An apparatus and method for ultrasonic assisted melt-spinning of hydrogen storage alloy fibers

Abstract

This invention belongs to the field of metal hydrogen storage material preparation and processing technology, and relates to an apparatus and method for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt quenching. The apparatus includes a melting furnace, an alloy melting heating system, a gas protection system, an ultrasonic melt treatment system, a melt quenching fiber forming system, a control system, and a fiber collection box. This invention effectively solves the shortcomings of conventional melt quenching methods, such as uneven sample length and thickness and irregular cross-sectional shape; it effectively improves the compositional uniformity of the alloy melt in the crucible, significantly reducing the proportion of bubbles and impurities in the hydrogen storage alloy fibers. It enables the preparation of high-capacity magnesium-based hydrogen storage alloy fibers with low-dimensional morphology, which is beneficial for increasing the contact area between the material and hydrogen gas and shortening the diffusion distance of hydrogen atoms within the material; simultaneously, the quality of the hydrogen storage alloy fibers is stable.

Description

Technical Field

[0001] This invention belongs to the field of metal hydrogen storage material preparation and processing technology, and relates to an apparatus and method for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching. Background Technology

[0002] High-capacity magnesium-based hydrogen storage alloys are a class of solid-state hydrogen storage materials with a magnesium matrix, possessing both higher hydrogen storage capacity and higher bulk density than mainstream rare-earth and titanium alloys, and are considered one of the core candidates for large-scale hydrogen storage and transportation. However, a large number of alloying elements can lead to a decrease in the hydrogen storage capacity of magnesium-based hydrogen storage alloys. For high-capacity hydrogen storage systems, the content of alloying elements is relatively low, and they are usually distributed in a segregated manner, which seriously affects the optimization of their thermodynamic and kinetic properties for hydrogen absorption and desorption. For metallic materials, although there are many methods for homogenizing composition and structure, such as quenching, powder metallurgy, and heat treatment, magnesium-based hydrogen storage alloys are extremely sensitive to oxygen and water molecules, and the sample size of the alloys is on the micrometer scale, making these methods unsuitable. The methods commonly used in scientific research, such as nanoconfining and vapor deposition, for preparing low-dimensional hydrogen storage materials are usually cumbersome and costly. Therefore, developing a short-process method to prepare materials with uniform composition and structure and small size is of paramount importance for the industrial application of high-capacity magnesium-based hydrogen storage alloys. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that the preparation process of traditional high-capacity magnesium-based hydrogen storage materials is complex and the composition and structural distribution are uneven, making it difficult to significantly optimize the thermodynamic and kinetic properties of hydrogen absorption and desorption. Therefore, this invention discloses an apparatus and method for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching, providing a simple and low-cost means for preparing high-capacity magnesium-based hydrogen storage alloy fibers with micron-scale and uniform elemental distribution, resulting in hydrogen storage materials with excellent hydrogen absorption and desorption performance.

[0004] To achieve the above objectives, the present invention provides the following technical solution: An apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching includes a melting furnace, an alloy melting heating system, a gas protection system, an ultrasonic melt treatment system, a melt spin quenching fiber forming system, a control system, and a fiber collection box. The alloy melting heating system is installed inside the melting furnace and is used to heat the alloy melt contained inside the alloy melting heating system; The gas protection system is installed outside the smelting furnace and connected to the smelting furnace to control the gas environment inside the smelting furnace; The ultrasonic melt treatment system is located below the alloy melting heating system inside the melting furnace and is used to apply ultrasonic treatment to the alloy melt contained in the alloy melting heating system. The melt spin-quenching fiber forming system is located inside the melting furnace and above the center of the alloy melting heating system. It is used to spin-quench the alloy melt contained in the alloy melting heating system to prepare hydrogen storage alloy fibers. The control system is located outside the melting furnace and is electrically connected to the alloy melting and heating system, the gas protection system, the ultrasonic melt treatment system, and the melt spin quenching and fiber forming system. It is used to control the alloy melting and heating system, the gas protection system, the ultrasonic melt treatment system, and the melt spin quenching and fiber forming system. The fiber collection box is located inside the melting furnace and on the lower side of the lowest point of the rotation direction of the melt spin quenching fiber forming system, and is used to collect the hydrogen storage alloy fibers prepared by melt spin quenching.

[0005] Furthermore, the smelting furnace includes a furnace body, a furnace door, and an observation window. The furnace door is located on one side of the furnace body, and a sealing strip is provided between the furnace body and the furnace door. An observation window is provided at the upper end of the furnace body.

