Al-Sc alloy and preparation method and application thereof

Abstract

The invention discloses an Al-Sc alloy and a preparation method and application thereof. The preparation method of the Al-Sc alloy comprises the following steps that (1) metal aluminum is added into metal scandium in a molten state in batches for smelting, and an Al-Sc alloy ingot is obtained; the smelting mode is suspension smelting; the adding frequency n of the metal aluminum is greater than 1; (2) the Al-Sc alloy ingot is subjected to ultrasonic powder making, and Al-Sc alloy powder is obtained; a crucible adopted in the ultrasonic powder preparation process is made of aluminum nitride; and (3) the Al-Sc alloy powder is sequentially subjected to cold isostatic pressing forming and hot isostatic pressing sintering, and the Al-Sc alloy is obtained. The Al-Sc alloy provided by the invention can cover the Sc content of 5at.%-70at.%, and has the advantages of low oxygen content and high density.

Description

Technical Field

[0001] The present invention specifically relates to an Al-Sc alloy and a preparation method and application thereof. Background Art

[0002] Compared with traditional piezoelectric materials such as ZnO, PZT, LT / LN, scandium-doped aluminum nitride (AlScN) thin film materials have excellent physical properties such as high resistivity, high thermal conductivity, high stability and high acoustic wave transmission rate. In addition, AlScN thin film materials can be preferentially grown on substrates such as sapphire, silicon carbide, silicon and various metal bottom electrode materials. The above unique properties of AlScN thin film make it an ideal piezoelectric thin film material for RF filter chips, and it has also been widely used in optoelectronic devices, electronic components and MEMS.

[0003] As the substrate for preparing AlScN thin films, high-purity Al-Sc alloy targets have very strict requirements on material purity and grain size. In the prior art, Al-Sc alloy targets are mainly prepared by vacuum casting and powder metallurgy.

[0004] Patent CN113652657B discloses an Al-Sc alloy target material and a manufacturing method using atmospheric high-temperature diffusion sintering. Spherical aluminum powder and spherical scandium powder are used as raw materials, which are placed in a closed elastic sleeve and then vacuumed for ultra-high pressure cold isostatic pressing to obtain a green blank with a density of more than 95%, and then diffusion sintered in a large atmosphere sintering furnace to obtain an alloy target blank. Patent CN111910160B discloses a method for preparing an Al-Sc target material, which comprises mixing and smelting metal Sc and metal Al raw materials to obtain an intermediate alloy; wet ball milling the intermediate alloy with alcohol as a medium, and obtaining alloy powder after vacuum drying; mixing the alloy powder and metal aluminum powder evenly, and pressing them into a green blank; sintering the alloy green blank under vacuum or atmosphere protection to obtain an alloy target blank. Although the above-mentioned prior art adopts powder metallurgy to prepare Al-Sc alloy, it can solve the problems of shrinkage, segregation and excessive grain size. However, due to the high activity of metal Sc and AlSc powders, the oxygen content of the powder will be greatly increased by mixing aluminum powder and scandium powder or by ball milling, resulting in excessive oxygen content in the target material.

[0005] Patent CN114774865B discloses a method for preparing an Al-Sc alloy target material, wherein metal aluminum and metal scandium are mixed and subjected to vacuum magnetic suspension melting to achieve alloying of the raw materials; an alloy blank is then cast, and the alloy is densified by hot isostatic pressing. This method is used to prepare an AlSc target material containing 5 to 20 at.% scandium. Patent CN111455223B discloses an Al-Sc alloy target material and a method for preparing the same, wherein metal aluminum is mixed into metal scandium in multiple times, and a target blank is obtained by repeated melting and casting. The above-mentioned prior art adopts the vacuum casting method to obtain an alloy with a Sc content of less than 25at.%, which is composed of two phases of Al and Al3Sc. Since the density and melting point of Al and Al3Sc are very different, Al3Sc will precipitate first during the solidification process, resulting in a large component segregation; while for alloys with a Sc content higher than 25at.%, the constituent phases are intermetallic compounds (Al3Sc, Al2Sc, AlSc, AlSc2), all of which are brittle phases. Therefore, the alloy ingot has high hardness and high brittleness, and is very prone to cracking and corner collapse during casting and processing, and is not suitable for preparing Al-Sc targets with high Sc content.

