Preparation method of high specific surface area metal-based composite getter material

Abstract

The application discloses a preparation method of a high specific surface area metal-based composite getter material, and belongs to the technical field of getter materials, and is used for solving the technical problems that the specific surface area, getter performance, activation temperature and anti-powder loss performance of the metal-based composite getter material in the prior art need to be further improved, and specifically comprises the following steps: a porous Ti-Mo bearing skeleton is prepared by compressing and forming a mixture of titanium powder, molybdenum powder, a pore forming agent and a binder skeleton mixture and vacuum sintering; zirconium-vanadium alloy powder, hydrogenated metal particles and amorphous alloy powder are prepared into composite microparticles, the composite microparticles are introduced into the pore channels of the Ti-Mo skeleton through a vacuum impregnation method, and then heat pulse treatment is performed, so that a composite material with a multi-stage pore structure and a stable bearing structure is formed, the composite material has the advantages of a high specific surface area, a low activation temperature, excellent getter performance and a reduced powder loss rate.

Description

Technical Field

[0001] This invention relates to the field of air-getting materials technology, and specifically to a method for preparing a high specific surface area metal-based composite air-getting material. Background Technology

[0002] Getter materials are a class of functional materials that can absorb residual gases such as hydrogen, oxygen, carbon monoxide, and water vapor in the environment. They are widely used in vacuum electronic devices, optoelectronic devices, microelectronic packaging, vacuum insulation devices, and high vacuum systems. Among them, non-evaporative metal getter materials have become an important type of getter material due to their characteristics such as no evaporation pollution during use, good structural stability, and reactivation.

[0003] There are already published patents proposing zirconium-based non-evaporable getters and their preparation methods. For example, Chinese patent CN111621671B involves a zirconium-based non-evaporable getter comprising the following components by mass percentage: 60%-80% zirconium, 5%-25% vanadium, 2%-15% iron, 2%-15% titanium, and 2%-10% aluminum. This getter is obtained by mixing zirconium, vanadium, iron, titanium, and aluminum evenly, heating to liquefaction and holding at that temperature for at least 30 minutes, then cooling, crushing, ball milling, and sieving to obtain a sample smaller than 200 micrometers. This getter has better antioxidant properties than traditional low-temperature activated zirconium vanadium iron getters, a higher combustion point than zirconium vanadium iron getters, and better getter performance than zirconium vanadium iron getter alloys. It is more conducive to the application of medium and high temperature vacuum devices and fills the gap in medium-temperature getters activated at 500℃-800℃.

[0004] However, the disclosed patent mainly focuses on the control of alloy composition and powder pressing molding. For conventional pressed and sintered metal getter materials, if the material pore structure is insufficient and the gas diffusion channels are limited, it is easy to result in a low effective specific surface area and insufficient exposure of active sites. In particular, it is difficult to obtain the ideal getter rate and getter volume at low activation temperatures. At the same time, when the powder particle size is reduced or the active phase loading is increased in order to improve the getter performance, it is easy to cause insufficient bonding strength between particles, resulting in powder shedding, falling off or dust contamination during transportation, assembly or use, which affects the reliability of vacuum devices. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a high specific surface area metal-based composite air-getting material, which solves the technical problem that the specific surface area, air-getting performance, activation temperature and anti-powdering and weight loss performance of metal-based composite air-getting materials in the prior art need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solution: a method for preparing a high specific surface area metal-based composite air-getting material, comprising the following steps:

[0007] S1. After mixing the metal hydride raw material with polyvinylpyrrolidone and anhydrous ethanol, the mixture is dispersed by ball milling under argon protection and then spray granulated to obtain hydride metal particles.

[0008] S2. Composite microparticles are prepared by combining hydride metal particles, zirconium vanadium alloy powder, and amorphous alloy powder.

[0009] S3. After mixing and stirring terpineol, ethyl cellulose and anhydrous ethanol for 20-30 minutes, add composite microparticles and stir and disperse for 60-80 minutes to obtain impregnation slurry;

[0010] S4. The impregnation slurry is introduced into the porous Ti-Mo support skeleton through vacuum impregnation. After centrifugation to remove excess impregnation slurry from the pores and drying, the impregnated modified support skeleton is obtained.

[0011] S5. The impregnated modified support skeleton is subjected to thermal pulse treatment under vacuum conditions to obtain a metal-based composite air-getting material blank; then the metal-based composite air-getting material blank is subjected to low-temperature activation treatment in an oxygen-containing inert atmosphere to obtain the high specific surface area metal-based composite air-getting material.

