Al-Sc alloy, preparation method and application thereof

Abstract

The application discloses an Al-Sc alloy and a preparation method and application thereof. The preparation method of the Al-Sc alloy comprises the following steps: (1) adding metal aluminum into molten metallic scandium in batches to carry out smelting, so as to obtain an Al-Sc alloy ingot; the smelting mode is suspension smelting; the adding times of the metal aluminum is n>1; (2) carrying out ultrasonic powdering on the Al-Sc alloy ingot, so as to obtain an Al-Sc alloy powder; the crucible material used in the ultrasonic powdering process is aluminum nitride; (3) sequentially carrying out cold isostatic pressing forming and hot isostatic pressing sintering on the Al-Sc alloy powder, so that the Al-Sc alloy is obtained. The Al-Sc alloy provided by the application can cover the Sc content of 5at.%-70at.% and has the advantages of low oxygen content and high density.

Description

Technical Field

[0001] This invention specifically relates to an Al-Sc alloy, its preparation method, and its application. Background Technology

[0002] Compared to traditional piezoelectric materials such as ZnO, PZT, and LT / LN, scandium-doped aluminum nitride (AlScN) thin films possess superior physical properties, including high resistivity, high thermal conductivity, high stability, and high acoustic wave propagation rate. Furthermore, AlScN thin films can be selectively grown on substrates such as sapphire, silicon carbide, and silicon, as well as various metal bottom electrode materials. These unique properties make AlScN an ideal piezoelectric thin film material for radio frequency filter chips, and it has also found wide application in optoelectronic devices, electronic components, and MEMS.

[0003] High-purity Al-Sc alloy sputtering targets, used as substrates for preparing AlScN thin films, have very strict requirements regarding material purity and grain size. Currently, Al-Sc alloy sputtering targets are mainly prepared using two methods: vacuum casting and powder metallurgy.

[0004] Patent CN113652657B discloses an Al-Sc alloy target and its manufacturing method using atmospheric high-temperature diffusion sintering. Spherical aluminum powder and spherical scandium powder are used as raw materials. These are placed in a sealed elastic sleeve and then subjected to ultra-high pressure cold isostatic pressing under vacuum to obtain a green blank with a density of over 95%. Then, diffusion sintering is performed in a large atmosphere sintering furnace to obtain the alloy target blank. Patent CN111910160B discloses a method for preparing an Al-Sc target. Metallic Sc ​​and metallic Al raw materials are mixed and melted to obtain an intermediate alloy. Using alcohol as a medium, the intermediate alloy is wet-ball-milled and vacuum-dried to obtain alloy powder. The alloy powder is mixed uniformly with metallic aluminum powder and pressed into a green blank. The alloy green blank is sintered under vacuum or atmospheric protection to obtain the alloy target blank. While the existing technology of preparing Al-Sc alloys using powder metallurgy can solve the problems of shrinkage cavities, segregation, and excessively large grain size, the high reactivity of metallic Sc ​​and AlSc powders means that mixing aluminum powder and scandium powder or ball milling will greatly increase the oxygen content of the powder, resulting in excessively high oxygen content in the target material.

[0005] Patent CN114774865B discloses a method for preparing Al-Sc alloy targets, which involves mixing metallic aluminum and metallic scandium and performing vacuum magnetic levitation melting to achieve alloying of the raw materials; then casting to obtain an alloy blank; and finally densifying the alloy through hot isostatic pressing. This method is used to prepare AlSc targets with a scandium content of 5~20 at.%. Patent CN111455223B discloses an Al-Sc alloy target and its preparation method, which involves repeatedly adding metallic aluminum to metallic scandium, repeatedly melting and then casting to obtain a target blank. The aforementioned existing technology uses vacuum casting to obtain alloys with a Sc content of less than 25 at.%, which consist of two phases: Al and Al3Sc. Due to the significant difference in density and melting point between Al and Al3Sc, Al3Sc will precipitate first during solidification, resulting in significant component segregation. For alloys with a Sc content higher than 25 at.%, the constituent phases are intermetallic compounds (Al3Sc, Al2Sc, AlSc, AlSc2), all of which are brittle phases. Therefore, the alloy ingots have high hardness and high brittleness, and are prone to cracking and chipping during casting and processing, making them unsuitable for preparing high Sc content Al-Sc sputtering targets.

[0006] Furthermore, patent CN111485207A discloses a fine-grained, homogeneous aluminum-scandium alloy sintering target and its preparation method. High-purity aluminum and high-purity scandium blocks are mixed and sequentially subjected to vacuum suspension melting and gas atomization to obtain atomized aluminum-scandium alloy powder. The alloy powder is then pressure-sintered at 500-1350℃. While suspension melting avoids crucible contamination of the furnace charge, it suffers from significant heat dissipation due to the use of a water-cooled copper crucible. Patent CN202011032616.9 points out that after a metal or corresponding alloy is melted, further increasing the heating power does not significantly raise the molten pool temperature. Experiments have shown that the temperature hardly increases beyond 100-150℃ above the melting point. Therefore, the vacuum suspension melting of high-purity aluminum and high-purity scandium blocks described in patent CN111485207A may result in incomplete alloying due to the large difference in melting points between Al and Sc. Meanwhile, the alloyed Al3Sc will precipitate due to insufficient melt superheat and accumulate at the bottom of the crucible under gravity, resulting in uneven melt composition. During powder production, the large contact area between the melt and the crucible sidewall during crucible rotation causes rapid shell growth, resulting in a large amount of material forming a shell inside the crucible and causing low powder yield. On the other hand, the low melt superheat caused by the aforementioned reasons leads to poor alloy fluidity, easily causing nozzle blockage and making it difficult to control powder quality. In addition, during gas atomization powder production, the melt reacts with the flow channel and nozzle, introducing impurities.