[0006] Furthermore, the alloy melting heating system includes a ceramic crucible, an electromagnetic induction coil, and a movable ceramic substrate. The ceramic crucible is a cylindrical shape that runs vertically through the interior of the furnace and is located in the center. The electromagnetic induction coil is wound around the outer periphery of the ceramic crucible, and the movable ceramic substrate is located inside the ceramic crucible. The outer diameter of the movable ceramic substrate is equal to the inner diameter of the ceramic crucible.

[0007] Furthermore, the ultrasonic melt processing system includes an ultrasonic transducer, an ultrasonic amplitude transformer, a tool head, and a feeding device inside the furnace. The upper end of the ultrasonic transducer is connected to the ultrasonic amplitude transformer, and the lower end is fixed to the bottom of the furnace. The upper end of the ultrasonic amplitude transformer is connected to the tool head. When the feeding device is retracted to its shortest length, the upper end of the tool head rests against the lower surface of the movable ceramic substrate. Multiple feeding devices are evenly distributed around the ultrasonic transducer. The lower end of the feeding device is fixed to the bottom of the furnace, and the upper end of the feeding device is below the movable ceramic substrate. When the feeding device extends, it can cause the movable ceramic substrate to move upward. When the feeding device shortens, it can cause the movable ceramic substrate to move downward until the lower end of the movable ceramic substrate contacts the upper end of the tool head and stops. When the feeding device is retracted to its shortest length, it does not contact the movable ceramic substrate.

[0008] Furthermore, the melt spin quenching fiber forming system includes a rotary motor and a copper roller. One end of the rotary motor is fixed to the side wall of the furnace body, and the other end of the rotary motor extends onto a rotating shaft on which a copper roller is fixed. The copper roller is located above the center of the ceramic crucible, and the rim cross-section of the copper roller is conical.

[0009] Furthermore, the gas protection system includes a vacuum pump and an argon cylinder. The vacuum pump is connected to the furnace body through a vacuuming pipeline, and the argon cylinder is connected to the furnace body through a filling pipeline. A valve a is installed on the vacuuming pipeline, a valve b is installed on the filling pipeline, and a pressure gauge is installed on the furnace body.

[0010] Furthermore, the control system includes an induction coil current controller, a temperature-measuring thermocouple, a temperature sensor, an ultrasonic vibration frequency controller, a rotary motor output current controller, and a feed device output current controller. The induction coil current controller is electrically connected to the electromagnetic induction coil. The temperature-measuring thermocouple is placed on top of the ceramic crucible. The temperature sensor is electrically connected to the temperature-measuring thermocouple. The ultrasonic vibration frequency controller is electrically connected to the ultrasonic transducer. The rotary motor output current controller is electrically connected to the rotary motor and is used to control the rotation speed of the copper roller driven by the rotary motor. The feed device output current controller is electrically connected to the feed device and is used to control the extension and retraction of the feed device.

[0011] Furthermore, the fiber collection box consists of a box hook and a box body. The box hook is fixed to one side inside the furnace body, and the box body is hung on the box hook. The box body is located on the lower side of the lowest point tangential to the direction of rotation of the copper roller.

[0012] A method for preparing hydrogen storage alloy fibers using the apparatus described above, comprising the following steps: Step 1: Place the high-capacity magnesium-based hydrogen storage alloy into a ceramic crucible, close and lock the furnace door; Step 2: Open valve a on the vacuum pump and the extraction pipeline to perform vacuuming, creating a negative pressure inside the furnace body, and then close valve a on the vacuum pump and the extraction pipeline. Step 3: Open valve b on the argon cylinder and filling pipeline to fill with protective argon gas; when the pressure gauge shows a pressure value of 0.5±0.02 bar, close valve b on the argon cylinder and filling pipeline. Step 4: Repeat steps 2 and 3 to further reduce the oxygen content in the furnace. Step 5: Turn on the induction coil current controller to energize the electromagnetic induction coil and heat it, thereby completely melting the high-capacity magnesium-based hydrogen storage alloy. When the temperature of the alloy melt is 50±5℃ higher than the melting point, keep it at that temperature. Step 6: Turn on the ultrasonic vibration frequency controller and adjust the ultrasonic vibration frequency to 22±1kHz. Then, the ultrasonic vibration is transmitted to the movable ceramic substrate. The movable ceramic substrate drives the alloy melt to vibrate ultrasonically for 5±1min, which promotes the removal of bubbles, the precipitation of impurities and the uniformity of composition in the alloy melt. Then, turn off the ultrasonic vibration frequency controller and the induction coil current controller. Step 7: Turn on the rotary motor output current controller to make the rotary motor drive the copper roller to rotate, turn on the feed device output current controller to make the feed device extend upward and press against the lower end of the movable ceramic substrate, thereby driving the movable ceramic substrate to rise and detach from the tool head, and the movable ceramic substrate drives the alloy melt to rise. Step 8: The tip of the copper roller comes into contact with the alloy melt, allowing the hydrogen storage alloy fiber prepared by spun quenching of the melt to enter the fiber collection box; Step 9: Turn off the output current controller of the feeding device and the output current controller of the rotary motor. After the hydrogen storage alloy fiber cools naturally to room temperature, open valve b on the argon cylinder and the filling pipeline. When the pressure gauge shows a pressure value of 1.0 bar, open the furnace door and take out the prepared hydrogen storage alloy fiber from the fiber collection box.