[0006] In addition, patent CN111485207A discloses a fine-grained homogeneous aluminum-scandium alloy sintering target with high scandium content and its preparation method, wherein a high-purity aluminum block and a high-purity scandium block are mixed and vacuum suspended and gas atomized in turn to obtain atomized aluminum-scandium alloy powder, and the alloy powder is pressure sintered at 500-1350°C. The crucible is prevented from polluting the charge by the suspension smelting method, but the suspension smelting has serious heat dissipation due to the use of a water-cooled copper crucible. Patent CN202011032616.9 points out that after the metal or the corresponding alloy is melted, continuing to increase the heating power cannot significantly increase the temperature of the molten pool. Experiments have shown that the temperature almost no longer rises after it is 100 to 150°C above the melting point. Therefore, the high-purity aluminum block and the high-purity scandium block described in patent CN111485207A are mixed and vacuum suspended and smelted in turn, which will result in incomplete alloying due to the large difference in the melting points of the two metals Al and Sc. At the same time, the alloyed Al3Sc will precipitate due to insufficient superheat of the melt, and gather at the bottom of the crucible under the action of gravity, resulting in uneven melt composition. During powder making, the contact area between the melt and the side wall of the crucible is large during the turning of the crucible, and the solidified shell grows rapidly. A large amount of material will form a solidified shell and remain in the crucible, resulting in a low powder yield. On the other hand, the low superheat of the melt caused by the aforementioned reasons leads to poor alloy fluidity, which is prone to nozzle clogging and the powder quality is difficult to control. At the same time, during the aerosol powder making process, the melt will also react with the flow channel, nozzle, etc., bringing in impurities.

[0007] Metal Sc has a high reactivity and will react with most ceramic crucibles to introduce impurities. For crucibles made of metal oxide ceramic material (MeO), the following reaction will occur: Sc+MeOSc2O3+Me, resulting in the introduction of impurity elements and an increase in the oxygen content of the crucible during the smelting process. Patent document CN202010492396.1 uses suspension smelting to first prepare Al-Sc alloy, and then uses vacuum gas atomization to prepare aluminum-scandium powder. The use of suspension smelting to prepare Al-Sc alloy effectively avoids the reaction between Sc and the crucible during the alloying process; however, alumina / zirconia / magnesia crucibles are used in vacuum powder making. When the scandium content of the alloy is high, it still inevitably reacts with the crucible, introducing metal and scandium oxide impurities, and the prepared powder has a high oxygen content. Summary of the invention

[0008] The present invention is mainly to overcome the defects of insufficient alloying, high oxygen content, low density and low Sc content of Al-Sc alloy in the prior art, and provides an Al-Sc alloy and its preparation method and application. The Al-Sc alloy provided by the present invention can cover the Sc content of 5 at.%~70 at.%, and has the advantages of low oxygen content and high density.

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

[0010] The present invention provides a method for preparing an Al-Sc alloy, which comprises the following steps:

[0011] (1) adding metal aluminum to molten metal scandium in batches for smelting to obtain an Al-Sc alloy ingot; the smelting method is suspension smelting; the number of times the metal aluminum is added is n>1;

[0012] (2) subjecting the Al-Sc alloy ingot to ultrasonic pulverization to obtain Al-Sc alloy powder; the crucible used in the ultrasonic pulverization process is made of aluminum nitride;

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

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

[0015] In the present invention, the purity of the metallic aluminum is 4N or above.

[0016] In the present invention, the purity of the metal scandium is 4N or above.

[0017] In the present invention, the number of times n of adding the metal aluminum can be 2-5, such as 2, 4 or 5.

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

[0019] In the present invention, the smelting process comprises: adding metal scandium into a vacuum induction suspension smelting furnace, and sequentially performing vacuuming, degassing and pressurizing.

[0020] Preferably, the vacuuming is to evacuate to a vacuum degree of 7×10 3 Below Pa.

[0021] Preferably, the degassing temperature is 300-800°C, for example 800°C.

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

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

[0024] In some specific embodiments, the step of adding the metal aluminum is as follows: the mass of the metal aluminum added for the first time is 0.3 times the mass of the metal scandium, the mass of the metal aluminum added for the second time is 0.3 times the mass of the metal scandium, the mass of the metal aluminum added for the third time is 0.6 times the mass of the metal scandium, the mass of the metal aluminum added for the fourth time is 0.6 times the mass of the metal scandium, and the balance of metal aluminum is added for the fifth time;

[0025] In some specific embodiments, the steps of 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, and the remainder metallic aluminum is added for the fourth time.

[0026] In the present invention, during the smelting process, smelting needs to be performed more than twice after each addition of the metal Al raw material, and the material in the suspension smelting crucible needs to be turned over and cooled each time the smelting is performed.

[0027] In the present invention, before the ultrasonic pulverization, the Al-Sc alloy ingot is generally polished to remove the surface oxide layer and impurities.

[0028] In the present 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. The heating temperature is preferably 1200°C, 1250°C

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

[0032] In some specific embodiments, the Al-Sc alloy has a scandium content of ≥20 at.%, and is heated by plasma.

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

[0034] In the present invention, the ultrasonic powder making 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, evacuating the ultrasonic powder making equipment to a vacuum of 7×10 -3 Pa, then argon was filled in to a vacuum degree of 0.04 MPa, and the ultrasonic frequency was set to 20-40 kHz for ultrasonic powder making.

