Preparation method of tungsten-titanium alloy

Abstract

The invention relates to the technical field of tungsten-titanium alloy production, and particularly discloses a preparation method of a tungsten-titanium alloy, which comprises the following steps: (1) putting tungsten powder, titanium powder and titanium hydride powder into a ball milling tank of a ball mill, then adding a grinding body and a liquid medium into the ball milling tank, and carrying out wet ball milling to obtain a powder mixed solution; (2) drying the powder mixed solution in a drying oven, and transferring the dried powder mixed solution to a tank mill for grinding to obtain mixed powder; (3) the mixed powder is put into a mold, the mold is put into a vacuum hot-pressing sintering furnace for vacuum hot-pressing sintering, and the tungsten-titanium alloy is obtained; according to the preparation method of the tungsten-titanium alloy, the particle size uniformity and mixing uniformity of the alloy raw material powder can be effectively improved, and then the performance of the tungsten-titanium alloy product is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tungsten-titanium alloy production, and in particular to a method for preparing a tungsten-titanium alloy. Background Art

[0002] Tungsten-titanium alloy is an alloy based on tungsten with titanium added. It has excellent high-temperature strength, creep resistance, good thermal conductivity, electrical conductivity and electron emission properties. It is widely used in the electronics and electric light source industries. It is also used in the aerospace, casting, weapons and other departments to make rocket nozzles, die-casting molds, armor-piercing cores, contacts, heating elements and heat shields.

[0003] In the prior art, when preparing tungsten-titanium alloy, it is first necessary to prepare tungsten-titanium alloy powder. However, the tungsten-titanium alloy powder mixing process in the prior art is mostly simple mixing, the alloy powder particle size is uneven, there is no solid solution process, and the powder mixing uniformity is poor, which leads to poor uniformity of the prepared alloy structure, affecting the performance quality of the tungsten-titanium alloy products. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a method for preparing a tungsten-titanium alloy with uniform alloy raw material powder particle size and uniform mixing and excellent alloy product performance.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A method for preparing a tungsten-titanium alloy comprises the following steps:

[0007] (1) placing tungsten powder, titanium powder and titanium hydride powder in a ball mill of a ball mill, then adding a grinding body and a liquid medium into the ball mill to perform wet ball milling to obtain a powder mixture;

[0008] (2) drying the powder mixture in an oven, transferring it to a pot mill for grinding to obtain a mixed powder;

[0009] (3) The mixed powder is loaded into a mold and placed in a vacuum hot pressing sintering furnace for vacuum hot pressing sintering to obtain a tungsten-titanium alloy.

[0010] As a further solution of the present invention: the mass ratio of the tungsten powder, titanium powder and titanium hydride powder is 5-10:0.5-3:0.5-3.

[0011] As a further solution of the present invention: the ball mill in step (1) is a planetary ball mill, the grinding body is one or more combinations of tungsten carbide balls, tungsten carbide columns, zirconia balls, and zirconia columns, and the liquid medium for wet ball milling is one of water and anhydrous ethanol.

[0012] As a further solution of the present invention: the mass ratio of the total mass of the tungsten powder, titanium powder and titanium hydride powder to the grinding body in step (1) is 1:3-1:8, the grinding body is a combination of tungsten carbide balls and tungsten carbide columns, and the liquid medium is anhydrous ethanol.

[0013] As a further solution of the present invention: the mass gradation of the tungsten carbide balls in the ball mill is 10mm balls: 5mm balls: 1mm balls = 2:5:3; the size of the tungsten carbide columns in the ball mill is: the bottom circle diameter is 1-3mm, and the length is 1-5mm; the mass ratio of tungsten carbide balls to tungsten carbide columns is 2:1-5:1, the rotation speed of the planetary ball mill is 120-500r / min, and the ball milling time is 6-20h.

[0014] As a further solution of the present invention: the powder mixture after wet ball milling in step (1) is placed in an oven for drying, and after drying to constant weight, it is transferred to the grinding jar of a jar mill, and tungsten carbide, tungsten carbide columns and dispersants are added at the same time for dry grinding to obtain a mixed powder.

[0015] As a further solution of the present invention: the mass ratio of the tungsten carbide balls to the tungsten carbide columns in the grinding jar is 1:2-1:5, and the grinding time is 0.5-2h.

[0016] As a further solution of the present invention: the dispersant is one or a combination of triethanolamine and glycerol, and the amount of the dispersant is 0.5%-2% of the mass of the mixed powder.

