An apparatus and method for preparing titanium-based hydrogen storage alloys for solid hydrogen storage

Abstract

This invention discloses an apparatus for preparing titanium-based hydrogen storage alloys for solid-state hydrogen storage, comprising a vacuum induction melting system and an ultrasonic generating system. The vacuum induction melting system includes a vacuum chamber, a melting mechanism disposed within the vacuum chamber, a heatable mold, and a vacuum pump connected to the vacuum chamber. The ultrasonic generating system includes an ultrasonic generator, an amplitude transformer, and an ultrasonic probe connected in sequence, with one end of the ultrasonic probe extending into the vacuum chamber. The vacuum induction melting system is equipped with a moving positioning system for controlling the position of the ultrasonic probe. This invention also discloses a method for preparing titanium-based hydrogen storage alloys for solid-state hydrogen storage. The apparatus of this invention, by incorporating an ultrasonic generating system, applies ultrasound during the raw material melting process, effectively suppressing the segregation of Ti element. Simultaneously, it breaks dendrite arms during alloy solidification, forming more nucleation sites to refine the grains, making it suitable for preparing titanium-based hydrogen storage alloys for solid-state hydrogen storage.

Description

Technical Field

[0001] This invention belongs to the field of solid hydrogen storage material preparation technology, and in particular relates to a device and method for preparing titanium-based hydrogen storage alloys for solid hydrogen storage. Background Technology

[0002] With the rapid development of the hydrogen energy industry, the efficient and safe storage and transportation of hydrogen has become a key technological bottleneck restricting its large-scale application. Currently, the mainstream hydrogen storage methods include high-pressure gaseous hydrogen storage (35MPa~70MPa) and cryogenic liquid hydrogen storage (-253℃). However, the former suffers from high energy consumption and significant safety hazards, while the latter requires extremely high liquefaction costs and stringent insulation requirements, limiting its economic viability and applicability. Solid-state hydrogen storage achieves hydrogen storage through the physical / chemical adsorption of hydrogen by materials, offering significant advantages such as high volumetric hydrogen storage density, low operating pressure, good safety, and low energy consumption, and is considered the most promising next-generation hydrogen storage technology.

[0003] Existing solid-state hydrogen storage materials mainly include four categories: rare-earth based (such as LaNi5), magnesium based (such as MgH2), titanium based (TiFe / Ti-Mn based), and vanadium based solid solution hydrogen storage alloys. Among them, titanium-based hydrogen storage materials have become ideal candidates for stationary hydrogen storage and vehicle-mounted systems due to their significant cost advantages, mild operating conditions, long cycle life, and high volumetric hydrogen storage density. Titanium-based hydrogen storage alloys are mainly prepared using a melting process. During melting, Ti elements are prone to segregation, which usually requires homogenization annealing to eliminate segregation. In addition, titanium-based hydrogen storage alloys prepared by melting processes typically have relatively large grains, which is detrimental to the alloy's hydrogen storage performance. Existing melting equipment is unable to solve the problems of Ti element segregation and coarse alloy grains, thus worsening the alloy's hydrogen storage performance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device for preparing titanium-based hydrogen storage alloys for solid-state hydrogen storage. This device, by incorporating an ultrasonic generation system, applies ultrasound during the raw material melting process, effectively suppressing the segregation of Ti elements. Simultaneously, it breaks dendrite arms during alloy solidification, forming more nucleation sites to refine the grains, thus solving the problems of segregation and coarse microstructure caused by direct melting in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a device for preparing titanium-based hydrogen storage alloys for solid hydrogen storage, comprising a vacuum induction melting system and an ultrasonic generating system. The vacuum induction melting system includes a vacuum chamber, a melting mechanism disposed within the vacuum chamber, a heatable mold, and a vacuum pump connected to the vacuum chamber. The ultrasonic generating system includes an ultrasonic generator, an amplitude transformer, and an ultrasonic probe connected in sequence. One end of the ultrasonic probe extends into the vacuum chamber. The vacuum induction melting system is equipped with a motion positioning system for controlling the position of the ultrasonic probe.

