Preparation method of Si-Zr high-entropy alloy for infiltration reaction

Abstract

The invention discloses a preparation method of a Si-Zr high-entropy alloy for infiltration reaction, the silicon-zirconium alloy is composed of metal elements Si and Zr, raw materials Zr-Si2.9 alloy powder and pure Si are subjected to ball milling in a vacuum ball mill and fully and uniformly mixed to obtain a mixed material, the mixed material is put into an oil press to be pressed into a cake-shaped block material, and the cake-shaped block material is dried to obtain the Si-Zr high-entropy alloy for infiltration reaction. And putting the pressed block material into a vacuum induction melting furnace for melting, discharging and cooling after the block material is fully melted, and carrying out finishing crushing, ball milling and powder preparation on the discharged silicon-zirconium alloy. In the technological process, Zr-Si2.9 alloy powder is used for replacing pure Zr powder, the preparation temperature is lowered, volatilization of pure Si at the high temperature is reduced, element composition of the silicon-zirconium alloy is relatively stable, the synthesis temperature is low, and the silicon-zirconium alloy can be effectively applied to industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy preparation, and particularly to a preparation method of Si-Zr high-entropy alloy for infiltration reaction. Background Art

[0002] With the development of new-generation rockets and advanced spacecrafts, future thermal protection systems require that the materials used in this field should be able to operate in an oxidizing atmosphere above 2000°C. By combining the excellent ablation resistance of ZrC ultra-high temperature ceramics and the oxidation resistance of SiC, introducing ZrC-SiC ceramics into the C / C substrate through reactive melt infiltration (RMI) can improve the oxidation resistance and ablation resistance of C / C composites. At the same time, Si-Zr alloy can effectively reduce the infiltration temperature and reduce the damage of high-temperature melt to fibers.

[0003] In the preparation process of traditional Si-Zr alloy, silicon and zirconium need to be melted successively under certain pressure and temperature conditions. However, when silicon is affected by high temperature, silicon may directly volatilize, changing from solid state directly to gaseous state without passing through the liquid state. The volatilization of silicon may lead to material loss and performance degradation. From the Si-Zr binary phase diagram, it can be seen that the Si-Zr binary system has two eutectic points, namely the Si-Zr26.5 alloy with a zirconium content of 26.5 wt.% and the Zr-Si2.9 alloy with a silicon content of 2.9 wt.%, and their melting points are 1370°C and 1570°C respectively, which are 480°C and 285°C lower than that of pure zirconium respectively. Therefore, we propose to use the Zr-Si2.9 alloy to prepare Si-Zr alloy to reduce the preparation temperature and reduce the loss of Si. Summary of the Invention

[0004] In order to solve the above problems, the present invention proposes a preparation method of Si-Zr high-entropy alloy for infiltration reaction to more precisely solve the above-mentioned problems.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention proposes a preparation method of Si-Zr high-entropy alloy for infiltration reaction, and the preparation method includes the following steps:

[0007] Step 1: Raw material preparation: Prepare silicon powder and zirconium powder;

[0008] Step 2: Prepare Zr-Si2.9 alloy powder: Weigh the raw materials according to the mass ratio of Zr:Si = 97.1:2.9, put the zirconium powder and silicon powder into a vacuum ball milling tank, evacuate and then fill with argon for protection and grind.

[0009] Step 3: Melting: Add the ground alloy powder into a crucible, evacuate the air and fill it with argon for protection. Heat it up to 1400 to 1500 °C and keep it warm for 1 to 2 hours to partially melt silicon and initiate a preliminary reaction with zircon. Then continue to heat it up to 1570 to 1650 °C and keep it warm for 2 to 3 hours to completely melt zircon and silicon. During the melting process, turn the crucible 3 to 4 times;

[0010] Step 4: Ultra-rapid cooling treatment: Pour the molten liquid into a copper mold for ultra-rapid cooling to form a uniform eutectic structure, and grind the block into powder using a ball mill;

