A tantalum material and a method of making the same

Abstract

The application provides a tantalum material and a preparation method thereof. The preparation method comprises the following steps: S1, obtaining a carbonized tantalum by reducing tantalum pentoxide by using a carbon material, wherein the carbon material is selected from any one or more of graphite and carbon black; S2, mixing the carbonized tantalum and the tantalum pentoxide to form a mixture, wrapping the mixture with a tantalum metal, and then performing vacuum reduction sintering to obtain a tantalum reduction material block; and S3, performing electron beam melting on the tantalum reduction material block to obtain the tantalum material. In step S2, the sintering of the carbonized tantalum and the tantalum pentoxide is performed under the premise of being wrapped with the tantalum metal, that is, no organic binder is introduced in the sintering forming process, so that the carbon, oxygen and nitrogen caused by the sintering residue of the organic binder are effectively avoided, and the content of carbon, oxygen and nitrogen in the tantalum reduction material block is effectively reduced; and then the electron beam melting is further adopted to further reduce the content of interstitial elements such as nitrogen and oxygen by using the characteristics of the electron beam melting, so that the obtained tantalum material has the characteristics of low carbon, oxygen and nitrogen.

Description

Technical Field

[0001] This application relates to the field of metallurgical technology, specifically to a tantalum material and its preparation method. Background Technology

[0002] Tantalum, with its high temperature resistance, high strength, chemical stability, and good processing properties, has become an indispensable material in the aerospace, nuclear energy, and high-temperature technology industries. With the development of my country's military industry and the accelerated localization of equipment in the aerospace and power sectors, the demand for tantalum as a high-temperature alloy additive in aircraft engines and gas turbines is increasing. Therefore, there is an urgent need to introduce a new method for the rapid preparation and smelting of tantalum to meet the growing demand for high-temperature alloy additives in the aerospace, nuclear energy, and high-temperature technology industries.

[0003] Traditional tantalum bars are produced by reducing tantalum with potassium fluorotantalate and sodium, followed by water washing, acid washing, deoxidation, re-acid washing, and heat treatment to obtain tantalum powder. This powder is then cold-pressed and sintered at high temperature in a vacuum to produce tantalum bars. Alternatively, tantalum oxide is carbon-reduced, bonded, and then further carbon-reduced and sintered to obtain tantalum bars. However, tantalum bars prepared by traditional processes have a high content of interstitial elements such as carbon, oxygen, and nitrogen. When used as additives in high-temperature alloys, these interstitial elements can affect the mechanical properties of the high-temperature alloys. Summary of the Invention

[0004] This application provides a tantalum material and a method for preparing the same, to reduce the oxygen and nitrogen content therein.

[0005] The first aspect of this application provides a method for preparing a tantalum material, the method comprising:

[0006] Step S1: Tantalum pentoxide is reduced with carbon material to obtain tantalum carbide. The carbon material is selected from any one or more of graphite and carbon black.

[0007] Step S2: Tantalum carbide and tantalum pentoxide are mixed to form a mixture. The mixture is then coated with tantalum metal and subjected to vacuum reduction sintering to obtain a tantalum reduction material block.

[0008] Step S3: Electron beam melting is performed on the tantalum reducing material block to obtain tantalum material.

[0009] In any embodiment of this application, step S2 includes:

[0010] Tantalum carbide and tantalum pentoxide are mixed to form a mixture;

[0011] The mixture encapsulated in tantalum metal is placed in a graphite crucible, the inner wall of which is tantalum oxide.

[0012] The graphite crucible was placed in a vacuum reduction furnace for vacuum reduction sintering to obtain tantalum reduction raw material blocks;

[0013] The tantalum metal can be selected as tantalum foil, more preferably as tantalum foil with a thickness of 0.001mm-0.5mm, and even more preferably as tantalum foil with a thickness of 0.01mm-0.2mm.

[0014] In any embodiment of this application, in step S2, the weight ratio of tantalum carbide to tantalum pentoxide is 2:(1.01-1.05).

