Aluminum-scandium alloy target and method for manufacturing the same

Abstract

The application belongs to the technical field of target material production and discloses a preparation method of an aluminum-scandium alloy target material. First, metal aluminum and metal scandium are smelted in a crucible, and then cast into a mold to cool to obtain a cast blank and a residual shell on the inner wall of the crucible. Then, the cast blank is horizontally cut into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1-1.5:1.5-2. The shell is horizontally cut into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1-1.5:1.5-2. The first blank body, the second blank body, the first shell body and the second shell body are sequentially placed in the crucible in the order of the first blank body, the first shell body, the second blank body and the second shell body, smelted and poured into the mold to cool, and the aluminum-scandium alloy target material is obtained. Through the design, the uniformity of the distribution of aluminum and scandium in the target material is effectively improved, and the loss of raw materials in the preparation process of the aluminum-scandium alloy target material is reduced. In addition, the application also discloses an aluminum-scandium alloy target material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of target material production, in particular to an aluminum-scandium alloy target material and a preparation method thereof. BACKGROUND

[0002] The ScAlN piezoelectric body film has the advantages of high sound wave speed, high thermal conductivity, low dielectric loss, excellent thermal stability, compatibility with the complementary metal oxide semiconductor (CMOS) process and the like, and becomes an ideal material for preparing high-frequency, high-power and high-integration piezoelectric elements. With the rapid development of science and technology, and the emphasis on the research of key materials for key fields in various countries, the demand for aluminum-scandium alloy blanks as key materials required for the preparation of ScAlN piezoelectric films is increasing.

[0003] Common methods for producing aluminum-scandium alloys include the co-doping method, the molten salt electrolysis method, the thermal reduction method and the powder sintering method. In order to prepare aluminum-scandium target materials with higher purity, numerous studies have been conducted on the co-doping method for preparing aluminum-scandium alloy target materials. The co-doping method, also known as the mixed melting method, is a traditional method for preparing aluminum-scandium alloys, which specifically uses pure scandium and pure aluminum as raw materials, pure argon gas as a protective gas in a vacuum state, pours the molten aluminum and scandium into a water-cooled mold after melting in a crucible, and obtains the aluminum-scandium alloy. This method is simple, but it is prone to casting defects, such as uneven distribution of aluminum and scandium, low density of the alloy target material and the like.

[0004] Chinese Patent Application 202210574325.5 discloses a preparation method of an aluminum-scandium target material, which comprises the following steps: mixing and melting metal aluminum and metal scandium in a certain proportion to obtain an aluminum-scandium alloy, wherein the scandium content in the aluminum-scandium alloy is 2at% or 43at%; crushing the aluminum-scandium alloy to obtain an aluminum-scandium alloy powder; mixing the aluminum-scandium alloy powder in a certain proportion to obtain a mixed aluminum-scandium alloy powder; and performing hot pressing treatment on the mixed aluminum-scandium alloy powder under the protection of an argon atmosphere to obtain an aluminum-scandium ingot; and processing the aluminum-scandium ingot to obtain the aluminum-scandium target material. Among them, the aluminum-scandium alloy powder is not easy to oxidize compared with pure scandium powder and pure aluminum powder, and the segregation of the aluminum-scandium alloy itself does not need to be considered, which greatly improves the quality of the aluminum-scandium target material. At the same time, by producing only aluminum-scandium alloys with scandium contents of 43at% and 2at%, and mixing the two aluminum-scandium alloys with different scandium contents, an aluminum-scandium target material with a scandium content of 2-43at% can be obtained, which can shorten the production time and improve the efficiency.

[0005] However, it can be seen from the above scheme that the above scheme directly crushes and mixes aluminum-scandium alloys with different scandium contents to prepare the target material.