[0017] As a further solution of the present invention: the mold in step (3) is a graphite mold, and a layer of graphite paper is attached to the inner side of the graphite mold.

[0018] As a further solution of the present invention: the temperature of the vacuum hot pressing sintering in step (3) is 1300-1500°C, the sintering pressure is 22-30MPa, the heating and cooling rate of the vacuum hot pressing sintering furnace is set to 5-10°C / min, and the holding time is 1.5-3h.

[0019] Beneficial effects of the present invention:

[0020] The invention discloses a method for preparing a tungsten-titanium alloy, comprising the steps of wet-milling tungsten powder, titanium powder and titanium hydride powder in a certain ratio to obtain a powder mixture, dry-grinding the powder mixture to obtain a mixed powder, and finally vacuum hot-pressing and sintering the mixed powder to obtain a tungsten-titanium alloy. Wet ball milling of alloy raw material powder using a ball mill can effectively enhance the mutual solid solution effect between tungsten and titanium powders. The particle size after wet ball milling is smaller than that after dry ball milling in the prior art, and the specific surface area is larger. During the dry ball milling process, the powder is prone to agglomeration and ball sticking. In addition, during the ball milling process, the powder is squeezed and crushed, which increases the surface energy of the powder, and the mechanical energy is also converted into thermal energy. The energy in the entire ball mill increases, which makes the powder easy to oxidize and the powder yield is low. When anhydrous ethanol is added as a grinding medium in the wet ball milling, the ball milling effect is significantly improved, and the agglomeration and ball sticking phenomena are greatly reduced. This is because after the addition of anhydrous ethanol, a thin "liquid film" will be formed between the grinding body and the powder during the ball milling process. This liquid film can not only effectively prevent the contact between the powder and the grinding body and the ball mill, but also greatly promote the solid solution diffusion rate between the powders. At the same time, during the ball milling process, anhydrous ethanol will preferentially adhere to the new surface of the particles, thereby continuously reducing the surface activity of the powder particles and preventing the powder from agglomerating. In addition, anhydrous ethanol also has a cooling effect, which reduces the temperature in the ball mill during the ball milling process and prevents the powder from being oxidized. This shows that wet ball milling using anhydrous ethanol as a liquid medium has a significant effect on promoting the uniformity of the powder particle size distribution and the rounding of the shape during the mechanical alloying ball milling process, thereby improving the uniformity of the mixed powder and the uniformity of the particle size, thereby ensuring the uniformity of the alloy structure after high-temperature sintering, and effectively improving the performance quality of the tungsten-titanium alloy. The powder mixture obtained by wet ball milling is further added to the tungsten carbide, tungsten carbide columns and A mixed powder is obtained under the action of the dispersant. The dispersant gives the mixed powder a better structural uniformity. The dispersant has a lower surface tension, which can reduce the attraction between the mixed powders, making it easier for the alloy elements to disperse in the matrix. At the same time, the dispersant can be adsorbed on the surface of the mixed powder to form a charge barrier, preventing the agglomeration and coagulation between the mixed powders and maintaining the dispersed state of the mixed powder. Finally, the mixed powder is wrapped in a layer of graphite paper in a graphite mold to effectively prevent the chemical reaction between the mixed powder and the mold during the vacuum hot pressing sintering process and facilitate demolding. At the same time, the sintering temperature, pressure and time during the vacuum hot pressing sintering process further improve the alloy density and structural properties, making the prepared tungsten-titanium alloy product have better performance. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] Embodiment 1:

[0023] This embodiment is a method for preparing a tungsten-titanium alloy, comprising the following steps:

[0024] Step 1: Place tungsten powder, titanium powder and titanium hydride powder in a ball mill of a planetary ball mill, the mass ratio of tungsten powder, titanium powder and titanium hydride powder is 8:1:0.5, then add grinding body and liquid medium to the ball mill, perform wet ball milling, and obtain a powder mixture, wherein the grinding body is a combination of tungsten carbide balls and tungsten carbide columns, and the liquid medium is anhydrous ethanol; the total mass ratio of tungsten powder, titanium powder and titanium hydride powder to the grinding body is 1:4, and the mass gradation of tungsten carbide balls in the ball mill is 10mm balls: 5mm balls: 1mm balls = 2:5:3; the size of tungsten carbide columns in the ball mill is: bottom circle diameter is 2mm, length is 3.5mm; the mass ratio of tungsten carbide balls to tungsten carbide columns is 3:1, the rotation speed of the planetary ball mill is 400r / min, and the ball milling time is 10h;