[0012] Furthermore, the fabrication of the porous Ti-Mo support framework includes the following steps:

[0013] A1. Under an inert gas atmosphere, ammonium bicarbonate, polyvinyl alcohol and deionized water are mixed and stirred until dissolved, then titanium powder and molybdenum powder are added, and the mixture is stirred and dispersed at room temperature for 2-3 hours to obtain the skeleton mixture.

[0014] A2. The skeleton mixture is loaded into a mold and pressed into a circular blank under a pressure of 350-360MPa; then vacuum sintering is performed to obtain a porous Ti-Mo support skeleton.

[0015] Further, in step A1, the ratio of ammonium bicarbonate, polyvinyl alcohol, deionized water, titanium powder, and molybdenum powder is 6-7g:1.1-1.3g:20mL:95-100g:8-9g, the particle size of the titanium powder is 20-50μm, and the particle size of the molybdenum powder is 8-12μm; in step A2, the vacuum sintering operation includes: placing the circular blank in a vacuum furnace, heating it to 120-130℃ at a vacuum degree of 1-5Pa at a rate of 2℃ / min and holding it for 60-80min, then heating it to 280-300℃ at a rate of 1℃ / min and holding it for 160-180min, then heating it to 900℃ at a rate of 10℃ / min and holding it for sintering for 20-30min, and then discharging it after natural cooling to obtain a porous Ti-Mo support skeleton.

[0016] Furthermore, the metal hydride raw materials include titanium dihydrogenide, yttrium hydride, and cerium hydride; the ratio of titanium dihydrogenide, yttrium hydride, cerium hydride, polyvinylpyrrolidone, and anhydrous ethanol is 40g:10-12g:5-7g:3-4g:500mL.

[0017] Furthermore, the ball-to-material ratio for ball milling dispersion is 15-20:1, the ball milling speed is 500 r / min, and the ball milling time is 2-3 h; the abrasive used in ball milling includes 316L stainless steel grinding balls with a diameter of 3 mm and 316L stainless steel grinding balls with a diameter of 5 mm, and the weight ratio of the two is 1:3-4; after ball milling, hydride metal particles with a particle size of 5-12 μm are obtained by spray granulation.

[0018] Furthermore, the method for preparing the composite microparticles is as follows: under the protection of an inert gas atmosphere, hydride metal particles, zirconium vanadium alloy powder and amorphous alloy powder are added to a mechanical fusion machine, the reaction system is heated to 430-450℃, stirred and dispersed for 80-100 min and then cooled naturally, and composite microparticles with a particle size of 1-5 μm are obtained by sieving.

[0019] Furthermore, the weight ratio of the hydrogenated metal particles, zirconium-vanadium alloy powder, and amorphous alloy powder is 5-6:35-38:2-3.

[0020] Furthermore, the ratio of terpineol, ethyl cellulose, anhydrous ethanol and composite microparticles is 13-15g:1-2g:50-60mL:18-22g.

[0021] Furthermore, the vacuum degree during vacuum impregnation is 30-100 Pa, and the pressure holding time is 3-5 min; the solid-liquid ratio of the porous Ti-Mo support skeleton to the impregnation slurry is 1:10-15; after impregnation, it is centrifuged at 800-1000 r / min for 30-50 s, and dried at 60-70℃ for 30-50 min under inert atmosphere protection; the vacuum impregnation, centrifugation and drying operations are repeated twice.

[0022] Furthermore, the thermal pulse treatment operation is as follows: the impregnated modified support skeleton is placed in a vacuum sintering furnace with pulse current assisted heat treatment, the vacuum is evacuated to 1-5 Pa, the temperature is increased to 150-160℃ at 2℃ / min and held for 60-80 min, the temperature is increased to 280-300℃ at 1℃ / min and held for 100-120 min, and then the temperature is increased to 420-450℃ at 10-15℃ / min and held for 10-20 min; pulse current is applied in multiple holding stages, the on / off ratio of the pulse current is 12:2, and the current density is 30-50 A / cm².

[0023] Furthermore, the low-temperature activation treatment is carried out in an argon-oxygen mixture with an oxygen volume fraction of 0.2-0.5%, at an activation temperature of 80-90°C, and for an activation time of 20-30 minutes.

