A titanium alloy shell component for multi-grain boundary tritium solid helium storage and its preparation method

Abstract

The present invention belongs to the technical field of powder metallurgy, and relates to a titanium alloy shell component for storing tritium and solid helium in a multi-grain boundary and a preparation method thereof. The present invention adopts the PREP powder making process and selects narrow particle size powder as raw material powder after vibration screening, and adopts a lower sintering molding temperature to effectively inhibit grain growth; in the powder preparation process, the molten droplets are rapidly cooled and solidified (the cooling rate is 10 4 ℃ / s~10 5 ℃ / s), so that the fine-grained structure in the prepared raw material powder can be retained, and finally a titanium alloy with multiple grain boundaries, fine grains and uniform structure is obtained, which can significantly improve the tritium and helium storage effect and extend the service life. Moreover, the material utilization rate of the titanium alloy shell parts is significantly improved through the sheath and core shape control.

Description

Technical Field

[0001] The invention belongs to the technical field of powder metallurgy, and relates to a titanium alloy shell component for storing tritium and solid helium at multiple grain boundaries and a preparation method thereof. Background Art

[0002] At present, due to the continuous reduction of non-renewable energy such as fossil fuels, the demand for renewable new energy is becoming more and more urgent. Fusion energy generated by the fusion of deuterium and tritium, energy released by nuclear reactions or decay, and hydrogen energy are renewable clean energy. In order to ensure the safe and convenient storage and transportation of hydrogen, as well as the efficiency and safety of tritium production and use, the research on high-performance tritium storage materials is of great significance. To this end, my country has proposed to vigorously develop nuclear energy and solve nuclear safety issues. Pure titanium and titanium alloys are one of the metal materials with the highest hydrogen absorption density discovered and used so far, and the room temperature equilibrium pressure of titanium tritium is extremely low, and it is often used as a target material or hydrogen storage material for storing tritium.

[0003] Tritium decays during storage and produces helium that is insoluble in tritiated compounds. The different tritium concentrations in titanium tritiated compounds, as well as the helium generated by the decay of tritium, will affect the structural stability of tritium storage components. As tritium decays, helium will continue to deposit in the tritiated compound system and gather at the grain boundaries, gradually gathering into helium bubbles, causing the tritiated compound system to expand in volume and change in mechanical properties. When the concentration exceeds the critical threshold (the He / Ti atomic ratio reaches about 0.27), the pressure inside the bubble increases sharply, and the helium bubbles expand and connect and move toward the metal surface or grain boundaries, eventually causing the material to fail. Previous studies have shown that increasing the number of interfaces in the material by refining the grain size can significantly improve the material's tritium and helium storage performance.

[0004] At present, the commonly used large-scale titanium materials for tritium and solid helium storage have the disadvantages of coarse grains, few grain boundaries, uneven organization, low purity, and low material utilization rate, or cannot take into account the cleanliness and material utilization rate while ensuring fine grains and uniform organization. For example, obtaining fine-grained organization by rapid cooling is an effective means in current industrial production, but for large-scale structures, it is extremely difficult to achieve high-speed cooling of parts. In addition, in the solidification process, promoting grain nucleation and inhibiting grain growth through inoculation or modification treatment to obtain fine casting grains is a widely used method in industrial production, but this method cannot achieve the molding of large-scale shell parts, and the addition of inoculants and inhibitors deteriorates the purity of the parts. Physical methods such as mechanical stirring and electromagnetic stirring are used to promote the fracture and crushing of dendrites to increase the number of grains, which can effectively control the solidification organization, but it is impossible to achieve the organization control of large-scale shell parts. For example, combined with molding processes such as die forging on the basis of casting, it is impossible to achieve uniform distribution of organization, and the material utilization rate is low. If the forging or precision casting forming process is used for segmented processing and then welded, there will be a risk of failure due to the inherent performance difference between the weld and the matrix. None of the above existing processes can achieve the net near-forming manufacturing of high-purity large-sized tritium storage titanium alloy shell parts with uniform structure, fine grains, and multiple crystal boundaries while ensuring the material utilization and purity of the parts. Summary of the invention

