion path of the corrosion medium (such as O2, Cl⁻) towards the substrate ring, providing an ultra-strong physical barrier effect that single plating layer cannot match, and realizing long-term protection of the substrate ring. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1It is a sectional view of the metal valve sealing ring; Fig. 2 It is an alternative superposition structure diagram of nanometer multilayer; Fig. 3 It is a manufacturing flow chart of the metal valve sealing ring; In the figure, 1 is the base ring, 2 is the bonding layer, 3 is the nanometer multilayer, 4 is the functional layer, 5 is the soft metal sublayer, and 6 is the two-dimensional material sublayer. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be described in detail below with reference to the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0019] Referring to Figs. 1-3 The present application provides a technical solution: A nanometer multilayer structure reinforced metal valve sealing ring, comprising a base ring 1, a bonding layer 2, a nanometer multilayer 3 and a functional layer 4, the base ring 1 is provided with the bonding layer 2, and at least two nanometer multilayers 3 are arranged between the bonding layer 2 and the functional layer 4. The nanometer multilayer 3 comprises a soft metal sublayer 5 and a two-dimensional material sublayer 6, the soft metal sublayer 5 and the two-dimensional material sublayer 6 are arranged alternately and superimposed, the soft metal sublayer 5 is in contact with the bonding layer 2, and the two-dimensional material sublayer 6 is in contact with the functional layer 4. The thickness of the bonding layer 2 is 1-5 μm, the single-layer thickness of the soft metal sublayer 5 is 50-200 nanometers, the single-layer thickness of the two-dimensional material sublayer 6 is 5-20 nanometers, and the thickness of the functional layer 4 is 5-50 μm. The material of the base ring 1 is stainless steel or nickel-based alloy, the material of the bonding layer 2 is copper, molybdenum or tantalum, the material of the soft metal sublayer 5 is gold, silver or copper, the material of the two-dimensional material sublayer 6 is boron nitride or graphene oxide, and the material of the functional layer 4 is gold, silver or copper. The stainless steel includes 304 and 316, and the nickel-based alloy includes 690, 718 and 625.