[0024] The present invention has the following beneficial effects:

[0025] 1. This invention uses ammonium bicarbonate and polyvinyl alcohol as pore-forming agents. During vacuum sintering, the pore-forming agents decompose upon heating, releasing gases and leaving interconnected channels in the Ti-Mo metal powder sintered body. In the subsequent heat treatment of composite microparticles, hydride metal particles such as titanium dihydrogenide, yttrium hydride, and cerium hydride undergo partial dehydrogenation or structural rearrangement, forming fine pores, microcracks, and rough interfaces inside the microparticles. This results in a multi-level porous structure where macroscopic channels of the Ti-Mo framework, interparticle gaps of composite microparticles, and hydride dehydrogenation-induced micropores coexist. This increases the specific surface area of ​​the material and allows hydrogen to enter the material more smoothly and contact more gas-absorbing active sites, providing a structural basis for subsequent high specific gas absorption rates and specific gas absorption volumes.

[0026] 2. This invention uses zirconium-vanadium alloy powder as the main gas-absorbing active phase. During vacuum activation, the surface passivation layer gradually thins, oxygen migrates inward, and the metal active sites are gradually exposed. At the same time, the defects, cavities, and cracks generated by the hydride metal particles during heat treatment and activation provide more pathways for hydrogen diffusion, making it easier for hydrogen to reach the interior of the zirconium-vanadium active phase. Moreover, the zirconium-vanadium gas-absorbing active phase is distributed adjacent to the microporous structure induced by hydrides and is embedded in the Ti-Mo framework channels, reducing the activation temperature of the material, thereby obtaining high hydrogen absorption performance at a lower activation temperature.

[0027] 3. This invention promotes the entry of composite microparticles into the internal channels of the framework through vacuum impregnation, and then removes excess slurry from the pore openings and surface by centrifugation, avoiding the formation of a loose accumulation layer of active powder on the surface. During the thermal pulse treatment, the amorphous alloy powder plays a role in metal bonding and interface fixation at the particle contact points, promoting the formation of local bonding between composite microparticles and between composite microparticles and Ti-Mo pore walls. The resulting product forms a composite structure with a metal framework support, active microparticles embedded in the channels, and local sintering fixation at the interface. This allows the material to have a high specific surface area and a high active phase loading, while also being able to withstand the stress when the material is subjected to vibration or friction, avoiding powder shedding in the metal-based composite getter material and improving the mechanical strength of the composite getter material. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 These are SEM images of the porous Ti-Mo support framework and the metal-based composite getter material of the present invention. In the images, Figure a shows the low-magnification morphology of the porous Ti-Mo support framework; Figure b shows the high-magnification morphology of the pore walls of the porous Ti-Mo support framework; Figure c shows the low-magnification morphology of the metal-based composite getter material; and Figure d shows the high-magnification morphology of the combination of composite microparticles and the pore walls of the framework in the metal-based composite getter material. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] In this application, ammonium bicarbonate is a commercially available product with a particle size of 40-60 μm and an active ingredient content of 99%.

[0032] In this application, the titanium powder is a commercially available product with a particle size of 35-40 μm;

[0033] In this application, the molybdenum powder is a commercially available product with a particle size of 10-15 μm;

[0034] In this application, the zirconium-vanadium alloy powder has a particle size of 0.3-0.8 μm and comprises the following elements by mass percentage: 68% zirconium, 20% vanadium, with the balance being iron and unavoidable impurities.

[0035] In this application, the amorphous alloy powder has a particle size of 0.1-0.6 μm and comprises the following elements by mass percentage: 30% copper, 10% aluminum, 5% nickel, with the balance being zirconium and unavoidable impurities.

[0036] Preparation Example 1

[0037] This preparation example provides a method for preparing a porous Ti-Mo support framework, specifically including the following steps:

[0038] Step 1: Preparation of the skeleton mixture

[0039] Weigh out 30g of ammonium bicarbonate, 5.5g of polyvinyl alcohol and 100mL of deionized water and add them to a reaction flask under argon protection. Stir the mixture and add 475g of titanium powder and 40g of molybdenum powder to the reaction flask. Set the stirring speed to 1000r / min and stir and disperse at room temperature for 2h to obtain the skeleton mixture.

[0040] Step 2: Prepare the circular blank

[0041] The skeleton mixture is loaded into a mold with a diameter of 10 mm and pressed into a circular blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 350 MPa.