[0011] Step 5: Preparation of mixed materials: Weigh 6.9 kg of Zr-Si2.9 alloy powder and 3.09 kg of silicon powder, put them into a ball mill, and ball mill for 12 hours under the conditions of evacuating the air and filling it with argon;

[0012] Step 6: Compression molding: Add a binder to the ball-milled mixed materials and press them into cylindrical blocks using a hydraulic press;

[0013] Step 7: Vacuum induction melting: Put the pressed blocks into a graphite crucible or kaolin crucible in a vacuum induction melting furnace, evacuate the air and then fill it with high-purity argon, repeat 2 to 3 times, keep the furnace pressure at 100 Pa, set the power supply power to 20 to 25 kW, gradually heat it up to 1400 to 1500 °C and keep it warm for 2.5 to 3 hours, continue to heat it up to 1600 - 1650 °C and keep it warm for 1 to 1.5 hours, cool it down to 1350 - 1500 °C and keep it warm for 1 to 1.5 hours, cut off the power and cool it down to below 50 °C and then take out the furnace;

[0014] Step 8: Finishing and crushing: Finish, crush and powder the silicon-zircon alloy blocks after taking out the furnace;

[0015] Step 9: Composition detection: Detect the content of each element in the powder.

[0016] Further, the silicon content in the Zr-Si2.9 alloy powder is 2.9 wt.%, the zircon content is 97.1 wt.%, the purity of the silicon powder is 99.99%, and the purity of the zircon powder is 99.99%.

[0017] Further, the binder is a polyvinyl butyral ethanol solution with a concentration of 10 wt.%.

[0018] Further, in Step 6, the hydraulic press presses cylindrical blocks at 1000 g per block, the pressing pressure is 20 MPa, and the size of the pressed block is Φ50×90 mm.

[0019] Further, the rotation speed of the ball mill in Step 5 is 100 revolutions / min.

[0020] Further, in Step 7, each furnace of alloy is turned and melted three to four times.

[0021] Further, in the ninth step, the powder is decomposed with hydrofluoric acid and perchloric acid and leached with hydrochloric acid to prepare a solution, and the content of each element is determined by inductively coupled plasma atomic emission spectrometry.

[0022] Further, when the content of Si or Zr measured in the ninth step is low, the prepared finished product is reground into powder, and the missing materials are added for re-preparation.

[0023] Advantages of the present invention:

[0024] 1. In the process proposed by the present invention, Zr-Si2.9 alloy powder is used instead of pure Zr powder, which reduces the preparation temperature, reduces the volatilization of pure Si at high temperature, makes the elemental composition of the silicon-zirconium alloy relatively stable, and has a relatively low synthesis temperature, which can be effectively applied to industrial production.

[0025] 2. By comparing the effects of different process parameters, the present invention provides a variety of optimization schemes. This diversified process design provides more choices for actual production and can be flexibly adjusted according to different production requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 is a flow chart of the preparation method of the Si-Zr high-entropy alloy for infiltration reaction of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] In order to more clearly and completely illustrate the technical solution of the present invention, the present invention will be further described below with reference to the drawings.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0030] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0031] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to terms such as "one solution", "some solutions", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the solution or example are included in at least one solution or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same solution or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more solutions or examples.

[0033] Please refer to Figure 1 , the present invention provides a method for preparing a Si-Zr high-entropy alloy for infiltration reaction,

[0034] Example 1

[0035] including the following steps;

[0036] Step 1: Raw material preparation, prepare silicon powder and zirconium powder, the purity of the silicon powder is 99.99%, and the purity of the zirconium powder is 99.99%;

[0037] Step 2: Prepare Zr-Si2.9 alloy powder, weigh the raw materials according to the mass ratio Zr:Si = 97.1:2.9, put the zirconium powder and silicon powder into a vacuum ball mill tank, evacuate and then fill with argon for protection and grinding;

[0038] Step 3: Add the alloy powder ground in the above Step 2 into a crucible. Use a graphite or kaolin crucible, evacuate the air and fill it with argon for protection. Raise the temperature to 1500 °C and keep it warm for 2 hours to partially melt silicon and initiate a preliminary reaction with zircon. Then continue to raise the temperature to 1600 °C and keep it warm for 3 hours to completely melt zircon and silicon. During the smelting process, turn the crucible 4 times to avoid composition segregation;