[0020] A preparation method of a metal valve sealing ring, a nanometer multilayer 3 structure reinforced metal valve sealing ring is manufactured, and the preparation method comprises the following steps: (1) The base ring 1 is manufactured by precision machining, and the surface of the base ring 1 is pretreated; the manufacturing of the base ring 1 comprises the following steps: a sealing blank ring is manufactured by using stainless steel or nickel-based alloy material; after the sealing blank ring is roughly machined to remove most of the machining allowance, a rough blank ring is formed; the rough blank ring is annealed to eliminate the stress generated in the rough machining process; the rough blank ring after stress removal is semi-finished machining to obtain a semi-precision blank ring; the semi-precision blank ring is precisely machined by using diamond or cubic boron nitride tool to obtain a precision blank ring with a surface roughness Ra≤0.8μm; the precision blank ring is precisely chamfered or passivated to obtain the base ring 1. The purpose of precision machining of the base ring 1 is to obtain accurate geometric shape, size tolerance and specific surface initial state. The specific steps are as follows: a numerical control lathe or milling machine is used, a higher feed rate and cutting depth are adopted, most of the machining allowance on the sealing blank ring is quickly removed, and a rough blank ring is initially formed; the rough blank ring after rough machining is annealed (such as annealing in a protective atmosphere at a proper temperature) to eliminate internal residual stress and prevent subsequent machining deformation and size instability in use; then secondary machining is performed to further approach the final size and leave a precision machining allowance; then diamond or cubic boron nitride tool is used, and the strategy of "high speed, small cutting depth and slow feed" is adopted to finally turn or grind the sealing working surface of the semi-precision blank ring, so as to ensure that the size accuracy reaches IT7 level or above, and the surface roughness Ra≤0.8μm, which provides guarantee for the uniformity of the subsequent plating layer; finally, all sharp edges are precisely chamfered or passivated (about 0.1mm round corner is formed) to prevent the plating layer from cracking or falling off due to stress concentration at the edge. The surface pretreatment of the base ring 1 comprises the following steps: high-purity acetone or isopropyl alcohol is used as a solvent, and the base ring 1 is cleaned at 40-50°C for 10-15 minutes; the base ring 1 is soaked in alkaline degreasing liquid for 10-15 minutes, and the soaking temperature is 60-70°C; first, the base ring 1 is cleaned in a deionized water tank at room temperature for 1-2 minutes by shaking vigorously, then the base ring 1 is cleaned in a deionized water tank at a temperature of 40-50°C for 3-5 minutes by using ultrasonic cleaning, and finally the base ring 1 is rinsed in a deionized water tank at a temperature of 70-80°C for 1-2 minutes; the cleaned base ring 1 is placed in an oven with a temperature not higher than 80°C for 10-15 minutes; an activation liquid is prepared; the dried base ring 1 is soaked in the activation liquid for 30 seconds to 2 minutes for activation; the activated base ring 1 is taken out and then quickly rinsed in flowing deionized water. The surface pretreatment of the base ring 1 comprises cleaning and activation. The purpose of cleaning is to thoroughly remove contaminants such as oil stains, particulate matter and fingerprints on the surface of the base ring 1. First, the base ring 1 is immersed in an ultrasonic cleaner, high-purity acetone or isopropyl alcohol is used as a solvent, and the base ring 1 is ultrasonically cleaned at 40-50°C for 10-15 minutes. After the base ring 1 is taken out, it is blown dry with clean compressed air or nitrogen; then the base ring 1 is immersed in heated alkaline degreasing liquid.The alkaline oil removal liquid formula is: sodium hydroxide 20~40g / L, sodium carbonate 20~30g / L, trisodium phosphate 10~20g / L, sodium silicate 3~8g / L (as corrosion inhibitor), surfactant 1~3mL / L, at a temperature of 60~70°C, soaking for 10~15 minutes, and assisted by mechanical or air stirring. This is followed by three-stage countercurrent rinsing: the first stage (rough washing): in a flowing room temperature deionized water tank, shake vigorously for 1~2 minutes to remove most of the residual alkaline solution; the second stage (fine washing): in a warm deionized water tank at 40~50°C, start the ultrasonic wave again, and process for 3~5 minutes to completely remove particles and impurities embedded in the surface microstructure; the third stage (final washing): in a hot deionized water tank at 70~80°C, rinse for 1~2 minutes. Hot water has small surface tension, is easy to separate from the surface of the workpiece, and promotes rapid drying, reducing water stains. Finally, drying, immediately place the workpiece in a clean oven at ≤80°C, and dry for 10~15 minutes. The purpose of activation treatment is to completely remove the extremely thin natural oxide film on the surface of the substrate, exposing the fresh metal surface with high chemical activity, which is the key to achieving high-strength bonding between the coating and the substrate. The specific steps of activation are as follows: first, activation liquid preparation: according to the substrate material, select and prepare a special weakly corrosive activation liquid. For stainless steel, nickel-based alloy: use hydrochloric acid or sulfuric acid aqueous solution with a volume concentration of 10%~20%. For refractory metals such as tungsten and molybdenum: use a mixture of low-concentration (such as 3%~5%) hydrofluoric acid and nitric acid. Then, at room temperature, completely immerse the cleaned and dried workpiece in the activation liquid. The soaking time is strictly controlled to be 30 seconds to 2 minutes. At this time, fine bubbles should be observed uniformly on the surface of the workpiece. If the time is insufficient, the oxide film will not be completely removed; if the time is too long, the substrate will be over-etched, the surface will become rough, and the adhesion will be damaged. Finally, terminate the reaction and perform the final cleaning: immediately remove the workpiece after the predetermined time. Quickly immerse it in a large amount of flowing deionized water for rapid rinsing to completely terminate the chemical reaction and remove all residual acid. Immediately transfer: the activated workpiece should be kept wet. It must be transferred to the next process (such as a PVD vacuum chamber or an electroplating tank) within 1 hour to minimize the waiting time and prevent the surface from being oxidized again.

[0021] (2) Place the activated substrate ring 1 in the PVD device, and then perform vacuum pumping on the PVD device; the PVD device is a prior art device, and the PVD device is pumped to ≤5.0×10⁻³Pa. Before placing the substrate ring 1 into the PVD device, the target material of the adhesion layer 2 and the nanometer multilayer 3 is placed into the PVD device. After the vacuum pumping is completed, the target material of the adhesion layer 2 is first processed and deposited.