[0007] Metallic silica (Sc) is highly reactive and reacts with most ceramic crucibles, introducing impurities. For crucibles made of metal oxide ceramics (MeO), the following reaction occurs: Sc + MeO → Sc₂O₃ + Me, leading to the introduction of impurity elements and an increase in oxygen content during the melting process. Patent document CN202010492396.1 describes a method for preparing Al-Sc alloys using suspension melting, followed by vacuum atomization to prepare aluminum-scandium powder. While suspension melting effectively avoids the reaction between Sc and the crucible during alloying, the use of alumina / zirconia / magnesium oxide crucibles in vacuum powder preparation inevitably results in a reaction with the crucible when the scandium content is high, introducing metallic and scandium oxide impurities, and producing powder with a high oxygen content. Summary of the Invention

[0008] This invention aims to overcome the shortcomings of existing Al-Sc alloys, such as insufficient alloying, high oxygen content, low density, and low Sc content, by providing an Al-Sc alloy, its preparation method, and its applications. The Al-Sc alloy provided by this invention can cover Sc content ranging from 5 at.% to 70 at.%, and has the advantages of low oxygen content and high density.

[0009] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0010] This invention provides a method for preparing an Al-Sc alloy, comprising the following steps:

[0011] (1) Add aluminum to molten scandium in portions to obtain Al-Sc alloy ingots; the smelting method is suspension smelting; the number of times aluminum is added is n>1;

[0012] (2) The Al-Sc alloy ingot is subjected to ultrasonic powdering to obtain Al-Sc alloy powder; the crucible material used in the ultrasonic powdering process is aluminum nitride.

[0013] (3) The Al-Sc alloy powder is subjected to cold isostatic pressing and hot isostatic pressing sintering in sequence to obtain the Al-Sc alloy.

[0014] In this invention, the atomic ratio of scandium to aluminum can be (5:95)-(70:30), for example 10:90, 30:70 or 43:57.

[0015] In this invention, the purity of the aluminum metal is 4N or higher.

[0016] In this invention, the purity of the metallic scandium is 4N or higher.

[0017] In this invention, the number of times the metallic aluminum is added, n, can be 2-5, for example, 2, 4 or 5.

[0018] In this invention, the equipment used for suspension melting can be conventional equipment in the art, such as a vacuum induction suspension melting furnace; the crucible used in the suspension melting furnace may optionally be a water-cooled copper crucible.

[0019] In this invention, the smelting process includes: adding metallic scandium into a vacuum induction levitation smelting furnace, and sequentially performing vacuuming, degassing, and pressurization.

[0020] Preferably, the vacuuming is performed to a vacuum level of 7 × 10⁻⁶. 3 Below Pa.

[0021] Preferably, the temperature during degassing is 300~800℃, for example 800℃.

[0022] Preferably, the degassing time is 2 to 10 minutes, for example, 5 minutes.

[0023] Preferably, the pressurization is performed by filling the gas with argon gas to a pressure of 0.04 MPa-0.08 MPa, for example, 0.06 MPa.

[0024] In some specific implementations, the steps for adding metallic aluminum are as follows: the mass of metallic aluminum added for the first time is 0.3 times the mass of metallic scandium; the mass of metallic aluminum added for the second time is 0.3 times the mass of metallic scandium; the mass of metallic aluminum added for the third time is 0.6 times the mass of metallic scandium; the mass of metallic aluminum added for the fourth time is 0.6 times the mass of metallic scandium; and the remaining metallic aluminum is added for the fifth time.

[0025] In some specific implementations, the steps for adding aluminum are as follows: the mass of aluminum added for the first time is 0.3 times the mass of scandium; the mass of aluminum added for the second time is 0.3 times the mass of scandium; the mass of aluminum added for the third time is 0.6 times the mass of scandium; and the remaining aluminum is added for the fourth time.

[0026] In this invention, during the smelting process, more than two smelting processes are required after each addition of metallic Al raw material. Each smelting process requires the material in the suspended smelting crucible to be turned over and cooled.

[0027] In this invention, the Al-Sc alloy ingot is typically polished before ultrasonic powdering. The purpose is to remove the surface oxide layer and impurities.

[0028] In this invention, the ultrasonic powder making includes heating and powder making.

[0029] The heating method is preferably induction heating or plasma heating.

[0030] When induction heating is used, the heating temperature is 50°C higher than the liquidus temperature of the corresponding component in the phase diagram, and the holding time is 5-10 minutes. Preferably, the heating temperature is 1200°C or 1250°C.

[0031] In some specific implementations, the scandium content in the Al-Sc alloy is <20 at.%, and induction heating is used.

[0032] In some specific implementations, the scandium content in the Al-Sc alloy is ≥20 at.%, and plasma heating is used.

[0033] The ultrasonic frequency of the powder-making process is preferably 10-60 kHz, more preferably 20-40 kHz, for example 20 kHz or 40 kHz.

[0034] In this invention, the ultrasonic powder preparation can be carried out under vacuum or argon protection.

[0035] In some specific embodiments, the ultrasonic powder-making step includes: heating the Al-Sc alloy ingot, and then evacuating the ultrasonic powder-making equipment to a vacuum level of 7×10⁻⁶. -3 After Pa, argon gas is introduced to a vacuum of 0.04 MPa, and ultrasonic powdering is performed by setting the ultrasonic frequency to 20-40 kHz.

