Dysprosium target material preparation method and dysprosium target material prepared through dysprosium target material preparation method

Abstract

The invention relates to the field of preparation of high-purity dysprosium target materials, in particular to a preparation method of a dysprosium target material and the dysprosium target material prepared by the dysprosium target material. The preparation method comprises the steps that surface defects of a dysprosium casting are removed, hot rolling and grinding are conducted, and the dysprosium target material is obtained; the hot rolling conditions comprise that heating is conducted for 30 min to 40 min at the temperature of 680 DEG C to 720 DEG C, heating is conducted for 30 min to 40 min at the temperature of 680 DEG C to 720 DEG C, first rolling is conducted, the first rolling is conducted for 2 passes to 3 passes, the first rolling temperature is 550 DEG C to 700 DEG C, the total deformation amount after first rolling is 45% to 55%, and heat preservation is conducted for 10 min to 15 min at the temperature of 680 DEG C to 720 DEG C after first rolling; second rolling is conducted, the second rolling is conducted for 2-3 passes, the second rolling temperature is 550-700 DEG C, the total deformation amount after second rolling is 65-75%, and heat preservation is conducted for 10-15 min at the temperature of 680-720 DEG C after second rolling; third rolling is conducted, the third rolling is conducted for 2-3 passes, the third rolling temperature ranges from 500 DEG C to 700 DEG C, and the total deformation amount after third rolling ranges from 80% to 90%. According to the preparation method, the dysprosium target material which is large in size specification, uniform in internal structure and fine and consistent in crystal grain can be prepared.

Description

Technical Field

[0001] The invention relates to the field of high-purity dysprosium target material preparation, and in particular to a method for preparing a dysprosium target material and the dysprosium target material prepared thereby. Background Art

[0002] Metallic dysprosium (Dy) is a rare earth metal element with high melting and boiling points, as well as large magnetic moments. Dysprosium is widely used in magnetic materials, catalysts, luminescent materials and other fields. Especially in the field of magnetic materials, it is often used as an additive to increase the coercivity of NdFeB permanent magnet materials, but the direct addition of heavy rare earth elements increases the cost and reduces the remanence and magnetic energy product of permanent magnet materials; magnetron sputtering coating combined with grain boundary diffusion process Dy infiltration technology can solve the above problems well; target material is the key raw material for preparing thin films, and its quality and performance have an important influence on the performance of the film. In order to obtain high-quality thin films, large-sized fine-grained dysprosium rare earth targets are widely needed.

[0003] Chinese patent CN106637100B discloses a rare earth metal target material and a preparation method thereof, wherein the preparation method comprises subjecting a dysprosium ingot to free forging, cold rolling the free forging product to obtain a cold rolled product, and subjecting the cold rolled product to a heat treatment of quenching and tempering to obtain a dysprosium target material having a target diameter of 320 mm and an average grain size of 115 μm.

[0004] Chinese patent CN112725675B discloses a method for manufacturing a dysprosium / terbium target, which comprises melting and casting into an ingot, high temperature insulation and low temperature deformation processing, and finally mechanical processing into a dysprosium target of a desired shape.

[0005] Although the above preparation methods all use large plastic deformation methods such as forging and rolling to refine the grains, the above preparation methods still have insufficient grain refinement effect, resulting in uneven target material structure and cannot simultaneously meet the requirements of large-size fine-grained targets.

[0006] It is difficult to produce large-sized dysprosium targets with uniform and fine grains in the existing technology, because as the size of the dysprosium target increases, the difficulty of controlling the overall size will increase. There are few studies on dysprosium targets, and the current large-sized dysprosium target range is 100-300mm. However, it is difficult to achieve a grain size of less than 50μm for large-sized dysprosium targets.

[0007] In summary, there is an urgent need to solve the problem of how to provide a method for preparing a dysprosium target material with large size specifications, uniform internal structure, and fine and consistent grains. Summary of the invention

[0008] The present invention aims to solve the technical problem of how to provide a method for preparing a dysprosium target material with large size specifications, uniform internal structure and fine and uniform grains.

[0009] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a dysprosium target, characterized in that the preparation method comprises:

[0010] Remove surface defects of dysprosium castings, perform hot rolling and grinding to obtain dysprosium targets;

[0011] The hot rolling conditions include:

[0012] Heating at 680-720°C for 30-40min, performing the first rolling, the first rolling is 2-3 passes, the first rolling temperature is 550-700°C, the total deformation after the first rolling is 45-55%, and keeping at 680-720°C for 10-15min after the first rolling;

[0013] The second rolling is performed for 2-3 times, the second rolling temperature is 550-700°C, the total deformation after the second rolling is 65-75%, and the temperature is kept at 680-720°C for 10-15 minutes after the second rolling;

[0014] The third rolling is performed for 2-3 times, the third rolling temperature is 500-700° C., and the total deformation after the third rolling is 80-90%.