[0006] The problem to be solved by the present application is: how to provide a preparation method of an aluminum-scandium alloy target material different from the prior art and having good component distribution uniformity. SUMMARY

[0007] The purpose of the present application is to provide a preparation method of an aluminum scandium alloy target material, which effectively improves the uniformity of the distribution of aluminum scandium in the target material and reduces the loss of raw materials in the preparation process of the aluminum scandium alloy target material by segmenting and crushing the cast ingot obtained by co-melting of the aluminum scandium alloy and the shell attached to the inner wall of the mold, and then re-mixing the co-melting.

[0008] To achieve the above-mentioned purpose, the present application discloses a preparation method of an aluminum scandium alloy target material, which comprises the following steps:

[0009] Then, the cast blank is horizontally cut into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1-1.5:1.5-2;

[0010] The shell is horizontally cut into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1-1.5:1.5-2;

[0011] The blank body and the shell after melting, different positions of the blank body, and different positions of the shell may cause uneven distribution of components due to temperature difference, density of raw materials, etc., so by segmenting the blank body and the shell, the target material is obtained by re-melting, which further suppresses the uneven distribution of components, and through a large number of experiments, we surprisingly found that when the first blank body, the second blank body, the first shell body, and the second shell body after segmentation are fed in a specific order, the uniformity of the component distribution of the target material can be further improved.

[0012] Preferably, the method comprises the following steps:

[0013] Step 1: melting metal aluminum and metal scandium in a crucible and pouring into a mold to cool down to obtain an intermediate alloy;

[0014] Step 2: turning over the intermediate alloy and melting in a crucible, then pouring into a mold to cool down to obtain a cast blank and a shell remaining on the inner wall of the crucible;

[0015] Step 3: horizontally cutting the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1-1.5:1.5-2;

[0016] Horizontally cutting the shell into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1-1.5:1.5-2;

[0017] Step 4: sequentially placing the first billet, the second billet, the first shell, and the second shell into the crucible in the order of the first billet, the first shell, the second billet, and the second shell, and then pouring the molten liquid into a mold to cool, thereby obtaining the aluminum-scandium alloy target material.

[0018] Further, the intermediate alloy is obtained by co-melting the aluminum and scandium metals. However, due to the difference in density and melting point between the aluminum and scandium metals, the difference in temperature at different positions of the melting crucible, and the difference in cooling speed at different positions during the cooling process, the aluminum and scandium in the intermediate alloy inevitably have uneven distribution.

[0019] Subsequently, the intermediate alloy is flipped and re-melted, which to some extent reduces the uneven distribution of the aluminum and scandium caused by the difference in density and melting point. However, the component segregation caused by the difference in temperature at different positions of the melting crucible and the difference in cooling speed at different positions during the cooling process is still difficult to be greatly alleviated.

[0020] Finally, by splitting the cast billet and the solidified shell, and feeding the split first billet, the second billet, the first shell, and the second shell in a specific order, the uniformity of the component distribution of the target material can be further improved.

[0021] Preferably, the mass ratio of the aluminum metal to the scandium metal is 70-90:10-30.

[0022] Preferably, the height ratio of the first billet to the second billet is 1.1-1.3:1.7-1.9.

[0023] The height ratio of the first shell to the second shell is 1.1-1.3:1.8-2.0.

[0024] Preferably, in step 4, the first billet, the second billet, the first shell, and the second shell are added to the crucible in the form of particles, and the particle size of the first billet, the second billet, the first shell, and the second shell is 30-50 mm.

[0025] Preferably, the particle size of the first billet and the second billet is 40-50 mm, and the particle size of the first shell and the second shell is 30-40 mm and does not include 40 mm.

[0026] Preferably, the operation in step 4 is specifically as follows: sequentially placing the first billet, the second billet, the first shell, and the second shell into the crucible in the order of the first billet, the first shell, the second billet, and the second shell, and then heating to 1180-1350℃ and maintaining for 15-18 min to obtain a molten liquid and pour the molten liquid into a mold.