[0013] Furthermore, in step five, the initial heating rate of the alloy melt is 30℃ / min, and when it is 50±5℃ below the alloy melting point, the heating rate is adjusted to 10℃ / min.

[0014] The advantages and effects of this invention include the following aspects: 1. This invention utilizes the synergistic effect of multiple devices to push the high-capacity magnesium-based hydrogen storage alloy melt upwards into contact with a high-speed rotating copper roller. This allows the prepared hydrogen storage alloy fibers to easily achieve a length greater than 20 cm and a diameter of only 50-150 μm, with uniform thickness. This effectively solves the shortcomings of conventional melt quenching methods, which result in uneven sample length and thickness, and irregular cross-sectional shapes.

[0015] 2. This invention effectively improves the compositional uniformity of the alloy melt in the crucible by introducing ultrasonic melt treatment after the alloy is heated and melted. With the help of the "three major effects" of ultrasonic vibration, the rapid flow of the alloy melt, the expulsion of bubbles and the precipitation of impurities are promoted, which effectively reduces the adverse effects of gravity segregation on the compositional uniformity of the alloy fibers and significantly reduces the proportion of bubbles and impurity defects in the hydrogen storage alloy fibers.

[0016] 3. This invention utilizes a short-process method combining rapid solidification melt quenching with ultrasonic-assisted alloy melt pretreatment to prepare high-capacity magnesium-based hydrogen storage alloy fibers with low-dimensional morphology. This method is beneficial for increasing the contact area between the material and hydrogen gas and shortening the diffusion distance of hydrogen atoms within the material. Simultaneously, the hydrogen storage alloy fibers exhibit stable quality. Their internal composition is uniform and their microstructure is refined, effectively avoiding the coarse α-Mg grains and segregated distribution of catalytic elements found in alloys prepared by conventional solidification methods. This improves the catalytic efficiency of the hydrogen storage system and enhances the diffusion environment for hydrogen atoms. Attached Figure Description

[0017] Figure 1A schematic diagram of the external structure of an apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching. Figure 2 A front view of the internal structure of an apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching; Figure 3 A side view of the internal structure of an apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching. Figure 4 This is a schematic diagram of the structure when a copper roller comes into contact with the alloy melt. Figure 5 This is a schematic diagram of the fiber collection box. Figure 6 Morphology and microstructure of high-capacity magnesium-nickel hydrogen storage alloy fibers prepared using an ultrasonic-assisted melt spin quenching apparatus. Figure 7 For conventional solidified as-cast Mg 97 Microstructure of Ni2Y1 alloy; Figure 8 for Figure 6 The isothermal hydrogen absorption and desorption curves of the hydrogen storage alloy fiber are shown. Figure 9 for Figure 7 The isothermal hydrogen absorption and desorption curves of the as-cast hydrogen storage alloy are shown.

[0018] Explanation of reference numerals in the attached drawings: 1—Furnace body; 2—Furnace door; 3—Sealing strip; 4—Furnace door lock; 5—Observation window; 6—Ceramic crucible; 7—Electromagnetic induction coil; 8—Movable ceramic substrate; 9—Ultrasonic transducer; 10—Ultrasonic amplitude converter; 11—Tool head; 12—Rotary motor; 13—Copper roller; 14—Feeding device; 15—Sealing ring; 16—Vacuum pump; 17—Argon cylinder; 18—Evacuation pipeline; 19—Inflation pipeline; 20—Valve a; 21—Valve b; 22—Pressure gauge; 23—Induction coil current controller; 24—Thermocouple; 25—Temperature sensor; 26—Ultrasonic vibration frequency controller; 27—Rotary motor output current controller; 28—Feeding device output current controller; 29—Fiber collection box; 291—Box hook; 292—Box body. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to specific implementations. The parts of the technical features or connection relationships described in the present invention that are not described in detail are all existing technologies.

