Metal lithium target material and preparation method thereof

Abstract

The invention discloses a metal lithium target material and a preparation method thereof, and belongs to the technical field of metal lithium targets. The method comprises the following steps: carrying out hot isostatic pressing on a metal target material bottom plate and a powder material to obtain a lithium target material bottom plate; and the lithium strip and the lithium target material bottom plate are vertically pressed and punched, and the metal lithium target material is obtained. By adopting hot isostatic pressing, the metal target material bottom plate and the powder material are effectively and integrally connected in a solid state, the junction of the metal target material bottom plate and the powder material is tightly combined, and the defects of welding seams, heat affected zones, surface air holes, inclusions, undercuts or cracks and the like generated in a traditional preparation process are overcome. The embedded combination of the lithium strip and the bottom plate is completed by adopting a vertical punching mode, so that the damage to the bottom plate of the lithium target material is effectively avoided. The preparation method is simple, easy to operate, high in efficiency and low in cost, conditions are easy to control, and preparation of the special-shaped metal lithium target material and industrial continuous production of the metal lithium target material can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium metal target materials, and in particular to a lithium metal target material and a preparation method thereof. Background Art

[0002] Metallic lithium is widely used in batteries, ceramics, glass, lubricants, refrigerants, nuclear industry, and optoelectronics.

[0003] The current preparation methods of lithium metal targets mainly include:

[0004] (1) 3D printing technology inlay: This method combines hot metal lithium with the base plate. However, due to the very large surface tension of metal lithium, the winding or coating process usually results in a loose metal lithium layer or local leakage of the inlay, resulting in a large loss of metal lithium in the inlay area. At the same time, the metal lithium needs to be heated and softened, which requires a large amount of energy consumption and is prone to deterioration.

[0005] (2) Combination of heating and rolling: In this method, the surface tension of lithium metal is large, which is easy to deteriorate and bend. A large rolling pressure is required to ensure that the lithium metal is tightly combined with the bottom plate. At the same time, this method is inefficient and difficult to achieve large-scale production.

[0006] (3) Vacuum diffusion welding method: This method is to weld the lithium target blank and the back plate together to obtain a planar lithium target assembly, but it requires a mold to complete the preparation of lithium planar targets of different sizes.

[0007] (4) High-temperature lithium melting, magnetron sputtering lithium plating or vacuum evaporation lithium plating: This method is costly and easily produces metallic lithium residue during lithium plating. Metallic lithium is highly viscous and difficult to clean. In addition, this method is difficult to achieve the preparation of high-thickness metallic lithium targets, has low efficiency and high cost, and is not suitable for industrial production.

[0008] In view of this, the present invention is proposed. Summary of the invention

[0009] The object of the present invention is to provide a metal lithium target material and a preparation method thereof, so as to solve or improve the above technical problems.

[0010] The present invention can be implemented like this:

[0011] In a first aspect, the present invention provides a method for preparing a metallic lithium target, comprising the following steps:

[0012] Hot isostatic pressing the metal target base plate and the powder material to obtain a lithium target base plate;

[0013] The lithium ribbon and the lithium target base plate are vertically pressed to obtain a metallic lithium target.

[0014] In an optional embodiment, the metallic lithium target satisfies: Among them, R a Th is the roughness of the surface of the lithium target base plate combined with the powder material, in μm; Li is the thickness of the lithium strip, in μm.

[0015] In an alternative embodiment, the thickness of the lithium ribbon is ≥ 20 μm.

[0016] In an optional embodiment, the metal target base plate is made of a metal with heat dissipation properties.

[0017] In an optional embodiment, the metal target base plate is made of copper.

[0018] In an optional embodiment, the powder material includes at least one of metal element powder, alloy powder and ceramic powder.

[0019] In an optional embodiment, the metal target base plate has a first plate surface and a second plate surface that are arranged opposite to each other;

[0020] The powder material is hot isostatically pressed with at least one of the first plate surface and the second plate surface.

[0021] In an optional embodiment, the powder material is hot isostatically pressed with any one of the first plate surface and the second plate surface, and a heat dissipation structure is provided on the remaining plate surface.