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

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

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

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

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

[0041] In the present invention, the specific steps of the hot isostatic pressing sintering may be: placing the ingot obtained by cold pressing into a metal sheath, performing vacuum sealing welding, and sintering in a hot isostatic pressing device.

[0042] Wherein, the material of the metal sheath is preferably 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 sheath made of Al or aluminum alloy is selected. When the Sc content in the Al-Sc alloy is not less than 25 at.%, a metal sheath made of Ti or titanium alloy is selected.

[0044] The gas extraction is preferably performed to reduce the pressure to 7×10 -2 Below MPa.

[0045] In the present invention, the temperature of the 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°C, the holding time is 2-6 hours, and the holding pressure is 80-160 MPa;

[0046] When the Sc content is 25at.%~33at.%, 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 33at.%, the sintering temperature is 1050~1150℃, the holding time is 4~6 hours, and the holding pressure is 120~160Mpa.

[0048] In the present invention, the prepared Al-Sc alloy can generally be machined to obtain a specified size according to application requirements.

[0049] Among them, when the Sc content is lower than 20at.%, turning is used to remove the metal sheath and process the target material; when the Sc content is not lower than 20at.%, ultrasonic processing is used to remove and process the sheath.

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

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

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

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

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

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

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

[0057] The present invention provides the use of the Al-Sc alloy as mentioned above as a target material in preparing an AlScN film.

[0058] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0059] The reagents and raw materials used in the present invention are commercially available.

[0060] The positive and progressive effects of the present invention are:

[0061] The preparation method of the present invention uses suspension smelting for alloying smelting, thereby avoiding impurities and oxygenation introduced by the reaction between the material and the suspension smelting crucible. Ultrasonic waves are used in the powder making process, and aluminum nitride crucibles are used to avoid impurity contamination caused by the contact between the flow channel and the nozzle in the gas atomization powder making process. There is no contact with air during the whole process of powder preparation, powder mixing, filling, and transfer, thereby minimizing the introduction of impurities in the gas. The obtained powder can be fully utilized without screening, thereby greatly improving the product yield.

[0062] The Al-Sc alloy prepared by the preparation method provided by the present invention has high density, small component segregation, low oxygen content, high purity, uniform grain distribution, and is not easy to crack during processing, and can cover the preparation of Al-Sc alloys with 5-70at.% Sc content. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a preparation flow chart of the preparation method of the Al-Sc alloy of the present invention.

[0064] Figure 2 This is the phase diagram of the Al-Sc alloy prepared in Example 1.

[0065] Figure 3 This is the phase diagram of the Al-Sc alloy prepared in Example 2.

[0066] Figure 4 This is the phase diagram of the Al-Sc alloy prepared in Example 3.

[0067] Figure 5This is the phase diagram of the Al-Sc alloy prepared in Example 7.

[0068] Figure 6 This is the phase diagram of the Al-Sc alloy prepared in Comparative Example 3. DETAILED DESCRIPTION

[0069] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[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 ingot

[0073] S1. Place 2.34 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; then heat up until the metal Sc is molten; add 0.7kg of metal aluminum particles through the feeding bin for the first time, and stop heating after smelting for 5 minutes;

[0074] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 0.7kg of aluminum particles are added through the feeding bin for the second time, and heating is stopped after smelting for 5 minutes;

[0075] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.4kg of aluminum particles are added for the third time through the feeding bin, and heating is stopped after smelting for 5 minutes;

[0076] S4. After the material obtained in step S3 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the temperature is below 0.06 MPa, argon gas is added to 0.06 MPa, and induction heating is turned on. After the material is melted, 1.4 kg of aluminum particles are added through the feeding bin for the fourth time. After smelting for 5 minutes, heating is stopped.

[0077] S5. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10-3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 8.44kg of aluminum particles are added for the fifth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an 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 powder making; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is started to melt the alloy ingot. After the temperature rises to 1200°C, the heating power is adjusted so that the temperature does not exceed 1250°C. After keeping the temperature for 10 minutes, powder making is carried out. The ultrasonic frequency of powder making is 20kHz. The powder is collected by a collecting tank to obtain Al-Sc alloy powder.

[0079] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 600 MPa and the holding time of 8 min. Then, the pressed ingot was placed in a 6061 aluminum alloy bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace. The sintering temperature is 500°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained; and then mechanical processing is carried out to obtain the Al-Sc alloy.

[0080] The Al-Sc alloy obtained in step (3) was sampled, and its XRD phase diagram was as follows: Figure 2 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 ingot

[0086] S1. Place 4.17 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3After the induction heating reaches 1.004 MPa, the material temperature is kept below 800°C by controlling the power. After degassing for 5 minutes, argon is filled to 0.06 MPa. The temperature is then raised to melt the metal Sc. 1.25 kg of aluminum particles are added through the feeding bin for the first time. After smelting for 5 minutes, the heating is stopped.