[0006] The aforementioned apparatus for preparing titanium-based hydrogen storage alloys for solid hydrogen storage includes a mobile positioning system comprising a cross slide table at the top of a vacuum chamber and a second liftable support frame for adjusting the height of an ultrasonic probe. The second liftable support frame is fixedly connected to the slider of the cross slide table. The amplitude transformer is fixedly connected to both the end of the ultrasonic probe away from the vacuum chamber and the second liftable support frame. The end of the ultrasonic probe extending out of the vacuum chamber is fitted with a magnetohydrodynamic sealing assembly and a vacuum bellows. The amplitude transformer integrates a microchannel cooling mechanism.

[0007] The above-mentioned apparatus for preparing titanium-based hydrogen storage alloys for solid hydrogen storage includes a microchannel cooling mechanism connected to a high-pressure gas device, wherein the pressure of the high-pressure gas device is 0.5 MPa to 1 MPa.

[0008] The above-mentioned apparatus for preparing titanium-based hydrogen storage alloys for solid hydrogen storage includes a melting mechanism that is a metal oxide crucible, a tilting mechanism that is fixedly connected to the metal oxide crucible, heating coils that are provided on the outside of the metal oxide crucible and the mold, and a first liftable support frame that is provided at the bottom of the mold.

[0009] This invention also discloses a method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage, which utilizes the aforementioned apparatus and includes the following steps:

[0010] Step 1: According to the chemical formula Ti a Zr 1-a-b Y b Mn x Cr 1.8-x Fe 0.2 Raw materials are prepared and placed in a melting mechanism for ultrasonic-assisted vacuum melting to obtain an alloy melt; in the chemical formula, the subscripts indicate the atomic ratio of each element, where a is 0.70~0.90, b is 0~0.07, and x is 1.10~1.25;

[0011] Step 2: Pour the alloy melt obtained in Step 1 into a mold under vacuum conditions, and apply ultrasound during the solidification process of the alloy melt. After cooling, a titanium-based hydrogen storage alloy is obtained.

[0012] In the AB2 type hydrogen storage alloy, side A represents the hydrogen-absorbing element, and side B represents the activating element. In this invention, Ti and Zr are chosen as the hydrogen-absorbing elements. Since the activation of titanium-based hydrogen storage materials is relatively difficult, elements such as Mn and Cr need to be added to improve their activation performance, enhance hydrogen absorption and desorption kinetics, and adjust the plateau pressure. Because the activating element cannot absorb hydrogen, this invention designs the atomic ratio to be Ti. a Zr 1-a- b Y b Mn x Cr1.8-x Fe 0.2 This ensures that the alloy has both high hydrogen storage capacity and good activation performance and kinetics.

[0013] The above-mentioned method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage includes, in step one, the raw materials comprising sponge titanium, sponge zirconium, yttrium blocks, electrolytic manganese sheets, chromium blocks, and iron granules. The order in which the raw materials are placed in the melting mechanism is as follows: bottom layer is electrolytic manganese sheets, middle layer is sponge zirconium and chromium blocks, and top layer is sponge titanium, yttrium blocks, and iron granules. When preparing the raw materials, Mn is increased by 3% to 5% by mass to compensate for burn-off.

[0014] This invention improves the melting rate by placing the electrolytic manganese sheet with the lowest melting point at the bottom layer. After the electrolytic manganese sheet melts, it can promote the melting of the high-melting-point sponge zirconium and chromium blocks on the upper layer.

[0015] In the above-mentioned method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage, the vacuum melting temperature in step one is 1500℃~1650℃, and the holding time is 5min~10min.

[0016] This invention sets the vacuum melting temperature at 1500℃~1650℃, near the melting point of the titanium-based hydrogen storage alloy, to avoid the alloy not being fully melted due to excessively low melting temperature. In particular, high-melting-point elements such as Zr and Cr are difficult to melt, and low-melting-point elements (such as Mn) volatilize significantly.

[0017] In the above-mentioned method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage, the ultrasonic parameters in steps one and two are as follows: processing time 3 min to 5 min, ultrasonic frequency 15 kHz to 25 kHz, and ultrasonic power 800 W to 2000 W.

[0018] The titanium-based hydrogen storage alloy of this invention has a high melting point and viscosity, requiring sufficient time (3-5 minutes) for the ultrasonic effect to be transmitted to the entire melt area to ensure uniform processing. Excessive processing time will cause overheating, leading to grain coarsening and increased tool head wear. Meanwhile, the cavitation threshold (the minimum sound intensity required to generate cavitation bubbles) is proportional to the frequency. The lower the frequency, the lower the cavitation threshold, and the easier it is to generate strong and violent cavitation, resulting in a stronger refining effect. Therefore, low-frequency ultrasound of 15kHz-25kHz is used, which is within the audible sound wave range.

