Homogenizing pressure sintering device based on BJ titanium alloy

Abstract

The utility model discloses a homogenizing pressure sintering device based on BJ titanium alloy, which belongs to the field of additive manufacturing and comprises a furnace body, a heating body and kiln furniture. The heating body is sleeved in the furnace body, and the kiln furniture is sleeved in the heating body; a first protective gas inlet is formed above the furnace body, and a vacuum extraction opening is formed below the furnace body; the kiln furniture is provided with a kiln furniture air inlet and a pressure gauge. According to the utility model, through a pressure sintering mode, loose powder blanks are subjected to external pressure while being densified by sintering driving force in the sintering densification process, so that the sintering densification of titanium alloy is further promoted. In the titanium alloy sintering process, uniform pressure bearing of a titanium alloy blank in different directions is achieved through the sintering saggar with the specific structure and layout, titanium alloy sintering uniformity and densification are further promoted, and titanium alloy sintering densification consistency is improved.

Description

Technical Field

[0001] This utility model relates to the field of additive manufacturing, and more specifically to a novel pressure sintering device and method for achieving sintering densification of binder-sprayed additive manufacturing titanium alloy billets. Background Technology

[0002] In recent years, with the rapid development of 3D printing technology, binder jetting metal 3D printing technology, especially for printing titanium alloys, has achieved significant breakthroughs. Currently, titanium alloy binder jetting 3D printing technology has shown broad application prospects in multiple fields such as aerospace, shipbuilding, and automotive.

[0003] Several companies and research institutions have successfully achieved binder-jet 3D printing of titanium alloys. This technological breakthrough not only improves the manufacturing efficiency of titanium alloy parts but also significantly reduces the manufacturing difficulty and production cost of titanium alloy components with complex shapes. The current development of binder-jet titanium alloys is characterized by technological breakthroughs, cost reductions, and widespread applications. In the future, with continuous technological advancements and the expansion of application areas, binder-jet 3D printing technology for titanium alloys will play an important role in more fields, injecting new vitality into industrial manufacturing and technological innovation.

[0004] Compared to thermoforming additive manufacturing technologies such as SLM, the binder jet additive manufacturing cold forming process effectively controls the sensitivity of titanium alloys to oxygen during the printing process when applied to materials that are highly reactive with oxygen. This effectively avoids the reaction between titanium alloys and oxygen, ensuring the forming quality of titanium alloys while fully leveraging the advantages of 3D printing manufacturing technology. It solves the manufacturing challenges of complex structures and special-shaped titanium alloy parts, effectively filling the limitations of titanium alloy casting and processing technologies when dealing with special-structure titanium alloy products.

[0005] However, the titanium alloy forming process based on binder spraying additive manufacturing technology requires sintering densification to achieve the final titanium alloy metal parts. Currently, titanium alloy sintering mainly adopts vacuum sintering, with a sintering density of around 95% and an ultimate tensile strength generally below 1000 MPa. The density of titanium alloy blanks prepared by binder spraying is relatively lower than that of blanks prepared by dry pressing or injection molding, making sintering densification more difficult. At the same time, titanium alloys are prone to oxidation at high temperatures, forming an oxide layer on the surface, which hinders the sintering process and ultimately affects the sintering quality. Furthermore, due to the low sintering density, many irregular residual pores are easily retained in the titanium alloy. These pores cause stress concentration when the alloy deforms, making the pores the weakest areas of the material, seriously affecting the service life and application scenarios of the sintered titanium alloy.

[0006] Therefore, optimizing the sintering equipment and process to maintain small-sized grains in the sintered titanium alloy while reducing the number and size of internal pores is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0007] This invention aims to at least partially solve one of the aforementioned technical problems in the prior art. This invention provides a device for densification sintering of titanium alloys, designed to achieve uniform pressure in all directions during the titanium alloy sintering process, thereby increasing the sintering density of the titanium alloy. Through a built-in sintering kiln with a pressurization function, a certain pressure is formed in the furnace by introducing argon gas. Simultaneously, two independent argon gas pipelines are used to introduce argon gas into a specially designed sintering kiln with certain sealing and pressure-bearing capabilities. Gas is simultaneously and uniformly introduced from all directions of the sintering kiln, ensuring that the sintered body is subjected to uniform pressure in all directions during the sintering process.

[0008] Therefore, one objective of this utility model is to provide a homogenization pressure sintering device based on BJ titanium alloy, including a furnace body, a heating element and kiln furniture;

[0009] The heating element is fitted inside the furnace body, and the kiln furniture is fitted inside the heating element;

[0010] The furnace body is provided with a first protective gas inlet at the top and a vacuum extraction port at the bottom.

[0011] The kiln furniture is equipped with an air inlet and a pressure gauge.

[0012] Furthermore, the device of this utility model also includes a second protective gas inlet, which is connected to the kiln furniture air inlet and the pressure gauge.

[0013] Furthermore, the air inlet of the kiln furniture and the pressure gauge are symmetrically arranged in a plane at any two apex corners of the kiln furniture.

[0014] Furthermore, the kiln furniture is equipped with a special firing plate, on which the titanium alloy billet is placed for sintering.

[0015] Furthermore, this utility model also provides a homogenization pressure sintering method based on BJ titanium alloy, including the following steps:

[0016] (1) Place the prepared titanium alloy billet on a special firing plate and place it inside the sintering kiln; seal the sintering kiln and tighten it with graphite screws, and place graphite paper in the sealing position to assist in sealing; seal and lock the furnace door.