[0042] Step 3: Prepare a porous Ti-Mo support framework

[0043] The circular blank was placed in a vacuum furnace, which was evacuated to 1 Pa. The furnace was heated to 120°C at 2°C / min and held for 60 min. The furnace was then heated to 280°C at 1°C / min and held for 160 min. The furnace was then heated to 900°C at 10°C / min and held for sintering for 20 min. The furnace was then allowed to cool naturally to room temperature and then restored to atmospheric pressure before being discharged to obtain a porous Ti-Mo support skeleton.

[0044] Preparation Example 2

[0045] This preparation example provides a method for preparing a porous Ti-Mo support framework, specifically including the following steps:

[0046] Step 1: Preparation of the skeleton mixture

[0047] Weigh out 33g of ammonium bicarbonate, 6.0g of polyvinyl alcohol and 100mL of deionized water and add them to a reaction flask under argon protection. Stir the mixture and add 483g of titanium powder and 43g of molybdenum powder to the reaction flask. Set the stirring speed to 1000r / min and stir and disperse at room temperature for 2.5h to obtain the skeleton mixture.

[0048] Step 2: Prepare the circular blank

[0049] The skeleton mixture is loaded into a mold with a diameter of 10 mm and pressed into a circular blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 355 MPa.

[0050] Step 3: Prepare a porous Ti-Mo support framework

[0051] The circular blank was placed in a vacuum furnace, which was evacuated to 3 Pa. The furnace was heated to 125°C at 2°C / min and held for 70 min. Then, the furnace was heated to 290°C at 1°C / min and held for 170 min. The furnace was then heated to 900°C at 10°C / min and held for sintering for 25 min. The furnace was then allowed to cool naturally to room temperature and then restored to atmospheric pressure before being discharged to obtain a porous Ti-Mo support skeleton.

[0052] Preparation Example 3

[0053] This preparation example provides a method for preparing a porous Ti-Mo support framework, specifically including the following steps:

[0054] Step 1: Preparation of the skeleton mixture

[0055] Weigh out 35g of ammonium bicarbonate, 6.5g of polyvinyl alcohol and 100mL of deionized water and add them to a reaction flask under argon protection. Stir the mixture and add 500g of titanium powder and 45g of molybdenum powder to the reaction flask. Set the stirring speed to 1000r / min and stir and disperse at room temperature for 3h to obtain the skeleton mixture.

[0056] Step 2: Prepare the circular blank

[0057] The skeleton mixture is loaded into a mold with a diameter of 10 mm and pressed into a circular blank with a diameter of 10 mm and a thickness of 2 mm under a pressure of 360 MPa.

[0058] Step 3: Prepare a porous Ti-Mo support framework

[0059] The circular blank was placed in a vacuum furnace, which was evacuated to 5 Pa. The temperature of the vacuum furnace was increased to 130°C at 2°C / min and held for 80 min. The temperature of the vacuum furnace was then increased to 300°C at 1°C / min and held for 180 min. The temperature of the vacuum furnace was then increased to 900°C at 10°C / min and held for sintering for 30 min. The vacuum furnace was then allowed to cool naturally to room temperature and then restored to atmospheric pressure. The material was then discharged to obtain a porous Ti-Mo support skeleton.

[0060] Example 1

[0061] This embodiment provides a method for preparing a high specific surface area metal-based composite air-getting material, including the following steps:

[0062] Step 1: Preparation of hydride metal particles

[0063] Weigh out 40g of titanium dihydrogen hydride, 10g of yttrium hydride, 5g of cerium hydride, 3g of polyvinylpyrrolidone, and 500mL of anhydrous ethanol and mix them to obtain a mixture.

[0064] The mixture and abrasive were added to an argon-protected ball mill at a ball-to-material ratio of 15:1. The ball milling speed was set to 500 r / min, and the milling was carried out at room temperature for 2 hours. The abrasive was removed by filtration to obtain a hydride metal dispersion. The abrasive consisted of 316L stainless steel grinding balls with a diameter of 3 mm and 316L stainless steel grinding balls with a diameter of 5 mm at a weight ratio of 1:3.

[0065] Under an argon atmosphere, the hydride metal dispersion was spray-granulated with an inlet air temperature of 85℃, an outlet air temperature of 45℃, and a spray pressure of 1.8MPa. After sieving, hydride metal particles with a particle size of 5-12μm were obtained.

[0066] Step 2: Preparation of impregnation slurry

[0067] Weigh out 50g of hydride metal particles, 350g of zirconium vanadium alloy powder, and 20g of amorphous alloy powder and add them to an argon-protected mechanical fusion machine. Stir the machine at 1300r / min, heat it to 430℃, stir and disperse for 80min, then let it cool naturally to room temperature and sieve to obtain composite microparticles with a particle size of 1-5μm.