[0022] (3) The adhering layer 2 is deposited on the base ring 1 by physical vapor deposition. The compact metal layer formed on the working surface of the base ring 1 by the physical vapor deposition in the prior art is the adhering layer 2, and the thickness of the adhering layer 2 is 1-5 μm.

[0023] (4) The soft metal sublayer 5 is deposited on the adhesion layer 2 by physical vapor deposition, and the two-dimensional material sublayer 6 is deposited on the soft metal sublayer 5, at least two times of alternately stacking the soft metal sublayer 5 and the two-dimensional material sublayer 6; the soft metal sublayer 5 is deposited by magnetron sputtering or electron beam evaporation, and the two-dimensional material sublayer 6 is deposited by magnetron sputtering; when the target material of the two-dimensional material sublayer 6 is boron nitride, the boron nitride is deposited by introducing nitrogen gas; when the target material of the two-dimensional material sublayer 6 is graphene oxide, the graphene oxide is deposited by introducing a mixture of oxygen and argon gas. Above the adhesion layer 2, the biomimetic concept of "brick and mortar structure" is used for precise arrangement: the soft metal sublayer 5 (silver, copper or gold) plays the role of "mortar", which is a continuous and dense matrix with good toughness; the two-dimensional material sublayer 6 (boron nitride or graphene oxide) plays the role of "brick". It is a piece of nanosheet parallel to the surface of the matrix ring 1 and nearly perfectly spread. The arrangement order starts from the adhesion layer 2, and the arrangement order is: adhesion layer 2-first soft metal sublayer 5-first two-dimensional material sublayer 6-second soft metal sublayer 5-second two-dimensional material sublayer 6-…-Nth two-dimensional material sublayer 6-functional layer 4. The step details are as follows: after the adhesion layer 2 is deposited, the vacuum state is maintained, the first step is to deposit the soft metal sublayer 5, only the power supply of the silver, copper or gold target is turned on for sputtering or evaporation, the thickness is monitored by a film thickness instrument, and when the thickness reaches 50-200 nanometers, the target power supply is automatically turned off; the second step is to introduce the corresponding reaction gas (nitrogen gas for depositing boron nitride BN, and a mixture of oxygen and argon gas for depositing graphene oxide GO), and the power supply of the boron nitride target or high-purity graphene oxide target is turned on for reactive sputtering, the sputtering power and time are controlled, and when the thickness monitored by the film thickness instrument reaches 5-20 nanometers, the target and reaction gas are automatically turned off; then the cycle is judged and repeated, the first step and the second step above constitute a complete deposition cycle, and the cycle is repeated until at least five groups (i.e. at least five layers of soft metal sublayer 5 and five layers of two-dimensional material sublayer 6) of alternating deposition are completed. The core of the nanometer multilayer 3 is to use the high automation of the PVD equipment to control the opening and closing of different targets and the on-off of process gas through time sequence, and to accurately build the designed composite structure layer by layer in nanometer scale.Sputter deposition: a negative high voltage (DC or RF) is applied to the target, argon is ionized into Ar+, which is accelerated to bombard the target under the action of the electric field, and the target atoms / molecules are ejected with high kinetic energy and deposited on the workpiece surface to form a film. The target thickness and film quality are obtained by precisely controlling the sputtering power, gas pressure and deposition time. After deposition, the power and gas are turned off, and after the chamber cools down, high-purity nitrogen gas is filled into the chamber to atmospheric pressure, and the workpiece is taken out. Electron beam evaporation process steps: the principle of evaporation is to use high-energy electron beam to bombard the source material, so that it is locally heated to evaporation temperature, and then deposited on the workpiece in vapor form. Put high-purity block or granular source material (such as gold, silver) into a water-cooled copper crucible, and clamp the workpiece on the support above the crucible. Similarly, it needs to be pumped to high vacuum (≤5.0×10⁻³Pa), and the environmental requirements are more stringent than sputtering. First, use a low-power electron beam to scan the source material to slightly melt it, expel internal adsorbed gas and low-melting-point impurities, and improve the purity of the film. Electron beam evaporation deposition, increase the electron beam power to the set value, focus on the center of the source material, and make it evaporate quickly. The material vapor flies in a straight line from the source to all directions, and condenses into a film when it encounters a lower temperature work. A baffle is usually provided between the evaporation source and the workpiece to accurately control the start and end of deposition. The evaporation rate and film thickness are controlled by controlling the electron beam current, acceleration voltage and deposition time. After cooling, inert gas is filled and the workpiece is taken out.