[0027] Subsequently, the molten liquid is cooled to room temperature within 30-65 min to obtain the aluminum-scandium alloy target material.

[0028] Preferably, the cooling operation in step 4 is specifically: cooling the melt to room temperature at a cooling rate of 25-30℃ / min, to obtain the aluminum-scandium alloy target material.

[0029] In addition, the application further discloses an aluminum-scandium alloy target material prepared by the preparation method of the aluminum-scandium alloy target material, and the relative density of the aluminum-scandium alloy target material is not less than 99%.

[0030] The application has the following beneficial effects:

[0031] The application provides a preparation method of an aluminum-scandium alloy target material, which effectively improves the uniformity of aluminum and scandium in the target material and reduces the loss of raw materials in the preparation process of the aluminum-scandium alloy target material by splitting and crushing the cast ingot obtained by eutectic of the aluminum-scandium alloy and the shell attached to the inner wall of the crucible, and then re-mixing eutectic. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A diagram for selection of test positions in a test process. DETAILED DESCRIPTION

[0033] The application will be described in detail below with reference to the embodiments of the application. In the description of the application, it should be noted that, if no specific conditions are indicated in the embodiments, the conditions are implemented according to conventional conditions or the conditions recommended by the manufacturer. If no manufacturer of the reagent or instrument is indicated, the reagent or instrument is a conventional product that can be purchased in the market.

[0034] Embodiment 1

[0035] Step 1: mixing metal aluminum and metal scandium according to a mass ratio of 70:30, and melting at 1350℃ for 20 min to obtain an intermediate alloy;

[0036] Step 2: turning the intermediate alloy and melting at 1350℃ for 15 min in the crucible to obtain a cast blank and a solidified shell remaining on the inner wall of the crucible;

[0037] Step 3: horizontally cutting the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1:2;

[0038] horizontally cutting the solidified shell into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1:2;

[0039] Step 4: crushing the first blank body, the second blank body, the first shell body and the second shell body into particles with a size of 47±2 mm, and then sequentially placing the first blank body, the first shell body, the second blank body and the second shell body into the crucible to melt at 1350℃ for 15 min, and then pouring into a mold and cooling the melt to room temperature at 62 min to obtain the aluminum-scandium alloy target material.

[0040] Example 2

[0041] Step 1: mix the metal aluminum and the metal scandium in a mass ratio of 80:20, smelt at 1350℃ for 20min to obtain an intermediate alloy;

[0042] Step 2: turn over the intermediate alloy and smelt in a crucible at 1350℃ for 15min, cast into a mold to obtain a cast blank and a solidified shell remaining on the inner wall of the crucible;

[0043] Step 3: horizontally cut the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1.1:1.9;

[0044] horizontally cut the solidified shell into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1.1:2;

[0045] Step 4: crush the first blank body, the second blank body, the first shell body and the second shell body into particles of 38±2mm, sequentially put them into a crucible to smelt at 1180℃ for 18min in the order of the first blank body, the first shell body, the second blank body and the second shell body, then pour into a mold and cool the melt to room temperature in 48min to obtain an aluminum scandium alloy target material.

[0046] Example 3

[0047] Step 1: mix the metal aluminum and the metal scandium in a mass ratio of 90:10, smelt at 1350℃ for 20min to obtain an intermediate alloy;

[0048] Step 2: turn over the intermediate alloy and smelt in a crucible at 1350℃ for 15min, cast into a mold to obtain a cast blank and a solidified shell remaining on the inner wall of the crucible;

[0049] Step 3: horizontally cut the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1.3:1.7;

[0050] horizontally cut the solidified shell into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1.3:1.8;

[0051] Step 4: crush the first blank body, the second blank body, the first shell body and the second shell body into particles of 32±2mm, sequentially put them into a crucible to smelt at 1250℃ for 17min in the order of the first blank body, the first shell body, the second blank body and the second shell body, then pour into a mold and cool the melt to room temperature in 54min to obtain an aluminum scandium alloy target material.