[0039] Step 4: Use a copper mold to rapidly cool the mixed molten liquid to inhibit the precipitation of brittle phases and form a uniform eutectic structure, and then grind the block into powder using a ball mill;

[0040] Step 5: Weigh 6.9 kg of Zr-Si2.9 alloy powder and 3.09 kg of silicon powder, put them into a ball mill, and ball mill in a vacuum ball mill under the conditions of evacuating the air and filling it with argon. The ball milling time is 12 h, and the rotational speed of the ball mill is 100 revolutions per minute to obtain a mixed material;

[0041] Step 6: Add an industrial binder of polyvinyl butyral ethanol solution with a concentration of 10 wt.% to the mixed material ball milled by the vacuum ball mill, and press cylindrical briquettes at 1000 g per piece using a hydraulic press. The pressing pressure is 20 MPa, and the briquette size is Φ50×90 mm;

[0042] Step 7: Put the pressed briquettes into a graphite crucible and a kaolin crucible in a vacuum induction melting furnace. After evacuating the air, fill the melting furnace with high-purity argon, and repeat the evacuation and argon filling 3 times; Under an argon atmosphere, keep the pressure in the furnace at 100 Pa; The power supply power is 20 kW for preheating by raising the temperature; Continue to supply power to gradually raise the temperature for smelting. The vacuum pump system is continuously turned on during the whole smelting process. From 0 °C to 1450 °C, modulate the power, raise the temperature to 1400 °C, wait until the vacuum degree reaches 50 Pa, keep it warm for 3 h, continue to adjust the temperature to 1600 °C, continue smelting, wait until the vacuum degree reaches 25 Pa, lower the temperature to 1400 °C, continue to keep it warm, control the vacuum degree at 25 Pa during the warming process, keep it warm for 1 h, cut off the power, cool down, and the temperature in the furnace should not be higher than 50 °C when taking out the furnace to obtain a silicon-zirconium alloy. In order to ensure the uniformity of the smelted alloy structure and composition, each furnace of the alloy is turned over and smelted 4 times;

[0043] Step 8: Finish, break, and powder the silicon-zirconium alloy block after taking it out of the furnace;

[0044] Step 9: Decompose the powder with hydrofluoric acid and perchloric acid, leach it with hydrochloric acid to prepare a solution, use inductively coupled plasma atomic emission spectrometry (ICP-AES) to measure the intensity values at the analysis spectral lines of the main elements and impurity elements in it, and calculate the concentration of each element in the test solution according to the established standard curve, so as to calculate the mass fraction of each element in the test sample.

[0045] Test results, the elemental contents of the prepared silicon-zirconium alloy powder: Si: balance (32.879); Zr: 67.017;

[0046] Cr: 0.007; Fe: 0.075; V: 0.004; O: 0.018.

[0047] Example 2

[0048] It includes the following steps:

[0049] Step 1: Raw material preparation, prepare silicon powder and zirconium powder, the purity of the silicon powder is 99.99%, and the purity of the zirconium powder is 99.99%;

[0050] Step 2: Prepare Zr-Si2.9 alloy powder, weigh the raw materials according to the mass ratio of Zr:Si = 97.1:2.9, put the zirconium powder and silicon powder into a vacuum ball mill pot, evacuate and then fill with argon for protection and grind;

[0051] Step 3: Add the alloy powder ground in the above step 2 into a crucible, use a graphite or kaolin crucible, evacuate and fill with argon for protection, raise the temperature to 1500 °C, keep it warm for 2 hours to partially melt the silicon and react preliminarily with zirconium, and then continue to raise the temperature to 1600 °C and keep it warm for 3 hours to completely melt zirconium and silicon. During the melting process, turn the crucible 4 times to avoid compositional segregation;