[0015] In any embodiment of this application, the mixing in step S2 is carried out in a mixer; the total weight of tantalum carbide and tantalum pentoxide in step S2 is M1, and the weight of the mixing medium used in the mixer is M2, optionally M2:M1 is 1:(3-5); optionally the mixing medium used in the mixer is rubber balls.

[0016] In any embodiment of this application, the process of placing a graphite crucible in a vacuum reduction furnace for vacuum reduction sintering includes:

[0017] After the temperature of the vacuum reduction furnace is raised to T1, it is held at that temperature for t1 time, where T1 is 1200℃-1300℃ and t1 is 1.5h-2.5h.

[0018] Then, the temperature is increased to T3 by a program of holding at T2 for t2 times after each increase in temperature, and then held at T3 for t3 times. Here, T2 is 150℃-250℃, t2 is 1.5h-2.5h, T3 is 1700℃-2000℃, t3 is 8h-12h, and the heating rate is 350℃ / h-450℃ / h.

[0019] In any embodiment of this application, in step S1, the weight ratio of carbon material to tantalum pentoxide is (15-25):100.

[0020] In any embodiment of this application, step S1 includes:

[0021] After mixing carbon materials and tantalum pentoxide in a mixer, the mixture is placed in a graphite boat and carbonized at high temperature under hydrogen protection. The mixing medium used in the mixer is a rubber ball, and the preferred carbonization temperature is 1800℃-2300℃.

[0022] In any embodiment of this application, step S3 before electron beam melting of the tantalum reduction material block further includes a process of crushing the tantalum reduction material block to 20mm-60mm.

[0023] In any embodiment of this application, in step S3, the tantalum reducing material block is melted at least twice in a vacuum horizontal electron beam furnace. Preferably, the vacuum degree of the electron beam furnace is controlled below 0.05 Pa, the energy density of the electron beam is 3500 J / m-5000 J / m, and the electron beam melting power is 350 kW-450 kW.

[0024] The second embodiment of this application provides a tantalum material, which is prepared using any of the preparation methods provided in the first embodiment.

[0025] In the preparation method of this application, step S1 uses a single carbonization reduction process to prepare tantalum carbide; then, tantalum carbide and tantalum pentoxide are sintered and formed under the premise of tantalum metal encapsulation, that is, no organic binder is introduced during the sintering process, thus effectively avoiding the carbon, oxygen and nitrogen residues due to organic binder sintering, thereby effectively reducing the carbon, oxygen and nitrogen content in the tantalum reduction raw material block; further, electron beam melting is used, and the content of interstitial elements such as nitrogen and oxygen is further reduced by utilizing the characteristics of electron beam melting, and the resulting tantalum material has the characteristics of low carbon, oxygen and nitrogen, which can improve the mechanical properties of high-temperature alloys when used as an additive. Detailed Implementation

[0026] The embodiments of this application will be described in further detail below with reference to the examples. The detailed description of the following embodiments is used to illustrate the principles of this application, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0027] As analyzed in the background section of this application, tantalum bars prepared by existing processes have a high content of interstitial elements such as carbon, oxygen, and nitrogen. To address this issue, this application provides a tantalum material and a method for preparing the same.

[0028] In the first embodiment of this application, a method for preparing tantalum material is provided. The method includes: step S1, reducing tantalum pentoxide with carbon material to obtain tantalum carbide, wherein the carbon material is selected from any one or more of graphite and carbon black; step S2, mixing tantalum carbide and tantalum pentoxide to form a mixture, encapsulating the mixture with tantalum metal, and then performing vacuum reduction sintering to obtain a tantalum reduction material block; step S3, performing electron beam melting on the tantalum reduction material block to obtain tantalum material.