[0036] In this invention, the Al-Sc alloy powder is typically homogenized and mixed before cold isostatic pressing. Preferably, this homogenization and mixing is performed in a three-dimensional mixer.

[0037] In this invention, step (3) is performed in a glove box protected by inert gas, and the material does not come into contact with air throughout the process.

[0038] In this invention, the container formed by cold isostatic pressing (CIP) can be conventional in the art, such as an elastic sleeve.

[0039] In this invention, the pressure of the cold isostatic pressing can be 400MPa-800MPa, for example 650MPa.

[0040] In this invention, the holding time for cold isostatic pressing can be 5-20 minutes, for example, 10 minutes.

[0041] In this invention, the specific steps of hot isostatic pressing sintering are as follows: the billet obtained by cold pressing is placed into a metal sleeve, vacuum-sealed, and then sintered in a hot isostatic pressing device.

[0042] The metal sheath is preferably made of any one of Al, aluminum alloy, Ti, and titanium alloy.

[0043] When the Sc content in the Al-Sc alloy is less than 25 at.%, a metal cladding made of Al or aluminum alloy should be selected. When the Sc content in the Al-Sc alloy is not less than 25 at.%, a metal cladding made of Ti or titanium alloy should be selected.

[0044] Preferably, the air extraction reduces the pressure to 7 × 10⁻⁶. -2 Below MPa.

[0045] In this invention, the temperature of hot isostatic pressing sintering is designed according to the Sc content in the powder: when the Sc content is less than 25 at.%, the sintering temperature is 400~600℃, the holding time is 2~6 hours, and the holding pressure is 80~160 MPa.

[0046] When the Sc content is 25 at.%~33 at.% and the sintering temperature is 1100~1200℃, the holding time is 4~6 hours and the holding pressure is 100~150Mpa;

[0047] When the Sc content is greater than 33 at.%, the sintering temperature is 1050~1150℃, the holding time is 4~6 hours, and the holding pressure is 120~160 MPa.

[0048] In this invention, the Al-Sc alloy can generally be machined to the specified dimensions according to the application requirements.

[0049] When the Sc content is less than 20 at.%, machining is used to remove the metal casing and process the target material; when the Sc content is not less than 20 at.%, ultrasonic processing is used to remove the casing and process the target material.

[0050] In some specific implementation schemes, when the Sc content is not less than 20 at.%, the outer diameter of the target material is machined by external cylindrical grinding; and the surface of the target material is machined by frustum grinding.

[0051] This invention provides an Al-Sc alloy, which is prepared by the preparation method described above.

[0052] In some specific embodiments, the Al-Sc alloy comprises an Al3Sc phase and an Al phase.

[0053] In some specific embodiments, the Al-Sc alloy comprises Al3Sc phase and Al2Sc phase.

[0054] In this invention, the Sc content in the Al-Sc alloy can be 5 at.% to 70 at.%, for example, 10 at.%, 30 at.% or 43 at.%.

[0055] In this invention, the oxygen content in the Al-Sc alloy can be 107 ppm to 243 ppm, for example 107 ppm, 243 ppm, 251 ppm, 197 ppm, 83 ppm, 224 ppm or 227 ppm.

[0056] In this invention, the density of the Al-Sc alloy can be 100% or higher, for example, 100.8%, 101.2%, 101.7%, 101.5%, 99.9% or 100.7%.

[0057] This invention provides the application of the Al-Sc alloy as a target material in the preparation of AlScN thin films, as described above.

[0058] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0059] The reagents and raw materials used in this invention are all commercially available.

[0060] The positive and progressive effects of this invention are as follows:

[0061] The preparation method of this invention uses suspension melting for alloying, avoiding impurities and oxygenation introduced by the reaction between the material and the suspension melting crucible. Ultrasonic methods and aluminum nitride crucibles are used in the powder preparation process to avoid contamination caused by contact between the flow channel and nozzle in gas atomization powdering. The powder preparation, mixing, filling, and transfer processes are all conducted without contact with air, minimizing the introduction of impurities from the gas. The resulting powder can be fully utilized without sieving, significantly improving product yield.

[0062] The Al-Sc alloy prepared by the method provided by this invention has high density, low compositional segregation, low oxygen content, high purity, uniform grain distribution, and is not prone to cracking during processing. It can cover the preparation of Al-Sc alloys with a content of 5~70 at.% Sc. Attached Figure Description

[0063] Figure 1 This is a flowchart illustrating the preparation method of the Al-Sc alloy according to the present invention.

[0064] Figure 2 The image shows the phase diagram of the Al-Sc alloy obtained in Example 1.

[0065] Figure 3 The image shows the phase diagram of the Al-Sc alloy obtained in Example 2.

[0066] Figure 4 The image shows the phase diagram of the Al-Sc alloy obtained in Example 3.

[0067] Figure 5The image shows the phase diagram of the Al-Sc alloy obtained in Example 7.

[0068] Figure 6 The phase diagram is shown for the Al-Sc alloy prepared in Comparative Example 3. Detailed Implementation

[0069] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0070] Example 1

[0071] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 10 at.%, comprising the following steps:

[0072] (1) Preparation of Al-Sc alloy ingots

[0073] S1. Place 2.34 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then the temperature is raised to the point where the metal Sc melts. 0.7 kg of metal aluminum particles are added for the first time through the feeding hopper, and heating is stopped after melting for 5 minutes.