[0020] like Figures 1-5As shown, an apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching includes a melting furnace, an alloy melting heating system, a gas protection system, an ultrasonic melt treatment system, a melt spin quenching fiber forming system, a control system, and a fiber collection box 29. The alloy melting heating system is installed inside the melting furnace and is used to heat the alloy melt contained within the alloy melting heating system; The gas protection system is installed outside the smelting furnace and connected to the smelting furnace to control the gas environment inside the smelting furnace; The ultrasonic melt treatment system is located below the alloy melting heating system inside the melting furnace and is used to apply ultrasonic treatment to the alloy melt contained in the alloy melting heating system. The melt spin-quenching fiber forming system is located inside the melting furnace and above the center of the alloy melting heating system. It is used to spin-quench the alloy melt contained in the alloy melting heating system to prepare hydrogen storage alloy fibers. The control system is located outside the melting furnace and is electrically connected to the alloy melting and heating system, the gas protection system, the ultrasonic melt treatment system, and the melt spin quenching and fiber forming system. It is used to control the alloy melting and heating system, the gas protection system, the ultrasonic melt treatment system, and the melt spin quenching and fiber forming system. The fiber collection box 29 is located inside the melting furnace and on the side tangential to the lowest point of the rotation direction of the melt spin quenching fiber forming system, and is used to collect the hydrogen storage alloy fibers prepared by melt spin quenching.

[0021] The smelting furnace includes a furnace body 1, a furnace door 2, and an observation window 5. The furnace body 1 is a three-dimensional structure with a rounded top. The furnace body 1 and the furnace door 2 are made of stainless steel and are covered with insulation material, preferably asbestos. The furnace door 2 is located on one side of the furnace body 1. A sealing strip 3 is provided between the furnace body 1 and the furnace door 2. The sealing strip 3 is preferably made of EPDM and is pasted on the inner circumference of the furnace door 2. The sealing strip 3 achieves compression sealing and isolates the atmosphere inside and outside the furnace. One end of the furnace door 2 is connected to one side of the furnace body 1 by a hinge, and the other end of the furnace door 2 is connected to the furnace body 1 by a furnace door lock 4. The furnace door lock 4 can be a conventional latch or snap lock. An observation window 5 is provided at the upper end of the furnace body 1 for observing the alloy melting and heating process and the alloy fiber preparation process.

[0022] The alloy melting heating system includes a ceramic crucible 6, an electromagnetic induction coil 7, and a movable ceramic substrate 8. The ceramic crucible 6 is a cylindrical shape that runs vertically through the furnace body 1 and is located in the center. The electromagnetic induction coil 7 is wound around the outer periphery of the ceramic crucible 6. The movable ceramic substrate 8 is located inside the ceramic crucible 6, and the outer diameter of the movable ceramic substrate 8 is equal to the inner diameter of the ceramic crucible 6. The alloy is placed on the upper end of the movable ceramic substrate 8 during the melting and heating process.

[0023] The ultrasonic melt processing system includes an ultrasonic transducer 9, an ultrasonic amplitude transformer 10, a tool head 11, and a feeding device 14 within a furnace body 1. The upper end of the ultrasonic transducer 9 is connected to the ultrasonic amplitude transformer 10, and the lower end is fixed to the bottom of the furnace body 1 by screws. The upper end of the ultrasonic amplitude transformer 10 is connected to the tool head 11. When the feeding device 14 is retracted to its shortest length, the upper end of the tool head 11 rests against the lower surface of the movable ceramic substrate 8. Multiple feeding devices 14 are evenly distributed around the ultrasonic transducer 9, and the number of ultrasonic transducers 9 is greater than or equal to 2. In this embodiment, the feeding device 14... The device used is a HOODLAND electric push rod telescopic rod IP800, with a quantity of 2 or more and the circuit is connected in parallel. The lower end of the feeding device 14 is fixed to the bottom of the furnace body 1 by screws. The upper end of the feeding device 14 is below the movable ceramic substrate 8. When the feeding device 14 extends, it can make the movable ceramic substrate 8 move upward. When the feeding device 14 shortens, it can make the movable ceramic substrate 8 move downward until the lower end of the movable ceramic substrate 8 contacts the upper end of the tool head 11 and stops. When the feeding device 14 is shortened to its shortest length, it does not contact the movable ceramic substrate 8.