[0015] A second aspect of the present invention provides a dysprosium target material obtained by the above preparation method.

[0016] The beneficial effects of the present invention are:

[0017] The method provided by the present invention adopts rolling at a temperature greater than the recrystallization temperature of dysprosium target material, thereby improving the formability, reducing the rolling defects caused by the poor plasticity of the hexagonal structure, improving the product specifications, and performing multiple rolling processes. On the one hand, the grains are continuously broken, and on the other hand, dynamic recrystallization is continuously performed to achieve the purpose of refining the grains and uniform organization. At the same time, recrystallization annealing is not required after hot rolling, which reduces the process. The obtained dysprosium target has large size specifications and uniform internal organization, and the grains are fine and consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the EBSD image of the dysprosium target in Example 1;

[0019] Figure 2 This is a data diagram of the grain size of the dysprosium target material in Example 1. DETAILED DESCRIPTION

[0020] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0021] The dysprosium target material prepared by the dysprosium target material preparation method adopted in the prior art has insufficient grain refinement effect, resulting in uneven target material structure and failing to simultaneously meet the requirements of large-size fine-grained target materials.

[0022] In the present invention, the inventors found that if the rolling method is optimized, the dysprosium target material can have large size specifications and uniform internal structure, with fine and consistent grains.

[0023] To achieve this goal, the inventors tried to optimize the preparation method of the dysprosium target material. The inventors found that the above-mentioned purpose can be achieved through a specific rolling method.

[0024] To this end, the first aspect of the present invention provides a method for preparing a dysprosium target, wherein the preparation method comprises:

[0025] Remove surface defects of dysprosium castings, perform hot rolling and grinding to obtain dysprosium targets;

[0026] The hot rolling conditions include:

[0027] Heating at 680-720°C for 30-40min, performing the first rolling, the first rolling is 2-3 passes, the first rolling temperature is 550-700°C, the total deformation after the first rolling is 45-55%, and keeping at 680-720°C for 10-15min after the first rolling;

[0028] The second rolling is performed for 2-3 times, the second rolling temperature is 550-700°C, the total deformation after the second rolling is 65-75%, and the temperature is kept at 680-720°C for 10-15 minutes after the second rolling;

[0029] The third rolling is performed for 2-3 times, the third rolling temperature is 500-700° C., and the total deformation after the third rolling is 80-90%.

[0030] In the present invention, the total deformation is the ratio of the thickness of the dysprosium target material after each rolling to the thickness of the initial dysprosium casting.

[0031] In the present invention, the defects on the casting surface are removed in order to ensure the quality of rolling and improve the surface quality of the rolled product.

[0032] In the present invention, the dysprosium casting after removing surface defects is rolled after the temperature is greater than the recrystallization temperature, the larger columnar grains in the dysprosium casting are broken, the grains are further refined, and during the rolling process, the dysprosium casting undergoes dynamic recrystallization, thereby effectively refining the grains and making the structure uniform. In addition, during the rolling process, the temperature of the dysprosium casting is greater than the recrystallization temperature, which effectively improves the plasticity of the dysprosium casting and thereby reduces the deformation resistance of the dysprosium casting.

[0033] In the present invention, the dysprosium material has poor plasticity, and increasing the temperature can reduce rolling cracking, but the rolling process will cause the temperature to drop. Therefore, three rollings can ensure the temperature, reduce cracking, and form dynamic recrystallization to refine the grains. The reason for selecting a specific rolling temperature is to improve the plastic deformation ability through high temperature and promote the occurrence of dynamic recrystallization.

[0034] In the present invention, hot rolling technology is selected. The existing technology is generally cold rolling and warm rolling. The reason for the lack of hot rolling is that there is little research on the pure dysprosium system. In addition, it is found through actual operation that the oxidation produced by hot rolling only exists in a very thin layer. In the final product, surface treatment is performed to facilitate the removal of the oxide layer.

[0035] According to the present invention, the first rolling is continuously rolled for three passes, the second rolling is continuously rolled for two passes, and the third rolling is continuously rolled for three passes, and the rolling reduction rate of the initial passes of the first rolling, the second rolling and the third rolling is less than the rolling reduction rate of the subsequent passes.