[0074] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 0.7 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0075] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0076] S4. After the material obtained in step S3 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0077] S5. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶.-3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 8.44 kg of aluminum particles are added for the fifth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0078] (2) After the oxide scale on the surface of the obtained Al-Sc alloy ingot is polished, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is turned on to melt the alloy ingot. After the temperature rises to 1200℃, the heating power is adjusted to keep the temperature below 1250℃. After holding at this temperature for 10 minutes, powdering is carried out. The ultrasonic frequency for powdering is 20kHz. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0079] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 600 MPa for 8 minutes. Then, in a glove box, the pressed billet is placed into a 6061 aluminum alloy sheath, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 500℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0080] The Al-Sc alloy obtained in step (3) was sampled, and its XRD phase diagram is shown below. Figure 2 As shown in Table 1, the impurity content detected by GDMS is shown in Table 1.

[0081] Table 1. GDMS component detection results of Example 1

[0082]

[0083] Example 2

[0084] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.%, comprising the following steps:

[0085] (1) Preparation of Al-Sc alloy ingots

[0086] S1. Place 4.17 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then, the temperature is raised to the point where the metal Sc melts. 1.25 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0087] S2. After the material obtained in step S1 has cooled, invert the material and place it in a water-cooled copper crucible, then evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.25 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0088] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 2.5 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0089] S4. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 830g of aluminum particles are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0090] (2) After the oxide scale on the surface of the Al-Sc alloy ingot is polished, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering. The heating method is plasma heating, and the vacuum is evacuated to 7×10. -3 After Pa, argon gas is introduced to 0.04 MPa, and the ultrasonic frequency for powder preparation is 40 kHz. The obtained powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0091] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 650 MPa for 10 minutes. Then, the pressed billet is placed into a titanium sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and then sintered in a hot isostatic pressing furnace at a temperature of 1150℃ for 5 hours and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0092] The Al-Sc alloy obtained in step (3) was sampled, and its XRD phase diagram is shown below. Figure 3 As shown in Table 2, the impurity content detected by GDMS is shown in Table 2.

[0093] Table 2. GDMS component detection results of Example 2

[0094]

[0095] Example 3

[0096] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 43 at.%, which includes the following steps:

[0097] (1) Preparation of Al-Sc alloy ingots

[0098] S1. Place 5.67 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 6 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. The temperature is raised to the point where the metal Sc melts, and 1.7 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0099] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.7 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0100] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. - 3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 1.11 kg of aluminum particles are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0101] (2) After the oxide scale on the surface of the alloy ingot is polished, it is placed in an aluminum nitride crucible for ultrasonic powdering. The heating method is plasma heating, and the vacuum is 7×10. -3 After Pa, argon gas is introduced to 0.04 MPa, the ultrasonic frequency for powder making is set to 40 kHz, and the alloy ingot is heated to melt and powder is made. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0102] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 650 MPa for 10 minutes. The pressed billet is then placed into a titanium sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target blank is sealed and then sintered in a hot isostatic pressing furnace at a temperature of 1100℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0103] The Al-Sc alloy obtained in step (3) was sampled, and its XRD phase diagram is shown below. Figure 4 As shown in Table 3, the impurity content detected by GDMS is shown in Table 3.

[0104] Table 3. GDMS component detection results of Example 3

[0105]

[0106] Example 4

[0107] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 10 at.%, comprising the following steps:

[0108] (1) Preparation of Al-Sc alloy ingots

[0109] S1. Place 2.34 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then the temperature is raised to the point where the metal Sc melts. 0.7 kg of metal aluminum particles are added for the first time through the feeding hopper, and heating is stopped after melting for 5 minutes.

[0110] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 0.7 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0111] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0112] S4. After the material obtained in step S3 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0113] S5. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 8.44 kg of aluminum particles are added for the fifth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0114] (2) After polishing the oxide scale on the surface of the obtained Al-Sc alloy ingot, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is turned on to melt the alloy ingot. After the temperature rises to 1200℃, the heating power is adjusted to keep the temperature below 1250℃. After holding at this temperature for 10 minutes, powdering is carried out. The ultrasonic frequency for powdering is 40kHz. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0115] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 600 MPa for 8 minutes. Then, in a glove box, the pressed billet is placed into a 6061 aluminum alloy sheath, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 500℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0116] The Al-Sc alloy obtained in step (3) was sampled, and the impurity content was detected by GDMS as shown in Table 4.

[0117] Table 4. GDMS component detection results of Example 4

[0118]

[0119] Example 5

[0120] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 10 at.%, comprising the following steps:

[0121] (1) Preparation of Al-Sc alloy ingots

[0122] S1. Place 2.34 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then the temperature is raised to the point where the metal Sc melts. 0.7 kg of metal aluminum particles are added for the first time through the feeding hopper, and heating is stopped after melting for 5 minutes.

[0123] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 0.7 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0124] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0125] S4. After the material obtained in step S3 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0126] S5. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 8.44 kg of aluminum particles are added for the fifth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0127] (2) After polishing the oxide scale on the surface of the obtained Al-Sc alloy ingot, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3After Pa, heating is turned on to melt the alloy ingot. After the temperature rises to 1200℃, the heating power is adjusted to keep the temperature below 1250℃. After holding at this temperature for 10 minutes, powdering is carried out. The ultrasonic frequency for powdering is 10kHz. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0128] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 600 MPa for 8 minutes. Then, in a glove box, the pressed billet is placed into a 6061 aluminum alloy sheath, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 500℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0129] The Al-Sc alloy obtained in step (3) was sampled, and the impurity content was detected by GDMS as shown in Table 5.

[0130] Table 5. GDMS component detection results of Example 5

[0131]

[0132] Example 6

[0133] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 10 at.%, comprising the following steps:

[0134] (1) Preparation of Al-Sc alloy ingots

[0135] S1. Place 2.34 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then the temperature is raised to the point where the metal Sc melts. 0.7 kg of metal aluminum particles are added for the first time through the feeding hopper, and heating is stopped after melting for 5 minutes.