[0025] Step 2: Place the powder mixture after wet ball milling in step (1) in an oven for drying, and after drying to constant weight, transfer it to the grinding jar of the jar mill, and add tungsten carbide, tungsten carbide columns and dispersant for dry grinding to obtain a mixed powder, wherein the mass ratio of tungsten carbide balls to tungsten carbide columns in the grinding jar is 1:3, and the grinding time is 1h. The dispersant is triethanolamine, and the amount of the dispersant is 0.8% of the mass of the mixed powder;

[0026] Step 3: Load the mixed powder into a graphite mold with a layer of graphite paper on the inner side of the graphite mold, and place it in a high-temperature furnace for vacuum hot pressing sintering. The sintering temperature is 1300°C, the sintering pressure is 22MPa, the heating and cooling rate of the high-temperature furnace is set to 8°C / min, and the insulation time is 2h, then tungsten-titanium alloy is obtained.

[0027] Embodiment 2:

[0028] This embodiment is a method for preparing a tungsten-titanium alloy, comprising the following steps:

[0029] Step 1: Place tungsten powder, titanium powder and titanium hydride powder in a ball mill of a planetary ball mill, the mass ratio of tungsten powder, titanium powder and titanium hydride powder is 5:0.5:0.5, then add grinding body and liquid medium to the ball mill, perform wet ball milling, and obtain a powder mixture, wherein the grinding body is a combination of tungsten carbide balls and tungsten carbide columns, and the liquid medium is anhydrous ethanol; the total mass ratio of tungsten powder, titanium powder and titanium hydride powder to the grinding body is 1:6, and the mass gradation of tungsten carbide balls in the ball mill is 10mm balls: 5mm balls: 1mm balls = 2:5:3; the size of tungsten carbide columns in the ball mill is: bottom circle diameter is 2mm, length is 3.5mm; the mass ratio of tungsten carbide balls to tungsten carbide columns is 3:1, the rotation speed of the planetary ball mill is 400r / min, and the ball milling time is 15h;

[0030] Step 2: Place the powder mixture after wet ball milling in step (1) in an oven for drying, and after drying to constant weight, transfer it to the grinding jar of the jar mill, and add tungsten carbide, tungsten carbide columns and dispersant for dry grinding to obtain a mixed powder, wherein the mass ratio of tungsten carbide balls to tungsten carbide columns in the grinding jar is 1:3, and the grinding time is 1h. The dispersant is triethanolamine, and the amount of the dispersant is 0.8% of the mass of the mixed powder;

[0031] Step 3: Load the mixed powder into a graphite mold with a layer of graphite paper on the inner side of the graphite mold, and place it in a high-temperature furnace for vacuum hot pressing sintering. The sintering temperature is 1400°C, the sintering pressure is 26MPa, the heating and cooling rate of the high-temperature furnace is set to 8°C / min, and the insulation time is 2h, then tungsten-titanium alloy is obtained.

[0032] Embodiment 3:

[0033] This embodiment is a method for preparing a tungsten-titanium alloy, comprising the following steps:

[0034] Step 1: Place tungsten powder, titanium powder and titanium hydride powder in a ball mill of a planetary ball mill, the mass ratio of tungsten powder, titanium powder and titanium hydride powder is 10:0.5:0.5, then add grinding body and liquid medium to the ball mill, perform wet ball milling, and obtain a powder mixture, wherein the grinding body is a combination of tungsten carbide balls and tungsten carbide columns, and the liquid medium is anhydrous ethanol; the total mass ratio of tungsten powder, titanium powder and titanium hydride powder to the grinding body is 1:8, and the mass gradation of tungsten carbide balls in the ball mill is 10mm balls: 5mm balls: 1mm balls = 2:5:3; the size of tungsten carbide columns in the ball mill is: bottom circle diameter is 2mm, length is 3.5mm; the mass ratio of tungsten carbide balls to tungsten carbide columns is 3:1, the rotation speed of the planetary ball mill is 400r / min, and the ball milling time is 20h;

[0035] Step 2: Place the powder mixture after wet ball milling in step (1) in an oven for drying, and after drying to constant weight, transfer it to the grinding jar of the jar mill, and add tungsten carbide, tungsten carbide columns and dispersant for dry grinding to obtain a mixed powder, wherein the mass ratio of tungsten carbide balls to tungsten carbide columns in the grinding jar is 1:3, and the grinding time is 1h. The dispersant is triethanolamine, and the amount of the dispersant is 0.8% of the mass of the mixed powder;

[0036] Step 3: Load the mixed powder into a graphite mold with a layer of graphite paper on the inner side of the graphite mold, and place it in a high-temperature furnace for vacuum hot pressing sintering. The sintering temperature is 1500°C, the sintering pressure is 30MPa, the heating and cooling rate of the high-temperature furnace is set to 10°C / min, and the insulation time is 3h, after which tungsten-titanium alloy is obtained.