[0022] In an optional embodiment, hot isostatic pressing includes a heating stage, a pressurizing stage, a heat and pressure holding stage, and a cooling stage;

[0023] Among them, the temperature of the heating stage is 25℃~3000℃; the pressure of the pressurizing stage is 0MPa~1000MPa; the time of the heat preservation and pressure holding stage is 0h~24h; the cooling rate is 5℃ / min~20℃ / min, and the temperature is reduced to room temperature.

[0024] In an optional embodiment, the vertical punching pressure is 1KN / cm 2 ~10KN / cm 2 .

[0025] In an optional embodiment, in a press machine used for vertical punching, a surface for contacting with the lithium strip is provided with a protective film.

[0026] In an optional embodiment, the protective film includes a PP film and / or a PET film.

[0027] In an optional embodiment, the preparation of the lithium strip includes: placing the original metal lithium strip on a unwinding roller, allowing the metal lithium strip to enter a correction system under the guidance of a guide roller, and after the correction, the metal lithium strip passes through a tension roller and enters a laser slitting system for slitting.

[0028] In a second aspect, the present invention provides a metal lithium target material prepared by the preparation method of any one of the aforementioned embodiments.

[0029] In an optional embodiment, the metal lithium target is a medical metal lithium target.

[0030] The beneficial effects of the present invention include:

[0031] The present invention uses hot isostatic pressing to effectively integrate the metal target base plate and the powder material into a solid-state connection. The junction of the metal target base plate and the powder material is tightly combined, which reduces and eliminates tiny pores or cracks on the outside of the connection area, avoids defects such as welds, heat-affected zones, surface pores, inclusions, undercuts or cracks generated in traditional preparation processes, and the performance of the junction between the metal target base plate and the powder material is basically the same as that of the parent material. The inlaid combination of the lithium belt and the base plate is completed by vertical punching, which effectively avoids damage to the lithium target base plate. The above-mentioned preparation method provided by the present invention is simple, easy to operate, easy to control conditions, high efficiency, low cost, and the lithium belt can be set to different thicknesses and shapes according to needs. It can prepare special-shaped metal lithium targets and can be industrially produced continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 A flow chart of a method for preparing a metallic lithium target provided by the present invention;

[0034] Figure 2 A schematic diagram of the structure of the equipment used for preparing the lithium ribbon and stamping the lithium ribbon and the lithium target base plate provided by the present invention;

[0035] Figure 3 This is a schematic structural diagram of the metal lithium target provided by the present invention.

[0036] Icons: 1-unwinding roller; 2-guide roller; 3-correction system; 4-metal lithium belt; 5-tension roller; 6-laser slitting system; 7-conveyor belt; 8-guide roller; 9-punch machine; 10-winding roller; 11-mechanical arm; 12-punch table; 13-metal target base plate; 14-solid layer of powder material; 15-metal lithium. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0038] The metal lithium target material and the preparation method thereof provided by the present invention are described in detail below.

[0039] Please refer to Figure 1 The present invention provides a method for preparing a metallic lithium target, comprising the following steps:

[0040] Hot isostatic pressing the metal target base plate 13 and the powder material to obtain a lithium target base plate;

[0041] The lithium ribbon and the lithium target base plate are vertically pressed to obtain a metallic lithium target.

[0042] In some optional embodiments, the metal lithium target satisfies: Among them, R a Th is the roughness of the surface of the lithium target base plate combined with the powder material, in μm; Li is the thickness of the lithium strip in μm. In other words, Figure 3 As shown, the thicker the thickness of the metal lithium 15 in the metal lithium target, the greater the roughness of the surface of the lithium target base plate combined with the powder material. In the present invention, the above roughness can be controlled by hot isostatic pressing process conditions. In addition, it is not excluded that the roughness can be controlled by lathe grinding, chemical corrosion or electrochemical corrosion.

[0043] It should be noted that the present invention controls the performance of the metal lithium target within The range can make the lithium belt and the lithium target base plate combine well and prevent bubbles from appearing between the two.