[0136] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 0.7 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0137] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0138] S4. After the material obtained in step S3 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.4 kg of aluminum granules are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0139] S5. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 8.44 kg of aluminum particles are added for the fifth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0140] (2) After polishing the oxide scale on the surface of the obtained Al-Sc alloy ingot, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is turned on to melt the alloy ingot. After the temperature rises to 1200℃, the heating power is adjusted to keep the temperature below 1250℃. After holding at this temperature for 10 minutes, powdering is carried out. The ultrasonic frequency for powdering is 60kHz. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0141] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 600 MPa for 8 minutes. Then, in a glove box, the pressed billet is placed into a 6061 aluminum alloy sheath, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 500℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0142] The Al-Sc alloy obtained in step (3) was sampled, and the impurity content was detected by GDMS as shown in Table 6.

[0143] Table 6. GDMS component detection results of Example 6

[0144]

[0145] Example 7

[0146] This embodiment provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.% and an evaluation of its coating. The preparation method includes the following steps:

[0147] (1) Preparation of Al-Sc alloy ingots

[0148] S1. Place 4.17 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. The temperature is raised to the point where the metal Sc melts. 1.25 kg of aluminum particles are added for the first time through the feeding hopper. After melting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible.

[0149] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 4.58 kg of aluminum particles are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0150] (2) After the oxide scale on the surface of the Al-Sc alloy ingot is polished, it is placed in an aluminum nitride crucible for ultrasonic powdering. The heating method is plasma heating; the vacuum is evacuated to 7×10 -3 After Pa, argon gas is introduced to 0.04 MPa, and the alloy ingot is heated to melt. The ultrasonic frequency for powder making is set to 40 kHz, and the powder is collected through a collection tank.

[0151] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 650 MPa for 10 minutes. The pressed billet is then placed into a titanium sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and then sintered in a hot isostatic pressing furnace at 1150℃ for 5 hours under a holding pressure of 150MPa. This yields an Al-Sc alloy target blank, which is then machined to obtain the Al-Sc alloy. Its XRD phase diagram is shown below. Figure 5 As shown.

[0152] Comparative Example 1

[0153] This comparative example provides a method for preparing an Al-Sc alloy with a Sc content of 10 at.%, the method comprising the following steps:

[0154] (1) Preparation of Al-Sc alloy ingots

[0155] S1. Place 5.26 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. The temperature is raised to the point where the metal Sc melts. 1.58 kg of aluminum particles are added for the first time through the feeding hopper. After melting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible.

[0156] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.58 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0157] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 1.58 g of aluminum particles are added for the third time through the feeding hopper. Heating is stopped after melting for 5 minutes, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0158] (2) After grinding off the oxide scale on the surface of the alloy ingot, it is placed in an Al2O3 crucible and then placed in an ultrasonic powder-making device for ultrasonic powder making; the heating method is induction heating, and the vacuum is drawn to 7×10 -3 After Pa, heating is turned on to melt the alloy ingot. After the temperature rises to 1200℃, the heating power is adjusted to keep the temperature below 1250℃. After holding at this temperature for 10 minutes, powdering is carried out. The ultrasonic frequency for powdering is set to 20kHz. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0159] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 600 MPa for 8 minutes. The pressed billet is then placed into a 6061 aluminum alloy sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶.-2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 500℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0160] The difference between Comparative Example 1 and Example 1 is that the crucible in step (2) is made of Al2O3 material.

[0161] Comparative Example 2

[0162] This comparative example provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.%, comprising the following steps:

[0163] (1) Preparation of Al-Sc alloy ingots

[0164] S1. Place 4.17 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. The temperature is raised to the point where the metal Sc melts, and 1.25 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0165] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.25 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0166] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 2.5 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0167] S4. After the material obtained in step S3 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 830g of aluminum particles are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0168] (2) After grinding off the oxide scale on the surface of the alloy ingot, it is placed in an Al2O3 crucible and put into an ultrasonic powder making device. The heating method is induction heating, and the vacuum is evacuated to 7×10. -3After Pa, argon gas is introduced to 0.04 MPa and heating is started to melt the alloy ingot. After the temperature rises to 1400℃, the heating power is adjusted to keep the temperature below 1450℃. After holding at this temperature for 10 minutes, the ultrasonic wave is turned on and the ultrasonic frequency is set to 20 kHz to produce powder. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0169] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 650 MPa for 10 minutes. The pressed billet is then placed into a titanium sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 1150℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0170] The difference between Comparative Example 2 and Example 2 is that the crucible in step (2) is made of Al2O3 material.

[0171] Comparative Example 3

[0172] This comparative example provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.%, the method comprising the following steps:

[0173] (1) Preparation of Al-Sc alloy ingots

[0174] 5.26 kg of 99.99% pure metallic Sc ​​was placed in a suspension melting furnace. After evacuating to 7 × 10⁻³ Pa, induction heating was turned on. The material temperature was kept below 800 °C by controlling the power. After degassing for 5 minutes, argon gas was introduced to 0.06 MPa. The temperature was raised to the point where metallic Sc ​​melted. 4.75 kg of aluminum granules were added at once through the feeding hopper. After melting for 5 minutes, the heating was turned off. The material was cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingots.

[0175] (2) After the oxide scale on the surface of the Al-Sc alloy ingot is polished, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering. The heating method is plasma heating; the vacuum is evacuated to 7×10 -3 After Pa, argon gas is introduced to 0.04 MPa, and the alloy ingot is heated to melt. The resulting powder is collected through a collection tank.