[0052] Step 4: Use a copper mold to rapidly cool the mixed molten liquid to inhibit the precipitation of brittle phases, form a uniform eutectic structure, and grind the block into powder by a ball mill;

[0053] Step 5: Weigh 6.9 kg of Zr-Si2.9 alloy powder and 3.09 kg of silicon powder, put them into a ball mill, and ball mill in a vacuum ball mill under the conditions of evacuation and filling with argon. The ball milling time is 12 h, and the rotation speed of the ball mill is 100 r / min to obtain a mixed material;

[0054] Step 6: Add an industrial binder of polyvinyl butyral (PVB) ethanol solution with a concentration of 10 wt.% to the mixed material ball milled by the vacuum ball mill, press cylindrical blocks at 1000 g per block with a hydraulic press, the pressing pressure is 20 MPa, and the size of the pressed block is Φ50×90 mm;

[0055] Step 7: Put the pressed briquettes into the graphite crucible and kaolin crucible of the vacuum induction melting furnace. After evacuating the air, fill the melting furnace with high-purity argon gas, and repeat the evacuation and argon gas filling 3 times. Under the argon gas atmosphere, keep the furnace pressure at 100 Pa. The power supply is 25 kW for preheating with temperature rising. Continue to supply power to gradually raise the temperature for melting. The vacuum pump system is continuously turned on during the whole melting process. From 0 °C to 1500 °C, the power is modulated. When the temperature rises to 1500 °C and the vacuum degree reaches 55 Pa, keep it warm for 2.5 h. Then continue to adjust the temperature to 1650 °C for continuous melting. When the vacuum degree reaches 20 Pa, lower the temperature to 1350 °C and continue to keep it warm. During the warming process, the vacuum degree is controlled at 20 Pa and keep it warm for 1.5 h. Cut off the power and let it cool down. The temperature in the furnace should not be higher than 50 °C when taking out the furnace to obtain the silicon-zirconium alloy. In order to ensure the uniformity of the melting alloy structure and composition, the alloy in each furnace is turned over and melted 4 times;

[0056] Step 8: Finish, break and powder the silicon-zirconium alloy blocks after taking out of the furnace;

[0057] Step 9: Decompose the powder with hydrofluoric acid and perchloric acid, leach it with hydrochloric acid to prepare a solution, use inductively coupled plasma atomic emission spectrometry (ICP-AES) to measure the intensity values at the analysis spectral lines of the main elements and impurity elements in it, and calculate the concentration of each element in the test sample solution according to the established standard curve, so as to calculate the mass fraction of each element in the test sample;

[0058] Test results, the content of each element in the prepared silicon-zirconium alloy powder, Si: balance (32.8534); Zr: 67.0902;

[0059] Cr: 0.0027; Fe: 0.0354; V: 0.0029; O: 0.0154.

[0060] Example 3

[0061] Including the following steps;

[0062] Step 1: Prepare raw materials, prepare silicon powder and zirconium powder, the purity of the silicon powder is 99.99%, and the purity of the zirconium powder is 99.99%;

[0063] Step 2: Prepare Zr-Si2.9 alloy powder, weigh the raw materials according to the mass ratio of Zr:Si = 97.1:2.9, put the zirconium powder and silicon powder into a vacuum nodular can, evacuate the air and then fill it with argon gas for protection and grind;

[0064] Step 3: Add the alloy powder ground in the above step 2 into the crucible, use a graphite or kaolin crucible, evacuate the air and fill it with argon gas for protection, raise the temperature to 1500 degrees and keep it warm for 2 hours to partially melt the silicon and react with zirconium initially. Then continue to raise the temperature to 1600 degrees and keep it warm for 3 hours to completely melt zirconium and silicon. During the melting process, turn the crucible 4 times to avoid composition segregation;

[0065] Step 4: Utilize a copper mold to rapidly cool the mixed molten liquid to inhibit the precipitation of brittle phases, form a uniform eutectic structure, and grind the block into powder using a ball mill.