[0044] In some optional embodiments, the material of the metal target base plate 13 is a metal with heat dissipation performance, including but not limited to at least one of copper, aluminum, zinc and alloys thereof. In some preferred embodiments, the material of the metal target base plate 13 is copper.

[0045] The powder material may include at least one of a metal element powder, an alloy powder, and a ceramic powder.

[0046] Among them, metal element powders may exemplarily but not limitatively include metals with low chemical reactivity such as copper, aluminum, titanium, etc.; alloy powders may exemplarily but not limitatively include hard alloys and corrosion-resistant alloys such as copper alloys, aluminum alloys, titanium alloys, nickel alloys, and cobalt alloys; ceramic powders may exemplarily but not limitatively include at least one of zirconium oxide, aluminum oxide, silicon carbide, aluminum nitride, and silicon nitride.

[0047] In some optional embodiments, the metal target base plate 13 has a first plate surface and a second plate surface that are arranged opposite to each other; the powder material is hot isostatically pressed with at least one of the first plate surface and the second plate surface. For example, the powder material can be hot isostatically pressed with both plate surfaces, or can be hot isostatically pressed with only one of the plate surfaces (the first plate surface or the second plate surface).

[0048] When the powder material is hot isostatically pressed with any one of the first plate surface and the second plate surface, the remaining plate surface can be selectively provided with a heat dissipation structure as required. For example, the heat dissipation structure can be provided with protrusions or depressions or a combination of the two to increase the heat dissipation area and improve the heat dissipation effect. In addition, the heat dissipation structure can also be in any other form that can achieve the effect of increasing the heat dissipation area.

[0049] In some optional embodiments, hot isostatic pressing includes a heating stage, a pressurizing stage, a heat and pressure holding stage, and a cooling stage. Before the heating stage, a preparation stage may be included; after the cooling stage, a finished product processing stage may be included.

[0050] The preparation stage mainly involves placing the metal target base plate 13 and the powder material into a high-pressure container to ensure that the materials are correctly placed to facilitate the subsequent heating and pressurization process.

[0051] The heating stage mainly uses a heating device to evenly heat the material. This stage can increase the temperature of the material and make the particles inside it active, preparing for the subsequent pressurization process.

[0052] The pressurization stage is mainly to inject high-pressure gas into the high-pressure container through a high-pressure pump as the temperature rises, and apply equal pressure to the material in all directions. This stage requires maintaining a certain isostatic pressure at high temperature to ensure that the material maintains a certain shape and structure under high pressure.

[0053] The heat preservation and pressure holding stage is mainly to maintain a certain pressure and temperature for a period of time after the pressure is applied, so that the material can be fully densified under the high pressure and high temperature environment. This stage can increase the density of the material and improve the microstructure.

[0054] The cooling and depressurization stage is mainly to cool down and gradually reduce the pressure after the heat preservation and pressure maintenance. This stage allows the material to gradually return to normal temperature and pressure to avoid deformation or rupture of the material due to rapid pressure reduction.

[0055] The finished product processing stage mainly involves taking out the finished products and performing subsequent processing, such as polishing and testing, to ensure that the finished products meet the expected quality standards and usage requirements.

[0056] Among them, the temperature in the heating stage can be 25℃~3000℃, such as 25℃, 50℃, 100℃, 200℃, 500℃, 800℃, 1000℃, 1500℃, 2000℃, 2500℃ or 3000℃, or other values ​​within the range of 25℃~3000℃.

[0057] The pressure in the pressurization stage can be 0 MPa to 1000 MPa, such as 0 MPa, 5 MPa, 10 MPa, 20 MPa, 50 MPa, 80 MPa, 100 MPa, 200 MPa, 400 MPa, 600 MPa, 800 MPa or 1000 MPa, or other values ​​within the range of 0 MPa to 1000 MPa.

[0058] The time of the heat preservation and pressure holding stage can be 0h to 24h, such as 0h, 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h or 24h, or other values ​​within the range of 0h to 24h.

[0059] The cooling rate can be 5°C / min to 20°C / min, such as 5°C / min, 8°C / min, 10°C / min, 12°C / min, 15°C / min, 18°C / min or 20°C / min, or other values ​​within the range of 5°C / min to 20°C / min.