[0029] In the above preparation method, step S1 uses a single carbonization reduction process to prepare tantalum carbide; then, tantalum carbide and tantalum pentoxide are sintered under the premise of tantalum metal encapsulation, that is, no organic binder is introduced during the sintering process, thus effectively avoiding the carbon, nitrogen and oxygen residues caused by organic binder sintering, and thus effectively reducing the carbon, nitrogen and oxygen content in the tantalum reduction material block; further, electron beam melting is used to further reduce the content of interstitial elements such as nitrogen and oxygen by utilizing the characteristics of electron beam melting, and the resulting tantalum material has the characteristics of low carbon, oxygen and nitrogen, which can improve the mechanical properties of high-temperature alloys when used as an additive.

[0030] In some embodiments of this application, step S2 includes: mixing tantalum carbide and tantalum pentoxide to form a mixture; placing the mixture coated with tantalum metal in a graphite crucible, the inner wall material of the graphite crucible being tantalum oxide; and placing the graphite crucible in a vacuum reduction furnace for vacuum reduction sintering to obtain a tantalum reduced material block. The inner wall of the graphite crucible is made of tantalum oxide (e.g., tantalum pentoxide), effectively solving the carbon contamination problem caused by the adhesion of the tantalum reduced material block to the graphite crucible after high-temperature sintering.

[0031] The aforementioned tantalum metal is primarily used to encapsulate mixtures without introducing impurities, allowing the mixture to be sintered and formed. Therefore, tantalum sheets or foils that achieve the above functions can both be used as tantalum metal. In some embodiments, the aforementioned tantalum metal can be selected as tantalum foil, and more preferably as tantalum foil with a thickness of 0.001mm-0.5mm. A thicker tantalum foil provides better encapsulation and impurity isolation in the mixture, but it also affects the removal of nitrogen and oxygen, and leads to increased energy consumption and reduced efficiency in vacuum reduction sintering. Conversely, a thinner tantalum foil weakens the encapsulation and forming effects on the mixture, potentially increasing the carbon content, but has less impact on the energy consumption and efficiency of vacuum reduction sintering. In some embodiments, the tantalum metal can be further selected as tantalum foil with a thickness of 0.01mm-0.2mm. This achieves both good impurity removal and forming effects, while effectively controlling the impact on vacuum reduction sintering.

[0032] After carbonization is completed in step S1, the weight ratio of tantalum carbide to tantalum pentoxide is calculated to be 2:1 according to the chemical reaction equation. However, oxygen is needed in the later stage of the reduction process to remove residual carbon. Therefore, excess Ta2O5 can be selected to remove residual carbon. To reduce the carbon content in the reducing material, in some embodiments, the weight ratio of tantalum carbide to tantalum pentoxide in step S2 is 2:(1.01-1.05). Experiments have shown that when the excess Ta2O5 is less than 4%, the carbon and oxygen content in the product decreases as the excess Ta2O5 increases. When the excess Ta2O5 is greater than 4%, the carbon content in the product decreases as the excess Ta2O5 increases, while the oxygen content increases. To reduce the carbon content in the tantalum reducing material block, the weight ratio of tantalum carbide to tantalum pentoxide is preferably 2:(1.01-1.05), and more preferably 2:1.04.

[0033] After completing step S1, in order to improve the vacuum reduction sintering efficiency in step S2, in some embodiments, tantalum carbide is crushed, ground, and sieved. Preferably, tantalum rods are used for grinding to avoid introducing impurities at this stage. For example, tantalum rods with a specification of [specification missing] are used. The tantalum rods are crushed and ground. To improve efficiency, the mass ratio of tantalum rods to tantalum carbide is (2-5):1. In some embodiments, the preferred sieve size is 100 mesh, that is, tantalum carbide powder with a particle size of less than 100 mesh is selected for step S2.

[0034] In some embodiments, to improve the mixing uniformity of tantalum carbide and tantalum pentoxide, the mixing in step S2 is carried out in a mixer; the total weight of tantalum carbide and tantalum pentoxide in step S2 is M1, and the weight of the mixing medium used in the mixer is M2, optionally M2:M1 is 1:(3-5). Optionally, the mixing medium used in the mixer is rubber balls, which have the characteristics of good elasticity, wear resistance, high temperature resistance, and non-detachment, and can be reused repeatedly. Using soft rubber material as the mixing medium avoids microscopic deformation caused by collision between powder particles and the medium, and utilizes the elasticity of the rubber balls to improve the material mixing effect.