[0068] Weigh out 130g of terpineol, 10g of ethyl cellulose and 500mL of anhydrous ethanol and add them to a reaction flask. Stir for 20min. Add 180g of composite microparticles to the reaction flask. Set the stirring speed to 800r / min and stir and disperse at room temperature for 60min to obtain the impregnation slurry.

[0069] Step 3: Preparation of impregnation-modified load-bearing skeleton

[0070] The porous Ti-Mo support skeleton prepared in Preparation Example 1 was placed in a vacuum impregnation tank, and a vacuum of 30 Pa was drawn. After maintaining this vacuum for 3 min, the impregnation slurry was introduced to allow the slurry to enter the interconnected channels of the porous Ti-Mo support skeleton. After restoring to normal pressure under inert gas protection, the sample was removed and centrifuged at 800 r / min for 30 s to remove excess slurry from the channels. The material was then transferred to a drying oven under inert gas protection and dried at 60 °C for 30 min. The above operation was repeated twice to obtain the impregnated modified support skeleton. The solid-liquid ratio of the porous Ti-Mo support skeleton to the impregnation slurry was 1:10.

[0071] Step 4: Preparation of metal-based composite getter materials

[0072] The impregnated modified support skeleton was placed in a vacuum sintering furnace with pulsed current assisted heat treatment. The vacuum sintering furnace was evacuated to 1 Pa, and the temperature was increased to 150℃ at 2℃ / min and held for 60 min. Then, the temperature was increased to 280℃ at 1℃ / min and held for 100 min. Finally, the temperature was increased to 420℃ at 10℃ / min and held for 10 min. During the holding process, a pulsed current was applied in the vacuum sintering furnace with a pulse on / off ratio of 12:2 and a current density of 30 A / cm². 2 After vacuum sintering, the vacuum sintering furnace is naturally cooled to room temperature and then restored to atmospheric pressure before being discharged to obtain a metal-based composite gas-absorbing material blank.

[0073] The metal-based composite getter material blank was placed in a tube furnace protected by an argon-oxygen mixture with an oxygen content of 0.2%. The tube furnace was heated to 80°C and held for 20 minutes to obtain the metal-based composite getter material.

[0074] Example 2

[0075] This embodiment provides a method for preparing a high specific surface area metal-based composite air-getting material, including the following steps:

[0076] Step 1: Preparation of hydride metal particles

[0077] Weigh out 40g of titanium dihydrogen hydride, 11g of yttrium hydride, 6g of cerium hydride, 3.5g of polyvinylpyrrolidone, and 500mL of anhydrous ethanol and mix them to obtain a mixture.

[0078] The mixture and abrasive were added to an argon-protected ball mill at a ball-to-material ratio of 17:1. The ball milling speed was set to 500 r / min, and the milling was carried out at room temperature for 2.5 h. The abrasive was removed by filtration to obtain a hydride metal dispersion. The abrasive consisted of 316L stainless steel grinding balls with a diameter of 3 mm and 316L stainless steel grinding balls with a diameter of 5 mm at a weight ratio of 1:3.5.

[0079] Under an argon atmosphere, the hydride metal dispersion was spray-granulated with an inlet air temperature of 90℃, an outlet air temperature of 47℃, and a spray pressure of 2.1MPa. After sieving, hydride metal particles with a particle size of 5-12μm were obtained.

[0080] Step 2: Preparation of impregnation slurry

[0081] Weigh out 55g of hydride metal particles, 365g of zirconium vanadium alloy powder, and 25g of amorphous alloy powder and add them to an argon-protected mechanical fusion machine. Stir the machine at 1400r / min, heat it to 440℃, stir and disperse for 90min, then let it cool naturally to room temperature and sieve to obtain composite microparticles with a particle size of 1-5μm.

[0082] Weigh out 140g of terpineol, 15g of ethyl cellulose and 550mL of anhydrous ethanol and add them to a reaction flask. Stir for 25min. Add 200g of composite microparticles to the reaction flask. Set the stirring speed to 850r / min and stir and disperse at room temperature for 70min to obtain the impregnating slurry.