[0087] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.25kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0088] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the material is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 2.5kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0089] S4. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 830g of aluminum particles are added for the fourth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an 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 for ultrasonic powder making. The heating method is plasma heating and the vacuum is evacuated to 7×10 -3 Pa, argon gas was filled to 0.04MPa, the ultrasonic frequency of powder making was 40kHz, and the obtained powder was collected by a collection tank to obtain Al-Sc alloy powder;

[0091] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 650 MPa and the holding time of 10 min. Then, the pressed ingot was placed in a titanium bag in a glove box and the bag was evacuated to 6×10 -2 After Pa, sealing welding is performed, and HIP sintering is performed in a hot isostatic pressing furnace. The sintering temperature is 1150°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, an Al-Sc alloy target blank is obtained; and then machining is performed to obtain an Al-Sc alloy;

[0092] The Al-Sc alloy obtained in step (3) was sampled, and its XRD phase diagram was as follows: Figure 3 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 comprises the following steps:

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

[0098] S1. Place 5.67 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 6×10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; heat until the metal Sc is molten, add 1.7kg aluminum particles through the feeding bin for the first time, and stop heating after smelting for 5 minutes;

[0099] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.7kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0100] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 - 3 After the pressure is below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.11kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

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

[0102] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 650 MPa and the holding time of 10 min. The pressed ingot was placed in a titanium bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is performed, and HIP sintering is performed in a hot isostatic pressing furnace. The sintering temperature is 1100°C, the holding time is 5h, and the holding pressure is 150MPa. After sintering, an Al-Sc alloy target blank is obtained; and then mechanical processing is performed to obtain an Al-Sc alloy;

[0103] The Al-Sc alloy obtained in step (3) was sampled, and its XRD phase diagram was as follows: Figure 4 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 ingot

[0109] S1. Place 2.34 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; then heat up until the metal Sc is molten; add 0.7kg of metal aluminum particles through the feeding bin for the first time, and stop heating after smelting for 5 minutes;

[0110] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 0.7kg of aluminum particles are added through the feeding bin for the second time, and heating is stopped after smelting for 5 minutes;

[0111] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.4kg of aluminum particles are added for the third time through the feeding bin, and heating is stopped after smelting for 5 minutes;

[0112] S4. After the material obtained in step S3 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the temperature is below 0.06 MPa, argon gas is added to 0.06 MPa, and induction heating is turned on. After the material is melted, 1.4 kg of aluminum particles are added through the feeding bin for the fourth time. After smelting for 5 minutes, heating is stopped.

[0113] S5. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 8.44kg of aluminum particles are added for the fifth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[0114] (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 powder making; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is started to melt the alloy ingot. After the temperature rises to 1200°C, the heating power is adjusted so that the temperature does not exceed 1250°C. After keeping the temperature for 10 minutes, powder making is carried out. The ultrasonic frequency of powder making is 40kHz. The powder is collected by a collecting tank to obtain Al-Sc alloy powder.

[0115] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 600 MPa and the holding time of 8 min. Then, the pressed ingot was placed in a 6061 aluminum alloy bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace. The sintering temperature is 500°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained; and then mechanical processing is carried out to obtain the Al-Sc alloy.

[0116] The Al-Sc alloy obtained in step (3) was sampled, and the impurity content detected by GDMS is 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 ingot

[0122] S1. Place 2.34 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; then heat up until the metal Sc is molten; add 0.7kg of metal aluminum particles through the feeding bin for the first time, and stop heating after smelting for 5 minutes;

[0123] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 0.7kg of aluminum particles are added through the feeding bin for the second time, and heating is stopped after smelting for 5 minutes;

[0124] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.4kg of aluminum particles are added for the third time through the feeding bin, and heating is stopped after smelting for 5 minutes;

[0125] S4. After the material obtained in step S3 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the temperature is below 0.06 MPa, argon gas is added to 0.06 MPa, and induction heating is turned on. After the material is melted, 1.4 kg of aluminum particles are added through the feeding bin for the fourth time. After smelting for 5 minutes, heating is stopped.

[0126] S5. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 8.44kg of aluminum particles are added for the fifth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[0127] (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 powder making; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3After Pa, heating is started to melt the alloy ingot. After the temperature rises to 1200°C, the heating power is adjusted so that the temperature does not exceed 1250°C. After keeping the temperature for 10 minutes, powder making is carried out. The ultrasonic frequency of powder making is 10kHz. The powder is collected by a collecting tank to obtain Al-Sc alloy powder.

[0128] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 600 MPa and the holding time of 8 min. Then, the pressed ingot was placed in a 6061 aluminum alloy bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace. The sintering temperature is 500°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained; and then mechanical processing is carried out to obtain the Al-Sc alloy.

