Low-oxygen tungsten-silicon alloy powder, preparation method thereof and tungsten-silicon alloy target material

Abstract

The invention provides low-oxygen tungsten-silicon alloy powder, a preparation method of the low-oxygen tungsten-silicon alloy powder and a tungsten-silicon alloy target material. The preparation method comprises the following steps: (1) mixing tungsten powder and silicon powder, and carrying out ball milling to obtain a ball-milled material; (2) mixing the ball-milled material with metal Ca particles, and carrying out an oxidation-reduction reaction to obtain a reaction product; and (3) carrying out post-treatment on the reaction product to obtain the low-oxygen tungsten-silicon alloy powder. According to the method, the ball-milled material obtained after ball milling is mixed with the metal Ca particles to be subjected to the oxidation-reduction reaction, the oxygen content in the tungsten-silicon alloy powder is reduced, and the prepared tungsten-silicon alloy powder has the advantages of being high in compactness, rich in WSi2 phase and the like. Compared with a tungsten-silicon alloy target prepared by a traditional method, the tungsten-silicon alloy target prepared on the basis of the method is more excellent in performance.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy material processing, and in particular relates to a low-oxygen tungsten-silicon alloy powder and a preparation method thereof, and a tungsten-silicon alloy target material. Background Art

[0002] Tungsten silicon alloy refers to an alloy prepared by tungsten atoms and silicon atoms in a certain ratio. The sputtered film of this alloy has the characteristics of low resistivity, strong thermal stability and excellent chemical corrosion resistance. It is an important component of semiconductor integrated circuits and is mainly used as a gate contact layer, diffusion barrier layer or adhesion layer. Since the melting points of tungsten and silicon are quite different and tungsten has a higher melting point, the preparation of tungsten silicon alloy by smelting will produce serious segregation and serious energy consumption, so powder metallurgy is often used in preparation.

[0003] However, in the powder metallurgy method, the tungsten silicon alloy prepared by directly sintering the tungsten powder and silicon powder after uniform mixing contains more tungsten phase and silicon phase, and less WSi2 phase. Therefore, the tungsten powder and silicon powder are ball-milled when the powders are mixed. The tungsten powder and silicon powder are formed into WSi2 phase through ball milling and then sintered. The tungsten silicon alloy prepared in this way has better performance, but the mixed powder is seriously oxygenated during ball milling, which will deteriorate the performance of the tungsten silicon sputtered film.

[0004] Therefore, it is urgent to design a method to reduce the oxygen content in the tungsten silicon alloy powder after ball milling, and at the same time realize the WSi2-rich phase to improve the performance of the tungsten silicon alloy powder. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a low-oxygen tungsten-silicon alloy powder and a preparation method thereof and a tungsten-silicon alloy target. The present invention not only reduces the oxygen content in the tungsten-silicon alloy powder by mixing the ball-milled material with metal Ca particles for oxidation-reduction reaction, but also the tungsten-silicon alloy powder obtained has the advantages of high density and rich WSi2 phase. The tungsten-silicon alloy target prepared based on this has better performance than the tungsten-silicon alloy target prepared by the traditional method.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0008] (1) Tungsten powder and silicon powder are mixed and ball-milled to obtain ball-milled material.

[0009] (2) The ball mill material and metal Ca particles are mixed to carry out an oxidation-reduction reaction to obtain a reaction product.

[0010] (3) Post-treating the reaction product to obtain low-oxygen tungsten-silicon alloy powder.

[0011] The present invention not only reduces the oxygen content in the tungsten silicon alloy powder by mixing the ball-milled material with metal Ca particles for oxidation-reduction reaction, but also has the advantages of high density and rich WSi2 phase. The tungsten silicon alloy target prepared in this way has better performance than the tungsten silicon alloy target prepared by the traditional method.

[0012] The preparation method provided by the invention has simple process, low energy consumption and good development potential.

[0013] It should be noted that the present invention does not limit the purity of tungsten powder or silicon powder. For example, it can be 3N tungsten powder or 3N silicon powder.

[0014] As a preferred technical solution of the present invention, the tungsten powder in step (1) has a Fisher particle size of 2-6 μm, for example, 2 μm, 3 μm, 4 μm, 5 μm or 6 μm.