[0035] In some embodiments, the process of placing the graphite crucible in a vacuum reduction furnace for vacuum reduction sintering includes: heating the vacuum reduction furnace to T1 and holding it at that temperature for t1 time, where T1 is 1200℃-1300℃ and t1 is 1.5h-2.5h; then heating to T3 at a rate of 350℃ / h-450℃ / h, where T2 is 150℃-250℃ and t2 is 1.5h-2.5h, and T3 is 1700℃-2000℃ and t3 is 8h-12h. Since no binder is used in step S2, there is no need to extend the holding time for binder decomposition and volatilization during sintering, resulting in a shorter total vacuum reduction sintering time and improved efficiency.

[0036] The process of reducing tantalum pentoxide with carbon material in step S1 of this application can refer to the conventional process of reducing tantalum oxide with carbon. In order to improve the degree of reduction of tantalum oxide, in some embodiments, the weight ratio of carbon material to tantalum pentoxide in step S1 is (15-25):100.

[0037] In some embodiments, step S1 includes: mixing carbon material and tantalum pentoxide in a mixer, then placing the mixture in a graphite boat for high-temperature carbonization under hydrogen protection. The mixing medium used in the mixer is rubber balls, and the preferred carbonization temperature is 1800℃-2300℃. Rubber balls are used as the mixing medium to mix the carbon material and tantalum pentoxide.

[0038] The advantage of electron beam melting is that it can further reduce the content of interstitial elements such as nitrogen and oxygen. In order to improve the efficiency of electron beam melting and the nitrogen and oxygen removal effect, in some embodiments, step S3 before electron beam melting of tantalum reduction material block also includes the process of crushing tantalum reduction material block to 20mm-60mm.

[0039] The specific process and operating parameters of electron beam melting can be referenced from the conventional tantalum electron beam melting process. In some embodiments, in step S3, the tantalum reducing material block is melted at least twice in a vacuum horizontal electron beam furnace. Preferably, the vacuum degree of the electron beam furnace is controlled below 0.05 Pa, the energy density of the electron beam is 3500 J / m-5000 J / m, and the electron beam melting power is 350 kW-450 kW.

[0040] In a second embodiment of this application, a tantalum material is provided, which is prepared by any of the above-described preparation methods.

[0041] The tantalum material prepared by the above preparation method of this application can be tantalum bar or tantalum block, wherein the carbon, oxygen and nitrogen content is low. For example, in some embodiments, the carbon content of the tantalum material prepared is less than 20 ppm, the nitrogen content is less than 30 ppm and the oxygen content is less than 30 ppm.

[0042] The beneficial effects of this application will be further illustrated below with reference to embodiments and comparative examples, but the scope of the present invention is not limited to these embodiments.

[0043] Example 1

[0044] Step 1: Weigh the raw materials tantalum oxide and carbon black according to the weight ratio and load them into a V-type mixer with a speed of 60-120 rpm. The mixing medium is rubber balls, and the weight ratio of the mixing medium to the raw materials is 1:4. Mix for 12 hours to obtain a mixed powder.

[0045] Step two: The mixed powder obtained in step one is removed and filled into a graphite boat, which is then placed in a high-temperature carbonization furnace under hydrogen protection for carbonization to obtain tantalum carbide. The carbonization temperature is 2000℃, the loading amount is 2kg / boat, the boat pushing speed is 30min / boat, and the hydrogen flow rate is ≥0.4m³ / min. 3 / h.