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

[0135] S1. Place 2.34 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; then heat up until the metal Sc is molten; add 0.7kg of metal aluminum particles through the feeding bin for the first time, and stop heating after smelting for 5 minutes;

[0136] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 0.7kg of aluminum particles are added through the feeding bin for the second time, and heating is stopped after smelting for 5 minutes;

[0137] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.4kg of aluminum particles are added for the third time through the feeding bin, and heating is stopped after smelting for 5 minutes;

[0138] S4. After the material obtained in step S3 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the temperature is below 0.06 MPa, argon gas is added to 0.06 MPa, and induction heating is turned on. After the material is melted, 1.4 kg of aluminum particles are added through the feeding bin for the fourth time. After smelting for 5 minutes, heating is stopped.

[0139] S5. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 8.44kg of aluminum particles are added for the fifth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[0140] (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 powder making; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is started to melt the alloy ingot. After the temperature rises to 1200°C, the heating power is adjusted so that the temperature does not exceed 1250°C. After keeping the temperature for 10 minutes, powder making is carried out. The ultrasonic frequency of powder making is 60kHz. The powder is collected by a collecting tank to obtain Al-Sc alloy powder.

[0141] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 600 MPa and the holding time of 8 min. Then, the pressed ingot was placed in a 6061 aluminum alloy bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace. The sintering temperature is 500°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained; and then mechanical processing is carried out to obtain the Al-Sc alloy.

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

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

[0144]

[0145] Example 7

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

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

[0148] S1. Place 4.17 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; heat until the metal Sc is molten, add 1.25kg aluminum particles for the first time through the feeding bin, stop heating after smelting for 5 minutes, and cool the material in a water-cooled copper crucible;

[0149] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 4.58kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an 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 powder making. The heating method is plasma heating; the vacuum is evacuated to 7×10 -3 After the pressure reaches 0.04 MPa, argon gas is filled in and the alloy ingot is heated to melt. The ultrasonic frequency of powder making is set to 40 kHz, and the obtained powder is collected in a collection tank;

[0151] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 650 MPa and the holding time of 10 min. The pressed ingot was placed in a titanium bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is performed, and HIP sintering is performed in a hot isostatic pressing furnace. The sintering temperature is 1150℃, the holding time is 5h, and the holding pressure is 150MPa. After sintering, the Al-Sc alloy target blank is obtained; and then mechanical processing is performed to obtain the Al-Sc alloy. Its XRD crystal phase diagram is shown as follows Figure 5 shown.

[0152] Comparative Example 1

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

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

[0155] S1. Place 5.26 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; heat until the metal Sc is molten, add 1.58kg aluminum particles for the first time through the feeding bin, stop heating after smelting for 5 minutes, and cool the material in a water-cooled copper crucible;

[0156] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.58kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0157] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.58g of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[0158] (2) After the surface oxide scale of the alloy ingot is polished, it is placed in an Al2O3 crucible and placed in an ultrasonic powder making device for ultrasonic powder making; the heating method is induction heating, and the vacuum is evacuated to 7×10 -3 After Pa, heating is started to melt the alloy ingot. After the temperature rises to 1200°C, the heating power is adjusted so that the temperature does not exceed 1250°C. After keeping the temperature for 10 minutes, powder making is carried out. The ultrasonic frequency of powder making is set to 20kHz. The powder is collected through a collection tank to obtain Al-Sc alloy powder.

[0159] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 600 MPa and the holding time of 8 min. The pressed ingot was placed in a 6061 aluminum alloy bag in a glove box, and the bag was evacuated to 6×10-2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace. The sintering temperature is 500°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained; and then mechanical processing is carried out 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.

[0161] Comparative Example 2

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

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

[0164] S1. Place 4.17 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; heat until the metal Sc is molten, add 1.25kg aluminum particles for the first time through the feeding bin, and stop heating after smelting for 5 minutes;

[0165] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.25kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0166] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the material is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 2.5kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0167] S4. After the material obtained in step S3 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 830g of aluminum particles are added for the fourth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[0168] (2) After the surface oxide scale of the alloy ingot is polished, it is placed in an Al2O3 crucible and placed in an ultrasonic powder making device. The heating method is induction heating and the vacuum is evacuated to 7×10 -3After the pressure reaches 0.04 MPa, argon gas is filled in and heated to melt the alloy ingot. After the temperature reaches 1400°C, the heating power is adjusted so that the temperature does not exceed 1450°C. After keeping the temperature for 10 minutes, the ultrasonic wave is turned on and the ultrasonic frequency is set to 20 kHz for powder making. The powder is collected in a collection tank to obtain Al-Sc alloy powder.

[0169] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 650 MPa and the holding time of 10 min. The pressed ingot was placed in a titanium bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace with a sintering temperature of 1150°C, a holding time of 5h, and a holding pressure of 150MPa. After sintering, an Al-Sc alloy target blank is obtained; and then mechanical processing is carried out to obtain an Al-Sc alloy.