[0015] Preferably, the silicon powder in step (1) has a Fisher particle size of 12-18 μm, for example, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm or 18 μm.

[0016] Preferably, based on the total mass of the tungsten powder and silicon powder in step (1), the mass fraction of the silicon powder is 10-40%, for example, 10%, 20%, 30% or 40%.

[0017] As a preferred technical solution of the present invention, the ball-to-material ratio of the ball milling in step (1) is 1:(3-8), for example, it can be 1:3, 1:4, 1:5, 1:6, 1:7 or 1:8.

[0018] It should be noted that the ball-to-material ratio refers to the mass ratio of the material to the grinding balls.

[0019] Preferably, the rotation speed of the ball mill in step (1) is 300-500 rpm, for example, it can be 300 rpm, 350 rpm, 400 rpm, 450 rpm or 500 rpm.

[0020] Preferably, the ball milling time in step (1) is 8-16 h, for example, 8 h, 10 h, 12 h, 14 h or 16 h.

[0021] As a preferred technical solution of the present invention, the ball milling in step (1) is carried out in a protective gas with a slightly positive pressure.

[0022] Preferably, the shielding gas comprises argon.

[0023] As a preferred technical solution of the present invention, the mass ratio of the metal Ca particles and the oxygen atoms in the ball mill in step (2) is 1.2-2 times the stoichiometric ratio, for example, it can be 1.2 times, 1.4 times, 1.6 times, 1.8 times or 2 times.

[0024] In the present invention, if the mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is too small, the oxygen reduction effect is poor. If the mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is too large, it is difficult to separate the tungsten silicon alloy powder and Ca after Ca is melted.

[0025] Preferably, the temperature of the redox reaction in step (2) is 600-1200°C, for example, it can be 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C or 1200°C.

[0026] In the present invention, if the temperature of the redox reaction is too low, the reaction is slow or incomplete, and the oxygen reduction effect is poor. If the temperature of the redox reaction is too high, the Ca particles melt the tungsten silicon alloy powder and stick to the container, making it difficult to remove.

[0027] Preferably, the insulation time of the redox reaction in step (2) is 2-6 h, for example, 2 h, 3 h, 4 h, 5 h or 6 h.

[0028] As a preferred technical solution of the present invention, a dispersant is also added during the mixing process in step (2).

[0029] In the present invention, the function of the dispersant is to prevent the difficulty in obtaining the powder after the metal Ca particles melt.

[0030] Preferably, the dispersant comprises CaO powder.

[0031] Preferably, the mass ratio of the dispersant to the ball mill is (2-3):1, for example, it can be 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1 or 3:1, etc.

[0032] As a preferred technical solution of the present invention, the post-treatment step in step (3) includes acid washing and water washing.

[0033] In the present invention, the purpose of pickling is to remove the remaining metal Ca particles and CaO powder.

[0034] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0035] (1) Tungsten powder with a Fisher particle size of 2-6 μm and silicon powder with a Fisher particle size of 12-18 μm are mixed, and ball-milled for 8-16 hours in a ball mill filled with a slightly positive pressure protective gas to obtain a ball mill material.

[0036] Wherein, based on the total mass of the tungsten powder and the silicon powder, the mass fraction of the silicon powder is 10-40%, the ball-to-material ratio of the ball mill is 1:(3-8), and the rotation speed of the ball mill is 300-500rpm.

[0037] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then subjected to a redox reaction at a temperature of 600-1200° C. for 2-6 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0038] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.2-2 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is (2-3):1.

[0039] (3) The reaction product is acid-washed to remove the remaining metal Ca particles and CaO powder, and then washed with water to obtain low-oxygen tungsten-silicon alloy powder.

[0040] The acid used for pickling includes any one of hydrochloric acid, nitric acid or hydrofluoric acid or a combination of at least two thereof, and the concentration of the acid is 5-20% (eg, 5%, 10%, 15% or 20%, etc.).

[0041] In a second aspect, the present invention provides a low-oxygen tungsten-silicon alloy powder, wherein the low-oxygen tungsten-silicon alloy powder is prepared by the preparation method described in the first aspect.

[0042] The oxygen content in the low-oxygen tungsten-silicon alloy powder is 0.05-0.08wt%, for example, it can be 0.05wt%, 0.06wt%, 0.07wt% or 0.08wt%.