[0060] Cool down to room temperature (such as 20-30°C).

[0061] As mentioned above, by adopting hot isostatic pressing, in a high-temperature and high-pressure sealed container, high-pressure argon is used as the medium to apply isostatic pressure in all directions to the metal target base plate 13 and the powder material therein, so that the powder material forms a powder material solid layer 14, and the corresponding product has high density. This method enables the metal target base plate 13 and the powder material to be effectively integrated and solid-state connected, and the junction of the metal target base plate 13 and the powder material is tightly combined, reducing and eliminating tiny pores or cracks on the outside of the connection area, avoiding defects such as welds, heat-affected zones, surface pores, inclusions, undercuts or cracks generated in traditional preparation processes, and the performance of the junction of the metal target base plate 13 and the powder material is basically the same as that of the parent material. In addition, this method can not only connect parts with complex shapes on the contact surface and achieve strict dimensional control, but also connect multiple similar or heterogeneous materials (including brittle metals that cannot be connected by conventional methods or metals with large melting points) in one process, and achieve rapid and large-area connection. Therefore, by performing hot isostatic pressing according to the above conditions, a lithium target base plate with high density and good performance can be obtained.

[0062] In some optional embodiments, the lithium belt can be prepared by itself, and the schematic diagram of the preparation equipment can be referred to Figure 2 The preparation process may include: placing the original metal lithium belt 4 on the unwinding roller 1, and allowing the metal lithium belt 4 to enter the correction system 3 (corrector) under the guidance of the guide roller 2. After the correction, the metal lithium belt 4 passes through the tension roller 5 and enters the laser slitting system 6 to be slit according to the preset size. The slit metal lithium belt 4 falls on the conveyor belt 7 by its own gravity, and the remaining metal lithium belt 4 passes through the guide roller 8 and is wound on the winding roller 10 by tension.

[0063] In some other optional implementations, the lithium belt can also be purchased by itself.

[0064] In some optional embodiments, the thickness of the lithium ribbon is ≥20 μm, such as 80 μm to 300 μm. Under this thickness condition, the metal lithium target can be bombarded by neutrons to provide a stable neutron source.

[0065] In some optional embodiments, the vertical punching pressure may be 1 KN / cm 2 ~10KN / cm 2 , such as 1KN / cm 2 , 2KN / cm 2 , 2.5KN / cm 2 , 3KN / cm 2 、3.5KN / cm 2 , 4KN / cm 2 , 5KN / cm 2 , 6KN / cm 2 , 7KN / cm 2 , 8KN / cm 2, 9KN / cm 2 or 10KN / cm 2 etc., can also be 1KN / cm 2 ~10KN / cm 2 Other values ​​within the range.

[0066] During operation, Figure 2 Two telescopic robotic arms 11 are used, one for clamping the metal lithium belt 4 from the conveyor belt 7 and placing it on the punch 9, and the other for clamping the lithium target base plate and placing it on the punch 9. Through the vertical punching of the punch 9, the lithium belt and the lithium target base plate are embedded in each other, effectively avoiding damage to the lithium target base plate.

[0067] In some preferred embodiments, the surface of the punch 9 that is in contact with the metal lithium strip 4 may be provided with a protective film (such as a PP film and / or a PET film) to prevent the metal lithium from sticking.

[0068] Correspondingly, the present invention also provides a metallic lithium target material, which is prepared by the above-mentioned preparation method.

[0069] The above-mentioned metal lithium target can be used for conventional applications or for medical use. In general, the impact of light beams in the medical industry releases a large amount of heat. The bottom plate of the metal lithium target provided by the present invention is made of a metal with heat dissipation properties, which can play a role in heat dissipation. In addition, the heat dissipation structure provided on the bottom plate can also play a role in heat dissipation; therefore, the metal lithium target provided by the present invention can be used as a medical metal lithium target.

[0070] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0071] Example 1

[0072] This embodiment provides a square lithium metal target material with a size of 100 μm (thickness)×100 mm (length)×100 mm (width), and a preparation method thereof includes:

[0073] S1: Prepare lithium target base plate.