[0066] Step 5: Weigh 6.9 kg of Zr-Si2.9 alloy powder and 3.09 kg of silicon powder, put them into a ball mill, and ball mill in a vacuum ball mill under the conditions of vacuum pumping and argon filling. The ball milling time is 12 h, and the rotation speed of the ball mill is 100 r / min to obtain a mixed material.

[0067] Step 6: Add an industrial binder of polyvinyl butyral ethanol solution with a concentration of 10 wt.% to the mixed material ball milled by the vacuum ball mill, and press cylindrical briquettes at 1000 g per piece using a hydraulic press. The pressing pressure is 20 MPa, and the briquette size is Φ50×90 mm.

[0068] Step 7: Place the pressed briquettes into graphite crucibles and kaolin crucibles in a vacuum induction melting furnace. After vacuum pumping, fill the melting furnace with high-purity argon, and repeat the vacuum pumping and argon filling 3 times. Under an argon atmosphere, keep the furnace pressure at 100 Pa. The power supply is 20 kW for preheating. Continue to supply power and gradually increase the temperature for melting. The entire melting process keeps the vacuum pump system on. From 0 °C to 1450 °C, modulate the power, raise the temperature to 1500 °C. Wait until the vacuum degree reaches 50 Pa and hold for 3 h. Then continue to adjust the temperature to 1650 °C and continue melting. Wait until the vacuum degree reaches 25 Pa, lower the temperature to 1500 °C, and continue to hold. During the holding process, control the vacuum degree at 25 Pa and hold for 1 h. Cut off the power and cool down. The furnace temperature should not be higher than 50 °C when discharging to obtain a silicon-zirconium alloy. To ensure the uniformity of the melting alloy structure and composition, each furnace of alloy is flipped and melted 4 times.

[0069] Step 8: Finish, break, and powder the silicon-zirconium alloy blocks after discharging.

[0070] Step 9: Decompose the powder with hydrofluoric acid and perchloric acid, extract with hydrochloric acid to prepare a solution, measure the intensity values at the analytical spectral lines of the main elements and impurity elements in the solution using inductively coupled plasma atomic emission spectrometry (ICP-AES), and calculate the concentrations of various elements in the test solution according to the established standard curve, so as to calculate the mass fractions of various elements in the test sample.

[0071] Test results: The contents of various elements in the prepared silicon-zirconium alloy powder are as follows: Si: balance (32.843); Zr: 67.053;

[0072] Cr: 0.007; Fe: 0.075; V: 0.004; O: 0.018.

[0073] Example 4

[0074] It includes the following steps:

[0075] Step 1: Raw material preparation. Prepare silicon powder and zirconium powder. The purity of the silicon powder is 99.99%, and the purity of the zirconium powder is 99.99%.

[0076] Step 2: Prepare Zr-Si2.9 alloy powder. Weigh the raw materials according to the mass ratio of Zr:Si = 97.1:2.9. Put the zirconium powder and silicon powder into a vacuum ball mill pot, evacuate and then fill with argon for protection and grinding.

[0077] Step 3: Add the alloy powder ground in Step 2 into a crucible. Use a graphite or kaolin crucible, evacuate and fill with argon for protection. Raise the temperature to 1500 °C and keep it warm for 2 hours to partially melt the silicon and initially react with zirconium. Then continue to raise the temperature to 1600 °C and keep it warm for 3 hours to completely melt zirconium and silicon. During the melting process, turn the crucible 4 times to avoid composition segregation.

[0078] Step 4: Use a copper mold to rapidly cool the mixed molten liquid to inhibit the precipitation of brittle phases, form a uniform eutectic structure, and grind the block into powder using a ball mill.

[0079] Step 5: Weigh 6.9 kg of Zr-Si2.9 alloy powder and 3.09 kg of silicon powder, put them into a ball mill, and ball mill in a vacuum ball mill under the conditions of evacuation and filling with argon. The ball milling time is 12 h, and the rotational speed of the ball mill is 100 r / min to obtain a mixed material.

[0080] Step 6: Add an industrial binder of polyvinyl butyral (PVB) ethanol solution with a concentration of 10 wt.% to the mixed material ball milled by the vacuum ball mill. Press cylindrical blocks at 1000 g per block using a hydraulic press. The pressing pressure is 20 MPa, and the size of the pressed block is Φ50×90 mm.