[0043] The content of WSi2 phase in the low-oxygen tungsten-silicon alloy powder is 30-50wt%, for example, 30wt%, 35wt%, 40wt%, 45wt% or 50wt%.

[0044] In a third aspect, the present invention provides a tungsten-silicon alloy target material, wherein the tungsten-silicon alloy target material is prepared from the low-oxygen tungsten-silicon alloy powder described in the second aspect.

[0045] It should be noted that the present invention does not limit the preparation steps of the tungsten-silicon alloy target. For example, the low-oxygen tungsten-silicon alloy powder can be subjected to hot pressing and sintering to obtain the tungsten-silicon alloy target.

[0046] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] (1) The present invention not only reduces the oxygen content in the tungsten silicon alloy powder by mixing the ball-milled material with metal Ca particles for oxidation-reduction reaction, but also has the advantages of high density and rich WSi2 phase. The tungsten silicon alloy target prepared in this way has better performance than the tungsten silicon alloy target prepared by the traditional method.

[0049] (2) The preparation method provided by the present invention has simple process, low energy consumption and good development potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of the preparation process of the low-oxygen tungsten-silicon alloy powder provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0052] Example 1

[0053] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder. Figure 1 As shown, the preparation method comprises the following steps:

[0054] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0055] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0056] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere to perform a redox reaction at a temperature of 900° C. for 4 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0057] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.5 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 2.5:1.

[0058] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0059] The acid used in the pickling is hydrochloric acid with a concentration of 12%.

[0060] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material comprises the following steps:

[0061] The low-oxygen tungsten-silicon alloy powder is hot-pressed and sintered at a temperature of 1200° C. and a pressure of 750 tons to obtain the tungsten-silicon alloy target.

[0062] Example 2

[0063] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0064] (1) 3N tungsten powder with a Fisher particle size of 6 μm and 3N silicon powder with a Fisher particle size of 18 μm were mixed and ball-milled for 16 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0065] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:8, the rotation speed of the ball mill is 500 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0066] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere to perform a redox reaction at a temperature of 600° C. for 6 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0067] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.2 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 2:1.

[0068] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0069] Wherein, the acid used in the pickling is nitric acid with a concentration of 5%.

[0070] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material comprises the following steps:

[0071] The low-oxygen tungsten-silicon alloy powder is hot-pressed and sintered at a temperature of 1200° C. and a pressure of 750 tons to obtain the tungsten-silicon alloy target.

[0072] Example 3

[0073] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0074] (1) 3N tungsten powder with a Fisher particle size of 2 μm and 3N silicon powder with a Fisher particle size of 12 μm were mixed and ball-milled for 8 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0075] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:3, the rotation speed of the ball mill is 300 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0076] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere to perform a redox reaction at a temperature of 1200° C. for 2 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0077] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is twice the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 3:1.

[0078] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0079] The acid used in the pickling is hydrofluoric acid with a concentration of 20%.

[0080] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material comprises the following steps:

[0081] The low-oxygen tungsten-silicon alloy powder is hot-pressed and sintered at a temperature of 1200° C. and a pressure of 750 tons to obtain the tungsten-silicon alloy target.

[0082] Example 4

[0083] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0084] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0085] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0086] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere to perform a redox reaction at a temperature of 900° C. for 4 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0087] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is a stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 2.5:1.

[0088] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0089] The acid used in the pickling is hydrochloric acid with a concentration of 12%.

[0090] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Embodiment 1.

[0091] Example 5

[0092] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0093] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0094] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0095] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere to perform a redox reaction at a temperature of 900° C. for 4 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0096] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 2.5 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 2.5:1.

[0097] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0098] The acid used in the pickling is hydrochloric acid with a concentration of 12%.

[0099] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Embodiment 1.

[0100] Example 6

[0101] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0102] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0103] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0104] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere to perform a redox reaction at a temperature of 300° C. for 4 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0105] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.5 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 2.5:1.

[0106] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0107] The acid used in the pickling is hydrochloric acid with a concentration of 12%.

[0108] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Embodiment 1.

[0109] Example 7

[0110] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0111] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0112] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0113] (2) The ball mill material, metal Ca particles and CaO powder are mixed uniformly, and then placed in a muffle furnace to perform a redox reaction at a temperature of 800° C. for 4 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0114] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.5 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is 2.5:1.