[0019] The present invention sets the ultrasonic power to 800W~2000W. Since the ultrasonic power directly determines the amplitude of the sound pressure, if the ultrasonic power is too low, the cavitation and acoustic flow range will be difficult to cover the entire processing area; while if the ultrasonic power is too high, it will cause strong cavitation corrosion of the tool head, and may remelt or break the already formed fine crystals into unfavorable shapes.

[0020] In the above-mentioned method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage, the mold is preheated to a temperature of not less than 800°C before ultrasonic treatment in step two.

[0021] This invention preheats the ultrasonic rod and copper mold at a temperature above 800°C before casting the alloy melt, thus preventing the alloy from solidifying rapidly after casting, which would be detrimental to ultrasonic treatment.

[0022] In the above-mentioned method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage, the temperature of the alloy melt during ultrasonic treatment in step two is maintained at 50°C to 100°C above the solidus line.

[0023] This invention sets the melt temperature 50°C to 100°C above the solidus line during ultrasonic treatment. This avoids the melt being completely liquid when the temperature is too high, resulting in limited grain breakage. Conversely, when the temperature is too low, the solid fraction is too high, the melt viscosity increases, the resistance to ultrasonic wave propagation increases, and energy dissipation is severe.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. This invention, by setting a movable amplitude transformer and an ultrasonic probe on an induction melting furnace, enables ultrasonic treatment of the melt in a vacuum environment, avoiding melt oxidation and improving alloy purity and microstructure uniformity; at the same time, the movable amplitude transformer and ultrasonic probe can apply ultrasound to titanium-based hydrogen storage alloys during melting and solidification through an ultrasonic system, reducing production costs.

[0026] 2. This invention enhances melt convection, breaks up solute enrichment zones, accelerates the diffusion of elements in the alloy, and shortens melting time by applying ultrasound during the alloy smelting stage. Ultrasound can also reduce melt viscosity and improve fluidity, thereby reducing energy consumption for stirring or heating. In addition, the shock waves generated by ultrasonic cavitation can strip non-metallic inclusions from the melt and improve the purity of the final ingot.

[0027] 3. This invention applies ultrasound during the solidification stage of the melt. The microjets generated by ultrasonic cavitation can break dendrite arms and form more nucleation sites, which can effectively refine the grains and improve the hydrogen storage performance of titanium-based hydrogen storage alloys.

[0028] 4. This invention controls the ultrasonic processing parameters and the temperature of the melt in the mold. By combining the two, the degree of refinement of the alloy can be precisely controlled based on the ability of ultrasound to be transmitted to all parts of the alloy. This ensures that the alloy is uniformly processed in all parts while obtaining a high-quality hydrogen storage alloy.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1This is a schematic diagram of the structure of the titanium-based hydrogen storage material preparation device of the present invention.

[0031] Figure 2 This is a microstructure diagram of the titanium-based hydrogen storage material prepared in Example 2 of the present invention.

[0032] Figure 3 The hydrogen absorption and desorption kinetics curves of the titanium-based hydrogen storage material prepared in Example 2 of the present invention at different temperatures are shown.

[0033] Figure 4 PCT curves of the titanium-based hydrogen storage material prepared in Example 2 of this invention at different temperatures.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1—Vacuum chamber; 2—Melting mechanism; 3—Mold; 4—Vacuum pump; 5—Ultrasonic generator; 6—Amplitude rod; 7—Ultrasonic probe; 8—Tilting mechanism; 9—Magnetofluid sealing assembly; 10—Cross slide; 11—Heating coil; 12—Thermocouple; 13—First liftable support frame; 14—Second liftable support frame. Detailed Implementation

[0036] Example 1

[0037] like Figure 1 As shown, the solid hydrogen storage titanium-based hydrogen storage alloy preparation device of this embodiment includes a vacuum induction melting system and an ultrasonic generation system. The vacuum induction melting system includes a vacuum chamber 1, a melting mechanism 2 disposed in the vacuum chamber 1, a heatable mold 3, and a vacuum pump 4 connected to the vacuum chamber 1. The ultrasonic generation system includes an ultrasonic generator 5, an amplitude transformer 6, and an ultrasonic probe 7 connected in sequence. One end of the ultrasonic probe 7 extends into the vacuum chamber 1. The vacuum induction melting system is equipped with a moving positioning system for controlling the position of the ultrasonic probe 7.

