Skeleton for preparing tungsten-based high-density alloy and method of using the same

Abstract

The present invention relates to a skeleton for preparing tungsten-based high-density alloys and a method for using the skeleton. The skeleton comprises an outer shell, a central axis inside the outer shell, and a plurality of blades whose two ends are respectively fixedly connected to the outer shell and the central axis. The axis of the central axis coincides with the axis of the outer shell, and the plurality of blades are evenly distributed on the central axis. The contact portion between the blade and the central axis is provided with a plurality of hollow portions, and the blades are twistedly arranged. The present invention uses low-melting-point materials to make a skeleton for preparing tungsten-based high-density alloys using 3D printing technology. The technology is mature and the cost is low. The product performance will be better after sintering.

Description

Technical Field

[0001] The invention belongs to the technical field of metal forming, and in particular relates to a skeleton for preparing a tungsten-based high-density alloy and a use method thereof. Background Art

[0002] The existing preparation method of tungsten-based high-density alloy with internal channels is mainly to realize the skeleton of the channel inside the product through 3D printing, and then put the channel skeleton together with alloy powder inside a rubber sleeve for pressing, and then remove the internal channel skeleton by heating.

[0003] However, the internal skeleton of 3D printed tungsten-based high-density alloys has the following limitations: First, due to the high sintering temperature of tungsten alloys, the temperature that can be reached by 3D printing equipment is high. At the same time, atmosphere protection is often required during the printing process to prevent the reaction of the material during printing, which means that the cost remains high; Second, 3D printing is achieved by stacking materials layer by layer, so the material performance of the printed product is poor, especially the strength and toughness of the material are poor; Third, the production cycle is long and it is not suitable for mass production. Summary of the invention

[0004] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to provide a skeleton for preparing a tungsten-based high-density alloy and a method of using the same. The present invention adopts a low-melting-point material and utilizes 3D printing technology to manufacture a tungsten-based high-density alloy skeleton. The technology is mature and the cost is low, and the product performance will be better after sintering.

[0005] The technical solution adopted by the present invention to solve the problems existing in the prior art is:

[0006] The skeleton for preparing tungsten-based high-density alloy includes an outer shell, a central axis inside the outer shell, and a plurality of blades whose two ends are respectively fixedly connected to the outer shell and the central axis. The axis of the central axis coincides with the axis of the outer shell, and the plurality of blades are evenly distributed on the central axis.

[0007] A plurality of hollow parts are arranged at the contacting parts of the blades and the central axis, and the blades are twistedly arranged.

[0008] Preferably, the shape of the shell is irregular.

[0009] Preferably, the shape of the shell is an inverted "U" shape, or an "S" shape, or an "L" shape.

[0010] Preferably, a support plate is fixed below the shell, and the skeleton for preparing the tungsten-based high-density alloy is placed inside the rubber sleeve together with the support plate.

[0011] Preferably, the shell, central axis and blades are all made of wax or PE material.

[0012] The method for using a skeleton for preparing a tungsten-based high-density alloy comprises the following steps:

[0013] A. Print the PE material with low melting point and no reaction with tungsten alloy powder into a skeleton for preparing tungsten-based high-density alloy by 3D printing technology;

[0014] B. Put the tungsten-based high-density alloy preparation skeleton printed in step A and the evenly mixed high-density metal powder into the rubber sleeve;

[0015] C. Place the rubber sleeve in step B into an isostatic pressing device for pressing;

[0016] D. Take out the pressed blank from the rubber sleeve and perform vacuum dewaxing treatment;

[0017] E. The dewaxed blank is placed in a molybdenum wire heating furnace and sintered under a hydrogen protective atmosphere to obtain a tungsten-based high-density alloy with an internal channel;

[0018] Preferably, the pressure at which the rubber sleeve is pressed in the isostatic pressing equipment is 200-220 MPa.

[0019] Preferably, the heating temperature of the molybdenum wire heating furnace in step E is 1200°C to 1400°C.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) Using 3D printing technology, wax or PE materials that can be dissolved by heating are used to make the skeleton for preparing tungsten-based high-density alloys. The production difficulty is low, the cost is low, and the production cycle is short.

[0022] (2) The tungsten-based high-density alloy with internal channels obtained after sintering has internal channels, which makes it easier for gas and heat to enter the interior of the blank during sintering, and the performance of the product after sintering is more superior. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0024] Figure 1 This is the skeleton appearance diagram for preparing the tungsten-based high specific gravity alloy of the present invention.

[0025] Figure 2 This is a diagram of the internal structure of the skeleton for preparing the tungsten-based high-density alloy of the present invention after removing the outer shell.

[0026] Figure 3 This is a cross-sectional view of a skeleton used for preparing the tungsten-based high-density alloy of the present invention.

[0027] In the figure: 1-housing, 2-central axis, 3-blades, 3a-hollow portion, 4-support plate. DETAILED DESCRIPTION

[0028] The accompanying drawings are the best embodiments of the skeleton for preparing the tungsten-based high-density alloy and the method for using the skeleton. The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0029] The skeleton used to prepare the tungsten-based high-density alloy is made of a material with a low melting point and does not react with tungsten alloy powder, such as wax or PE material, and is printed by 3D printing technology.