[0024] The melt spin quenching fiber forming system includes a rotary motor 12 and a copper roller 13. One end of the rotary motor 12 is fixed to the side wall of the furnace body 1 by bolts, and the copper roller 13 is fixed on the rotating shaft extending from the other end of the rotary motor 12. The copper roller 13 is located above the center of the ceramic crucible 6. The rim section of the copper roller 13 is conical, and the optimal cone angle is 60±2°.

[0025] The gas protection system includes a vacuum pump 16 and an argon cylinder 17. The vacuum pump 16 is connected to the furnace body 1 through a gas extraction pipe 18, and the argon cylinder 17 is connected to the furnace body 1 through a gas filling pipe 19. A valve a 20 is installed on the gas extraction pipe 18, and a valve b 21 is installed on the gas filling pipe 19. A pressure gauge 22 is installed on the furnace body 1 to display the gas pressure inside the smelting furnace.

[0026] The control system includes an induction coil current controller 23, a temperature-measuring thermocouple 24, a temperature sensor 25, an ultrasonic vibration frequency controller 26, a rotary motor output current controller 27, and a feed device output current controller 28. The induction coil current controller 23 is electrically connected to the electromagnetic induction coil 7 and controls the temperature of the alloy melt in the ceramic crucible 6 by adjusting the current in the electromagnetic induction coil. The temperature-measuring thermocouple 24 is placed on the upper part of the ceramic crucible 6 and is used to measure the temperature of the alloy melt. The temperature sensor 25 is electrically connected to the temperature-measuring thermocouple 24 and is used to convert the thermal signal into an electrical signal. The ultrasonic vibration frequency controller 26 is electrically connected to the ultrasonic transducer 9 and is used to control the ultrasonic vibration frequency during alloy melt processing. The rotary motor output current controller 27 is electrically connected to the rotary motor 12 and is used to control the rotation speed of the copper roller 13 driven by the rotary motor 12. The feed device output current controller 28 is electrically connected to the feed device 14 and is used to control the extension and retraction of the feed device 14. The wires connected to the induction coil current controller 23, temperature sensor 25, ultrasonic vibration frequency controller 26, rotary motor output current controller 27, and feed device output current controller 28 inside the furnace body 1 are covered by a rubber sealing ring 15, which is fixed to the side of the furnace body 1 and serves as a seal.

[0027] The fiber collection box 29 consists of a box hook 291 and a box body 292. The box hook 291 is fixed to one side inside the furnace body 1 by screws. The box body 292 is hung on the box hook 291. The box body 292 is located on the lower side of the lowest point of the rotation direction of the copper roller 13. After collecting the hydrogen storage alloy fiber, the box body 292 can be taken out separately and then hung back.