[0005] The purpose of the present invention is to overcome the disadvantages of the prior art and provide a titanium alloy shell component for storing tritium and solid helium with multiple grain boundaries and a preparation method thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] This method for preparing titanium alloy shell components for multi-grain boundary tritium and helium storage adopts the PREP powder making process (plasma rotating electrode atomization powder making process) and selects narrow particle size, fine particle powder as raw material powder after vibration screening; after hot isostatic pressing and low-temperature sintering treatment, the fine grain structure inside the raw material powder is retained in the titanium alloy shell component, and the tritium and helium storage performance of the titanium alloy shell component is improved by increasing the helium aggregation points in the tritium decay process.

[0008] Specifically, the raw material powder is TA0 titanium alloy powder, and its chemical composition, measured by mass percentage, includes the following components: Fe<0.15%, C<0.05%, N<0.01%, H<0.005%, O<0.10%, and the balance is Ti.

[0009] Specifically, the cooling rate of the molten droplets in the PREP powder making process is 10 4 ℃ / s~10 5 ℃ / s.

[0010] Specifically, the narrow particle size powder has a particle size range of 30 μm to 50 μm.

[0011] Specifically, an ultrasonic rotary vibrating screen is used and vibration screening is completed under an argon or helium protective atmosphere.

[0012] Specifically, the preparation method comprises the following steps:

[0013] Step 1: Utilize the PREP powder making process to make powder, and select powder with a particle size of 30 μm to 50 μm as raw material powder through vibration screening;

[0014] Step 2: Design the corresponding sheath and core according to the specifications of the titanium alloy shell for storing tritium and solid helium, and then use micro-plasma welding to complete the sheath production;

[0015] Step 3, heat treating the sleeve and the core;

[0016] Step 4: Vibration powder loading and degassing, electron beam sealing after degassing, degassing vacuum ≤ 1.0×10 -4 Pa;

[0017] Step 5, hot isostatic pressing the powder bag after welding to obtain a hot isostatic pressed blank; wherein the hot isostatic pressing temperature is 820°C to 850°C, the pressure is 100MPa to 150MPa, and the holding time is 150min to 180min;

[0018] Step 6, chemically corroding the hot isostatic pressed blank to obtain a processed blank;

[0019] Step 7: finishing the processed blank to obtain a titanium alloy shell component.

[0020] Specifically, the process parameters of the PREP milling process in step 1 are as follows:

[0021] The speed of titanium alloy rod is 30000r / min~32000r / min, the feed speed is 20mm / min~50mm / min, the distance between titanium alloy rod and plasma arc (PV value) is 30mm~50mm, the powder making current is 1000A~1400A, the powder making voltage is 80V~90V, and the powder making vacuum is <5×10 -3 Pa. In addition, before powder making, 3 to 5 rods are needed to wash the furnace to consume the residual gas components in the atomization chamber.

[0022] Specifically, the process parameters of the micro-plasma welding in step 2 are as follows: welding current is 10A~20A, arc voltage is 15V~30V, and welding speed is 0.5mm / s~2.5mm / s.

[0023] Specifically, in step 2, the outer diameter of the sheath is φ450mm~φ650mm, the inner diameter is φ420mm~φ620mm, and the height is 800mm~1200mm.

[0024] Specifically, step 3 includes:

[0025] The package is first cleaned with anhydrous ethanol, and then the package and the core are heat treated in a vacuum furnace. The temperature is set at 900°C~1100°C and the insulation time is 5h~8h.

[0026] Specifically, the electron beam current of the electron beam sealing welding in step 4 is 50mA~100mA, the acceleration voltage is 20~60kV, and the welding speed is 500mm / min~1500mm / min.

[0027] Specifically, the components and volume ratio of the etching solution used in the chemical etching in step 6 are as follows:

[0028] Water: sulfuric acid: nitric acid = (40%~50%): (20%~30%): (20%~30%), the corrosion liquid temperature is 40℃~60℃.

[0029] In addition, the present invention also provides a titanium alloy shell component prepared by the preparation method described in part or in whole above, wherein the titanium alloy shell component has a grain size of 5 μm to 10 μm, a thickness of 20 mm to 50 mm, and a length of 800 mm to 1200 mm.