[0083] Step 3: Preparation of impregnation-modified load-bearing skeleton

[0084] The porous Ti-Mo support skeleton prepared in Preparation Example 2 was placed in a vacuum impregnation tank, and a vacuum was drawn to 65 Pa. After maintaining this vacuum for 4 min, the impregnation slurry was introduced to allow the slurry to enter the interconnected channels of the porous Ti-Mo support skeleton. After restoring to normal pressure under inert gas protection, the sample was removed and centrifuged at 900 r / min for 40 s to remove excess slurry from the channels. The material was then transferred to a drying oven under inert gas protection and dried at 65 °C for 40 min. The above operation was repeated twice to obtain the impregnated modified support skeleton, wherein the solid-liquid ratio of the porous Ti-Mo support skeleton to the impregnation slurry was 1:13.

[0085] Step 4: Preparation of metal-based composite getter materials

[0086] The impregnated modified support skeleton was placed in a vacuum sintering furnace with pulsed current assisted heat treatment. The vacuum sintering furnace was evacuated to 3 Pa, and the temperature was increased to 155℃ at 2℃ / min and held for 70 min. Then, the temperature was increased to 290℃ at 1℃ / min and held for 110 min. Finally, the temperature was increased to 435℃ at 13℃ / min and held for 15 min. During the holding process, a pulsed current was applied in the vacuum sintering furnace with a pulse on / off ratio of 12:2 and a current density of 40 A / cm². 2 After vacuum sintering, the vacuum sintering furnace is naturally cooled to room temperature and then restored to atmospheric pressure before being discharged to obtain a metal-based composite gas-absorbing material blank.

[0087] The metal-based composite getter material blank was placed in a tube furnace protected by an argon-oxygen mixture with an oxygen content of 0.35%. The tube furnace was heated to 85°C and held for 25 minutes to obtain the metal-based composite getter material.

[0088] Example 3

[0089] This embodiment provides a method for preparing a high specific surface area metal-based composite air-getting material, including the following steps:

[0090] Step 1: Preparation of hydride metal particles

[0091] Weigh out 40g of titanium dihydrogen hydride, 12g of yttrium hydride, 7g of cerium hydride, 4g of polyvinylpyrrolidone, and 500mL of anhydrous ethanol and mix them to obtain a mixture.

[0092] The mixture and abrasive were added to an argon-protected ball mill at a ball-to-material ratio of 20:1. The ball milling speed was set to 500 r / min, and the mixture was milled at room temperature for 3 hours. The abrasive was removed by filtration to obtain a hydride metal dispersion. The abrasive consisted of 316L stainless steel grinding balls with a diameter of 3 mm and 316L stainless steel grinding balls with a diameter of 5 mm at a weight ratio of 1:4.

[0093] Under an argon atmosphere, the hydride metal dispersion was spray-granulated with an inlet air temperature of 95℃, an outlet air temperature of 50℃, and a spray pressure of 2.3MPa. After sieving, hydride metal particles with a particle size of 5-12μm were obtained.

[0094] Step 2: Preparation of impregnation slurry

[0095] Weigh out 60g of hydride metal particles, 380g of zirconium vanadium alloy powder, and 30g of amorphous alloy powder and add them to an argon-protected mechanical fusion machine. Stir the machine at 1500r / min, heat it to 450℃, stir and disperse for 100min, then let it cool naturally to room temperature and sieve to obtain composite microparticles with a particle size of 1-5μm.

[0096] Weigh out 150g of terpineol, 20g of ethyl cellulose and 600mL of anhydrous ethanol and add them to a reaction flask. Stir for 30min. Add 220g of composite microparticles to the reaction flask. Set the stirring speed to 900r / min and stir and disperse at room temperature for 80min to obtain the impregnation slurry.

[0097] Step 3: Preparation of impregnation-modified load-bearing skeleton

[0098] The porous Ti-Mo support skeleton prepared in Preparation Example 3 was placed in a vacuum impregnation tank, evacuated to 00 Pa, and kept for 5 min before the impregnation slurry was introduced to allow the slurry to enter the interconnected channels of the porous Ti-Mo support skeleton. After restoring to normal pressure under inert gas protection, the sample was removed, centrifuged at 1000 r / min for 50 s to remove excess slurry from the channels, and then the material was transferred to a drying oven under inert gas atmosphere protection. The drying temperature was set to 70℃ and the drying was maintained for 50 min. The above operation was repeated twice to obtain the impregnated modified support skeleton, wherein the solid-liquid ratio of the porous Ti-Mo support skeleton and the impregnation slurry was 1:15.