[0074] Prepare a square metal target base plate 13 (the base plate is made of copper) with a thickness of 1 mm and a length and width of 10 mm×10 mm, and prepare 50 g of metal aluminum powder.

[0075] The square metal target base plate 13 is placed in a hot isostatic pressing device, 1g of metal aluminum powder is weighed and attached to the first plate surface of the square metal target base plate 13, and the relevant mold is matched to perform hot isostatic pressing on the square metal target base plate 13 and the metal aluminum powder. The temperature in the heating stage is 650°C; the pressure in the pressurizing stage is 180MPa; the time of the heat preservation and pressure holding stage is 1h; the cooling rate is 5°C / min, and the temperature is reduced to 25°C.

[0076] According to the roughness tester, the roughness Ra of the surface of the obtained lithium target base plate combined with the metal aluminum powder is 30.2 μm.

[0077] S2: preparing lithium ribbon.

[0078] Prepare a rolled lithium ribbon with a thickness of 100μm, a length of 50m, and a width of 120mm as the original metal lithium ribbon 4, place the original metal lithium ribbon 4 on the unwinding roller 1, control the initial running speed to be 1m / min, and let the metal lithium ribbon 4 enter the correction system 3 (corrector) under the guidance of the guide roller 2. After the correction, the metal lithium ribbon 4 passes through the tension roller 5 and enters the laser slitting system 6 to be cut into the required shape and size of 100mm×100mm. The cut metal lithium ribbon 4 falls on the conveyor belt 7 by its own gravity, and the remaining metal lithium ribbon 4 passes through the guide roller 8 and is wound on the winding roller 10 by tension.

[0079] S3: Prepare metallic lithium target.

[0080] The lithium target base plate and lithium belt are transferred to the punching table 12 through the robot arm 11. The punching machine 9 provides a vertical downward pressure of 5KN / cm 2 , and obtain a metal lithium target material. The metal lithium target material can be transferred to a lithium target finished product storage area for storage and standby.

[0081] Calculated The formula is satisfied. After testing, the thickness of the lithium ribbon in the lithium metal target is 98μm, the lithium ribbon is tightly bonded to the lithium target base plate, there are no scratches on the surface, the lithium metal has a silvery white luster, and has not deteriorated. The lithium ribbon and the lithium target base plate cannot be manually peeled off, and the lithium target base plate has not deformed compared to before bonding.

[0082] Example 2

[0083] This embodiment provides a square lithium metal target with a dorsal fin and a size of 100 μm (thickness)×100 mm (length)×100 mm (width), and a preparation method thereof includes:

[0084] S1: Prepare lithium target base plate.

[0085] Prepare a square metal target base plate with a dorsal fin (the base plate is made of copper) with a thickness of 1 mm and a length and width of 10 mm×10 mm, and prepare 50 g of metal aluminum powder.

[0086] The square metal target base plate 13 is placed in a hot isostatic pressing device, 1g of metal aluminum powder is weighed and attached to the first plate surface of the square metal target base plate 13, a concave mold is matched on the second plate surface of the square metal target base plate 13, and the square metal target base plate 13 and the metal aluminum powder are subjected to hot isostatic pressing. The temperature of the heating stage is 650°C; the pressure of the pressurizing stage is 180MPa; the time of the heat preservation and pressure holding stage is 1h; the cooling rate is 5°C / min, and the temperature is reduced to 25°C.

[0087] According to the test by the roughness tester, the roughness Ra of the surface of the obtained lithium target base plate combined with the metal aluminum powder is 31 μm.

[0088] S2: preparing lithium ribbon.

[0089] Prepare a rolled lithium ribbon with a thickness of 100μm, a length of 50m, and a width of 120mm as the original metal lithium ribbon 4, place the original metal lithium ribbon 4 on the unwinding roller 1, control the initial running speed to be 1m / min, and let the original metal lithium ribbon 4 enter the correction system 3 (corrector) under the guidance of the guide roller 2. After the correction, the original metal lithium ribbon 4 passes through the tension roller 5 and enters the laser slitting system 6 to be cut into the required shape and size of 100mm×100mm. The cut metal lithium ribbon 4 falls on the conveyor belt 7 by its own gravity, and the remaining metal lithium ribbon 4 passes through the guide roller 8 and is wound on the winding roller 10 by tension.