[0052] Example 4

[0053] The same as example 1, except that step 3 is specifically: the cast blank is horizontally cut into the first blank and the second blank, and the height ratio of the first blank to the second blank is 1.5:1.5;

[0054] The solidified shell is horizontally cut into the first shell and the second shell, and the height ratio of the first shell to the second shell is 1.5:1.5.

[0055] Example 5

[0056] The same as example 1, except that step 4 is specifically: the first blank, the second blank, the first shell and the second shell are all crushed into particles of 47±2mm, and they are sequentially placed in the crucible in the order of the first blank, the first shell, the second blank and the second shell, and then melted at 1350℃ for 15min, and then poured into a casting mold and cooled to room temperature at a cooling rate of 21±0.5℃ / min, to obtain an aluminum-scandium alloy target material.

[0057] Example 6

[0058] The same as example 1, except that step 4 is specifically: the first blank, the second blank, the first shell and the second shell are all crushed into particles of 47±2mm, and they are sequentially placed in the crucible in the order of the first blank, the first shell, the second blank and the second shell, and then melted at 1350℃ for 15min, and then poured into a casting mold and cooled to room temperature at a cooling rate of 15±0.5℃ / min, to obtain an aluminum-scandium alloy target material.

[0059] Example 7

[0060] The same as example 1, except that step 4 is specifically: the first blank and the second blank are crushed into particles of 47±2mm, and the first shell and the second shell are both crushed into particles of 37±2mm, and they are sequentially placed in the crucible in the order of the first blank, the first shell, the second blank and the second shell, and then melted at 1350℃ for 15min, and then poured into a casting mold and cooled to room temperature in 62min, to obtain an aluminum-scandium alloy target material.

[0061] Example 8

[0062] The same as example 1, except that step 4 is specifically: the first blank and the second blank are crushed into particles of 37±2mm, and the first shell and the second shell are both crushed into particles of 47±2mm, and they are sequentially placed in the crucible in the order of the first blank, the first shell, the second blank and the second shell, and then melted at 1350℃ for 15min, and then poured into a casting mold and cooled to room temperature in 62min, to obtain an aluminum-scandium alloy target material.

[0063] Example 9

[0064] Step 1: mix the metal aluminum and the metal scandium in a mass ratio of 70:30 and smelt in a crucible at 1350℃ for 35min, and after casting, a cast blank and a skull adhering to the inner wall of the crucible are obtained;

[0065] Step 2: cut the cast blank horizontally into a first blank and a second blank, and the height ratio of the first blank to the second blank is 1:2;

[0066] cut the skull horizontally into a first shell and a second shell, and the height ratio of the first shell to the second shell is 1:2;

[0067] Step 3: break the first blank, the second blank, the first shell and the second shell into particles of 47±2mm, and sequentially put them into the crucible at 1350℃ for 15min, and then pour into a mold and cool the melt to room temperature in 62min, to obtain an aluminum scandium alloy target material.

[0068] Comparative Example 1

[0069] The same as Example 1, except that Step 4 is specifically: break the first blank, the second blank, the first shell and the second shell into particles of 47±2mm, and sequentially put them into the crucible at 1350℃ for 15min, and then cool the melt to room temperature in 62min, to obtain an aluminum scandium alloy target material.

[0070] Comparative Example 2

[0071] The same as Example 1, except that Step 4 is specifically: break the first blank, the second blank, the first shell and the second shell into particles of 47±2mm, and sequentially put them into the crucible at 1350℃ for 15min, and then cool the melt to room temperature in 62min, to obtain an aluminum scandium alloy target material.

[0072] Comparative Example 3

[0073] The same as Example 1, except that Step 4 is specifically: break the first blank, the second blank, the first shell and the second shell into particles of 47±2mm, and sequentially put them into the crucible at 1350℃ for 15min, and then cool the melt to room temperature in 62min, to obtain an aluminum scandium alloy target material.