[0038] In practical use, this embodiment uses a vacuum induction melting system and an ultrasonic generator system to prepare titanium-based hydrogen storage alloys under ultrasonic assistance. A melting mechanism 2 and a heatable mold 3 are installed in the vacuum chamber 1, along with an ultrasonic generator system. Raw materials are added to the melting mechanism 2, ultrasonically melted, and then injected into the mold 3. Ultrasonic solidification is then performed under a constant temperature in the mold 3, resulting in a high-quality hydrogen storage alloy. A vacuum pump 4 is used to evacuate the vacuum chamber 1, which is also connected to an argon-filling device. An ultrasonic generator 5 is used to provide ultrasonic vibration to the ultrasonic probe 7. An ultrasonic amplitude transformer 6 is used to generate high-intensity ultrasound. A motion positioning system is used to control the position of the ultrasonic probe 7, ensuring that ultrasound is applied during both melting and solidification processes.

[0039] It should be noted that in this embodiment, the mobile positioning system is operated by an experienced operator. By precisely adjusting the depth of the ultrasonic probe 7 into the melt to 1 / 3 to 2 / 3, it helps to form a circulation that covers the entire melt volume and can prevent disturbances near the ultrasonic probe 7 from drawing a large amount of surface oxide film into the melt, thus ensuring that the effects of suppressing segregation and refining grains can be achieved.

[0040] like Figure 1 As shown, in this embodiment, the mobile positioning system includes a cross slide 10 set at the top of the vacuum chamber 1 and a second liftable support frame 14 for adjusting the height of the ultrasonic probe 7. The second liftable support frame 14 is fixedly connected to the slider of the cross slide 10. The amplitude rod 6 is fixedly connected to the end of the ultrasonic probe 7 away from the vacuum chamber 1 and the second liftable support frame 14. The end of the ultrasonic probe 7 extending out of the vacuum chamber 1 is fitted with a magnetic fluid sealing assembly 9 and a vacuum bellows.

[0041] In practical use, in this embodiment, a cross slide 10 is set at the top of the vacuum chamber 1 to control the horizontal position of the ultrasonic probe 7, enabling it to move horizontally and appear above the melting mechanism 2 and the mold 3; a second liftable support frame 14 is set to control the vertical height of the ultrasonic probe 7, enabling it to move up and down, and to cooperate with the cross slide 10 to extend into the melting mechanism 2 or the mold 3; specifically, the second liftable support frame 14 is fixedly connected to the slider of the cross slide 10, so that the second liftable support frame 14 can move horizontally with the slider, and the amplitude rod 6 is fixedly connected to the second liftable support frame 14. When the slider moves, the amplitude rod 6 also moves, and can drive the ultrasonic probe 7 fixedly connected to it to move.

[0042] A magnetic fluid sealing assembly 9 and a vacuum bellows are fitted onto one end of the ultrasonic probe 7 extending out of the vacuum chamber 1. Specifically, the magnetic fluid sealing assembly 9 is connected to the top of the ultrasonic probe 7, one end of the vacuum bellows is fixedly connected to and sealed with the magnetic fluid sealing assembly 9, and the other end of the vacuum bellows completely covers the channel at the top of the vacuum chamber 1 used for inserting the ultrasonic probe 7, and the contact part between the vacuum bellows and the vacuum chamber 1 is sealed. While achieving vacuum sealing, the ultrasonic probe 7 is allowed to perform linear and rotational movements within a certain range. Specifically, the vacuum bellows is composed of several bellows with diameters ranging from small to large, which are sealed and connected by joints, and the smallest diameter end of the bellows matches the magnetic fluid sealing assembly 9.

[0043] like Figure 1 As shown, further, in this embodiment, the amplitude rod 6 has a microchannel cooling mechanism integrated inside, and the microchannel cooling mechanism is connected to a high-pressure gas device, the pressure of which is 0.5MPa~1MPa.