[0090] S3: Prepare metallic lithium target.

[0091] After the lithium target base plate and the protective plate are tightly attached, they are transferred to the punching table 12 through the robot arm 11. The punching machine 9 provides a vertical downward pressure of 5KN / cm 2 , and obtain a metal lithium target material. The metal lithium target material can be transferred to a lithium target finished product storage area for storage and standby.

[0092] In the metal lithium target, it is calculated that The formula is satisfied. After testing, the thickness of the lithium ribbon in the lithium metal target is 99μm, the lithium ribbon is tightly combined with the lithium target base plate, the two cannot be separated, and the lithium target base plate has not deformed compared to before the combination.

[0093] Example 3

[0094] This embodiment provides a square lithium metal target material with a size of 300 μm (thickness)×100 mm (length)×100 mm (width), and a preparation method thereof includes:

[0095] S1: Prepare lithium target base plate.

[0096] Prepare a square metal target base plate 13 (the base plate is made of copper) with a thickness of 1 mm and a length and width of 10 mm×10 mm, and prepare 50 g of metal aluminum powder.

[0097] The square metal target base plate 13 is placed in a hot isostatic pressing device, 3g of metal aluminum powder is weighed and attached to the first plate surface of the square metal target base plate 13, and a concave mold is matched on the second plate surface of the square metal target base plate 13 to perform hot isostatic pressing on the square metal target base plate 13 and the metal aluminum powder. The temperature in the heating stage is 660°C; the pressure in the pressurization stage is 200MPa; the time in the heat preservation and pressure holding stage is 1h; the cooling rate is 5°C / min, and the temperature is reduced to 25°C. According to the roughness tester, the surface roughness Ra of the obtained lithium target base plate combined with the metal aluminum powder is 92μm.

[0098] S2: preparing lithium ribbon.

[0099] Prepare a rolled lithium ribbon with a thickness of 300μm, a length of 50m, and a width of 120mm as the original metal lithium ribbon 4, place the original metal lithium ribbon 4 on the unwinding roller 1, control the initial running speed to be 1m / min, and let the original metal lithium ribbon 4 enter the correction system 3 (corrector) under the guidance of the guide roller 2. After the correction, the original metal lithium ribbon 4 passes through the tension roller 5 and enters the laser slitting system 6 to be cut into the required shape and size of 100mm×100mm. The cut metal lithium ribbon 4 falls on the conveyor belt 7 by its own gravity, and the remaining metal lithium ribbon 4 passes through the guide roller 8 and is wound on the winding roller 10 by tension.

[0100] S3: Prepare metallic lithium target.

[0101] The lithium target base plate and lithium belt are transferred to the punching table 12 through the robot arm 11. The punching machine 9 provides a vertical downward pressure of 6KN / cm 2 , and obtain a metal lithium target material. The metal lithium target material can be transferred to a lithium target finished product storage area for storage and standby.

[0102] According to calculations, in the lithium metal target, It meets the requirements. After testing, the thickness of the lithium ribbon in the metal lithium target is 298μm, the lithium ribbon is tightly combined with the lithium target base plate, the two cannot be separated, and the lithium target base plate has not been deformed compared to before the combination.

[0103] Example 4

[0104] This embodiment provides a square lithium metal target material with a size of 100 μm (thickness)×100 mm (length)×100 mm (width), and a preparation method thereof includes:

[0105] S1: Prepare lithium target base plate.

[0106] Prepare a square metal target base plate 13 (the base plate is made of copper) with a thickness of 1 mm and a length and width of 10 mm×10 mm, and prepare 50 g of nickel-cobalt alloy metal powder.

[0107] The square metal target base plate 13 is placed in a hot isostatic pressing device, 3g of nickel-cobalt alloy metal powder is weighed and attached to the first plate surface of the square metal target base plate 13, and a concave mold is matched on the second plate surface of the square metal target base plate 13 to perform hot isostatic pressing on the square metal target base plate 13 and the metal aluminum powder. The temperature in the heating stage is 1240°C; the pressure in the pressurization stage is 200MPa; the time in the heat preservation and pressure holding stage is 1h; the cooling rate is 5°C / min, and the temperature is reduced to 25°C. According to the roughness tester, the surface roughness Ra of the obtained lithium target base plate combined with the metal aluminum powder is 35μm.