[0024] (5) After the substrate ring 1 cools in the PVD device, the substrate ring 1 is taken out of the PVD device; all the target sources are closed, the PVD device is closed and argon is introduced. When the substrate ring 1 carrying the nanometer multilayer 3 is cooled in the PVD device, the hatch of the PVD device is opened and the substrate ring 1 is taken out.

[0025] (6) placing the base ring 1 in the electroplating tank, and depositing the functional layer 4 on the two-dimensional material sublayer 6 through the electroplating tank; the base ring 1 is subjected to pulse electrochemical plating or direct current plating in the electroplating tank. I. Direct current plating step: direct current plating is the most basic electroplating method, and its process is stable and continuous. Direct current plating process: the cleaned and activated workpiece (cathode) and a suitable anode (such as a soluble silver anode or an insoluble platinum-titanium anode) are installed on the electroplating hanger to ensure good conduction; the workpiece is immersed in the plating solution, and no electricity is passed, and the workpiece is left to stand for 30-60 seconds to make the temperature of the workpiece consistent with that of the plating solution and to remove surface bubbles; the direct current power supply is turned on, and the current is smoothly increased to the preset constant current density value (such as 1.0 A / dm2) within 5-15 seconds through a "step-by-step" or "soft start" method; the current density is kept constant throughout the electroplating process, and the target thickness is obtained by controlling the total power-on time; after the time is reached, the workpiece is taken out of the liquid surface, drained for a few moments above the plating tank, immediately subjected to three-stage counter-flow rinsing (cold and hot deionized water), and then dried. II. Pulse electrochemical plating step: pulse plating intervenes in the deposition process by precisely controlling the on-off of the current, and the core difference between its process and that of direct current plating lies in the precise control of the current. Step process: the cleaned and activated workpiece (cathode) and a suitable anode (such as a soluble silver anode or an insoluble platinum-titanium anode) are installed on the electroplating hanger to ensure good conduction; the workpiece is immersed in the plating solution, and no electricity is passed, and the workpiece is left to stand for 30-60 seconds to make the temperature of the workpiece consistent with that of the plating solution and to remove surface bubbles; three key parameters are set on the pulse power supply: peak current density: Jp, the value is usually 2-5 times (for example, 3.0 A / dm2) of the direct current density, pulse on time: Ton, usually 0.1-10 ms, pulse off time: Toff, usually 1-50 ms, the pulse power supply is turned on, and the current is output in the form of square wave pulse; pulse deposition process: during Ton: high-density Jp is applied to the workpiece instantaneously, generating extremely high cathode polarization, forming a large number of crystal nuclei, and depositing rapidly; during Toff: the current is zero. At this time, the metal ions depleted at the cathode / solution interface during Ton are supplemented by diffusion, the adsorbed hydrogen bubbles are desorbed, and the adsorbed impurities may be desorbed, preparing for the next pulse cycle. After the time is reached, the workpiece is taken out of the liquid surface, drained for a few moments above the plating tank, immediately subjected to three-stage counter-flow rinsing (cold and hot deionized water), and then dried.