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

[0171] Comparative Example 3

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

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

[0174] 5.26 kg of Sc metal with a purity of 99.99% was placed in a suspension smelting furnace, and after vacuuming to 7×10-3 Pa, induction heating was turned on, and the material temperature was kept below 800°C by controlling the power. After degassing for 5 minutes, argon gas was filled to 0.06 MPa; the temperature was raised until the Sc metal was molten, and 4.75 kg of aluminum particles were added at one time through the feeding bin. After smelting for 5 minutes, the heating was turned off, and the material was cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[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 for ultrasonic powder making. The heating method is plasma heating; the vacuum is evacuated to 7×10 -3 Pa, argon gas is filled to 0.04MPa, the alloy ingot is heated to melt, and the obtained powder is collected by a collection tank;

[0176] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 650 MPa and the holding time of 10 min. The pressed ingot was placed in a titanium bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is performed, and HIP sintering is performed in a hot isostatic pressing furnace. The sintering temperature is 1150℃, the holding time is 5h, and the holding pressure is 150MPa. After sintering, the Al-Sc alloy target blank is obtained; and then machining is performed to obtain the Al-Sc alloy. Its XRD crystal phase diagram is shown as follows Figure 6 Shown

[0177] Comparative Example 4

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

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

[0180] S1. Place 4.17 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 After the induction heating reaches 1.004 MPa, the material temperature is kept below 800°C by controlling the power. After degassing for 5 minutes, argon is filled to 0.06 MPa. The temperature is then raised to melt the metal Sc. 1.25 kg of aluminum particles are added through the feeding bin for the first time. After smelting for 5 minutes, the heating is stopped.

[0181] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.25kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0182] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the material is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 2.5kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0183] S4. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 830g of aluminum particles are added for the fourth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

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

[0185] (3) Dry the powder under vacuum and put it into a collection tank, put the collection tank into a three-dimensional mixer and fix it for mixing for 30 minutes. After the mixing is completed, move the collection tank and the elastic bag to a vacuum glove box, put the powder into the elastic bag in the glove box, and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) molding is performed, the pressure is set to 650MPa, and the holding time is 10min; the pressed ingot is placed in a titanium sleeve in a glove box, the sleeve is evacuated to 6×10-2Pa and then sealed, and HIP sintering is performed in a hot isostatic pressing furnace, the sintering temperature is 1150℃, the holding time is 5h, and the holding pressure is 150MPa. After sintering, an Al-Sc alloy target blank is obtained; the sintered target blank is mechanically processed to obtain an 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 measured by drainage method, the alloy phase composition was analyzed by XRD, and the oxygen content was detected by 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] The comparative example of the present invention provides a method for preparing an Al-Sc alloy having a Sc content of 43 at.%, the preparation method comprising the following steps:

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

[0190] S1. Place 5.67 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 6×10 -3 Pa, start induction heating, control the power to keep the material temperature below 800℃, degas for 5 minutes and fill with argon to 0.06Mpa; heat until the metal Sc is molten, add 1.7kg aluminum particles through the feeding bin for the first time, and stop heating after smelting for 5 minutes;

[0191] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.7kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0192] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 - 3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.11kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in the crucible to obtain an Al-Sc alloy ingot;

[0193] (2) After grinding the oxide skin on the surface of the Al-Sc alloy ingot, the powder is made by vacuum induction atomization using an aluminum nitride crucible. After the alloy is melted in the crucible, the temperature is raised to 1450°C and kept warm for 30 minutes. The atomizing gas is argon and the pressure is 5 MPa. The obtained powder is collected in a collection tank to obtain Al-Sc alloy powder;

[0194] (3) Place the collection tank in a three-dimensional mixer and fix it for mixing for 30 min. After mixing, move the collection tank and the elastic bag to a vacuum glove box. Place the powder in the elastic bag in the glove box and evacuate the bag to 6×10 -2 After Pa sealing, cold isostatic pressing (CIP) was performed, with the pressure set to 650 MPa and the holding time of 10 min. The pressed ingot was placed in a titanium bag in a glove box, and the bag was evacuated to 6×10 -2 After Pa, sealing welding is carried out, and HIP sintering is carried out in a hot isostatic pressing furnace. The sintering temperature is 1100°C, the holding time is 5h, and the holding pressure is 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained; then mechanical processing is carried out to obtain the Al-Sc alloy.

[0195] Comparative Example 6

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

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

[0198] S1. Place 4.17 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3After the induction heating reaches 1.004 MPa, the material temperature is kept below 800°C by controlling the power. After degassing for 5 minutes, argon is filled to 0.06 MPa. The temperature is then raised to melt the metal Sc. 1.25 kg of aluminum particles are added through the feeding bin for the first time. After smelting for 5 minutes, the heating is stopped.