[0030] By the attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 As shown, the outer shape of the skeleton for preparing tungsten-based high-density alloy is irregular, and the present embodiment is an inverted "U" shape. According to the requirements of the product, the outer shape of the skeleton for preparing tungsten-based high-density alloy can also be other shapes, such as "S" type, "L" type, etc. The skeleton for preparing tungsten-based high-density alloy comprises an outer shell 1, a central axis 2 inside the outer shell 1, and a plurality of blades 3 whose two ends are respectively fixedly connected to the outer shell 1 and the central axis 2. The axis of the central axis 2 coincides with the axis of the outer shell 1, and a plurality of blades 3 are evenly distributed on the central axis 2. By the attached Figure 3 As shown, there is a gap between two adjacent blades 3, which first ensures that the skeleton for preparing tungsten-based high-density alloy can be radially compressed during pressing and there is no rebound after pressing. At the same time, gas can flow in the gap between two adjacent blades 3. The contact part between the blade 3 and the central axis 2 is provided with a plurality of hollow parts 3a, and the hollow parts 3a make the blade 3 have a certain amount of contraction in the axial direction and the radial direction, so as to avoid rebound after compression of the skeleton for preparing tungsten-based high-density alloy. Figure 2 As shown, the blade 3 is twisted, that is, the single blade 3 gradually rotates around the axis of the central axis 2, and this arrangement ensures that the axial and radial compression can be performed simultaneously. The shape structure of the blade 3 can ensure that the blade surface is more easily deformed and fits to the central axis 2 during the isostatic pressing process, reducing the rebound of the material. In addition, the shape of the blade 3 can minimize the axial rebound of the material during axial contraction.

[0031] A support plate 4 is fixed below the tungsten-based high-density alloy preparation frame. The tungsten-based high-density alloy preparation frame and the support plate 4 are placed into the rubber sleeve together. The support plate 4 serves to position and prevent the tungsten-based high-density alloy preparation frame from tilting.

[0032] The method for using a skeleton for preparing a tungsten-based high-density alloy comprises the following steps:

[0033] B. A. Printing a PE material with a low melting point and not reactive with tungsten alloy powder into a skeleton for preparing tungsten-based high-density alloy by 3D printing technology;

[0034] B. Put the tungsten-based high-density alloy preparation skeleton printed in step A and the evenly mixed high-density metal powder into the rubber sleeve. The metal powder is generally tungsten, nickel, iron, tungsten, nickel, copper, or tungsten, molybdenum, nickel, iron, and the proportion of tungsten is 90%-98%;

[0035] C. Place the rubber sleeve in step B into an isostatic pressing device for pressing at a pressure of 200-220 MPa;

[0036] D. Take out the blank pressed in step C from the rubber sleeve, place it in a vacuum dewaxing furnace, heat it to melt and evaporate the wax, and perform vacuum dewaxing treatment;

[0037] E. The dewaxed blank is placed in a molybdenum wire heating furnace at a heating temperature of 1200°C to 1400°C. Sintering is performed under a hydrogen protective atmosphere to obtain a tungsten-based high-density alloy with an internal channel. During the sintering process, hydrogen will reduce the oxygen in the blank to prevent oxidation reaction between oxygen and the blank. Because there are channels inside the blank during sintering, gas and heat can more easily enter the blank, and the tensile strength, yield strength and elongation of the blank can be improved, especially the impact toughness of the product. Another point is that this kind of blank is usually used for casting molds after processing. This kind of internal pipeline can not only maximize the use of the shape of the mold to design the internal channel, but also because the surface of the internal channel after sintering is relatively rough, which increases the heat dissipation area and better heat dissipation for the mold.

[0038] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. Skeleton for the preparation of tungsten-based high-density alloys, Features: It comprises a shell (1), a central axis (2) inside the shell (1), and a plurality of blades (3) whose two ends are respectively fixedly connected to the shell (1) and the central axis (2), the axis of the central axis (2) coincides with the axis of the shell (1), and the plurality of blades (3) are evenly distributed on the central axis (2). A plurality of hollow portions (3a) are provided at the contact portion between the blade (3) and the central axis (2), and the blade (3) is twistedly arranged.

2. The skeleton for preparing tungsten-based high-density alloy according to claim 1, Features: The shape of the shell (1) is irregular.

3. The skeleton for preparing tungsten-based high-density alloy according to claim 1 or 2, Features: The shape of the housing (1) is an inverted "U" shape, or an "S" shape, or an "L" shape.

4. The skeleton for preparing tungsten-based high-density alloy according to claim 3, Features: A support plate (4) is fixed below the shell (1), and a skeleton for preparing the tungsten-based high-density alloy is placed together with the support plate (4) into the rubber sleeve.

5. The skeleton for preparing tungsten-based high-density alloy according to claim 4, Features: The shell (1), the central shaft (2) and the blades (3) are all made of wax or PE material.

6. The method for using the skeleton for preparing tungsten-based high-density alloy according to claim 5, It is characterized in that The following steps are involved: A. Print the PE material with low melting point and no reaction with tungsten alloy powder into a skeleton for preparing tungsten-based high-density alloy by 3D printing technology; B. Put the tungsten-based high-density alloy preparation skeleton printed in step A and the evenly mixed high-density metal powder into the rubber sleeve; C. Place the rubber sleeve in step B into an isostatic pressing device for pressing; D. Take out the pressed blank from the rubber sleeve and perform vacuum dewaxing treatment; E. The dewaxed blank is placed in a molybdenum wire heating furnace and sintered in a hydrogen protective atmosphere to obtain a tungsten-based high-density alloy with an internal channel.

7. The method for using the skeleton for preparing tungsten-based high-density alloy according to claim 6, Features: The pressure of the rubber sleeve in the isostatic pressing equipment is 200-220MPa.

8. A method for using the skeleton for preparing tungsten-based high-density alloy according to claim 6 or 7, Features: The heating temperature of the molybdenum wire heating furnace in step E is 1200°C to 1400°C.

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