[0099] Step 4: Preparation of metal-based composite getter materials

[0100] The impregnated modified support skeleton was placed in a vacuum sintering furnace with pulsed current assisted heat treatment. The vacuum sintering furnace was evacuated to 5 Pa, and the temperature was increased to 160℃ at 2℃ / min and held for 80 min. The temperature was then increased to 300℃ at 1℃ / min and held for 120 min. Finally, the temperature was increased to 450℃ at 15℃ / min and held for 20 min. During the holding process, a pulsed current was applied in the vacuum sintering furnace with a pulse on / off ratio of 12:2 and a current density of 50 A / cm². 2 After vacuum sintering, the vacuum sintering furnace is naturally cooled to room temperature and then restored to atmospheric pressure before being discharged to obtain a metal-based composite gas-absorbing material blank.

[0101] The metal-based composite getter material blank was placed in a tube furnace protected by an argon-oxygen mixture with an oxygen content of 0.5%. The tube furnace was heated to 90°C and held for 30 minutes to obtain the metal-based composite getter material.

[0102] Comparative Example 1

[0103] The difference between this comparative example and Example 3 is that in step one, titanium dihydrogenase is replaced by an equal amount of titanium powder.

[0104] Comparative Example 2

[0105] The difference between this comparative example and Example 3 is that, in step two, amorphous alloy powder was not added.

[0106] Comparative Example 3

[0107] The difference between this comparative example and Example 3 is that no pulsed current was applied in step four.

[0108] Performance testing:

[0109] The specific surface area (m²) of the metal-based composite getter materials prepared in Examples 1-3 and Comparative Examples 1-3 was determined according to standard GB / T 13390-2008 "Determination of Specific Surface Area of ​​Metal Powders - Nitrogen Adsorption Method". 2 / g;

[0110] The specific uptake rate and specific uptake volume of the metal-based composite uptake materials prepared in Examples 1-3 and Comparative Examples 1-3 were determined according to the standard GB / T 8763-2020 "Test Method for Uptake Performance of Non-evaporative Getting Materials and Products" at activation temperatures of 320℃, 380℃ and 450℃.

[0111] The weight loss of the metal-based composite getters prepared in Examples 1-3 and Comparative Examples 1-3 was determined according to the standard GB / T 25496-2010 "Methods for Testing Mechanical Properties of Getters", and the average weight loss rate was determined according to the standard. The specific test data are shown in Table 1 below.

[0112] Table 1 - Performance Test Data of Samples

[0113]

[0114] Data Analysis:

[0115] Comparative analysis of the data in Table 1 above shows that the specific surface area of ​​the metal-based composite air-getting material prepared by this invention reaches 4.83-4.98 m². 2 / g, the average weight loss rate decreased to 0.20-0.24%. After activation at 320℃, the specific uptake rate of the metal-based composite getter material for hydrogen reached 0.67-0.70 mL / (s·mg), and the specific uptake capacity reached 11.0-11.9 Pa·L / mg. After activation at 380℃, the specific uptake rate of the metal-based composite getter material for hydrogen reached 2.32-2.36 mL / (s·mg), and the specific uptake capacity reached 21.9-22.2 Pa·L / mg. After activation at 450℃, the specific uptake rate of the metal-based composite getter material for hydrogen reached 2.41-2.52 mL / (s·mg), and the specific uptake capacity reached 22.3-22.6 Pa·L / mg.

[0116] The performance test data of the embodiments are all better than those of the comparative examples, indicating that the present invention utilizes the decomposition and removal effect of ammonium bicarbonate and polyvinyl alcohol during vacuum sintering to form interconnected channels inside the Ti-Mo skeleton, providing space for subsequent loading of active components; subsequently, zirconium vanadium alloy powder, hydride metal particles and amorphous alloy powder are prepared into composite microparticles, which are then introduced into the skeleton channels by vacuum impregnation and subjected to thermal pulse treatment to form a composite material with a multi-level porous structure and a stable load-bearing structure working synergistically, so that it has both high specific surface area, low activation temperature and excellent gas absorption performance, while reducing the powder loss rate of the material.