[0108] S2: preparing lithium ribbon.

[0109] Prepare a rolled lithium ribbon with a thickness of 300μm, a length of 50m, and a width of 120mm as the original metal lithium ribbon 4, place the original metal lithium ribbon 4 on the unwinding roller 1, control the initial running speed to be 1m / min, and let the original metal lithium ribbon 4 enter the correction system 3 (corrector) under the guidance of the guide roller 2. After the correction, the original metal lithium ribbon 4 passes through the tension roller 5 and enters the laser slitting system 6 to be cut into the required shape and size of 100mm×100mm. The cut metal lithium ribbon 4 falls on the conveyor belt 7 by its own gravity, and the remaining metal lithium ribbon 4 passes through the guide roller 8 and is wound on the winding roller 10 by tension.

[0110] S3: Prepare metallic lithium target.

[0111] The lithium target base plate and lithium belt are transferred to the punching table 12 through the robot arm 11. The punching machine 9 provides a vertical downward pressure of 8KN / cm 2 , and obtain a metal lithium target material. The metal lithium target material can be transferred to a lithium target finished product storage area for storage and standby.

[0112] According to calculations, in the lithium metal target, It meets the requirements. After testing, the thickness of the lithium ribbon in the metal lithium target is 99μm, the lithium ribbon is tightly combined with the lithium target base plate, the two cannot be separated, and the lithium target base plate has not been deformed compared to before the combination.

[0113] Example 5

[0114] This embodiment provides a square lithium metal target material with a size of 100 μm (thickness)×100 mm (length)×100 mm (width), and a preparation method thereof includes:

[0115] S1: Prepare lithium target base plate.

[0116] A square metal target base plate 13 (the base plate is made of copper) with a thickness of 1 mm and a length and width of 10 mm×10 mm was prepared, and 50 g of silicon carbide powder was prepared.

[0117] The square metal target base plate 13 is placed in a hot isostatic pressing device, 2g of silicon carbide powder is weighed and attached to the first plate surface of the square metal target base plate 13, and a concave mold is matched on the second plate surface of the square metal target base plate 13 to perform hot isostatic pressing on the square metal target base plate 13 and the metal aluminum powder. The temperature in the heating stage is 1240°C; the pressure in the pressurization stage is 200MPa; the time in the heat preservation and pressure holding stage is 1h; the cooling rate is 5°C / min, and the temperature is reduced to 25°C. According to the roughness tester, the surface roughness Ra of the obtained lithium target base plate combined with the metal aluminum powder is 37μm.

[0118] S2: preparing lithium ribbon.

[0119] Prepare a rolled lithium ribbon with a thickness of 300μm, a length of 50m, and a width of 120mm as the original metal lithium ribbon 4, place the original metal lithium ribbon 4 on the unwinding roller 1, control the initial running speed to be 1m / min, and let the original metal lithium ribbon 4 enter the correction system 3 (corrector) under the guidance of the guide roller 2. After the correction, the original metal lithium ribbon 4 passes through the tension roller 5 and enters the laser slitting system 6 to be cut into the required shape and size of 100mm×100mm. The cut metal lithium ribbon 4 falls on the conveyor belt 7 by its own gravity, and the remaining metal lithium ribbon 4 passes through the guide roller 8 and is wound on the winding roller 10 by tension.

[0120] S3: Prepare metallic lithium target.

[0121] The lithium target base plate and lithium belt are transferred to the punching table 12 through the robot arm 11. The punching machine 9 provides a vertical downward pressure of 8KN / cm 2 , and obtain a metal lithium target material. The metal lithium target material can be transferred to a lithium target finished product storage area for storage and standby.

[0122] According to calculations, in the lithium metal target, It meets the requirements. After testing, the thickness of the lithium ribbon in the metal lithium target is 99μm, the lithium ribbon is tightly combined with the lithium target base plate, the two cannot be separated, and the lithium target base plate has not been deformed compared to before the combination.