[0044] In practical use, this embodiment incorporates a microchannel cooling mechanism inside the amplitude transformer 6, connected to a high-pressure gas device. This mechanism allows for the introduction of 0.5MPa~1MPa high-pressure helium gas to cool the amplitude transformer 6 and ultrasonic probe 7, preventing overheating that could cause the ultrasonic system to stop working. During actual use, high-pressure helium gas is used to cool the amplitude transformer 6 and ultrasonic probe 7 while simultaneously ultrasonicating the melt. When the high-pressure helium gas is ejected from the cooling mechanism, its internal energy decreases as it performs work, thus lowering its temperature and effectively cooling the amplitude transformer 6 and probe. Since the ultrasonic equipment generates heat during operation, and the radiant heat from the melt surface also causes the amplitude transformer 6 and ultrasonic probe 7 to heat up, excessively high temperatures can easily cause the amplitude transformer 6 to stop working; therefore, cooling is necessary.

[0045] like Figure 1 As shown, in this embodiment, the melting mechanism 2 is a metal oxide crucible, and a tilting mechanism 8 is fixedly connected to the metal oxide crucible. Heating coils 11 are provided on the outside of both the metal oxide crucible and the mold 3, and a first liftable support frame 13 is provided at the bottom of the mold 3.

[0046] In practical use, this embodiment uses a metal oxide crucible to avoid the reaction between Cr and graphite crucible during the alloy melting process. The metal oxide crucible is selected from magnesium oxide crucible, aluminum oxide crucible, and calcium oxide crucible. Heating coils 11 are provided on both the metal oxide crucible and the outside of the mold 3 to melt the raw materials and preheat the mold 3. A tilting mechanism 8 is fixedly connected to the metal oxide crucible to control the rotation of the metal oxide crucible, and a first liftable support frame 13 is provided at the bottom of the mold 3 to adjust the height of the mold 3. This allows for the operation of transferring the melt from the crucible to the mold 3.

[0047] Preferably, in this embodiment, a copper mold 3 with high thermal conductivity is used, which can quickly conduct heat, and copper is not easy to react with titanium alloy, avoiding serious pollution; and a thermocouple 12 is set on the copper mold 3, the instrument part of the thermocouple 12 extends out of the vacuum chamber 1, and the thermocouple 12 wire at the measuring end of the thermocouple 12 passes through the wall of the vacuum chamber 1 and extends into the melt, for real-time detection of the actual temperature of the melt.

[0048] Examples 2-4 all utilize the apparatus described in Example 1 to prepare titanium-based hydrogen storage alloys for solid-state hydrogen storage.

[0049] Example 2

[0050] The preparation method of this embodiment includes the following steps:

[0051] Step 1: Sponge titanium, sponge zirconium, yttrium blocks, electrolytic manganese sheets, chromium blocks, and iron granules are prepared according to the chemical formula Ti. 0.7 Zr0.3 Mn 1.1 Cr 0.7 Fe 0.2 Raw material preparation was carried out, with an additional 3% (by mass) of Mn added as a burn-off compensation. Electrolytic manganese sheets were placed at the bottom of the magnesium oxide crucible, followed by evenly distributed sponge zirconium and chromium blocks. Finally, sponge titanium and iron particles were evenly distributed on top, and then a vacuum of 1×10⁻⁶ was applied. -2 Below Pa, argon gas with a pressure of 0.01MPa~0.1MPa is introduced as a protective gas, the temperature is raised to 1600℃, and after the alloy is completely melted, it is held at the temperature for 5 minutes. After holding at the temperature for 2 minutes, the ultrasonic probe 7 is inserted into the melt and ultrasonic vibration at an ultrasonic frequency of 15kHz and an ultrasonic power of 2000W is performed for 3 minutes to obtain the alloy melt.

[0052] Step 2: Before casting, turn on the heating coil 11 to preheat the mold 3 to above 800°C. Pour the alloy melt obtained in Step 1 into the mold 3. Then, immediately move the position of the ultrasonic probe 7 through the moving positioning system to insert it into the alloy melt. At this time, the temperature of the melt is 50°C to 100°C above the solidus line. Perform ultrasonic vibration at a frequency of 15kHz and an ultrasonic power of 2000W for 3 minutes. After the ultrasonic vibration is completed, cool it to obtain the titanium-based hydrogen storage alloy.