[0030] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0031] 1) The present invention adopts the PREP powder making process and selects narrow particle size powder as raw material powder after vibration screening. During powder making, the molten droplets are rapidly cooled and solidified, and the cooling rate is 10 4 ℃ / s~10 5 ℃ / s, the raw material powder particles prepared are fine and of comparable size. After hot isostatic pressing and low-temperature sintering, the fine grain structure inside the particles is retained in the titanium alloy shell parts, so that the titanium alloy shell parts have more grain boundaries, increasing the helium accumulation points in the tritium decay process, thereby improving the material's tritium storage and helium solidification performance.

[0032] 2) Powders with a particle size of 30μm~50μm are selected for powder filling and hot isostatic pressing. Compared with the traditional hot isostatic pressing process (selecting 50μm~250μm powder for hot isostatic pressing sintering), the powder particle size range is narrow, the powder particle size is similar, and the raw material uniformity is good. Therefore, after sintering, the grain size of the titanium alloy shell parts is fine grains of about 5μm, and the distribution is uniform, and the mechanical properties are better.

[0033] 3) The cladding is made by micro-plasma welding with specific process parameters, which can effectively avoid the high-density tungsten inclusion phenomenon in the weld metal; the raw material powder used is prepared by the PREP powder making process, which does not involve crucibles and other media; before powder making, the powder making vacuum degree is controlled to be less than 5×10 -3 Pa, and 3 to 5 rods are used for furnace washing to fully consume the residual gas inside the equipment, so that the oxygen increment is significantly reduced (less than 30ppm); the screening process uses high-purity argon gas protection, and the obtained raw material powder has high purity, so that the purity of the final titanium alloy shell parts can be effectively guaranteed. Before loading the powder, the sheath is cleaned with anhydrous ethanol and subjected to high-temperature heat treatment to ensure that the impurities, oil stains, and oxide scale on the surface of the sheath are fully decomposed and removed, ensuring the cleanliness of the titanium alloy shell parts.

[0034] 4) The use of the sheathing and core control process can achieve the net near-forming of the titanium alloy shell parts, and the material utilization rate can be increased to 70%. In addition, the present invention adopts the pickling and finishing treatment method, which can significantly shorten the processing cycle of the titanium alloy shell parts and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 A flow chart of the method for preparing a titanium alloy shell component for storing tritium and solid helium at multiple grain boundaries provided by the present invention;

[0038] Figure 2 A scanning electron microscope photograph of a powder with a particle size of 30 μm to 50 μm provided by the present invention;

[0039] Figure 3 This is a metallographic photograph of the titanium alloy shell component provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0040] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.

[0041] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0042] It should be noted that the preparation method provided by the present invention is applicable to the preparation of all pure titanium alloys and other grades of titanium alloys with good tritium and helium storage properties, and is particularly applicable to the preparation of TA0 titanium alloy shell parts. Example 1

[0043] This embodiment provides a method for preparing a TA0 titanium alloy shell component for storing tritium and solid helium at multiple grain boundaries. Figure 1 As shown, the following steps are included:

[0044] Step 1: Use TA0 rods with a diameter of φ58 mm for PREP powder making. The powder making process parameters are as follows: TA0 rod speed is 30000r / min, feed speed is 20mm / min, PV value is 30mm, powder making current is 1000A, powder making voltage is 80V, powder making vacuum is 4.0×10 -3 Pa; before powdering, three rods were used to wash the furnace to consume the residual gas components in the atomization chamber; and the powder obtained by PREP was screened with argon protection using a rotary vibrating screen to obtain TA0 titanium alloy powder, with an argon purity of 99.999% and a powder particle size of 30μm~50μm (see Figure 2 As shown); wherein the chemical composition of the TA0 titanium alloy powder, in terms of mass percentage, includes the following components: Fe: 0.015%, C: 0.005%, N: 0.008%, H: 0.002%, O: 0.08%, and the balance is Ti;