[0081] Step 7: Put the pressed blocks into the graphite crucible and kaolin crucible of a vacuum induction melting furnace. After evacuation, fill the melting furnace with high-purity argon, and repeat the evacuation and argon filling 3 times. Under an argon atmosphere, keep the pressure in the furnace at 100 Pa. The power supply is 25 kW for preheating. Continue to supply power to gradually raise the temperature for melting. The entire melting process keeps the vacuum pump system on. From 0 °C to 1500 °C, modulate the power. When the temperature rises to 1500 °C and the vacuum degree reaches 55 Pa, keep it warm for 3 h. Then continue to adjust the temperature to 1650 °C for continuous melting. When the vacuum degree reaches 20 Pa, lower the temperature to 1350 °C and continue to keep it warm. During the warming process, control the vacuum degree at 20 Pa and keep it warm for 1 h. Cut off the power and cool down. The temperature in the furnace should not be higher than 50 °C when taking out the furnace to obtain a silicon-zirconium alloy. To ensure the uniformity of the alloy structure and composition, each furnace of the alloy is turned over and melted 4 times.

[0082] Step 8: Finish, break, and powder the silicon-zirconium alloy blocks after taking out of the furnace.

[0083] Step 9: Decompose the powder with hydrofluoric acid and perchloric acid, extract it with hydrochloric acid to prepare a solution, and use inductively coupled plasma atomic emission spectrometry (ICP-AES) to measure the intensity values at the analytical spectral lines of the main elements and impurity elements therein. According to the established standard curve, calculate the concentrations of various elements in the test sample solution, and thus calculate the mass fractions of various elements in the test sample;

[0084] Test results show that for the prepared silicon-zirconium alloy powder, the content of each element is as follows: Si: balance (32.8054); Zr: 67.1414;

[0085] Cr: 0.0027; Fe: 0.0324; V: 0.0028; O: 0.0153.

[0086] It can be seen from the above embodiments that the method of using Zr-Si2.9 alloy powder to replace silicon powder for preparation can reduce the melting temperature during preparation, reduce the volatilization of silicon in traditional preparation, and ensure the silicon content in the finished product.

[0087] The following is a comparison of variables in four embodiments:

[0088]

[0089] Analysis of key differences: In Examples 2 and 4, higher power and the highest temperature are used, which may accelerate the melting reaction and shorten the melting time, but it is necessary to control to avoid component volatilization or crucible erosion caused by overheating. In Examples 1 and 3, the temperature is slightly lower, which may be milder but the reaction time is longer. The final vacuum degree in Examples 2 and 4 is lower (20 Pa), and the holding temperature is lower (1350 °C), which may be more conducive to reducing oxidation and impurity residues. In Example 3, the holding temperature after cooling is higher (1500 °C), which may promote component homogenization, but may increase energy consumption and the risk of impurity precipitation.

[0090] The test results are compared as follows:

[0091] Example 1 Example 2 Example 3 Example 4 Si 32.879 32.8534 32.843 32.8054 Zr 67.017 67.0902 67.053 67.1414 Cr 0.007 0.0027 0.007 0.0027 Fe 0.075 0.0354 0.075 0.0324 V 0.004 0.0029 0.001 0.0028 O 0.018 0.0154 0.018 0.0153

[0092] Analysis of key differences: The Zr content in all embodiments is close to the target value (about 67%), but the Zr content in Example 4 is the highest (67.14%), which may be related to the promotion of the uniform distribution of Zr by its higher temperature and vacuum degree. The Si content shows a slightly decreasing trend (the lowest in Example 4), which may be related to the volatilization or oxidation of Si at high temperature.