[0046] Step three: The tantalum carbide produced in step two is removed from the graphite crucible and placed in a grinding and sieving machine for crushing, grinding, and sieving to obtain tantalum carbide powder. The crushing and grinding media is a tantalum rod, and the tantalum rod has the following specifications: The weight ratio of tantalum rod to tantalum carbide is 3:1, and the sieve size is 100 mesh.

[0047] Step 4: Tantalum pentoxide and tantalum carbide powder obtained in Step 3 are loaded into a V-type mixer with a rotation speed of 60-120 rpm and mixed for 12 hours to obtain a mixture. The mixing medium is rubber balls. The weight ratio of the mixing medium to the total weight of tantalum pentoxide and tantalum carbide powder is 1:4, and the weight ratio of tantalum carbide to tantalum pentoxide is 2:1.04.

[0048] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.1 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 2 hours for every 200℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours. Maintain a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0049] Step 6: Crush the tantalum reduction material block obtained in Step 5. The size of the crushed tantalum reduction material block should be 20-60mm.

[0050] Step 7: The tantalum reduction material block obtained in Step 6 is evenly spread in a horizontal electron beam furnace crystallizer for electron beam melting. The vacuum degree of the furnace chamber is controlled below 0.05 Pa, the electron beam energy density is 4000 J / m, the melting power is controlled at 450 kW, and the cooling water temperature during melting is controlled at 25℃±2℃. After melting, the furnace is cooled naturally to obtain molten tantalum.

[0051] Example 2

[0052] The only difference from Example 1 is the operation of step five:

[0053] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.2 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 2 hours for every 200℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours. Maintain a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0054] The remaining steps are the same as in Example 1.

[0055] Example 3

[0056] The only difference from Example 1 is the operation of step five:

[0057] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.01 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 2 hours for every 200℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours. Maintain a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0058] The remaining steps are the same as in Example 1.

[0059] Example 4

[0060] The only difference from Example 1 is the operation of step five:

[0061] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.001 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 2 hours for every 200℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours, maintaining a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0062] The remaining steps are the same as in Example 1.

[0063] Example 5

[0064] The only difference from Example 1 is the operation of step five:

[0065] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.5mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 2 hours for every 200℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours. Maintain a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0066] The remaining steps are the same as in Example 1.

[0067] Example 6

[0068] The only difference from Example 1 is the operation of step five:

[0069] Step 5: Place a 0.1 mm thick tantalum foil in the crucible, then place the mixture obtained in Step 4 into the tantalum foil and wrap it. Place the graphite crucible into a vacuum reduction furnace for sintering. During sintering, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. The temperature is then increased again at a rate of 400℃ / h, with a holding time of 2 hours for every 200℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours, maintaining a vacuum level of 5 × 10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0070] The remaining steps are the same as in Example 1.

[0071] Example 7

[0072] The only difference from Example 1 is the operation of step five:

[0073] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.1 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 1.5 hours for every 150℃ increase. When the temperature reaches 1700℃, the holding time is 12 hours, maintaining a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0074] The remaining steps are the same as in Example 1.

[0075] Example 8

[0076] The only difference from Example 1 is the operation of step five:

[0077] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.1 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 in the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible in a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased at a rate of 400℃ / h, and held for 2.5 hours for every 250℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours. Maintain a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0078] The remaining steps are the same as in Example 1.

[0079] Example 9

[0080] The only difference from Example 1 is the operation of step five:

[0081] Step 5: First, coat the inner wall of the graphite crucible with tantalum oxide. Then, place a 0.1 mm thick tantalum foil in the crucible. Next, place the mixture obtained in Step 4 into the tantalum foil and wrap it with the tantalum foil. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During the sintering process, the temperature is increased to 1200℃ at a rate of 400℃ / h and held for 2 hours. Then, the temperature is increased again at a rate of 400℃ / h, and held for 2 hours for every 400℃ increase. When the temperature reaches 2000℃, the holding time is 8 hours. Maintain a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0082] The remaining steps are the same as in Example 1.