[0045] Step 2: Design and manufacture a steel ladle (model 20 steel) with an outer diameter of φ650 mm, an inner diameter of φ620 mm, and a height of 1000 mm and a steel core (model 20 steel) assembly with a specification of φ618 mm×1000 mm; use micro-plasma to complete the welding of the ladle assembly, with a welding current of 15 A, an arc voltage of 16 V, and a welding speed of 1 mm / s;

[0046] Step 3: Clean the package with anhydrous ethanol, and then heat treat the package and the core in a vacuum furnace, with the temperature set to 1100° C. and the holding time being 5 hours;

[0047] Step 4: Vibrate and degas until the degassing vacuum reaches 8.5×10 -5 Pa, electron beam sealing welding was performed after degassing, the electron beam current was 50mA, the acceleration voltage was 50kV, and the welding speed was 600mm / min;

[0048] Step 5, hot isostatic pressing the powder bag after welding to obtain a hot isostatic pressed blank; wherein the hot isostatic pressing temperature is 850° C., the pressure is 140 MPa, and the holding time is 180 min;

[0049] Step 6, chemically corrode the hot isostatic pressed blank to remove the steel jacket, so as to obtain a processed blank; the temperature of the chemical corrosion process is maintained at 50° C., and the components and volume ratio of the corrosive liquid used in the chemical corrosion are water: sulfuric acid: nitric acid = 40%: 30%: 30%;

[0050] Step 7: Use a five-axis CNC lathe to finish the rough workpiece to obtain a titanium alloy shell part (see Figure 3 ), the grain size is about 5 μm, the structure is fine and uniform, and the material utilization rate is 65%. Compared with the traditional preparation method, the tritium absorption density of the product prepared in this embodiment is increased from 1.8×10 21 Tritium atoms / cm 3 Increased to 8.2×10 23 Tritium atoms / cm 3 . Example 2

[0051] This embodiment provides another method for preparing a TA0 titanium alloy shell component for storing tritium and solid helium at multiple grain boundaries, comprising the following steps:

[0052] Step 1: Use TA0 rods with a diameter of φ58 mm for PREP powder making. The powder making process parameters are as follows: TA0 rod speed is 30000r / min, feed speed is 35mm / min, PV value is 45mm, powder making current is 1400A, powder making voltage is 85V, powder making vacuum is 3.5×10 -3 Pa; before powdering, 4 rods were used to wash the furnace to consume the residual gas components in the atomization chamber; and the powder obtained by PREP was screened with argon protection using a rotary vibrating screen to obtain TA0 titanium alloy powder; the purity of argon was 99.999%, and the powder particle size was 30μm~50μm; wherein the chemical composition of the TA0 titanium alloy powder, in terms of mass percentage, included the following components: Fe: 0.015%, C: 0.005%, N: 0.005%, H: 0.002%, O: 0.075%, and the balance was Ti;

[0053] Step 2: Design and manufacture a steel ladle (model 20 steel) with an outer diameter of φ630 mm, an inner diameter of φ600 mm, and a height of 920 mm and a steel core (model 20 steel) with a specification of φ598 mm×920 mm; use micro-beam plasma to complete the welding of the ladle assembly, with a welding current of 12 A, an arc voltage of 20 V, and a welding speed of 1.5 mm / s;

[0054] Step 3: Clean the package with anhydrous ethanol, and then heat treat the package and the core in a vacuum furnace, with the temperature set to 1000° C. and the holding time being 6 hours;

[0055] Step 4: Vibrate and degas until the degassing vacuum reaches 8.5×10 -5 Pa, electron beam sealing welding was performed after degassing, the electron beam current was 100mA, the acceleration voltage was 40kV, and the welding speed was 800mm / min;

[0056] Step 5, hot isostatic pressing the powder bag after welding to obtain a hot isostatic pressed blank; wherein the hot isostatic pressing temperature is 830° C., the pressure is 120 MPa, and the holding time is 150 min;

[0057] Step 6, chemically corrode the hot isostatic pressed blank to remove the steel jacket, so as to obtain a processed blank; the temperature of the chemical corrosion process is maintained at 50° C., and the components and volume ratio of the corrosive liquid used in the chemical corrosion are water: sulfuric acid: nitric acid = 40%: 30%: 30%;