[0053] The microstructure and elemental distribution of the titanium-based hydrogen storage alloy prepared in this embodiment were tested, and the results are as follows: Figure 2 As shown, all elements are uniformly distributed in the matrix without obvious segregation, indicating that the preparation method of this embodiment can prepare a titanium-based hydrogen storage alloy with a uniform microstructure. Hydrogen absorption and desorption kinetics tests were performed on this titanium-based hydrogen storage alloy at different temperatures, and the results are as follows: Figure 3 As shown, the mass hydrogen storage densities of the alloy at 25℃, 45℃, 65℃, and 80℃ are 1.89wt%, 1.77wt%, 1.58wt%, and 1.36wt%, respectively, indicating that the material has a high hydrogen storage capacity. PCT tests were performed on this titanium-based hydrogen storage alloy at different temperatures, and the results are as follows: Figure 4 As shown, this titanium-based hydrogen storage alloy has a moderate plateau pressure and a small hysteresis.

[0054] Example 3

[0055] The preparation method of this embodiment includes the following steps:

[0056] Step 1: Sponge titanium, sponge zirconium, yttrium blocks, electrolytic manganese sheets, chromium blocks, and iron granules are prepared according to the chemical formula Ti. 0.8 Zr 0.17 Y 0.03 Mn 1.2 Cr 0.6 Fe 0.2Raw material preparation was carried out, with Mn added as a 4% (by mass) burn-off compensation. Electrolytic manganese sheets were placed at the bottom of the magnesium oxide crucible, followed by evenly distributed zirconium sponge and chromium blocks. Finally, titanium sponge and iron particles were evenly distributed on top, and then a vacuum of 1×10⁻⁶ was applied. -2 Below Pa, argon gas with a pressure of 0.01MPa~0.1MPa is introduced as a protective gas, the temperature is raised to 1650℃, and after the alloy is completely melted, it is held at the temperature for 7 minutes. After holding at the temperature for 3 minutes, the ultrasonic probe 7 is inserted into the melt and ultrasonic vibration at an ultrasonic frequency of 25kHz and an ultrasonic power of 1500W is performed for 4 minutes to obtain the alloy melt.

[0057] Step 2: Before casting, turn on the heating coil 11 to preheat the mold 3 to above 800°C. Pour the alloy melt obtained in Step 1 into the mold 3. Then immediately move the position of the ultrasonic probe 7 through the moving positioning system and insert it into the alloy melt. At this time, the temperature of the melt is 50°C to 100°C above the solidus line. Perform ultrasonic vibration at an ultrasonic frequency of 25kHz and an ultrasonic power of 1500W for 4 minutes. After the ultrasonic vibration is completed, cool it to obtain the titanium-based hydrogen storage alloy.

[0058] Testing revealed that the titanium-based hydrogen storage alloy prepared in this embodiment has a uniform microstructure and no obvious elemental segregation. The mass hydrogen storage density of this titanium-based hydrogen storage alloy at 25℃, 45℃, 65℃ and 80℃ is 1.91wt%, 1.76wt%, 1.62wt% and 1.39wt%, respectively, and it has a moderate plateau pressure and a small hysteresis.

[0059] Example 4

[0060] The preparation method of this embodiment includes the following steps:

[0061] Step 1: Sponge titanium, sponge zirconium, yttrium blocks, electrolytic manganese sheets, chromium blocks, and iron granules are prepared according to the chemical formula Ti. 0.9 Zr 0.03 Y 0.07 Mn 1.2 5Cr 0.55 Fe 0.2 Raw material preparation was carried out, with Mn added as a 5% (by mass) burn-off compensation. Electrolytic manganese sheets were placed at the bottom of the magnesium oxide crucible, followed by evenly distributed sponge zirconium and chromium blocks. Finally, sponge titanium and iron particles were evenly distributed on top, and then a vacuum of 1×10⁻⁶ was applied. -2 Below Pa, argon gas with a pressure of 0.01MPa~0.1MPa is introduced as a protective gas, the temperature is raised to 1700℃, and after the alloy is completely melted, it is held at the temperature for 10 minutes. After holding at the temperature for 5 minutes, the ultrasonic probe 7 is inserted into the melt and ultrasonic vibration at an ultrasonic frequency of 20kHz and an ultrasonic power of 800W is performed for 5 minutes to obtain the alloy melt.

[0062] Step 2: Before casting, turn on the heating coil 11 to preheat the mold 3 to above 800°C. Pour the alloy melt obtained in Step 1 into the mold 3. Then, immediately move the position of the ultrasonic probe 7 through the moving positioning system and insert it into the alloy melt. At this time, the temperature of the melt is 50°C to 100°C above the solidus line. Perform ultrasonic vibration at an ultrasonic frequency of 20kHz and an ultrasonic power of 800W for 5 minutes. After the ultrasonic vibration is completed, cool it to obtain the titanium-based hydrogen storage alloy.