[0115] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0116] The acid used in the pickling is hydrochloric acid with a concentration of 12%.

[0117] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Embodiment 1.

[0118] Example 8

[0119] This embodiment provides a method for preparing low-oxygen tungsten-silicon alloy powder, the preparation method comprising the following steps:

[0120] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0121] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0122] (2) The ball mill material and the metal Ca particles are mixed uniformly, and then placed in a muffle furnace with an argon atmosphere, and subjected to a redox reaction at a temperature of 900° C. for 4 hours. After the reaction is completed, the mixture is cooled to obtain a reaction product.

[0123] The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.5 times the stoichiometric ratio.

[0124] (3) The reaction product is acid-washed and then water-washed to obtain low-oxygen tungsten-silicon alloy powder.

[0125] The acid used in the pickling is hydrochloric acid with a concentration of 12%.

[0126] This embodiment also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Embodiment 1.

[0127] Comparative Example 1

[0128] This comparative example provides a method for preparing tungsten-silicon alloy powder, and the preparation method comprises the following steps:

[0129] (1) 3N tungsten powder with a Fisher particle size of 4 μm and 3N silicon powder with a Fisher particle size of 15 μm were mixed and ball-milled for 12 h in a ball mill filled with slightly positive pressure argon gas to obtain a ball mill material.

[0130] Wherein, based on the total mass of the 3N tungsten powder and the 3N silicon powder, the mass fraction of the silicon powder is 29%, the ball-to-material ratio of the ball mill is 1:5, the rotation speed of the ball mill is 400 rpm, and the pressure of the slightly positive pressure argon gas is 0.05 MPa.

[0131] (2) The ball mill material is placed in a muffle furnace and sintered at 900° C. for 4 h. After sintering, the sintered material is cooled to obtain a tungsten silicon alloy powder.

[0132] This comparative example also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Example 1.

[0133] Comparative Example 2

[0134] This comparative example provides a method for preparing tungsten-silicon alloy powder, and the preparation method comprises the following steps:

[0135] Silicon powder with purity ≥5N, oxygen content ≤400ppm and particle size ≤20μm was placed in a vibrating screen in a glove box for powder particle size screening, and ultrafine powder (particle size <5μm) was screened out to obtain powder of target particle size.

[0136] Tungsten powder with a purity of ≥5N, an oxygen content of ≤350ppm and a particle size of 1-10μm and the silicon powder sieved in step (1) are used as raw materials, and the powder ingredients are prepared in a glove box filled with inert gas according to the atomic ratio W:Si=1:2.7, and the powders are loaded into a powder mixing tank through the interface at the bottom of the glove box and sealed. The powder mixing tank is installed on a powder mixer, evacuated to 0.5Pa, and the powders are mixed for 30min / kg.

[0137] In a glove box filled with inert gas, the powder after thorough mixing in step (2) is placed in a bag and degassed and sealed. Degassing requirements: degassing at room temperature for 2 hours, and degassing at 400°C for 6 hours.

[0138] This comparative example also provides a tungsten-silicon alloy target material, and the preparation method of the tungsten-silicon alloy target material is consistent with that of Example 1.

[0139] Performance Testing

[0140] The purity, oxygen content and WSi2 phase content of the tungsten-silicon alloy targets prepared in the above examples and comparative examples were tested.

[0141] The test results are shown in Table 1.

[0142] Table 1

[0143]

[0144] analyze:

[0145] It can be seen from the above table that the present invention not only reduces the oxygen content in the tungsten silicon alloy powder by mixing the ball-milled material with metal Ca particles for redox reaction, but also the prepared tungsten silicon alloy target has the advantages of low oxygen, high density, and rich WSi2 phase.

[0146] It can be seen from Example 1 and Examples 4-5 that if the mass ratio of the metal Ca particles and the oxygen atoms in the ball mill is too small to the mass ratio of the ball mill and the metal Ca particles, the oxygen reduction effect is not good; if the mass ratio of the metal Ca particles and the oxygen atoms in the ball mill is too large to the mass ratio of the ball mill and the metal Ca particles, it is difficult to separate the tungsten silicon alloy powder and Ca after Ca is melted.