[0058] Step 7: The roughcast piece is finely processed by a five-axis CNC lathe to obtain a titanium alloy shell part, the grain size of which is about 5 μm, the structure is fine and uniform, and the material utilization rate is 62%, which is much higher than the processing level of forging. Compared with the traditional preparation method, the tritium absorption density of the part obtained in this embodiment is increased from 1.8×10 21 Tritium atoms / cm 3 Increased to 3.5×10 23 Tritium atoms / cm 3 . Example 3

[0059] This embodiment provides another method for preparing a TA0 titanium alloy shell component for storing tritium and solid helium at multiple grain boundaries, comprising the following steps:

[0060] Step 1: Use TA0 rods with a diameter of φ58 mm for PREP powder making. The powder making process parameters are as follows: TA0 rod speed is 32000r / min, feed speed is 50mm / min, PV value is 50mm, powder making current is 1200A, powder making voltage is 90V, powder making vacuum is 2.5×10 -3 Pa; before powdering, 5 rods were used to wash the furnace to consume the residual gas components in the atomization chamber; and the powder obtained by PREP was screened with argon protection using a rotary vibrating screen to obtain TA0 titanium alloy powder, the argon purity was 99.999%, and the powder particle size was 30μm~50μm; wherein the chemical composition of the TA0 titanium alloy powder, in terms of mass percentage, includes the following components: Fe: 0.015%, C: 0.005%, N: 0.005%, H: 0.002%, O: 0.070%, and the balance is Ti;

[0061] Step 2: Design and manufacture a steel ladle (model 20 steel) with an outer diameter of φ450 mm, an inner diameter of φ420 mm, and a height of 1200 mm and a steel core (model 20 steel) with a specification of φ618 mm × 1200 mm; use micro-beam plasma to complete the welding of the ladle assembly, with a welding current of 15 A, an arc voltage of 15 V, and a welding speed of 2.0 mm / s;

[0062] Step 3: Clean the package with anhydrous ethanol, and then heat treat the package and the core in a vacuum furnace at a temperature of 900° C. for 8 hours;

[0063] Step 4: Vibrate and degas until the degassing vacuum reaches 8.5×10 -5 Pa, electron beam sealing welding was performed after degassing, the electron beam current was 100mA, the acceleration voltage was 60kV, and the welding speed was 1200mm / min;

[0064] Step 5, hot isostatic pressing the powder bag after welding to obtain a hot isostatic pressed blank; wherein the hot isostatic pressing temperature is 850° C., the pressure is 140 MPa, and the holding time is 180 min;

[0065] Step 6, chemically corrode the hot isostatic pressed blank to remove the steel jacket, so as to obtain a processed blank; the temperature of the chemical corrosion process is maintained at 50° C., and the components and volume ratio of the corrosive liquid used in the chemical corrosion are water: sulfuric acid: nitric acid = 50%: 20%: 30%;

[0066] Step 7: The roughcast piece is finely processed by a five-axis CNC lathe to obtain a titanium alloy shell part, the grain size of which is about 5 μm, the structure is fine and uniform, and the material utilization rate is 65%. Compared with the traditional preparation method, the tritium absorption density of the part obtained in this embodiment is increased from 1.8×10 21 Tritium atoms / cm 3 Increased to 7.5×10 23 Tritium atoms / cm 3 .

[0067] Comparative Example

[0068] This comparative example adopts the existing preparation method to prepare the titanium alloy shell parts, such as the preparation method of Examples 1 to 3 disclosed in the existing patent document CN117259755A, which finally prepares the TC18 titanium alloy cylindrical thin-walled parts with a wall thickness of ≤3.5mm, which cannot meet the requirements of composition, structure, strength and plasticity and the tritium solid helium storage performance required in the present invention. This is because:

[0069] The present invention ensures the performance and purity of the product from the following four aspects: (1) The sheath is prepared by micro-plasma welding, which can effectively avoid the high-density tungsten inclusion phenomenon in the weld metal; (2) The welding sheath is cleaned with anhydrous ethanol and then further subjected to high-temperature heat treatment, which can effectively remove and decompose impurities, oil stains, and oxide scale on the surface of the sheath; (3) The vacuum degree before powder making is less than 5×10 -3 Pa, and 3 to 5 rods are used for furnace washing to fully consume the residual gas inside the equipment, thereby ensuring that the oxygen increment is far lower than the preparation method of large-sized TC18 titanium alloy thin-walled parts (the disclosed oxygen increment level is 50 to 150 ppm); (4) The present invention uses narrow particle size, fine particle powder of 30 μm to 50 μm as raw material, and the cooling rate during powder making is high (10 4 ℃ / s~10 5 ℃ / s), the grains are small and the particle size is comparable, so that the final product has uniform and fine-grained characteristics, which cannot be achieved by the preparation method disclosed in the existing patent document CN117259755A.

[0070] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0071] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for preparing a titanium alloy shell component for storing tritium and solid helium with multiple grain boundaries, characterized in that: A PREP powder making process is adopted and narrow particle size powder is selected as raw material powder after vibration screening; the fine grain structure inside the raw material powder is retained in the titanium alloy shell component through hot isostatic pressing and low temperature sintering, and the tritium storage and helium solidification performance of the titanium alloy shell component is improved by increasing the helium accumulation points in the tritium decay process; the preparation method comprises the following steps: Step 1: Powder is made by using the PREP powder making process, and powder with a particle size of 30 μm to 50 μm is selected as raw material powder by vibration screening; the cooling rate of the molten droplet in the PREP powder making process is 10 4 ℃ / s~10 5 °C / s; Step 2, designing the corresponding sheath and core according to the specifications of the titanium alloy shell for storing tritium and solid helium, and then using micro-beam plasma welding to complete the sheath production; the process parameters of micro-beam plasma welding are as follows: welding current is 10A-20A, arc voltage is 15V-30V, and welding speed is 0.5mm / s-2.5mm / s; Step 3, heat treating the sleeve and the core; Step 4: Vibrate powder loading and degassing, and then perform electron beam sealing welding. The degassing vacuum degree is ≤1.0×10 -4 Pa; Step 5, hot isostatic pressing the powder bag after welding to obtain a hot isostatic pressed blank; wherein the hot isostatic pressing temperature is 820° C. to 850° C., the pressure is 100 MPa to 150 MPa, and the holding time is 150 min to 180 min; Step 6, chemically corroding the hot isostatic pressed blank to obtain a processed blank; Step 7: fine-processing the processed blank to obtain a titanium alloy shell component; the titanium alloy shell component has a grain size of 5μm to 10μm, a thickness of 20mm to 50mm, and a length of 800mm to 1200mm.

2. The method for preparing a titanium alloy shell component for storing tritium and solid helium with multiple grain boundaries according to claim 1, characterized in that: The process parameters of the PREP milling process in step 1 are as follows: The speed of titanium alloy rod is 30000r / min~32000r / min, the feed speed is 20mm / min~50mm / min, the distance between titanium alloy rod and plasma arc is 30mm~50mm, the powder making current is 1000A~1400A, the powder making voltage is 80V~90V, and the powder making vacuum degree is <5×10 -3 Pa.

3. The method for preparing a titanium alloy shell component for storing tritium and solid helium with multiple grain boundaries according to claim 1, characterized in that: In step 2, the outer diameter of the sheath is φ450mm~φ650mm, the inner diameter is φ420mm~φ620mm, and the height is 800mm~1200mm.

4. The method for preparing a titanium alloy shell component for storing tritium and solid helium with multiple grain boundaries according to claim 1, characterized in that: Step 3 specifically includes: The package is first cleaned with anhydrous ethanol, and then the package and the core are heat treated in a vacuum furnace, the temperature is set at 900°C to 1100°C, and the insulation time is 5h to 8h.

5. The method for preparing a titanium alloy shell component for storing tritium and solid helium with multiple grain boundaries according to claim 1, characterized in that: The components and volume ratio of the etching solution used in the chemical etching in step 6 are as follows: Water: sulfuric acid: nitric acid = (40%~50%): (20%~30%): (20%~30%), the corrosion liquid temperature is 40℃~60℃.

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