[0036] In the present invention, the reduction rate is the ratio of the reduction amount after each rolling pass to the thickness of the dysprosium target material before each rolling pass.

[0037] In the present invention, the rolling reduction rate of the initial pass is smaller than the rolling reduction rate of the subsequent passes, which can break up the coarse grains and provide the energy required for dynamic recrystallization.

[0038] According to the present invention, in the first rolling, the rolling reduction rate of the first rolling first pass is 10-15%, the rolling temperature of the first rolling first pass is 650-700℃, the rolling reduction rate of the first rolling second pass is 20-25%, the rolling temperature of the first rolling second pass is 600-650℃, the rolling reduction rate of the first rolling third pass is 25-30%, and the rolling temperature of the first rolling third pass is 550-600℃.

[0039] According to the present invention, in the second rolling, the rolling reduction rate of the first pass of the second rolling is 10-15%, the rolling temperature of the first pass of the second rolling is 650-700°C, the rolling reduction rate of the second pass of the second rolling is 20-30%, and the rolling temperature of the second pass of the second rolling is 550-650°C.

[0040] According to the present invention, in the third rolling, the rolling reduction rate of the first pass of the third rolling is 10-15%, the rolling temperature of the first pass of the third rolling is 650-700°C, the rolling reduction rate of the second pass of the third rolling is 20-25%, the rolling temperature of the second pass of the third rolling is 600-650°C, the rolling reduction rate of the third pass of the third rolling is 20-25%, and the rolling temperature of the third pass of the third rolling is 500-600°C.

[0041] In the present invention, the above three rolling processes and the rolling reduction rate and rolling temperature of the specific passes are adopted, so that the obtained dysprosium target material has a large size specification and a more uniform grain size.

[0042] According to the present invention, the total deformation amount of the hot rolling is 80-90%.

[0043] According to the present invention, the purity of the dysprosium casting is 3N grade.

[0044] The second aspect of the present invention provides a dysprosium target material prepared by the above preparation method.

[0045] According to the present invention, the average grain size of the dysprosium target is 4-10 μm, and the size is 300-400 mm.

[0046] Test Method

[0047] The grain size measurement method of dysprosium target is:

[0048] Product sampling, cold mounting, acrylic powder and curing agent are mixed in a ratio of 2:1, the sample is placed at the bottom of the mold, the reagent is poured in, and after solidification, it is taken out for grinding and polishing. 600 mesh sandpaper, 1000 mesh sandpaper, 1200 mesh sandpaper, 1500 mesh sandpaper, 2000 mesh sandpaper, 3000 mesh sandpaper, 5000 mesh sandpaper are used to polish the sample in turn. Each time the sandpaper mesh is changed, it is necessary to ensure that the scratches on the previous layer are completely removed. Alcohol is used to cool the sample during the grinding process. The specific process of polishing is: first, rough polishing is performed, the dysprosium target is steadily pressed on a soft gray woolen polishing cloth, and rough polishing is performed with W2.5 diamond grinding paste, so that the dysprosium target moves back and forth in the radial direction while continuously rotating along itself. After the rough polishing is completed, velvet polishing cloth is used in combination with anhydrous alcohol for fine polishing until the surface is smooth. After the mechanical polishing is completed, the dysprosium target is further subjected to argon ion polishing to remove surface stress, and the test sample can be obtained.

[0049] Electron backscatter diffraction (EBSD) was used to characterize the samples and determine the grain size.

[0050] The technical scheme of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the embodiments described herein are only some embodiments of the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments implemented by ordinary technicians in this field without making creative improvements belong to the protection scope of the present invention.

[0051] Example 1

[0052] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0053] Heating at 700°C for 30 minutes, the first rolling is carried out, the first rolling first pass has a reduction ratio of 13.3%, the first rolling first pass has a rolling temperature of 660°C, the first rolling second pass has a rolling reduction ratio of 23%, the first rolling second pass has a rolling temperature of 620°C, the first rolling third pass has a rolling reduction ratio of 27%, the first rolling third pass has a rolling temperature of 570°C, the total deformation after the first rolling is 50%, and the steel is kept at 700°C for 10 minutes after the first rolling;

[0054] The second rolling is performed, the rolling reduction rate of the first pass of the second rolling is 14%, the rolling temperature of the first pass of the second rolling is 660°C, the rolling reduction rate of the second pass of the second rolling is 26%, the rolling temperature of the second pass of the second rolling is 600°C, the total deformation after the second rolling is 69%, and the temperature is kept at 700°C for 15 minutes after the second rolling;

[0055] The third rolling is performed, the rolling reduction rate of the first pass of the third rolling is 14%, the rolling temperature of the first pass of the third rolling is 670°C, the rolling reduction rate of the second pass of the third rolling is 25%, the rolling temperature of the second pass of the third rolling is 600°C, the rolling reduction rate of the third pass of the third rolling is 22%, the rolling temperature of the third pass of the third rolling is 540°C, and the total deformation after the third rolling is 84%;

[0056] A dysprosium target A1 was obtained.