[0199] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.25kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0200] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the material is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 2.5kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0201] S4. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 830g of aluminum particles are added for the fourth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

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

[0203] (3) The collection tank was placed in a three-dimensional mixer for mixing for 30 min. After mixing, the powder was placed in a titanium bag in a vacuum glove box and the bag was evacuated to 6 × 10 -2 After Pa, sealing welding is carried out and HIP sintering is carried out in a hot isostatic pressing furnace with a sintering temperature of 1150°C, a holding time of 5h, and a holding pressure of 150MPa. After the sintering is completed, the Al-Sc alloy target blank is obtained and then mechanically processed to obtain the Al-Sc alloy.

[0204] Comparative Example 7

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

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

[0207] S1. Place 4.17 kg of Sc metal with a purity of 99.99% into a suspension smelting furnace and evacuate to 7 × 10 -3 After the induction heating reaches 1.004 MPa, the material temperature is kept below 800°C by controlling the power. After degassing for 5 minutes, argon is filled to 0.06 MPa. The temperature is then raised to melt the metal Sc. 1.25 kg of aluminum particles are added through the feeding bin for the first time. After smelting for 5 minutes, the heating is stopped.

[0208] S2. After the material obtained in step S1 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure drops below Pa, argon is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 1.25kg of aluminum particles are added for the second time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0209] S3. After the material obtained in step S2 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the material is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 2.5kg of aluminum particles are added for the third time through the feeding bin. After smelting for 5 minutes, heating is stopped;

[0210] S4. After the material obtained in step S4 is cooled, the material is turned over and placed in a water-cooled copper crucible and evacuated to 7×10 -3 After the pressure is below Pa, argon gas is filled to 0.06Mpa, and induction heating is turned on. After the material is melted, 830g of aluminum particles are added for the fourth time through the feeding bin. After smelting for 5 minutes, heating is stopped, and the material is cooled in a water-cooled copper crucible to obtain an Al-Sc alloy ingot;

[0211] (2) Grind the surface oxide scale of the alloy ingot and put it into the Al2O3 crucible; evacuate to 7×10 -3 After the pressure reaches 0.04 MPa, argon gas is filled in and heated to melt the alloy ingot. After the temperature reaches 1400°C, the heating power is adjusted so that the temperature does not exceed 1450°C. After keeping the temperature for 10 minutes, the ultrasonic wave is turned on and the ultrasonic frequency is set to 20 kHz for powder making. The powder is collected in a collection tank to obtain Al-Sc alloy powder.

[0212] (3) After the powder is sieved through a 50-mesh sieve, the particle size is 47-300 μm. 0.5 kg of Al-Sc alloy powder is weighed and placed in 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 °C, the holding pressure is 30 MPa, the holding time is 4 h, and the vacuum degree is 6 × 10 -3 Pa, to obtain a target ingot, which is then machined to obtain an Al-Sc alloy.

[0213] Effect Example 1

[0214] The Al-Sc alloys prepared in the examples and comparative examples were sampled, and their Sc content was analyzed by ICP, their density was measured by drainage method, their alloy phase composition was analyzed by XRD, and their oxygen content was measured by gas analyzer. The test results are recorded in Table 7.

[0215] Table 7

[0216]

[0217] The preparation method provided by the present invention can be adjusted according to the crystal phase required for the application, and the desired Al-Sc alloy can be accurately prepared, and the prepared Al-Sc alloy can cover the Sc content of 5 at.%~70 at.%, and has the advantages of uniform grain size, uniform component distribution, high purity, low oxygen content, and high density. In some specific embodiments, it adopts Figure 1 According to the preparation process shown, the purity of the Al-Sc alloy obtained is higher than 99.99%, the oxygen content is lower than 251 ppm, the density is higher than 99.9%, and further, the yield is higher than 65.4%.

[0218] In Comparative Examples 1 and 2, alumina crucibles are used for powder preparation. Alumina reacts with Sc, resulting in an increase in the oxygen content in the alloy. The oxygen increment of the target with a high scandium content is higher.

[0219] Figure 6 The XRD phase diagram of the Al-Sc alloy obtained in Comparative Example 3 is shown in Table 7 and Figure 6 It can be seen that the multi-step feeding and smelting method can make the material alloying more complete, which is consistent with the phase ratio in the phase diagram. Comparative Example 3 adopts a one-step feeding method for smelting, and there is incomplete alloying, and free metal Sc phase exists in the final target material.

[0220] The difference between Comparative Example 4 and Example 2 is that the powder preparation method in step (2) is a wet ball milling process. 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 making method in step (2) is induction gas atomization powder making. It can be seen that for the 43at.% aluminum-scandium alloy, the oxygen content of the target material prepared by induction gas atomization powder is greatly increased compared with the example. The reason for this phenomenon may be that compared with ultrasonic atomization powder making, gas atomization powder making requires a larger cavity space, making it difficult to achieve a lower oxygen content in the equipment.

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

[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 greatly increased compared with Example 2, while its density is reduced.