[0026] (7) The base ring 1 is taken out from the electroplating tank, and then the metal valve sealing ring is obtained after cleaning, drying and heat treatment in sequence. The heat treatment comprises the following steps: the metal valve sealing ring is placed in a vacuum furnace for heat preservation for 2-4 hours, and the temperature in the vacuum furnace is controlled at 190-230 DEG C; the metal valve sealing ring is heated to 250-400 DEG C in the vacuum furnace and heat preserved for 1-3 hours; and finally heat preserved for 1-2 hours at 150-300 DEG C. The specific steps of the post-treatment of the base ring 1 are as follows: firstly, cleaning treatment, which aims to completely remove the residual electroplating solution or chemical plating solution on the surface of the workpiece, so as to prevent the residual from corroding the plating layer or polluting the use environment. The specific steps (multi-stage cooperative cleaning) are as follows: recovery rinsing, the workpiece after electroplating is first immersed in a static deionized water tank, and the concentration difference between the high-concentration plating solution carried on the surface of the workpiece and the clean water is utilized to perform preliminary dilution, the water in the tank can be periodically supplemented into the plating tank to recover metal salt. Three-stage countercurrent rinsing: first stage (rough cleaning): the workpiece is cleaned in a flowing room temperature deionized water tank for 1-2 minutes, so as to remove most of the residual solution, second stage (fine cleaning): the workpiece is cleaned in a flowing 40-50 DEG C warm deionized water tank for 2-3 minutes, the warm water can more effectively dissolve and remove the viscous additive, third stage (final cleaning / hot water scalding): the workpiece is immersed in a 70-80 DEG C hot deionized water tank for 1-2 minutes, this step utilizes the small surface tension of hot water, so that the water can quickly and uniformly separate from the surface of the workpiece, and also plays a certain "heat sealing" role, and greatly reduces the water stains after drying. Ultrasonic assisted cleaning (for high requirement products): the ultrasonic wave can be started in the second stage of rinsing, and the impurities in the gap or micro hole are "shaken" out by utilizing the cavitation effect. Secondly, drying treatment, which aims to quickly and completely remove the water on the surface of the workpiece, so as to prevent water stains and spots, and avoid corrosion in subsequent storage or heat treatment. The specific steps are as follows: air blowing to remove water: the workpiece after cleaning is taken out, and immediately cleaned by using filtered, oil-free and dry compressed air or nitrogen from all angles, especially the gap and blind hole, so as to remove most of the visible water. Hot air drying: the workpiece is placed in a clean air oven at 80-110 DEG C, and the drying time is generally 15-30 minutes, so as to ensure that the water in the deep layer and gap is completely evaporated. Vacuum drying (for extreme requirements, such as semiconductor and ultra-high vacuum application): the workpiece is placed in a vacuum oven, vacuumized to ≤1.0*10⁻² Pa, and heat preserved at 80-150 DEG C for 1-2 hours, this method can completely remove the water vapor and gas adsorbed on the surface of the workpiece and even in the material, so as to realize ultimate cleanliness and drying. Thirdly, necessary heat treatment, which aims to eliminate the internal stress of the plating layer, enhance the bonding force between the plating layer and the base (through diffusion), improve the stability of the plating layer, and completely eliminate the risk of "hydrogen embrittlement". The specific steps are as follows: hydrogen removal treatment (most commonly used and most critical): the purpose is to eliminate the "hydrogen embrittlement" caused by the hydrogen atoms generated in the cathode reaction during electroplating and penetrated into the base metal lattice, which is very important for high-strength steel and nickel-based alloy.The workpiece is placed in an oven and heated at a temperature of 190-230°C for 2-4 hours. The temperature and time should be accurately selected according to the strength and hardness of the substrate material. It is preferable to use an air-circulating oven or a vacuum furnace. Low-temperature diffusion annealing: the purpose is to promote atomic interdiffusion between the coating and the substrate, forming a micro diffusion layer, thereby revolutionarily improving the adhesion. The workpiece is heated to 250-400°C (lower than the recrystallization temperature of the substrate and the coating) under the protection of inert gas (such as argon) or vacuum for 1-3 hours, and then cooled with the furnace. It is particularly suitable for coating systems with good mutual solubility between gold, silver, copper and nickel, steel substrates. Finally, the heat curing / stabilization treatment: the purpose is to crystallize the amorphous structure in the coating, or to decompose and volatilize the additives, so that the coating structure is stable and the performance (such as conductivity) reaches the best state. According to the characteristics of the coating material, it is heated at 150-300°C for 1-2 hours.

[0027] Example 1: Nickel-based alloy sealing ring for valves used in high-pressure corrosive media 1) The Inconel 625 sealing ring is finished and then loaded into a multi-target magnetron sputtering device after cleaning and activation.

[0028] 2) Deposition of the adhesion layer: sputter a pure copper target to form a copper adhesion layer about 2 μm thick.

[0029] 3) Deposition of the nanometer multi-layer intermediate layer: in the same device, first sputter a pure silver target for 90 seconds to form a silver sub-layer about 100 nm thick. Then, reactively sputter a boron target in a mixed atmosphere of argon and nitrogen to form a boron nitride sub-layer about 10 nm thick. The above two steps are one cycle, and are repeated for 20 cycles, with a total time of about 70 minutes, to form a nanometer multi-layer intermediate layer with a total thickness of about 2.2 μm.