[0074] Comparative Example 4

[0075] The same as Example 1, except that the height ratio of the first blank to the second blank is 3:1, and the height ratio of the first shell to the second shell is 3:1.

[0076] Comparative Example 5

[0077] The same as Example 1, except that the height ratio of the first blank to the second blank is 1:3, and the height ratio of the first shell to the second shell is 1:3.

[0078] Performance test

[0079] Reference Figure 1 The target material was cut and the scandium content at nine positions shown in the figure was detected and recorded (it should be noted that the positions in the actual test process deviate slightly, but the site selection in the test process follows the principle of taking 3 points for testing at the top of the target material, taking 3 points for testing at the middle section of the target material, and taking 3 points for testing at the bottom of the target material. The unit of scandium content is (wt%)): Figure 1 Figure 1 Table 1

[0080] Table 1

[0081]

[0082] Result analysis:

[0083] 1. As can be seen from Examples 1-4, when the height ratio between the first blank and the second blank, and the height ratio between the first shell and the second shell change, the uniformity of the scandium content distribution of Examples 1-4 fluctuates to a certain extent. As can be seen from Table 1 and calculation, the difference between the maximum and minimum scandium content of Example 1 is 0.48%, that of Example 2 is 0.17%, that of Example 3 is 0.15%, and that of Example 6 is 0.43%. It can be seen that the related parameters of Examples 2 and 3 are more conducive to the uniform distribution of aluminum scandium.

[0084] 2. As can be seen from Examples 1 and 5, when the cooling rate is further optimized, the uniformity of the scandium distribution of Example 1 relative to the non-uniform cooling rate is improved to a certain extent. As can be seen from Table 1, the difference between the maximum and minimum scandium content of Example 5 is 0.25%, which is improved to a certain extent relative to Example 1.

[0085] Further observation of Example 6 shows that when the cooling rate is too low, the difference between the maximum and minimum scandium content of the target material prepared in Example 6 reaches 0.77%, which further decreases relative to Example 1.

[0086] 3. As can be seen from Examples 1 and 7, when the particle size of the first blank and the second blank is relatively larger, the uniformity of the scandium distribution of Example 7 relative to Example 1 has a certain improvement trend. Through the calculation of the scandium content of Example 7, the difference between the maximum and minimum values is 0.08%.

[0087] ​Further observation of Example 8 shows that when the particle size of the first and second blanks is relatively smaller, the uniformity of the distribution of scandium content in Example 8 does not show a significant difference from that in Example 1;

[0088] 4. It can be seen from Examples 1 and 9 that when the step of re-melting the intermediate alloy by turning is omitted, the difference between the maximum and minimum values of the scandium content in Example 9 reaches 0.7%, which is a certain improvement over Example 1. It can be seen that after omitting this step, the uniformity of the distribution of scandium shows a certain downward trend.

[0089] 5. It can be seen from Examples 1 and Comparative Examples 1-3 that when the order of adding the first blank, the second blank, the first shell and the second shell is changed, the uniformity of the distribution of scandium in Comparative Examples 1-3 shows a significant downward trend. The difference between the maximum and minimum values in Comparative Example 1 is 1.13%, in Comparative Example 2 is 1.87%, and in Comparative Example 3 is 1.68%.

[0090] It can be seen that when the first blank, the first shell, the second blank and the second shell are added in the order of the first blank, the first shell, the second blank and the second shell, the target material has a more excellent uniformity of component distribution. The reason for this phenomenon may be that there is a gap between the scandium and aluminum contents of the first blank, the first shell, the second blank and the second shell, and when they are processed in this order, it is more suitable for the further uniform diffusion of aluminum and scandium, thereby improving the uniformity of the distribution of aluminum and scandium in Example 1.