[0063] Testing revealed that the titanium-based hydrogen storage alloy prepared in this embodiment has a uniform microstructure and no obvious elemental segregation. The mass hydrogen storage density of this titanium-based hydrogen storage alloy at 25℃, 45℃, 65℃ and 80℃ is 1.88wt%, 1.79wt%, 1.61wt% and 1.41wt%, respectively, and it has a moderate plateau pressure and a small hysteresis.

[0064] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a titanium-based hydrogen storage alloy for solid-state hydrogen storage, characterized in that, The preparation method includes the following steps: Step 1: According to the chemical formula Ti a Zr 1-a-b Y b Mn x Cr 1.8-x Fe 0.2 The raw materials are prepared and placed in the melting mechanism (2) for ultrasonic-assisted vacuum melting to obtain an alloy melt; the subscripts in the chemical formula represent the atomic ratio of each element, where a is 0.70~0.90, b is 0~0.07, and x is 1.10~1.25; the raw materials include sponge titanium, sponge zirconium, yttrium blocks, electrolytic manganese sheets, chromium blocks, and iron granules. The order in which the raw materials are placed in the melting mechanism (2) is as follows: the bottom layer is electrolytic manganese sheets, the middle layer is sponge zirconium and chromium blocks, and the top layer is sponge titanium, yttrium blocks, and iron granules; Step 2: The alloy melt obtained in Step 1 is poured into the mold (3) under vacuum conditions. At the same time, ultrasound is applied during the solidification of the alloy melt. After cooling, a titanium-based hydrogen storage alloy is obtained.

2. The method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage according to claim 1, characterized in that, The vacuum melting temperature in step one is 1500℃~1650℃, and the holding time is 5min~10min.

3. The method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage according to claim 1, characterized in that, The ultrasonic parameters mentioned in steps one and two are as follows: processing time 3 min to 5 min, ultrasonic frequency 15 kHz to 25 kHz, and ultrasonic power 800 W to 2000 W.

4. The method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage according to claim 1, characterized in that, Before the ultrasonic treatment described in step two, the mold (3) is preheated to a temperature of not less than 800°C.

5. The method for preparing a titanium-based hydrogen storage alloy for solid hydrogen storage according to claim 1, characterized in that, During the ultrasonic treatment described in step two, the temperature of the alloy melt is maintained at 50°C to 100°C above the solidus line.

6. A device for preparing titanium-based hydrogen storage alloys for solid-state hydrogen storage, characterized in that, The preparation method described in any one of claims 1 to 5 includes a vacuum induction melting system and an ultrasonic generating system. The vacuum induction melting system includes a vacuum chamber (1), a melting mechanism (2) disposed in the vacuum chamber (1), a heatable mold (3), and a vacuum pump (4) connected to the vacuum chamber (1). The ultrasonic generating system includes an ultrasonic generator (5), an amplitude transformer (6), and an ultrasonic probe (7) connected in sequence. One end of the ultrasonic probe (7) extends into the vacuum chamber (1). The vacuum induction melting system is provided with a moving positioning system for controlling the position of the ultrasonic probe (7). The mobile positioning system includes a cross slide (10) set at the top of the vacuum chamber (1) and a second liftable support frame (14) for adjusting the height of the ultrasonic probe (7). The second liftable support frame (14) is fixedly connected to the slider of the cross slide (10). The amplitude rod (6) is fixedly connected to the end of the ultrasonic probe (7) away from the vacuum chamber (1) and the second liftable support frame (14). The end of the ultrasonic probe (7) extending out of the vacuum chamber (1) is fitted with a magnetic fluid sealing assembly (9) and a vacuum bellows.

7. The apparatus for preparing a titanium-based hydrogen storage alloy for solid-state hydrogen storage according to claim 6, characterized in that, The amplitude transformer (6) has an integrated microchannel cooling mechanism inside, which is connected to a high-pressure gas device with a pressure of 0.5MPa~1MPa.

8. The apparatus for preparing a titanium-based hydrogen storage alloy for solid-state hydrogen storage according to claim 6, characterized in that, The melting mechanism (2) is a metal oxide crucible. A tilting mechanism (8) is fixedly connected to the metal oxide crucible. Heating coils (11) are provided on the outside of both the metal oxide crucible and the mold (3). A first liftable support frame (13) is provided at the bottom of the mold (3).

Images