[0030] 4) Deposition of the soft metal functional layer: pulse electroplating silver at an average current density of 1.5 A / dm² for 60 minutes to obtain a dense silver functional layer about 25 μm thick.

[0031] 5) Effect verification: the hardness of the composite coating is 3 times that of the pure silver coating, and the toughness does not deteriorate. In the salt spray test, the time to appear red rust is more than 10 times that of the traditional silver coating sample.

[0032] Example 2: Hastelloy sealing ring for pumps used in strong corrosive media This example provides a mechanical sealing ring suitable for chemical pumps conveying mixed acids such as hydrochloric acid and sulfuric acid.

[0033] 1) The Hastelloy C-276 sealing ring is finished and then loaded into a multi-target magnetron sputtering device after cleaning and activation.

[0034] 2) Deposition of adhesion layer: sputtering pure molybdenum target to form a 2-μm-thick molybdenum adhesion layer.

[0035] 3) Deposition of nanolaminate intermediate layer: in the same equipment, first sputtering pure silver target for 60 seconds to form a 80-nm-thick silver sublayer. Then, reactive sputtering high-purity graphite target in a mixed atmosphere of argon and trace oxygen to form an 8-nm-thick graphene oxide sublayer. The above two steps are one cycle, and repeated for 25 cycles, with a total time of about 60 minutes, to form a nanolaminate intermediate layer with a total thickness of about 2.2 μm.

[0036] 4) Deposition of soft metal functional layer: pulsed electroplating silver at an average current density of 1.5 A / dm² for 50 minutes to obtain a 20-μm-thick dense silver functional layer.

[0037] 5) Effect verification: after 1000 hours of immersion in 30% hydrochloric acid solution at 80°C, the weight loss is only 1 / 5 of that of the traditional thick silver plating sample, and no pitting occurs. When rubbing against a silicon carbide ring, the friction coefficient is 15% lower than that of pure silver plating, and the wear amount is reduced by 50%.

[0038] Example 3: Tungsten alloy seal ring for super-high-temperature steam valve This example provides a seal ring suitable for super-high-temperature steam valves in supercritical power generation systems.

[0039] 1) Precision machining of powder metallurgy pure tungsten seal ring, after cleaning and activation, it is loaded into a multi-target magnetron sputtering equipment.

[0040] 2) Deposition of adhesion layer: sputtering pure tantalum target to form a 3-μm-thick tantalum adhesion layer.

[0041] 3) Deposition of nanolaminate intermediate layer: in the same equipment, first sputtering pure gold target for 120 seconds to form a 150-nm-thick gold sublayer. Then, reactive sputtering boron target in a mixed atmosphere of argon and nitrogen to form a 15-nm-thick boron nitride sublayer. The above two steps are one cycle, and repeated for 15 cycles, with a total time of about 70 minutes, to form a nanolaminate intermediate layer with a total thickness of about 2.5 μm.

[0042] 4) Deposition of soft metal functional layer: pulsed electroplating gold at an average current density of 0.8 A / dm² for 90 minutes to obtain a 10-μm-thick dense gold functional layer.

[0043] 5) Effect verification: after 500 hours of exposure to an argon atmosphere at 650°C, the plating layer is intact without blistering and peeling, and no obvious element interdiffusion zone is observed at the interface by scanning electron microscopy. In a superheated steam simulation condition of 600°C and 25 MPa, the leakage rate remains below 1×10⁻ 9 mbar•L / s.

[0044] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and operation described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the claims below and their equivalents.

Claims

1. A nanolaminate reinforced metal valve seal ring, characterized by: The base ring is provided with the adhesion layer, and at least two layers of the nanometer multilayer are arranged between the adhesion layer and the functional layer.

2. A nanolaminate reinforced metal valve seal ring according to claim 1, wherein: The nanometer multilayer comprises soft metal sub-layers and two-dimensional material sub-layers, the soft metal sub-layers and the two-dimensional material sub-layers are arranged alternately and superposed, the soft metal sub-layers are in contact with the adhesion layer, and the two-dimensional material sub-layers are in contact with the functional layer.

3. A nanolaminate reinforced metal valve seal ring according to claim 2, wherein: The thickness of the adhesion layer is 1-5 microns, the single-layer thickness of the soft metal sub-layer is 50-200 nanometers, the single-layer thickness of the two-dimensional material sub-layer is 5-20 nanometers, and the thickness of the functional layer is 5-50 microns.