[0176] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 650 MPa for 10 minutes. The pressed billet is then placed into a titanium sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and then sintered in a hot isostatic pressing furnace at 1150℃ for 5 hours under a holding pressure of 150MPa. This yields an Al-Sc alloy target blank, which is then machined to obtain the Al-Sc alloy. Its XRD phase diagram is shown below. Figure 6 As shown

[0177] Comparative Example 4

[0178] This comparative example provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.% and an evaluation of its coating. The preparation method includes the following steps:

[0179] (1) Preparation of Al-Sc alloy ingots

[0180] S1. Place 4.17 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then, the temperature is raised to the point where the metal Sc melts. 1.25 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0181] S2. After the material obtained in step S1 has cooled, invert the material and place it in a water-cooled copper crucible, then evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.25 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0182] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 2.5 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0183] S4. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 830g of aluminum particles are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0184] (2) Using alcohol as the medium, the Al-Sc alloy ingot was wet-milled for 1 hour. To avoid material contamination, a nylon ball mill jar and alumina grinding balls were used. After vacuum drying, Al-Sc alloy powder was obtained, and the median particle size measured by a laser particle size analyzer was 135 μm.

[0185] (3) Dry the powder under vacuum and put it into a collection tank. Place the collection tank into a three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to a vacuum glove box. Put the powder into the elastic sleeve in the glove box and evacuate the sleeve to 6×10. -2 After sealing with Pa, the ingot is cold isostatically pressed (CIP) at a pressure of 650 MPa for 10 min. The pressed ingot is then placed into a titanium sheath in a glove box, which is evacuated to 6 × 10⁻² Pa and then sealed. HIP sintering is then performed in a hot isostatic pressing furnace at 1150 °C for 5 h at a pressure of 150 MPa. After sintering, an Al-Sc alloy target ingot is obtained. The sintered target ingot is then machined to obtain the Al-Sc alloy.

[0186] The Al-Sc alloy obtained in step (3) was sampled, and its Sc content was analyzed by ICP, its density was determined by the water displacement method, the alloy phase composition was analyzed by XRD, and the oxygen content was detected by a gas analyzer. The results showed that the target material had an oxygen content of 4756 ppm, a density of 99.1%, and a Sc content of 28.63 at.%.

[0187] Comparative Example 5

[0188] This invention provides a comparative example of a method for preparing an Al-Sc alloy with a Sc content of 43 at.%, the method comprising the following steps:

[0189] (1) Preparation of Al-Sc alloy ingots

[0190] S1. Place 5.67 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 6 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. The temperature is raised to the point where the metal Sc melts, and 1.7 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0191] S2. After the material obtained in step S1 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.7 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0192] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. - 3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 1.11 kg of aluminum particles are added for the third time through the feeding hopper. Heating is stopped after melting for 5 minutes, and the material is cooled in the crucible to obtain Al-Sc alloy ingot.

[0193] (2) After the oxide scale on the surface of the Al-Sc alloy ingot is polished, it is powdered by vacuum induction gas atomization powdering using an aluminum nitride crucible. After the alloy melts in the crucible, it is heated to 1450℃ and held for 30 min. The atomizing gas is argon gas at a pressure of 5 MPa. The powder obtained is collected in a collection tank to obtain Al-Sc alloy powder.

[0194] (3) Place the collection tank into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, move the collection tank and the elastic sleeve to the vacuum glove box. In the glove box, put the powder into the elastic sleeve and evacuate the sleeve to 6×10. -2 After sealing, the billet is subjected to cold isostatic pressing (CIP) at a pressure of 650 MPa for 10 minutes. The pressed billet is then placed into a titanium sheath in a glove box, and the sheath is evacuated to a vacuum level of 6 × 10⁻⁶. -2 After Pa, the target is sealed and welded, and then sintered in a hot isostatic pressing furnace at a temperature of 1100℃, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; then it is machined to obtain the Al-Sc alloy.

[0195] Comparative Example 6

[0196] This comparative example provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.%, the method comprising the following steps:

[0197] (1) Preparation of Al-Sc alloy ingots

[0198] S1. Place 4.17 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then, the temperature is raised to the point where the metal Sc melts. 1.25 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0199] S2. After the material obtained in step S1 has cooled, invert the material and place it in a water-cooled copper crucible, then evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.25 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0200] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 2.5 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0201] S4. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 830g of aluminum particles are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0202] (2) After the oxide scale on the surface of the alloy ingot is polished, it is placed in an aluminum nitride crucible and subjected to ultrasonic powdering. The heating method is plasma heating; the vacuum is evacuated to 7×10 -3 After Pa, argon gas is introduced to 0.04 MPa, and the alloy ingot is heated to melt. The resulting powder is collected through a collection tank.

[0203] (3) Place the collection container into the three-dimensional mixer and fix it for mixing. The mixing time is 30 minutes. After mixing, put the powder into a titanium sleeve in a vacuum glove box and evacuate the sleeve to 6×10. -2 After Pa, the target blank is sealed and then sintered in a hot isostatic pressing furnace at a temperature of 1150℃ for 5 hours and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained and then machined to obtain the Al-Sc alloy.