[0224] Effect Example 2

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

[0226] Table 8 Number of particles on the sputtering coating surface

[0227]

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

[0229] Effect Example 3

[0230] The target materials of Example 2 and Example 7 were subjected to film coating tests. The coating substrate material was 4-inch single crystal silicon. Reactive sputtering was performed in a high-purity argon and high-purity nitrogen environment. The coating time was 120 minutes. XPS was used to detect the Al and Sc contents of the sputtered film material, and the comparison was as follows:

[0231] Table 9 Reactive sputtering film composition ratio

[0232]

[0233] The number of times aluminum is added during the alloying process and the proportion of each addition 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 ratio of scandium in Al3Sc and Al2Sc, the sputtering rates of Al and Sc are slightly different during the sputtering process, resulting in a certain degree of deviation in the composition ratio of the film material.

[0234] The above-described embodiments are only preferred embodiments of the present invention, which are convenient for those skilled in the art to understand and use the present invention. Obviously, any person skilled in the art can slightly modify or change the present embodiment and apply it to other embodiments without creative work. Therefore, the present invention is not limited to the above-described embodiments, and any equal changes, simple modifications and modifications made within the scope of the present invention still belong to the scope of the present invention.

Claims

1. A method for preparing an Al-Sc alloy, characterized in that: It includes the following steps: (1) adding metal aluminum to molten metal scandium in batches for smelting to obtain an Al-Sc alloy ingot; the smelting method is suspension smelting; the number of times the metal aluminum is added is n>1; (2) subjecting the Al-Sc alloy ingot to ultrasonic pulverization to obtain Al-Sc alloy powder; the crucible used in the ultrasonic pulverization process is made of aluminum nitride; (3) The Al-Sc alloy powder is subjected to cold isostatic pressing and hot isostatic sintering in sequence to obtain the Al-Sc alloy.

2. The method for preparing the Al-Sc alloy according to claim 1, characterized in that: The preparation method of the Al-Sc alloy satisfies one or more of the following conditions ac: a. The atomic ratio of the metal scandium and the metal aluminum is (5:95) - (70:30); b. The number of times the metal aluminum is added n is 2-5; c. During the smelting process, each time the metal Al raw material is added, smelting needs to be performed more than twice, and each smelting needs to turn over and cool the material in the suspension smelting crucible.

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

4. The method for preparing the Al-Sc alloy according to claim 1, characterized in that: The preparation method of the Al-Sc alloy satisfies one or two of the following conditions ab: a. The smelting process comprises: adding metal scandium into a vacuum induction suspension smelting furnace, and sequentially performing vacuuming, degassing and pressurizing; wherein the degassing temperature is 300-800°C; the degassing time is 2-10 minutes; and the pressurizing method is to fill argon gas to a pressure of 0.04MPa-0.08MPa; b. The ultrasonic powder making includes heating and powder making; the heating method is induction heating or plasma heating; the ultrasonic frequency of the powder making is 20kHz-40kHz.

5. The method for preparing the Al-Sc alloy according to claim 4, characterized in that: The heating method satisfies any one of the following conditions ab: a. The scandium content in the Al-Sc alloy is <20at.%, and the heating method is induction heating; b. The scandium content in the Al-Sc alloy is ≥20at.%, and the heating method is plasma heating.

6. The method for preparing the Al-Sc alloy according to claim 1, characterized in that: The preparation method of the Al-Sc alloy satisfies one or more of the following conditions ac: a. The cold isostatic pressing pressure is 400-800Mpa; b. The holding time of the cold isostatic pressing is 5-20min; c. The specific steps of the hot isostatic pressing sintering are: placing the ingot obtained by cold pressing into a metal sheath, performing vacuum sealing welding, and sintering in a hot isostatic pressing device.

7. The method for preparing the Al-Sc alloy according to claim 6, characterized in that: The hot isostatic pressing sintering satisfies one or more of the following conditions ac: a. The Sc content in the Al-Sc alloy is less than 25at.%, the sintering temperature is 400~600℃, the holding time is 2~6 hours, and the holding pressure is 80~160Mpa; b. The Sc content of the Al-Sc alloy is 25at.% ~ 33at.%, the sintering temperature is 1100 ~ 1200 ℃, the holding time is 4 to 6 hours, and the holding pressure is 100 ~ 150Mpa; c. The Sc content in the Al-Sc alloy is greater than 33at.%, the sintering temperature is 1050~1150℃, the holding time is 4~6 hours, and the holding pressure is 120~160Mpa.

8. An Al-Sc alloy, characterized in that: The alloy is prepared by the preparation method of the Al-Sc alloy described in any one of claims 1 to 7.

9. The Al-Sc alloy according to claim 8, 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 of the Al-Sc alloy is 107-243ppm; c. The density of the Al-Sc alloy is 100% or more; d. The Al-Sc alloy comprises an Al3Sc phase and an Al phase; e. The Al-Sc alloy includes an Al3Sc phase and an Al2Sc phase.

10. Use of the Al-Sc alloy according to claim 9 in preparing AlScN thin film.

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