4. A nanomultilayer-reinforced metal valve seal ring according to claim 2 or 3, characterized in that: The material of the base ring is stainless steel or nickel-based alloy, the material of the adhesion layer is copper, molybdenum or tantalum, the material of the soft metal sub-layer is gold, silver or copper, the material of the two-dimensional material sub-layer is boron nitride or graphene oxide, and the material of the functional layer is gold, silver or copper.

5. A method of making a metal valve seal ring, producing a nanolaminate reinforced metal valve seal ring as claimed in any one of claims 1-4, characterized by, The preparation method comprises the following steps: S1: manufacturing the base ring through precision machining, and pretreating the surface of the base ring; S2: placing the activated base ring in a PVD device, and performing vacuumizing operation on the PVD device; S3: depositing the adhesion layer on the base ring through physical vapor deposition; S4: depositing the soft metal sub-layer on the adhesion layer through physical vapor deposition, depositing the two-dimensional material sub-layer on the soft metal sub-layer, and alternately and superposing the soft metal sub-layer and the two-dimensional material sub-layer at least twice; S5: taking out the base ring from the PVD device after the base ring is cooled in the PVD device; S6: placing the base ring in an electroplating tank, and depositing the functional layer on the two-dimensional material sub-layer through the electroplating tank; S7: taking out the base ring from the electroplating tank, and then obtaining the metal valve sealing ring through cleaning, drying and heat treatment in sequence.

6. A method of making a metal valve seal ring according to claim 5, wherein: The base ring manufacturing comprises the following steps: S11: manufacturing a sealing blank ring by using stainless steel or nickel-based alloy material; S12: forming a rough blank ring after removing most of the machining allowance through rough machining of the sealing blank ring; S13: annealing the rough blank ring to eliminate stress generated in the rough machining process; S14: obtaining a semi-precision blank ring by semi-finishing the rough blank ring after removing stress; S15: performing precision machining on the semi-precision blank ring by using a diamond or cubic boron nitride tool to obtain a precision blank ring with a surface roughness Ra≤0.8 microns; S16: obtaining the base ring by performing precision chamfering or passivation on the precision blank ring.

7. The method of making a metal valve seal ring of claim 5, wherein: The surface pretreatment of the base ring comprises the following steps: S17: cleaning for 10-15 minutes at 40-50 DEG C by using high-purity acetone or isopropyl alcohol as a solvent; S18: soaking in an alkaline oil removal liquid for 10-15 minutes, and the soaking temperature is 60-70 DEG C; S19: first, cleaning for 1-2 minutes in a deionized water tank by shaking vigorously at room temperature, then, ultrasonic cleaning for 3-5 minutes in a deionized water tank at a temperature of 40-50 DEG C, and finally, rinsing for 1-2 minutes in a deionized water tank at a temperature of 70-80 DEG C. S110: the cleaned substrate ring is placed in an oven with a temperature not higher than 80℃ for baking for 10-15 minutes; S111: an activation solution is prepared; S112: the dried substrate ring is soaked in the activation solution for 30 seconds to 2 minutes for activation; S113: the activated substrate ring is taken out and then quickly rinsed with flowing deionized water.

8. The method of making a metal valve seal ring of claim 5, wherein: The soft metal sublayer is deposited by magnetron sputtering or electron beam evaporation, and the two-dimensional material sublayer is deposited by magnetron sputtering. When the target material of the two-dimensional material sublayer is boron nitride, boron nitride is deposited by introducing nitrogen gas. When the target material of the two-dimensional material sublayer is graphene oxide, graphene oxide is deposited by introducing a mixture of oxygen and argon.

9. The method of making a metal valve seal ring of claim 5, wherein: The substrate ring is subjected to pulse electrochemical plating or direct current plating in the electroplating tank.

10. The method of making a metal valve seal ring of claim 5, wherein: The heat treatment includes the following steps: S71: the metal valve sealing ring is placed in a vacuum furnace for heat preservation for 2-4 hours, and the temperature in the vacuum furnace is controlled at 190-230℃; S72: the metal valve sealing ring is heated to 250-400℃ in the vacuum furnace and is kept for 1-3 hours; S73: finally, heat preservation is carried out at 150-300℃ for 1-2 hours.

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