[0083] Example 10

[0084] The only difference from Example 1 is the operation of step six:

[0085] Step Six: Crush the tantalum reduction material blocks obtained in Step Five. The size of the crushed tantalum reduction material blocks should be 10-30mm. The smaller the crushed size of the tantalum reduction material, the easier it is to load. However, a lot of powder will be generated during the crushing process. The powdery material will be sucked away by the vacuum pump during the vacuuming process of melting, resulting in material loss.

[0086] The remaining steps are the same as in Example 1.

[0087] Example 11

[0088] The only difference from Example 1 is the operation of step six:

[0089] Step 6: Crush the tantalum reduction material block obtained in Step 5. The size of the crushed tantalum reduction material block should be 70-100mm.

[0090] The remaining steps are the same as in Example 1.

[0091] Example 12

[0092] The only difference from Example 1 is the operation of step two:

[0093] Step two: The mixed powder obtained in step one is taken out and filled into a graphite boat, which is then sent to a high-temperature carbonization furnace under hydrogen protection for carbonization to obtain tantalum carbide. The carbonization temperature is 2300℃, the loading amount is 2kg / boat, the boat pushing speed is 35min / boat, and the hydrogen flow rate is ≥0.3m³ / min.3 / h.

[0094] The remaining steps are the same as in Example 1.

[0095] Example 13

[0096] The only difference from Example 1 is the operation of step two:

[0097] Step two: The mixed powder obtained in step one is taken out and filled into a graphite boat, which is then sent to a high-temperature carbonization furnace under hydrogen protection for carbonization to obtain tantalum carbide. The carbonization temperature is 1800℃, the loading amount is 2kg / boat, the boat pushing speed is 25min / boat, and the hydrogen flow rate is ≥0.5m³ / min. 3 / h.

[0098] The remaining steps are the same as in Example 1.

[0099] Example 14

[0100] The only difference from Example 1 is that in step four, the weight ratio of tantalum carbide to tantalum pentoxide is 2:1.01.

[0101] Everything else is the same as in Example 1.

[0102] Example 15

[0103] The only difference from Example 1 is that in step four, the weight ratio of tantalum carbide to tantalum pentoxide is 2:1.05.

[0104] Everything else is the same as in Example 1.

[0105] Example 16

[0106] The only difference from Example 1 is that in step four, the weight ratio of tantalum carbide to tantalum pentoxide is 2:1.0.

[0107] Everything else is the same as in Example 1.

[0108] Comparative Example 1

[0109] The only difference from Example 1 is the operation of step five:

[0110] Step 5: Mix the mixture obtained in Step 4 with the shellac dissolved in alcohol and place it in a graphite crucible. Then, place the graphite crucible into a vacuum reduction furnace for sintering. During sintering, raise the temperature to 1200℃ at a rate of 400℃ / h and hold for 2 hours. Then, continue to raise the temperature at a rate of 400℃ / h, holding for 2 hours every 200℃ increase. When the temperature reaches 2000℃, hold for 8 hours, maintaining a vacuum degree of 5×10⁻⁶ in the vacuum reduction furnace. -2 Below Pa, after sintering, the material is cooled down in the furnace to obtain tantalum reduction raw material blocks.

[0111] The remaining steps are the same as in Example 1.

[0112] The following instruments were used to analyze the main elemental composition of smelted tantalum. C was analyzed using a carbon-sulfur analyzer, O and N were analyzed using an oxygen-nitrogen analyzer, and other metal elements were analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES). In each embodiment, the contents of W (5 ppm), Fe (3 ppm), Si (5 ppm), Ni (3 ppm), Cr (3 ppm), Mn (<1 ppm), Mo (<5 ppm), Zr (<1 ppm), Ti (<1 ppm), Nb (<10 ppm), and Cu (<1 ppm) were basically the same, but the contents of interstitial elements carbon, oxygen, and nitrogen differed. The specific contents of interstitial elements carbon, oxygen, and nitrogen are recorded in Table 1.