[0204] Comparative Example 7

[0205] This comparative example provides a method for preparing an Al-Sc alloy with a Sc content of 30 at.% and an evaluation of its coating. The preparation method includes the following steps:

[0206] (1) Preparation of Al-Sc alloy ingots

[0207] S1. Place 4.17 kg of 99.99% pure metallic Sc ​​into a suspension melting furnace and evacuate to a vacuum of 7 × 10⁻⁶. -3 After Pa, induction heating is turned on, and the material temperature is kept below 800℃ by controlling the power. After degassing for 5 minutes, argon gas is introduced to 0.06 MPa. Then, the temperature is raised to the point where the metal Sc melts. 1.25 kg of aluminum particles are added for the first time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0208] S2. After the material obtained in step S1 has cooled, invert the material and place it in a water-cooled copper crucible, then evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 1.25 kg of aluminum granules are added a second time through the feeding hopper. Heating is stopped after melting for 5 minutes.

[0209] S3. After the material obtained in step S2 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to a vacuum of 7×10⁻⁶. -3 After the pressure drops below 0.06 MPa, argon gas is introduced to 0.06 MPa, and induction heating is turned on. After the material melts, 2.5 kg of aluminum granules are added for the third time through the feeding hopper. Heating is stopped after 5 minutes of melting.

[0210] S4. After the material obtained in step S4 has cooled, turn the material over, place it in a water-cooled copper crucible, and evacuate it to 7×10⁻⁶. -3 After the pressure drops below Pa, argon gas is introduced to 0.06 MPa, and induction heating is started. After the material melts, 830g of aluminum particles are added for the fourth time through the feeding hopper. Heating is stopped after 5 minutes of melting, and the material is cooled in a water-cooled copper crucible to obtain Al-Sc alloy ingot.

[0211] (2) After polishing the oxide scale on the surface of the alloy ingot, place it into an Al2O3 crucible; evacuate to 7×10 -3 After Pa, argon gas is introduced to 0.04 MPa and heating is started to melt the alloy ingot. After the temperature rises to 1400℃, the heating power is adjusted to keep the temperature below 1450℃. After holding at this temperature for 10 minutes, the ultrasonic wave is turned on and the ultrasonic frequency is set to 20 kHz to produce powder. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0212] (3) After passing through a 50-mesh sieve, the particle size of the powder is 47-300 μm. Weigh 0.5 kg of Al-Sc alloy powder and place it into a hot pressing mold for vacuum hot pressing sintering. The mold material is high-strength graphite, the inner diameter of the mold is 105 mm, the sintering temperature is 1050℃, the holding pressure is 30 MPa, the holding time is 4 h, and the vacuum degree is 6 × 10⁻⁶. -3 Pa is used to obtain a target billet, which is then machined to obtain an Al-Sc alloy.

[0213] Example 1

[0214] Samples of the Al-Sc alloys prepared in the examples and comparative examples were taken, and their Sc content was analyzed by ICP, their density was determined by the water displacement method, their alloy phase composition was analyzed by XRD, and their oxygen content was detected by a gas analyzer. The test results are recorded in Table 7.

[0215] Table 7

[0216]

[0217] The preparation method provided by this invention can be adjusted according to the crystal phase required for the application, accurately producing the desired Al-Sc alloy. The obtained Al-Sc alloy can cover a Sc content range of 5 at.% to 70 at.%, and possesses advantages such as uniform grain size, uniform composition distribution, high purity, low oxygen content, and high density. In some specific embodiments, it employs methods such as... Figure 1 The preparation process shown yields Al-Sc alloys with a purity higher than 99.99%, an oxygen content lower than 251 ppm, a density higher than 99.9%, and a yield of over 65.4%.

[0218] In Comparative Examples 1 and 2, an alumina crucible was used for powder preparation. The alumina reacts with Sc, which increases the oxygen content in the alloy. The oxygen increase is even higher for the high scandium content target.

[0219] Figure 6 The XRD phase diagram of the Al-Sc alloy prepared in Comparative Example 3 is shown in Table 7. Figure 6 It can be seen that the multi-step feeding and melting method can make the material alloy more complete and conform to the phase ratio in the phase diagram. In contrast, Comparative Example 3 uses a one-step feeding method for melting, which results in incomplete alloying and the final target material contains free metallic Sc ​​phase.

[0220] The difference between Comparative Example 4 and Example 2 is that the powder preparation method in step (2) is wet ball milling. Due to the high hardness and activity of the alloy material, it will react with the grinding balls and grinding media during the ball milling process, resulting in an increase in oxygen content.

[0221] The difference between Comparative Example 5 and Example 3 is that the powder preparation method in step (2) is induction gas atomization powder preparation. It can be seen that for a 43 at.% aluminum-scandium alloy, the oxygen content of the target material prepared by induction gas atomization is significantly increased compared to the example. This phenomenon may be because, compared to ultrasonic atomization powder preparation, gas atomization powder preparation requires a larger cavity space, making it more difficult to achieve a lower oxygen content level in the equipment.

[0222] The difference between Comparative Example 6 and Example 2 is that the powder in step (3) was not subjected to a cold isostatic pressing preforming process, but was directly packed into a casing for hot isostatic pressing sintering. It can be seen that the target material that was preformed by cold isostatic pressing and then sintered by hot isostatic pressing has a higher density than the target material that was directly sintered by hot isostatic pressing.

[0223] The difference between Comparative Example 7 and Example 2 is that the target material in step (3) is formed by vacuum hot pressing sintering. Its oxygen content is significantly increased compared to Example 2, while its density is reduced.

[0224] Example 2

[0225] The Al-Sc alloys of Example 2 and Comparative Example 7 were subjected to coating tests. The substrate material was 4-inch single-crystal silicon, and the coating time was 5 minutes. The sputtered film material was then subjected to surface particle inspection using a wafer particle inspection system. The results are as follows:

[0226] Table 8 Number of particles on sputtered coating surface

[0227]

[0228] As can be seen from Table 8, different target forming methods will affect the sputtering quality of the target. Sputtering of targets with relatively low density will produce more particles on the film surface, and the increase of coating particles will affect the product yield and device performance.