[0123] Comparative Example 1

[0124] This comparative example provides a square lithium metal target material with a size of 100 μm (thickness) × 100 mm (length) × 100 mm (width), and the preparation method thereof includes:

[0125] S1: directly use a square metal target base plate 13 (the base plate is made of copper) with a thickness of 1 mm and a length and width of 10 mm×10 mm.

[0126] S2: Same as Example 1.

[0127] S3: Same as Example 1.

[0128] After testing, the thickness of lithium strip in the lithium metal target is 97μm, and the roughness of copper plate is Ra=5.6μm. The metal lithium 15 and the copper plate substrate can be peeled off manually, but the metal lithium target cannot be used in practice.

[0129] In summary, the method for preparing the metal lithium target provided by the present invention has at least the following advantages:

[0130] (1) The powder material is formed on the metal target base plate 13 by using hot isostatic pressing technology, and the thickness and roughness of the lithium target base plate can be controlled. Then, the lithium belt and the copper base plate of the lithium target base plate are vertically pressed and the preparation of the metal lithium target is completed by inlaying, which is easy to operate;

[0131] (2) The preparation method of the lithium ribbon provided by the present invention can realize roll-to-roll continuous production;

[0132] (3) The thickness and shape of the lithium strip can be customized according to customer needs;

[0133] (4) The powder material in the copper base plate of the lithium target can thermally control the shape of lithium in the lithium target, saving mold costs;

[0134] (5) The preparation of special-shaped lithium metal targets and medical lithium metal targets has been realized;

[0135] (6) High efficiency, low cost, and can realize industrial continuous production.

[0136] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a metallic lithium target, characterized in that: The following steps are involved: Hot isostatic pressing the metal target base plate and the powder material to obtain a lithium target base plate; The lithium ribbon and the lithium target base plate are vertically pressed to obtain a metal lithium target.

2. The preparation method according to claim 1, characterized in that: The lithium metal target material satisfies: Among them, R a Th is the roughness of the surface of the lithium target base plate combined with the powder material, in μm; Li is the thickness of the lithium strip, in μm; Preferably, the thickness of the lithium strip is ≥20 μm.

3. The preparation method according to claim 1 or 2, characterized in that: The material of the metal target base plate is a metal with heat dissipation performance; Preferably, the metal target base plate is made of copper.

4. The preparation method according to claim 1 or 2, characterized in that: The powder material includes at least one of metal element powder, alloy powder and ceramic powder.

5. The preparation method according to claim 1 or 2, characterized in that: The metal target base plate has a first plate surface and a second plate surface which are arranged opposite to each other; The powder material is hot isostatically pressed with at least one of the first plate surface and the second plate surface.

6. The preparation method according to claim 5, characterized in that: The powder material is hot isostatically pressed with any one of the first plate surface and the second plate surface, and a heat dissipation structure is provided on the remaining plate surface.

7. The preparation method according to claim 1 or 2, characterized in that: Hot isostatic pressing includes heating stage, pressurizing stage, heat and pressure holding stage and cooling stage; Among them, the temperature of the heating stage is 25℃~3000℃; the pressure of the pressurizing stage is 0MPa~1000MPa; the time of the heat preservation and pressure holding stage is 0h~24h; the cooling rate is 5℃ / min~20℃ / min, and the temperature is reduced to room temperature.

8. The preparation method according to claim 1, characterized in that: The vertical punching pressure is 1KN / cm 2 ~10KN / cm 2 ; and / or, a punch press used for vertical punching has a protective film disposed on the surface in contact with the lithium strip; Preferably, the protective film comprises a PP film and / or a PET film.

9. The preparation method according to claim 1, characterized in that: The preparation of the lithium ribbon comprises: placing the original metal lithium ribbon on a reel, allowing the metal lithium ribbon to enter a deviation correction system under the guidance of a guide roller, and after the deviation correction, the metal lithium ribbon passes through a tension roller and enters a laser slitting system for slitting.

10. A metal lithium target, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9; Preferably, the metal lithium target is a medical metal lithium target.

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