[0057] Example 2

[0058] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0059] Heating at 700°C for 30 minutes, the first rolling is carried out, the first rolling first pass has a reduction ratio of 10%, the first rolling first pass has a rolling temperature of 650°C, the first rolling second pass has a rolling reduction ratio of 20%, the first rolling second pass has a rolling temperature of 600°C, the first rolling third pass has a rolling reduction ratio of 25%, the first rolling third pass has a rolling temperature of 550°C, the total deformation after the first rolling is 45%, and the steel is kept at 700°C for 10 minutes after the first rolling;

[0060] The second rolling is performed, the rolling reduction rate of the first pass of the second rolling is 10%, the rolling temperature of the first pass of the second rolling is 650°C, the rolling reduction rate of the second pass of the second rolling is 20%, the rolling temperature of the second pass of the second rolling is 550°C, the total deformation after the second rolling is 65%, and the temperature is kept at 700°C for 15 minutes after the second rolling;

[0061] The third rolling is performed, the rolling reduction rate of the first pass of the third rolling is 10%, the rolling temperature of the first pass of the third rolling is 650°C, the rolling reduction rate of the second pass of the third rolling is 20%, the rolling temperature of the second pass of the third rolling is 600°C, the rolling reduction rate of the third pass of the third rolling is 20%, the rolling temperature of the third pass of the third rolling is 500°C, and the total deformation after the third rolling is 80%;

[0062] A dysprosium target A2 was obtained.

[0063] Example 3

[0064] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0065] Heating at 700°C for 30 minutes, the first rolling is carried out, the first rolling first pass has a reduction ratio of 15%, the first rolling first pass has a rolling temperature of 700°C, the first rolling second pass has a rolling reduction ratio of 25%, the first rolling second pass has a rolling temperature of 650°C, the first rolling third pass has a rolling reduction ratio of 30%, the first rolling third pass has a rolling temperature of 600°C, the total deformation after the first rolling is 55%, and the steel is kept at 700°C for 10 minutes after the first rolling;

[0066] The second rolling is performed, the rolling reduction rate of the first pass of the second rolling is 15%, the rolling temperature of the first pass of the second rolling is 700°C, the rolling reduction rate of the second pass of the second rolling is 30%, the rolling temperature of the second pass of the second rolling is 650°C, the total deformation after the second rolling is 75%, and the temperature is kept at 700°C for 15 minutes after the second rolling;

[0067] The third rolling is performed, the rolling reduction rate of the first pass of the third rolling is 15%, the rolling temperature of the first pass of the third rolling is 700°C, the rolling reduction rate of the second pass of the third rolling is 25%, the rolling temperature of the second pass of the third rolling is 650°C, the rolling reduction rate of the third pass of the third rolling is 25%, the rolling temperature of the third pass of the third rolling is 600°C, and the total deformation after the third rolling is 90%;

[0068] A dysprosium target A3 was obtained.

[0069] Example 4

[0070] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0071] Heating at 700°C for 30 minutes, the first rolling is carried out, the first rolling first pass has a reduction ratio of 15%, the first rolling first pass has a rolling temperature of 660°C, the second rolling second pass has a rolling reduction ratio of 20%, the first rolling second pass has a rolling temperature of 620°C, the total deformation after the first rolling is 45%, and the steel is kept at 700°C for 10 minutes after the first rolling;

[0072] The second rolling is performed, the rolling reduction rate of the first pass of the second rolling is 10%, the rolling temperature of the first pass of the second rolling is 660°C, the rolling reduction rate of the second pass of the second rolling is 20%, the rolling temperature of the second pass of the second rolling is 600°C, the total deformation after the second rolling is 65%, and the temperature is kept at 700°C for 15 minutes after the second rolling;

[0073] The third rolling is performed, the rolling reduction rate of the first pass of the third rolling is 15%, the rolling temperature of the first pass of the third rolling is 670° C., the rolling reduction rate of the second pass of the third rolling is 20%, the rolling temperature of the second pass of the third rolling is 600° C., and the total deformation after the third rolling is 80%;

[0074] A dysprosium target material A4 was obtained.