[0229] Example 3

[0230] The targets used in Examples 2 and 7 were subjected to coating tests. The substrate material was a 4-inch single-crystal silicon film. Reactive sputtering was performed in a high-purity argon and high-purity nitrogen atmosphere for 120 minutes. The Al and Sc content of the sputtered film was measured using XPS, and the results are compared below:

[0231] Table 9. Composition ratio of reactive sputtered films

[0232]

[0233] The number of times aluminum is added during alloying and the proportion added each time will have a certain impact on the phase composition of the alloy. The target material in Example 7 has an additional AlSc phase compared to Example 2. Since the composition of the AlSc phase is somewhat different from the scandium ratio in Al3Sc and Al2Sc, the sputtering rates of Al and Sc are slightly different during sputtering, resulting in a certain degree of deviation in the composition ratio of the film material.

[0234] The embodiments described above are merely preferred embodiments of the present invention, enabling those skilled in the art to understand and use the invention. Obviously, anyone skilled in the art can make slight modifications or variations to these embodiments without creative effort and apply them to other embodiments. Therefore, the present invention is not limited to the above embodiments, and any equivalent changes, simple modifications, and alterations made within the scope of the present invention still fall within its coverage.

Claims

1. A method for preparing an Al-Sc alloy, characterized in that, It includes the following steps: (1) Add aluminum to molten scandium in portions to obtain Al-Sc alloy ingots; the smelting method is suspension smelting; the number of times aluminum is added is n>1; The atomic ratio of scandium to aluminum is (5:95)-(70:30). The number of times the metallic aluminum is added, n, is 2-5; During the smelting process, after each addition of metallic Al raw material, more than two smelting processes are required. Each smelting process requires the material in the suspended smelting crucible to be turned over and cooled. The smelting process includes: adding metallic scandium into a vacuum induction levitation smelting furnace, and sequentially performing vacuuming, degassing, and pressurization; wherein the degassing temperature is 300~800℃; the degassing time is 2~10min; and the pressurization method is to fill with argon gas to a pressure of 0.04MPa-0.08MPa; (2) The Al-Sc alloy ingot is subjected to ultrasonic powdering to obtain Al-Sc alloy powder; the crucible material used in the ultrasonic powdering process is aluminum nitride. The ultrasonic powder making includes heating and powder making; the heating method is induction heating or plasma heating; the ultrasonic frequency of powder making is 20kHz-40kHz. (3) The Al-Sc alloy powder is subjected to cold isostatic pressing and hot isostatic pressing sintering in sequence to obtain the Al-Sc alloy; The pressure for cold isostatic pressing is 400-800 MPa; The holding time for the cold isostatic pressing is 5-20 minutes; The specific steps of hot isostatic pressing sintering are as follows: the billet obtained by cold pressing is placed into a metal sleeve, the gas is extracted and sealed, and sintering is carried out in a hot isostatic pressing equipment. When the Sc content in the Al-Sc alloy is less than 25 at.%, the sintering temperature is 400~600℃, the holding time is 2~6 hours, and the holding pressure is 80~160 MPa. When the Sc content in the Al-Sc alloy is 25 at.%~33 at.%, the sintering temperature is 1100~1200℃, the holding time is 4~6 hours, and the holding pressure is 100~150 MPa. When the Sc content in the Al-Sc alloy is greater than 33 at.%, the sintering temperature is 1050~1150℃, the holding time is 4~6 hours, and the holding pressure is 120~160 MPa.

2. The method for preparing the Al-Sc alloy as described in claim 1, characterized in that, The preparation method of the Al-Sc alloy satisfies any one of the following conditions ac: a. The steps for adding the aluminum metal are as follows: the mass of the aluminum metal added for the first time is 0.3 times the mass of the scandium metal, and the remaining aluminum metal is added for the second time; b. The steps for adding aluminum are as follows: the mass of aluminum added for the first time is 0.3 times the mass of scandium; the mass of aluminum added for the second time is 0.3 times the mass of scandium; the mass of aluminum added for the third time is 0.6 times the mass of scandium; the mass of aluminum added for the fourth time is 0.6 times the mass of scandium; and the remaining aluminum is added for the fifth time. c. The steps for adding aluminum are as follows: the mass of aluminum added for the first time is 0.3 times the mass of scandium; the mass of aluminum added for the second time is 0.3 times the mass of scandium; the mass of aluminum added for the third time is 0.6 times the mass of scandium; and the remaining aluminum is added for the fourth time.

3. The method for preparing the Al-Sc alloy as described in claim 1, characterized in that, The heating method satisfies any one of the following conditions ab: a. The scandium content in the Al-Sc alloy is <20 at.%, and the heating method is induction heating; b. The scandium content in the Al-Sc alloy is ≥20 at.%, and the heating method is plasma heating.

4. An Al-Sc alloy, characterized in that, It is prepared by the method of any one of claims 1-3 for preparing Al-Sc alloy.

5. The Al-Sc alloy as described in claim 4, characterized in that, The Al-Sc alloy satisfies one or more of the following conditions ae: a. The Sc content in the Al-Sc alloy is 5 at.%-70 at.%; b. The oxygen content in the Al-Sc alloy is 107-243 ppm; c. The Al-Sc alloy has a density of 100% or higher; d. The Al-Sc alloy comprises an Al3Sc phase and an Al phase; e. The Al-Sc alloy comprises Al3Sc phase and Al2Sc phase.

6. The application of the Al-Sc alloy as described in claim 5 in the preparation of AlScN thin films.

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