[0017] (2) Turn on the vacuum pump and evacuate the furnace until the pressure inside the furnace is below 10Pa. Expel the air from the furnace and turn on the argon gas, controlling the flow rate at 2-5L / min.

[0018] (3) Start heating and heat to 300-400℃ for degreasing; after holding at the degreasing temperature for 2-5 hours, complete the degreasing of the billet and raise the temperature to 1000-1100℃ at 5℃ per minute; after the furnace temperature is reached, hold for 30-60 minutes.

[0019] (4) After the heat preservation stage is completed, turn off the vacuum pump and increase the flow rate of argon gas through the 5-channel until the pressure inside the furnace increases to 5-7 MPa.

[0020] (4) Open the argon passage of the kiln furniture and slowly increase the argon gas intake in the kiln furniture until the argon pressure in the kiln furniture reaches 7-10MPa. Maintain the argon pressure and continue to keep the temperature at the sintering temperature for 1-2 hours until sintering is completed. After the sintering heating process is completed, cool the furnace to room temperature and then open the furnace door to take out the sintered parts.

[0021] The beneficial effects of this utility model are as follows:

[0022] Existing methods for titanium alloy sintering primarily employ vacuum sintering, resulting in a sintering density generally not exceeding 95%, which fails to fully utilize the superior material properties of titanium alloys. This invention utilizes pressure sintering, where the loose powder blank is subjected to both sintering driving force and external pressure during the densification process, further promoting the densification of the titanium alloy.

[0023] During the sintering process of titanium alloys, the titanium alloy billet is subjected to uniform pressure in different directions by using a saggar with a specific structure and layout, which further promotes the uniform densification of the titanium alloy and improves the consistency of the titanium alloy sintering density. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 The attached figure is a schematic diagram of the homogenization pressure sintering device based on BJ titanium alloy provided by this utility model.

[0026] The structural components represented by each number in the attached diagram are listed below: 1-furnace body, 2-heating element, 3-kiln furniture, 11-first protective gas inlet, 12-vacuum extraction port, 13-second protective gas inlet, 31-kiln furniture air inlet, 32-pressure gauge, 33-special firing plate, 34-titanium alloy blank. Detailed Implementation

[0027] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0028] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] Example

[0033] A homogenization pressure sintering device based on BJ titanium alloy includes a furnace body 1, a heating element 2, and kiln furniture 3;

[0034] Among them, heating element 2 is installed inside furnace body 1, and kiln furniture 3 is installed inside heating element 2;

[0035] A first protective gas inlet 11 is provided at the top of the furnace body 1, and a vacuum extraction port 12 is provided at the bottom of the furnace body 1;

[0036] The kiln furniture 3 is equipped with a kiln furniture air inlet 31 and a pressure gauge 32.

[0037] In some embodiments, the device of the present invention further includes a second protective gas inlet 13, which is connected to the kiln furniture air inlet 31 and the pressure gauge 32.

[0038] In some embodiments, the kiln furniture air inlet 31 and pressure gauge 32 are symmetrically arranged in a planar manner at any two apex corners of the kiln furniture 3.

[0039] In other embodiments, the kiln furniture 3 is provided with a special firing plate 33, on which the titanium alloy blank 34 is placed for sintering.

[0040] The sintering process using the above-mentioned device of this utility model is as follows:

[0041] (1) Place the prepared titanium alloy billet on a special firing plate and place it inside the sintering kiln; seal the sintering kiln and tighten it with graphite screws, and place graphite paper in the sealing position to assist in sealing; seal and lock the furnace door.

[0042] (2) Turn on the vacuum pump and evacuate the furnace until the pressure inside the furnace is below 10Pa. Expel the air from the furnace and turn on the argon gas, controlling the flow rate at 2-5L / min.

[0043] (3) Start heating and heat to the degreasing temperature for degreasing; after holding at the degreasing temperature for a period of time, complete the degreasing of the billet and gradually increase the temperature to 600℃; when the furnace temperature reaches 600℃, increase the argon gas intake and turn off the vacuum pump until the furnace pressure increases to 5Mpa.

[0044] (4) Open the argon gas passage in the kiln furniture and slowly increase the argon gas intake in the kiln furniture until the argon gas pressure in the kiln furniture reaches 7MPa. Maintain the argon gas pressure until sintering is completed. After the sintering heating process is completed, cool the furnace to room temperature and then open the furnace door to remove the sintered parts. The results show that the products sintered using the homogenization pressure sintering method of this application are more dense, while the products sintered using the conventional method have more internal pores.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A homogenization pressure sintering apparatus based on BJ titanium alloy, characterized in that, Includes furnace body, heating element and kiln furniture; The heating element is fitted inside the furnace body, and the kiln furniture is fitted inside the heating element; The furnace body is provided with a first protective gas inlet at the top and a vacuum extraction port at the bottom. The kiln furniture is equipped with an air inlet and a pressure gauge.

2. The homogenization pressure sintering apparatus based on BJ titanium alloy according to claim 1, characterized in that, It also includes a second protective gas inlet, which is connected to the kiln furniture air inlet and the pressure gauge.

3. The homogenization pressure sintering apparatus based on BJ titanium alloy according to claim 1, characterized in that, The air inlet of the kiln furniture and the pressure gauge are symmetrically arranged in a plane at any two apex corners of the kiln furniture.

4. The homogenization pressure sintering apparatus based on BJ titanium alloy according to claim 1 or 3, characterized in that, The kiln furniture is equipped with a special firing plate, on which the titanium alloy billet is placed for sintering.

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