[0091] 6. It can be seen from Examples 1 and Comparative Examples 4-5 that when the height ratio of the first blank to the second blank and the height ratio of the first shell to the second shell are too large or too small, the uniformity of the distribution of scandium in Comparative Examples 4-5 shows a certain downward trend. The difference between the maximum and minimum values in Comparative Example 4 is 1.77, and in Comparative Example 5 is 1.60, which are both a significant improvement over the uniformity of the distribution in Example 1. The reason may be that a too large or too small height ratio leads to a too large gap in the scandium content between the blanks and between the shells, making it difficult to correct the distribution of scandium in the subsequent repair process.

[0092] The above examples are preferred embodiments of the present application, but the embodiments of the present application are not limited to the above examples. Any changes, modifications, substitutions, combinations or simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement methods and shall be within the scope of protection of the present application.

Claims

1. A method for producing an aluminum scandium alloy target material, characterized by comprising: The method comprises the following steps: ​ Step 1: mixing metal aluminum and metal scandium according to a mass ratio of 70:30, smelting at 1350 DEG C for 20 min to obtain an intermediate alloy; Step 2: turning over the intermediate alloy and smelting in a crucible at 1350 DEG C for 15 min, and pouring into a mold to obtain a cast blank and a skull remaining on the inner wall of the crucible; Step 3: horizontally cutting the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1:2; horizontally cutting the skull into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1:2; Step 4: crushing the first blank body, the second blank body, the first shell body and the second shell body into particles with a size of 47±2 mm, sequentially placing the first blank body, the first shell body, the second blank body and the second shell body into a crucible to smelt at 1350 DEG C for 15 min, then pouring into a mold and cooling the molten liquid to room temperature in 62 min to obtain an aluminum scandium alloy target material.

2. A method of producing an aluminum scandium alloy target material, characterized by, The method comprises the following steps: Step 1: mixing metal aluminum and metal scandium according to a mass ratio of 80:20, smelting at 1350 DEG C for 20 min to obtain an intermediate alloy; Step 2: turning over the intermediate alloy and smelting in a crucible at 1350 DEG C for 15 min, and pouring into a mold to obtain a cast blank and a skull remaining on the inner wall of the crucible; Step 3: horizontally cutting the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1.1:1.9; horizontally cutting the skull into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1.1:2; Step 4: crushing the first blank body, the second blank body, the first shell body and the second shell body into particles with a size of 38±2 mm, sequentially placing the first blank body, the first shell body, the second blank body and the second shell body into a crucible to smelt at 1180 DEG C for 18 min, then pouring into a mold and cooling the molten liquid to room temperature in 48 min to obtain an aluminum scandium alloy target material.

3. A method of producing an aluminum scandium alloy target material, characterized by, The method comprises the following steps: Step 1: mixing metal aluminum and metal scandium according to a mass ratio of 90:10, smelting at 1350 DEG C for 20 min to obtain an intermediate alloy; Step 2: turning over the intermediate alloy and smelting in a crucible at 1350 DEG C for 15 min, and pouring into a mold to obtain a cast blank and a skull remaining on the inner wall of the crucible; Step 3: horizontally cutting the cast blank into a first blank body and a second blank body, and the height ratio of the first blank body to the second blank body is 1.3:1.7; horizontally cutting the skull into a first shell body and a second shell body, and the height ratio of the first shell body to the second shell body is 1.3:1.8; 4. An aluminum scandium alloy target material, characterized by, Step 4: crushing the first blank body, the second blank body, the first shell body and the second shell body into particles with a size of 32±2 mm, sequentially placing the first blank body, the first shell body, the second blank body and the second shell body into a crucible to smelt at 1250 DEG C for 17 min, then pouring into a mold and cooling the molten liquid to room temperature in 54 min to obtain an aluminum scandium alloy target material. The aluminum scandium alloy target material is prepared by the method of any one of claims 1-3, and the relative density of the aluminum scandium alloy target material is not less than 99%.

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