[0028] A method for preparing hydrogen storage alloy fibers using the above-mentioned apparatus comprises the following steps: Step 1: Place the high-capacity magnesium-based hydrogen storage alloy into the ceramic crucible 6, close and lock the furnace door 2; Step 2: Open valve a 20 on vacuum pump 16 and extraction pipeline 18 to perform vacuuming, create a negative pressure inside furnace body 1, and then close valve a 20 on vacuum pump 16 and extraction pipeline 18. Step 3: Open valve b 21 on argon cylinder 17 and filling pipeline 19 to fill with protective argon gas; when the pressure gauge 22 shows a pressure value of 0.5±0.02 bar, close valve b 21 on argon cylinder 17 and filling pipeline 19. Step 4: Repeat steps 2 and 3 to reduce the oxygen content in furnace 1; Step 5: Turn on the induction coil current controller 23 to energize the electromagnetic induction coil 7 and heat it, thereby completely melting the high-capacity magnesium-based hydrogen storage alloy. When the temperature of the alloy melt is 50±5℃ higher than the melting point, keep it at that temperature. The initial heating rate of the alloy melt is 30℃ / min. When it is lower than the alloy melting point of 50±5℃, the heating rate is adjusted to 10℃ / min. Step 6: Turn on the ultrasonic vibration frequency controller 26 and adjust the ultrasonic vibration frequency to 22±1kHz. Then, the ultrasonic vibration is transmitted to the movable ceramic substrate 8. The movable ceramic substrate 8 drives the alloy melt to vibrate ultrasonically for 5±1min, which promotes the discharge of bubbles, the precipitation of impurities and the uniformity of composition in the alloy melt. Then, turn off the ultrasonic vibration frequency controller 26 and the induction coil current controller 23. Step 7: Turn on the rotary motor output current controller 27 to make the rotary motor 12 drive the copper roller 13 to rotate, turn on the feed device output current controller 28 to make the feed device 14 extend upward and press against the lower end of the movable ceramic substrate 8, thereby driving the movable ceramic substrate 8 to rise and detach from the tool head 11, and the movable ceramic substrate 8 drives the alloy melt to rise. Step 8: The tip of the copper roller 13 comes into contact with the alloy melt, so that the hydrogen storage alloy fiber prepared by quenching the melt enters the fiber collection box 29. Step 9: Close the output current controller 28 of the feeding device and the output current controller 27 of the rotary motor. After the hydrogen storage alloy fiber cools naturally to room temperature, open valve b 21 on the argon cylinder 17 and the gas filling pipeline 19. When the pressure gauge 22 shows a pressure value of 1.0 bar, open the furnace door 2 and take out the prepared hydrogen storage alloy fiber from the fiber collection box 29. During the sampling process, reduce the contact between the alloy fiber and the air. Place the alloy fiber in the fiber collection box 29 into a sample bag, seal it quickly, and store it in a glove box.

[0029] Figure 6 (a) High-capacity Mg2+ prepared by ultrasonic-assisted melt spin quenching according to an embodiment of the present invention. 97 The morphology image of Ni2Y1 hydrogen storage alloy fiber shows that the alloy fiber has low-dimensional morphological characteristics, is longer than 20cm, and has uniform thickness. Figure 6 (b) is Figure 6 (a) shows the longitudinal section microstructure of the alloy fiber, which indicates that the fiber diameter ranges from 50 to 150 μm. Figure 6 (c) is Figure 6 (a) shows a magnified view of the internal microstructure of the alloy. The alloy fibers have a uniform microstructure with fine grains, uniform element distribution, and no significant segregation.

[0030] Figure 7 For conventional solidified as-cast Mg 97 The microstructure of Ni2Y1 alloy, and Figure 6(a) High-capacity Mg prepared by ultrasonic-assisted melt spin quenching in an embodiment of the present invention 97 A comparison of the microstructure of Ni2Y1 hydrogen storage alloy fibers reveals that the primary α-Mg grains are large and the Ni element is segregated, which has an adverse effect on the hydrogen storage performance of magnesium-based materials.

[0031] Figure 8 (a) and Figure 8 (b) are respectively Figure 6 Mg shown 97 Isothermal hydrogen absorption and desorption curves of Ni2Y1 hydrogen storage alloy fiber at 355℃. Figure 8 (a) shows that the hydrogen absorption rate at 4000 s was 5.87 wt.%; Figure 8 (b) shows that the fiber Mg 97 Ni2Y1 undergoes 5.50 wt.% dehydrogenation at 211s, exhibiting a rapid dehydrogenation rate.

[0032] Figure 9 (a) and Figure 9 (b) are respectively Figure 7 The conventional solidified as-cast Mg shown 97 Isothermal hydrogen absorption and desorption curves of Ni2Y1 hydrogen storage alloy at 355℃. Figure 9 (a) shows that the hydrogen absorption at 4000 s is 5.41 wt.%, compared with Mg 97 Compared to Ni2Y1 hydrogen storage alloy fibers, the hydrogen storage capacity is significantly reduced by 0.46 wt.%. Figure 9 (b) shows that the as-cast Mg 97 Ni2Y1 alloy underwent 5.04 wt.% dehydrogenation at 223 s, compared with Mg. 97 Compared to Ni2Y1 hydrogen storage alloy fibers, the dehydrogenation rate is significantly reduced.