[0037] Comparative Example 1:

[0038] The difference between this comparative example and Example 3 is that no liquid medium anhydrous ethanol is added in step 1.

[0039] Comparative Example 2:

[0040] The difference between this comparative example and Example 3 is that tungsten carbide, tungsten carbide columns and dispersant are not added in step 2.

[0041] It should be noted that the median particle size of the raw material powder in the above embodiment is 19.2 μm, and the particle size distribution range is 7.21-42.10 μm. The performance parameters of the tungsten-titanium alloy prepared in the above embodiments 1-3 and comparative examples 1-2 are as follows:

[0042]

[0043]

[0044] Referring to the data in the above table, it can be seen that the particle size uniformity and mixing uniformity of the tungsten-titanium alloy raw material powder prepared in the present invention are more excellent, which effectively improves the performance quality of the tungsten-titanium alloy product.

[0045] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art who is familiar with the present invention may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for preparing a tungsten-titanium alloy, characterized in that: The following steps are involved: (1) placing tungsten powder, titanium powder and titanium hydride powder in a ball mill of a ball mill, then adding a grinding body and a liquid medium into the ball mill to perform wet ball milling to obtain a powder mixture; (2) drying the powder mixture in an oven, transferring it to a pot mill for grinding to obtain a mixed powder; (3) The mixed powder is loaded into a mold and placed in a vacuum hot pressing sintering furnace for vacuum hot pressing sintering to obtain a tungsten-titanium alloy.

2. The method for preparing a tungsten-titanium alloy according to claim 1, characterized in that: The mass ratio of the tungsten powder, titanium powder and titanium hydride powder is 5-10:0.5-3:0.5-3.

3. The method for preparing a tungsten-titanium alloy according to claim 1, characterized in that: The ball mill in step (1) is a planetary ball mill, the grinding body is one or more combinations of tungsten carbide balls, tungsten carbide columns, zirconia balls, and zirconia columns, and the liquid medium for wet ball milling is one of water and anhydrous ethanol.

4. The method for preparing a tungsten-titanium alloy according to claim 3, characterized in that: The mass ratio of the total mass of the tungsten powder, titanium powder and titanium hydride powder to the grinding body in step (1) is 1:3-1:8, the grinding body is a combination of tungsten carbide balls and tungsten carbide columns, and the liquid medium is anhydrous ethanol.

5. The method for preparing a tungsten-titanium alloy according to claim 4, characterized in that: The mass gradation of the tungsten carbide balls in the ball mill is 10 mm balls: 5 mm balls: 1 mm balls = 2:5:3; the size of the tungsten carbide columns in the ball mill is: the bottom circle diameter is 1-3 mm, and the length is 1-5 mm; the mass ratio of the tungsten carbide balls to the tungsten carbide columns is 2:1-5:1, the rotation speed of the planetary ball mill is 120-500 r / min, and the ball milling time is 6-20 hours.

6. The method for preparing a tungsten-titanium alloy according to claim 1, characterized in that: The powder mixture after wet ball milling in step (1) is placed in an oven for drying, and after drying to constant weight, it is transferred to the grinding jar of a jar mill, and tungsten carbide, tungsten carbide columns and dispersants are added for dry grinding to obtain a mixed powder.

7. The method for preparing a tungsten-titanium alloy according to claim 6, characterized in that: The mass ratio of the tungsten carbide balls to the tungsten carbide columns in the grinding jar is 1:2-1:5, and the grinding time is 0.5-2h.

8. The method for preparing a tungsten-titanium alloy according to claim 6, characterized in that: The dispersant is one or a combination of triethanolamine and glycerol, and the amount of the dispersant is 0.5%-2% of the mass of the mixed powder.

9. The method for preparing a tungsten-titanium alloy according to claim 1, characterized in that: The mold described in step (3) is a graphite mold, and a layer of graphite paper is attached to the inner side of the graphite mold.

10. The method for preparing a tungsten-titanium alloy according to claim 1, characterized in that: The temperature of the vacuum hot pressing sintering in step (3) is 1300-1500° C., the sintering pressure is 22-30 MPa, the heating and cooling rate of the vacuum hot pressing sintering furnace is set to 5-10° C. / min, and the insulation time is 1.5-3 h.

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