[0117] The preferred embodiments of the present invention disclosed above are only for illustrating the present invention. These preferred embodiments do not describe all details exhaustively, nor do they limit the invention to specific implementations. Obviously, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a high specific surface area metal-based composite air-getting material, characterized in that, Includes the following steps: S1. After mixing the metal hydride raw material with polyvinylpyrrolidone and anhydrous ethanol, the mixture is dispersed by ball milling under argon protection and then spray granulated to obtain hydride metal particles. S2. Composite microparticles are prepared by combining hydride metal particles, zirconium vanadium alloy powder, and amorphous alloy powder. S3. After mixing and stirring terpineol, ethyl cellulose and anhydrous ethanol for 20-30 minutes, add composite microparticles and stir and disperse for 60-80 minutes to obtain impregnation slurry; S4. The impregnation slurry is introduced into the porous Ti-Mo support skeleton through vacuum impregnation. After centrifugation to remove excess impregnation slurry from the pores and drying, the impregnated modified support skeleton is obtained. S5. The impregnated modified support skeleton is subjected to thermal pulse treatment under vacuum conditions to obtain a metal-based composite air-getting material blank; then the metal-based composite air-getting material blank is subjected to low-temperature activation treatment in an oxygen-containing inert atmosphere to obtain the high specific surface area metal-based composite air-getting material.

2. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The preparation of the porous Ti-Mo support framework includes the following steps: A1. Under an inert gas atmosphere, ammonium bicarbonate, polyvinyl alcohol and deionized water are mixed and stirred until dissolved, then titanium powder and molybdenum powder are added, and the mixture is stirred and dispersed at room temperature for 2-3 hours to obtain the skeleton mixture. A2. The skeleton mixture is loaded into a mold and pressed into a circular blank under a pressure of 350-360MPa; then vacuum sintering is performed to obtain a porous Ti-Mo support skeleton.

3. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 2, characterized in that, In step A1, the ratio of ammonium bicarbonate, polyvinyl alcohol, deionized water, titanium powder, and molybdenum powder is 6-7g:1.1-1.3g:20mL:95-100g:8-9g, the particle size of the titanium powder is 20-50μm, and the particle size of the molybdenum powder is 8-12μm.

4. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The metal hydride raw materials include titanium dihydrogenide, yttrium hydride, and cerium hydride; the ratio of titanium dihydrogenide, yttrium hydride, cerium hydride, polyvinylpyrrolidone, and anhydrous ethanol is 40g:10-12g:5-7g:3-4g:500mL.

5. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The ball-to-material ratio for ball milling dispersion is 15-20:1, the ball milling speed is 500 r / min, and the ball milling time is 2-3 h. The abrasive used in the ball milling includes 316L stainless steel grinding balls with a diameter of 3 mm and 316L stainless steel grinding balls with a diameter of 5 mm, with a weight ratio of 1:3-4. After ball milling, hydride metal particles with a particle size of 5-12 μm are obtained by spray granulation.

6. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The method for preparing the composite microparticles is as follows: under the protection of an inert gas atmosphere, hydride metal particles, zirconium vanadium alloy powder and amorphous alloy powder are added to a mechanical fusion machine, the reaction system is heated to 430-450℃, stirred and dispersed for 80-100 min and then cooled naturally, and the composite microparticles with a particle size of 1-5 μm are obtained by sieving. The weight ratio of the hydride metal particles, zirconium vanadium alloy powder and amorphous alloy powder is 5-6:35-38:2-3.

7. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The ratio of terpineol, ethyl cellulose, anhydrous ethanol and composite microparticles is 13-15g:1-2g:50-60mL:18-22g.

8. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The vacuum degree during vacuum impregnation is 30-100 Pa, and the holding time is 3-5 min; the solid-liquid ratio of the porous Ti-Mo support skeleton to the impregnation slurry is 1:10-15; after impregnation, the sample is centrifuged at 800-1000 r / min for 30-50 s and dried at 60-70℃ for 30-50 min under an inert atmosphere; the vacuum impregnation, centrifugation and drying operations are repeated twice.

9. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The thermal pulse treatment operation is as follows: the impregnated modified support skeleton is placed in a vacuum sintering furnace with pulse current assisted heat treatment, the vacuum is evacuated to 1-5 Pa, the temperature is increased to 150-160℃ at 2℃ / min and held for 60-80 min, the temperature is increased to 280-300℃ at 1℃ / min and held for 100-120 min, and then the temperature is increased to 420-450℃ at 10-15℃ / min and held for 10-20 min; pulse current is applied in multiple holding stages, the on / off ratio of the pulse current is 12:2, and the current density is 30-50 A / cm².

10. The method for preparing a high specific surface area metal-based composite air-getting material according to claim 1, characterized in that, The low-temperature activation treatment is carried out in an argon-oxygen mixture with an oxygen volume fraction of 0.2-0.5%, at an activation temperature of 80-90℃, and for an activation time of 20-30 minutes.

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