[0033] Compared with existing technologies, the high-capacity magnesium-based hydrogen storage alloy fibers prepared by ultrasonic-assisted melt spin quenching of this invention exhibit low-dimensional morphology characteristics and increased contact surface area with hydrogen, allowing for direct hydrogen absorption and desorption. Compared to cast alloys, the α-Mg and Mg2Ni grains in the alloy fibers are significantly refined and uniformly distributed throughout the material, which is beneficial for optimizing hydrogen absorption and desorption rates and hydrogen storage capacity. Due to the "three major effects" of ultrasonic melt treatment, the solute distribution in the alloy melt is uniform, bubbles are expelled, and impurities are precipitated, effectively reducing the adverse effects of gravity segregation on the uniformity of alloy fiber composition and significantly reducing the proportion of bubbles and impurity defects in the alloy fibers. Compared with rapid solidification using gravity-assisted spinning, the alloy fibers prepared by using a pulling device to raise the melt exhibit high quality stability, more uniform fiber length and thickness, and a more significant fiber microstructure refinement effect, which is beneficial for further optimization of hydrogen absorption and desorption performance.

Claims

1. An apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching, characterized in that: It includes a melting furnace, an alloy melting heating system, a gas protection system, an ultrasonic melt treatment system, a melt spin quenching fiber forming system, a control system, and a fiber collection box (29). The alloy melting heating system is installed inside the melting furnace and is used to heat the alloy melt contained inside the alloy melting heating system; The gas protection system is installed outside the smelting furnace and connected to the smelting furnace to control the gas environment inside the smelting furnace; The ultrasonic melt treatment system is located below the alloy melting heating system inside the melting furnace and is used to apply ultrasonic treatment to the alloy melt contained in the alloy melting heating system. The melt spin-quenching fiber forming system is located inside the melting furnace and above the center of the alloy melting heating system. It is used to spin-quench the alloy melt contained in the alloy melting heating system to prepare hydrogen storage alloy fibers. The control system is located outside the melting furnace and is electrically connected to the alloy melting and heating system, the gas protection system, the ultrasonic melt treatment system, and the melt spin quenching and fiber forming system. It is used to control the alloy melting and heating system, the gas protection system, the ultrasonic melt treatment system, and the melt spin quenching and fiber forming system. The fiber collection box (29) is located in the melting furnace and on the side of the lowest point of the rotation direction of the melt spin quenching fiber forming system, and is used to collect the hydrogen storage alloy fibers prepared by melt spin quenching.

2. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 1, characterized in that: The smelting furnace includes a furnace body (1), a furnace door (2) and an observation window (5). The furnace door (2) is located on one side of the furnace body (1). A sealing strip (3) is provided between the furnace body (1) and the furnace door (2). An observation window (5) is provided at the upper end of the furnace body (1).

3. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 2, characterized in that: The alloy melting heating system includes a ceramic crucible (6), an electromagnetic induction coil (7), and a movable ceramic substrate (8). The ceramic crucible (6) is a cylindrical shape that runs vertically through the furnace body (1) and is located in the center. The electromagnetic induction coil (7) is wound around the outer periphery of the ceramic crucible (6). The movable ceramic substrate (8) is located inside the ceramic crucible (6) and its outer diameter is equal to the inner diameter of the ceramic crucible (6).

4. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 3, characterized in that: The ultrasonic melt processing system includes an ultrasonic transducer (9), an ultrasonic amplitude transformer (10), a tool head (11), and a feeding device (14) inside the furnace body (1). The upper end of the ultrasonic transducer (9) is connected to the ultrasonic amplitude transformer (10), and the lower end is fixed to the bottom of the furnace body (1). The upper end of the ultrasonic amplitude transformer (10) is connected to the tool head (11). When the feeding device (14) is retracted to its shortest length, the upper end of the tool head (11) rests on the lower surface of the movable ceramic substrate (8). Multiple feeding devices (14) are evenly distributed in the ultrasonic transducer. Around the wave transducer (9), the lower end of the feeding device (14) is fixed to the bottom of the furnace body (1), and the upper end of the feeding device (14) is below the movable ceramic substrate (8). When the feeding device (14) extends, it can make the movable ceramic substrate (8) move upward. When the feeding device (14) shortens, it can make the movable ceramic substrate (8) move downward until the lower end of the movable ceramic substrate (8) contacts the upper end of the tool head (11) and stops. When the feeding device (14) is shortened to its shortest length, it does not contact the movable ceramic substrate (8).

5. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 4, characterized in that: The melt spin quenching fiber forming system includes a rotary motor (12) and a copper roller (13). One end of the rotary motor (12) is fixed to the side wall of the furnace body (1), and the other end of the rotary motor (12) extends onto the rotating shaft, on which the copper roller (13) is fixed. The copper roller (13) is located above the center of the ceramic crucible (6), and the rim section of the copper roller (13) is conical.

6. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 5, characterized in that: The gas protection system includes a vacuum pump (16) and an argon cylinder (17). The vacuum pump (16) is connected to the furnace body (1) through a gas extraction pipeline (18), and the argon cylinder (17) is connected to the furnace body (1) through a gas filling pipeline (19). A valve a (20) is installed on the gas extraction pipeline (18), a valve b (21) is installed on the gas filling pipeline (19), and a pressure gauge (22) is installed on the furnace body (1).

7. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 6, characterized in that: The control system includes an induction coil current controller (23), a temperature measuring thermocouple (24), a temperature sensor (25), an ultrasonic vibration frequency controller (26), a rotary motor output current controller (27), and a feed device output current controller (28). The induction coil current controller (23) is electrically connected to the electromagnetic induction coil (7). The temperature measuring thermocouple (24) is placed on the upper part of the ceramic crucible (6). The temperature sensor (25) is electrically connected to the temperature measuring thermocouple (24). The ultrasonic vibration frequency controller (26) is electrically connected to the ultrasonic transducer (9). The rotary motor output current controller (27) is electrically connected to the rotary motor (12) and is used to control the rotation speed of the copper roller (13) driven by the rotary motor (12). The feed device output current controller (28) is electrically connected to the feed device (14) and is used to control the extension and retraction of the feed device (14).

8. The apparatus for preparing hydrogen storage alloy fibers by ultrasonic-assisted melt spin quenching according to claim 5, characterized in that: The fiber collection box (29) consists of a box hook (291) and a box body (292). The box hook (291) is fixed to one side inside the furnace body (1), and the box body (292) is hung on the box hook (291). The box body (292) is located on the side tangential to the lowest point of the rotation direction of the copper roller (13).

9. A method for preparing hydrogen storage alloy fibers using the apparatus as described in claim 7, characterized in that: The steps are as follows: Step 1: Place the high-capacity magnesium-based hydrogen storage alloy into the ceramic crucible (6), close the furnace door (2) and lock it; Step 2: Open the valve a (20) on the vacuum pump (16) and the extraction pipeline (18) to perform vacuuming, draw the inside of the furnace body (1) into negative pressure, and close the valve a (20) on the vacuum pump (16) and the extraction pipeline (18). Step 3: Open valve b (21) on argon cylinder (17) and filling pipeline (19) to fill with protective argon gas; when the pressure gauge (22) shows a pressure value of 0.5±0.02 bar, close valve b (21) on argon cylinder (17) and filling pipeline (19). Step 4: Repeat steps 2 and 3 to reduce the oxygen content of the furnace body (1); Step 5: Turn on the induction coil current controller (23) to energize the electromagnetic induction coil (7) and heat it, thereby completely melting the high-capacity magnesium-based hydrogen storage alloy. When the temperature of the alloy melt is 50±5℃ higher than the melting point, keep it warm. Step 6: Turn on the ultrasonic vibration frequency controller (26), adjust the ultrasonic vibration frequency to 22±1kHz, and then transmit the ultrasonic vibration to the movable ceramic substrate (8). The movable ceramic substrate (8) drives the alloy melt to vibrate ultrasonically for 5±1min, which promotes the discharge of bubbles, the precipitation of impurities and the uniformity of composition in the alloy melt. Turn off the ultrasonic vibration frequency controller (26) and the induction coil current controller (23). Step 7: Turn on the rotary motor output current controller (27) to make the rotary motor (12) drive the copper roller (13) to rotate, turn on the feed device output current controller (28) to make the feed device (14) extend upward and press against the lower end of the movable ceramic substrate (8), thereby driving the movable ceramic substrate (8) to rise and detach from the tool head (11), and the movable ceramic substrate (8) drives the alloy melt to rise; Step 8: The tip of the copper roller (13) comes into contact with the alloy melt, so that the hydrogen storage alloy fiber prepared by quenching the melt enters the fiber collection box (29). Step 9: Close the output current controller (28) of the feeding device and the output current controller (27) of the rotary motor. After the hydrogen storage alloy fiber cools naturally to room temperature, open valve b (21) on the argon cylinder (17) and the gas filling pipeline (19). When the pressure gauge (22) shows a pressure value of 1.0 bar, open the furnace door (2) and take out the prepared hydrogen storage alloy fiber from the fiber collection box (29).

10. The method according to claim 9, characterized in that: In step five, the initial heating rate of the alloy melt is 30℃ / min. When the temperature is 50±5℃ below the alloy melting point, the heating rate is adjusted to 10℃ / min.

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