[0147] It can be seen from Examples 1 and 6-7 that if the temperature of the redox reaction is too low, the reaction will be slow or incomplete, and the oxygen reduction effect will be poor; if the temperature of the redox reaction is too high, the Ca particles melt the tungsten silicon alloy powder and stick to the container, making it difficult to remove.

[0148] It can be seen from Examples 1 and 8 that if no dispersant is added during the mixing of the ball mill and the metal Ca particles, part of the Ca will not react to form CaO but will remain as Ca, which is difficult to separate from WSi after melting.

[0149] It can be seen from Example 1 and Comparative Example 1 that if the ball mill is directly sintered without adding other materials, the oxygen content of the tungsten silicon alloy powder is high.

[0150] It can be seen from Example 1 and Comparative Example 2 that if the preparation method described in the prior art is adopted, the oxygen reduction effect is poor.

[0151] The applicant declares that the present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing low-oxygen tungsten-silicon alloy powder, characterized in that: The preparation method comprises the following steps: (1) mixing tungsten powder and silicon powder, and ball milling to obtain a ball mill material; (2) mixing the ball mill material and metal Ca particles to perform an oxidation-reduction reaction to obtain a reaction product; (3) Post-treating the reaction product to obtain low-oxygen tungsten-silicon alloy powder.

2. The preparation method according to claim 1, characterized in that: The tungsten powder in step (1) has a Fisher particle size of 2-6 μm; Preferably, the silicon powder in step (1) has a Fisher particle size of 12-18 μm; Preferably, based on the total mass of the tungsten powder and silicon powder in step (1), the mass fraction of the silicon powder is 10-40%.

3. The preparation method according to claim 1 or 2, characterized in that: The ball-to-material ratio of the ball milling in step (1) is 1:(3-8); Preferably, the rotation speed of the ball mill in step (1) is 300-500 rpm; Preferably, the ball milling time in step (1) is 8-16 hours.

4. The preparation method according to any one of claims 1 to 3, characterized in that The ball milling in step (1) is carried out in a protective gas with a slight positive pressure; Preferably, the shielding gas comprises argon.

5. The preparation method according to any one of claims 1 to 4, characterized in that: In step (2), the mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.2-2 times the stoichiometric ratio; Preferably, the temperature of the redox reaction in step (2) is 600-1200°C; Preferably, the insulation time of the redox reaction in step (2) is 2-6 hours.

6. The preparation method according to any one of claims 1 to 5, characterized in that: A dispersant is also added during the mixing process of step (2); Preferably, the dispersant comprises CaO powder; Preferably, the mass ratio of the dispersant to the ball mill is (2-3):

1.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The post-treatment steps in step (3) include acid washing and water washing.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (1) mixing tungsten powder with a Fisher particle size of 2-6 μm and silicon powder with a Fisher particle size of 12-18 μm, and ball milling them for 8-16 hours in a ball mill filled with a slightly positive pressure protective gas to obtain a ball mill material; Wherein, based on the total mass of the tungsten powder and the silicon powder, the mass fraction of the silicon powder is 10-40%, the ball-to-material ratio of the ball mill is 1:(3-8), and the rotation speed of the ball mill is 300-500rpm; (2) mixing the ball mill material, metal Ca particles and CaO powder uniformly, and then performing a redox reaction at a temperature of 600-1200° C. for 2-6 hours, and cooling after the reaction to obtain a reaction product; The mass ratio of the metal Ca particles to the oxygen atoms in the ball mill is 1.2-2 times the stoichiometric ratio, and the mass ratio of the CaO powder to the ball mill is (2-3):1; (3) washing the reaction product with acid and then with water to obtain low-oxygen tungsten-silicon alloy powder; The acid used for pickling includes any one of hydrochloric acid, nitric acid or hydrofluoric acid or a combination of at least two thereof, and the concentration of the acid is 5-20%.

9. A low-oxygen tungsten-silicon alloy powder, characterized in that: The low-oxygen tungsten-silicon alloy powder is prepared by the preparation method according to any one of claims 1 to 8; The oxygen content of the low-oxygen tungsten-silicon alloy powder is 0.05-0.08wt%; The content of WSi2 phase in the low-oxygen tungsten-silicon alloy powder is 30-50wt%.

10. A tungsten-silicon alloy target, characterized in that: The tungsten-silicon alloy target is prepared from the low-oxygen tungsten-silicon alloy powder described in claim 9.

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