[0093] In summary, increasing the power (25 kW) and temperature (1650 °C) can accelerate the melting reaction, shorten the process time, and promote the volatilization of impurities (such as Fe and Cr). A lower vacuum degree (20 Pa) significantly reduces the oxygen content (O decreases from 0.018% to 0.015%), reduces oxide inclusions, and improves the purity of the alloy. Using a power of 25 kW, a melting temperature of 1650 °C, a vacuum degree of 20 Pa, and combined with heat preservation after cooling to 1350 °C can effectively reduce the impurity content (Fe, Cr, V, O) while ensuring the stability of the Zr / Si ratio.

[0094] Of course, the present invention can also have many other implementation manners. Based on this implementation manner, other implementation manners obtained by ordinary technicians in the art without any creative labor belong to the scope protected by the present invention.

Claims

1. A preparation method of Si-Zr high-entropy alloy for infiltration reaction, characterized in that, The preparation method includes the following steps: Step 1: Raw material preparation: Prepare silicon powder and zirconium powder. Step 2: Preparation of Zr-Si2.9 alloy powder: Weigh the raw materials according to the mass ratio of Zr:Si = 97.1:2.

9. Put the zirconium powder and silicon powder into a vacuum ball milling tank, evacuate and then fill with argon for protection and carry out milling. Step 3: Melting: Add the milled alloy powder into a crucible, evacuate and fill with argon for protection. Heat up to 1400 to 1500 °C and keep warm for 1 to 2 hours to partially melt silicon and make a preliminary reaction with zirconium. Then continue to heat up to 1570 to 1650 °C and keep warm for 2 to 3 hours to completely melt zirconium and silicon. During the melting process, turn the crucible 3 to 4 times. Step 4: Ultra-rapid cooling treatment: Pour the molten liquid into a copper mold for ultra-rapid cooling to form a uniform eutectic structure, and grind the block into powder with a ball mill. Step 5: Preparation of mixed materials: Weigh 6.9 kg of Zr-Si2.9 alloy powder and 3.09 kg of silicon powder, put them into a ball mill, and ball mill for 12 hours under the conditions of evacuation and filling with argon. Step 6: Compression molding: Add a binder to the ball-milled mixed materials and press into cylindrical blocks with a hydraulic press. Step 7: Vacuum induction melting: Put the pressed blocks into a graphite crucible or kaolin crucible of a vacuum induction melting furnace, evacuate and then fill with high-purity argon, repeat 2 to 3 times, keep the furnace pressure at 100 Pa, the power supply power at 20 to 25 kW, gradually heat up to 1400 to 1500 °C and keep warm for 2.5 to 3 hours, then continue to heat up to 1600 - 1650 °C and keep warm for 1 to 1.5 hours, cool down to 1350 - 1500 °C and keep warm for 1 to 1.5 hours, cut off the power and cool down to below 50 °C and then take out of the furnace. Step 8: Finishing and crushing: Finish, crush and powder the silicon-zirconium alloy blocks after taking out of the furnace. Step 9: Composition detection: Detect the content of each element in the powder.

2. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 1, characterized in that, In the Zr-Si2.9 alloy powder, the silicon content is 2.9 wt.%, the zirconium content is 97.1 wt.%, the purity of the silicon powder is 99.99%, and the purity of the zirconium powder is 99.99%.

3. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 1, characterized in that The binder is a polyvinyl butyral ethanol solution with a concentration of 10 wt.%.

4. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 1, wherein, In step 6, the hydraulic press presses cylindrical blocks at 1000 g per block, the pressing pressure is 20 MPa, and the block size is Φ50×90 mm.

5. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 1, characterized in that, In step 5, the rotation speed of the ball mill is 100 revolutions / min.

6. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 1, characterized in that, In step 7, each furnace of alloy is turned and melted three to four times.

7. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 1, characterized in that, In step 9, use hydrofluoric acid and perchloric acid to decompose and hydrochloric acid to leach the powder to prepare a solution, and use inductively coupled plasma atomic emission spectrometry to determine the content of each element.

8. The preparation method of the Si-Zr high-entropy alloy for infiltration reaction according to claim 7, characterized in that, When the content of Si or Zr measured in step 9 is low, re-ball mill the prepared finished product into powder and add the missing materials to re-prepare.

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