[0075] Example 5

[0076] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0077] Heating at 700°C for 30 minutes, the first rolling is carried out, the first rolling first pass has a reduction ratio of 15%, the first rolling first pass has a rolling temperature of 660°C, the first rolling second pass has a rolling reduction ratio of 25%, the first rolling second pass has a rolling temperature of 620°C, the total deformation after the first rolling is 55%, and the first rolling is kept at 700°C for 10 minutes;

[0078] The second rolling is performed, the rolling reduction rate of the first pass of the second rolling is 15%, the rolling temperature of the first pass of the second rolling is 660°C, the rolling reduction rate of the second pass of the second rolling is 30%, the rolling temperature of the second pass of the second rolling is 600°C, the total deformation after the second rolling is 75%, and the temperature is kept at 700°C for 15 minutes after the second rolling;

[0079] The third rolling is performed, the rolling reduction rate of the first pass of the third rolling is 15%, the rolling temperature of the first pass of the third rolling is 670° C., the rolling reduction rate of the second pass of the third rolling is 25%, the rolling temperature of the second pass of the third rolling is 600° C., and the total deformation after the third rolling is 90%;

[0080] A dysprosium target A5 was obtained.

[0081] Comparative Example 1

[0082] According to the preparation method of patent CN106637100B: put filamentary dysprosium with a purity of 99.9950% into a water-cooled copper crucible of a suspension smelting furnace, smelt it under an argon atmosphere, and control the pressure in the suspension smelting furnace to be 500Pa higher than the atmospheric pressure until the filamentary dysprosium is smelted into a dysprosium melt;

[0083] A water-cooled copper crucible containing dysprosium melt is pulled down at a speed of 1 mm / min. During the pulling down process, the dysprosium melt is gradually cooled and solidified, and the dysprosium melt is ultrasonically treated to refine the grains, thereby obtaining a dysprosium ingot; wherein the frequency of the ultrasonic wave is 40 kHz, and the power of the ultrasonic instrument is 20 kW;

[0084] The dysprosium ingot is placed at a temperature of 350-450° C., and free forging is performed in the X-axis and Y-axis directions respectively, with the deformation amount of each free forging being 21%, and after each free forging of the X-axis, the dysprosium ingot is heated to maintain the temperature of 350-450° C., and then the Y-axis free forging is performed, and then the dysprosium ingot is heated again to maintain the temperature of 350-450° C., and this cycle is repeated to obtain a final free forging product;

[0085] The free forging product is cold rolled, and the deformation amount of each cold rolling is maintained at 16% to obtain a cold rolled product; the cold rolled product is heat treated, wherein the heat treatment is carried out by quenching and tempering, the cold rolled product is heated to 650°C and immediately placed in oil for oil cooling, after oil cooling, it is placed at 300°C for tempering for 3.5 hours, and then mechanically processed to obtain the dysprosium target DA1.

[0086] Comparative Example 2

[0087] According to the preparation method of patent CN112725675B: metal dysprosium and metal copper are mixed in a weight ratio of 95% and 5% and placed in a vacuum induction melting furnace for smelting, high-purity argon is introduced to 1.2 atmospheres, and then the molten metal is poured into a water-cooled graphite mold. The weight of the ingot is 100 kg, and the shape is 15 cm in diameter and about 70 cm in length. Using the residual heat of the casting, the ingot is quickly transferred to an annealing furnace protected by 0.6 atmosphere argon for long-term annealing. The annealing furnace is set at 950°C, the holding time is 1440 minutes (24 hours), and then cooled to room temperature with the furnace. The annealed ingot is heated to 320°C and placed in a 1000-ton extruder with an extrusion ratio of 2:1. The diameter of the ingot becomes 10.5 cm after extrusion, and the extruded rod is directly cooled in oil. The cooled bar material is turned and milled to remove the head, tail and surface layer, and cut into short bars with a diameter of 10 cm and a length of about 50 cm. The bar material is cut into 25 mm thick wafer targets as needed, cleaned and then packaged to obtain dysprosium target DA2.