[0113] Table 1

[0114]

[0115]

[0116] As can be seen from the comparison of Examples 1 to 5 in Table 1, with the increase of tantalum foil thickness, the carbon content in the smelted tantalum gradually decreases while the nitrogen and oxygen content increases. This indicates that the tantalum foil has a good isolation effect, reducing carbon pollution in the environment, but it is not conducive to nitrogen and oxygen removal. When the tantalum foil thickness is too large, the smelting efficiency deteriorates, and the removal effects of carbon, nitrogen, and oxygen are all insufficient.

[0117] As can be seen from the comparison of Examples 1, 14 to 16 in Table 1, as the amount of Ta2O5 increases, the carbon content decreases, but the oxygen content increases.

[0118] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method of producing a tantalum material, characterized by, The preparation method comprises: Step S1, using carbon material to reduce the tantalum pentoxide to obtain the carbonized tantalum, the carbon material is selected from any one or more of graphite, carbon black; Step S2, the carbonized tantalum is mixed with the tantalum pentoxide to form a mixture, the mixture is wrapped with tantalum metal, and vacuum reduction sintering is performed to obtain a tantalum reduction material block; Step S3, the tantalum reduction material block is subjected to electron beam melting to obtain a tantalum material, The step S2 comprises: The carbonized tantalum is mixed with the tantalum pentoxide to form a mixture; The mixture wrapped with the tantalum metal is placed in a graphite crucible, and the inner wall material of the graphite crucible is tantalum oxide; The graphite crucible is placed in a vacuum reduction furnace for vacuum reduction sintering to obtain the tantalum reduction material block, The tantalum metal is a tantalum foil with a thickness of 0.01mm-0.2mm, Before the step S3 of electron beam melting of the tantalum reduction material block, the step S3 further comprises a process of crushing the tantalum reduction material block to 20mm-60mm.

2. The production method according to claim 1, characterized by, In the step S2, the weight ratio of the carbonized tantalum to the tantalum pentoxide is 2: (1.01-1.05).

3. The preparation method according to claim 1 or 2, characterized in that, The mixing in the step S2 is performed in a mixer, and the total weight of the carbonized tantalum and the tantalum pentoxide in the step S2 is M1, and the weight of the mixing medium used in the mixer is M2.

4. The preparation method according to claim 3, characterized in that, M2:M1 is 1: (3-5).

5. The preparation method according to claim 3, characterized in that, The mixing medium used in the mixer is a rubber ball.

6. The production method according to claim 1 or 2, characterized by, The process of placing the graphite crucible in a vacuum reduction furnace for vacuum reduction sintering comprises: After the temperature of the vacuum reduction furnace is raised to T1 and kept for t1, T1 is 1200℃-1300℃, and t1 is 1.5h-2.5h; Then, the temperature is raised to T3 with the program of raising the temperature by T2 and keeping for t2 each time, and the temperature is kept at T3 for t3, wherein T2 is 150℃-250℃, t2 is 1.5h-2.5h, T3 is 1700℃-2000℃, t3 is 8h-12h, and the rate of temperature rise is 350℃ / h-450℃ / h.

7. The production method according to claim 1 or 2, characterized by, In the step S1, the weight ratio of the carbon material to the tantalum pentoxide is (15-25):

100.

8. The production method according to claim 1 or 2, characterized by, The step S1 comprises: After the carbon material and the tantalum pentoxide are mixed in a mixer, they are placed in a graphite boat for high-temperature carbonization under hydrogen protection, and the mixing medium used in the mixer is a rubber ball.

9. The production method according to claim 8, characterized by, The carbonization temperature is 1800℃-2300℃.

10. The production method according to claim 1 or 2, characterized by, In the step S3, the tantalum reduction material block is melted at least twice in a vacuum horizontal electron beam furnace.

11. The method of claim 10, wherein, The vacuum degree of the electron beam furnace is controlled below 0.05Pa, the energy density of the electron beam is 3500 J / m-5000J / m, and the electron beam melting power is 350kw-450kw.

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