[0088] Comparative Example 3

[0089] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0090] Heating at 500°C for 30 minutes, performing the first rolling, the first rolling temperature is 480°C, the total deformation after the first rolling is 40%, and keeping at 500°C for 10 minutes after the first rolling;

[0091] Performing a second rolling process, the second rolling temperature is 460°C, the total deformation after the second rolling is 60%, and the temperature is kept at 500°C for 15 minutes after the second rolling;

[0092] Performing a third rolling process, wherein the third rolling temperature is 460° C., and the total deformation after the third rolling process is 75%;

[0093] The dysprosium target DA3 was obtained.

[0094] Comparative Example 4

[0095] Select dysprosium castings with a purity of 3N and remove surface defects of the dysprosium castings through machining;

[0096] Heating at 800°C for 30 minutes, performing the first rolling, the first rolling temperature is 780°C, the total deformation after the first rolling is 60%, and keeping at 800°C for 10 minutes after the first rolling;

[0097] Performing a second rolling process, the second rolling temperature is 780°C, the total deformation after the second rolling is 80%, and the temperature is kept at 800°C for 15 minutes after the second rolling;

[0098] Performing a third rolling process, wherein the third rolling temperature is 780° C., and the total deformation after the third rolling process is 90%;

[0099] The dysprosium target DA4 was obtained.

[0100] Mechanical properties of A1-A5 and DA1-DA4 were tested, and the grain size and size specifications are shown in Table 1

[0101] Table 1

[0102]

[0103]

[0104] By comparing the examples with the comparative examples, it can be seen that, through a specific rolling method, the dysprosium target material provided by the present invention has a large size specification and the grains are more uniform.

[0105] By the attached Figure 1 This is the EBSD image of the dysprosium target of Example 1, from which the grain morphology of A1 can be seen.

[0106] By the attached Figure 2 It can be seen that the average grain size of the dysprosium target material in Example 1 of the present invention is 6.4 μm, and the standard deviation is 4.3 μm, which is much better than the average grain size of the dysprosium target material in the comparative example.

[0107] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a dysprosium target, characterized in that: The preparation method comprises: Remove surface defects of dysprosium castings, perform hot rolling and grinding to obtain dysprosium targets; The hot rolling conditions include: Heating at 680-720°C for 30-40min, performing the first rolling, the first rolling is 2-3 passes, the first rolling temperature is 550-700°C, the total deformation after the first rolling is 45-55%, and keeping at 680-720°C for 10-15min after the first rolling; The second rolling is performed for 2-3 times, the second rolling temperature is 550-700°C, the total deformation after the second rolling is 65-75%, and the temperature is kept at 680-720°C for 10-15 minutes after the second rolling; The third rolling is performed for 2-3 times, the third rolling temperature is 500-700° C., and the total deformation after the third rolling is 80-90%.

2. The preparation method according to claim 1, characterized in that: The first rolling is performed continuously for three passes, the second rolling is performed continuously for two passes, and the third rolling is performed continuously for three passes. The rolling reduction ratio of the initial passes of the first rolling, the second rolling and the third rolling is smaller than the rolling reduction ratio of the subsequent passes.

3. The preparation method according to claim 2, characterized in that: In the first rolling, the rolling reduction rate of the first rolling first pass is 10-15%, the rolling temperature of the first rolling first pass is 650-700°C, the rolling reduction rate of the first rolling second pass is 20-25%, the rolling temperature of the first rolling second pass is 600-650°C, the rolling reduction rate of the first rolling third pass is 25-30%, and the rolling temperature of the first rolling third pass is 550-600°C; In the second rolling, the rolling reduction rate of the first pass of the second rolling is 10-15%, the rolling temperature of the first pass of the second rolling is 650-700°C, the rolling reduction rate of the second pass of the second rolling is 20-30%, and the rolling temperature of the second pass of the second rolling is 550-650°C; In the third rolling, the rolling reduction rate of the first pass of the third rolling is 10-15%, the rolling temperature of the first pass of the third rolling is 650-700℃, the rolling reduction rate of the second pass of the third rolling is 20-25%, the rolling temperature of the second pass of the third rolling is 600-650℃, the rolling reduction rate of the third pass of the third rolling is 20-25%, and the rolling temperature of the third pass of the third rolling is 500-600℃.

4. The preparation method according to claim 1, characterized in that: The total deformation amount of the hot rolling is 80-90%.

5. The preparation method according to claim 1, characterized in that: The purity of the dysprosium casting is 3N grade.

6. A dysprosium target material prepared by the preparation method according to any one of claims 1 to 5.

7. The dysprosium target according to claim 6, characterized in that The average grain size of the dysprosium target is 4-10 μm and the size is 300-400 mm.

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