Sintering furnace for medium-frequency sintering of tungsten bars

Abstract

According to the sintering furnace for medium-frequency sintering of the tungsten bars, a plurality of sintering pipes are vertically arranged on the inner side of a furnace body in a plug-in mode, the multiple sintering pipes are arranged at equal intervals in an array mode, the sintering pipes are connected with the furnace body in a heat conduction mode, a middle partition plate is arranged in the middle of each sintering pipe in a penetrating mode, and each sintering pipe is in the shape of a conductive circular pipe; the bottom ends of the sintering pipes are flush with the bottom face of the furnace body, an assembling base is arranged below the furnace body and connected with the bottom face of the furnace body in a guiding and connecting mode through a guiding and connecting column, a supporting sliding plate is arranged between the upper surface of the assembling base and the bottom face of the furnace body, and the upper surface of the assembling base is provided with a plurality of inserting and connecting bases in one-to-one alignment with the sintering pipes. The tungsten bars vertically penetrate through the supporting sliding plates on the inserting bases, the heating uniformity of the tungsten bars in the sintering process is improved, meanwhile, adhesion caused by accumulation is eliminated, and therefore the quality of the finished tungsten bars is improved, the sintering density of the tungsten bars can be effectively improved, and the problem of the bending phenomenon in the sintering process is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of tungsten bar sintering, and specifically relates to a sintering furnace for medium frequency sintering of tungsten bars. Background Art

[0002] Due to the high melting point of tungsten (3400℃±20℃), the processing of tungsten bars is generally carried out by traditional powder metallurgy. In the traditional powder metallurgy production, vertical melting sintering is used in the sintering process. Vertical melting sintering consumes a lot of energy. Therefore, the medium frequency sintering method has emerged in the industry. Medium frequency sintering has high efficiency and low energy consumption. Therefore, many manufacturers use this method for sintering.

[0003] Compared with the vertical melting sintering process, the process of sintering tungsten bars in medium frequency furnace not only improves the quality and performance of materials, but also improves production efficiency, reduces energy consumption, saves production costs, and achieves the dual advantages of production efficiency and cost control. Many studies have shown that sintering density is the most important basic performance of tungsten bars. Generally speaking, the higher the density of tungsten bars, the better the processing performance. At the same time, in a high temperature environment, tungsten bars will inevitably bend due to their own weight.

[0004] Existing tungsten wire manufacturers all use the method of vertically stacking tungsten bars for sintering. Vertical stacking for sintering will result in low density of the tungsten bars and severe bending of the tungsten bars during the sintering process.

[0005] In order to correct the bending deformation, an additional straightening process is required, which not only increases the complexity of production, but also makes the tungsten bar prone to stress concentration in subsequent processing, which may cause problems such as wire breakage and affect the quality and stability of the product. Utility Model Content

[0006] In order to solve the above problems, this paper proposes a sintering furnace for medium frequency sintering of tungsten bars. The furnace body of the sintering furnace is in the shape of a cylindrical cavity. A plurality of sintering tubes are arranged vertically and plug-inly on the inner side of the furnace body. A plurality of sintering tube arrays are arranged at equal intervals. The sintering tubes and the furnace body are thermally connected to each other. A middle partition is arranged through the middle of the sintering tube. The sintering tube is in the shape of a conductive round tube. The bottom end of the sintering tube is flush with the bottom surface of the furnace body. An assembly base is arranged at the bottom of the furnace body. The assembly base is connected to the bottom surface of the furnace body through a conductive column. The guide column is connected, a supporting slide plate is provided between the upper surface of the assembly base and the bottom surface of the furnace body, a plurality of sockets are provided on the upper surface of the assembly base which are aligned with the sintering tubes one by one, a tungsten bar is provided on the socket which vertically penetrates the supporting slide plate, and the outer edge surface of the supporting slide plate is connected to the guide column in a plug-in and sliding manner, which improves the heating uniformity of the tungsten bar during the sintering process and eliminates the adhesion caused by accumulation, thereby improving the quality of the finished tungsten bar, can effectively improve the sintering density of the tungsten bar, and improve the problem of bending during the sintering process.

[0007] The furnace body is a hollow cylindrical cavity, one end of the furnace body is sealed with an arc furnace cover, the other end of the furnace body is arrayed with a plurality of connection holes at equal distances, the outer side of one end of the connection hole of the furnace body is provided with a guide flange, the middle part of the inner side of the furnace body is transversely fixed with a middle partition, the connection hole is fixed with a sintering tube in a plug-in manner, the shape of the sintering tube is a through-hole round tube, the material of the sintering tube is the same as that of the furnace body, the bottom end of the sintering tube is connected to the furnace body by heat conduction welding, the outer side of the middle part of the sintering tube is connected to the middle partition by heat conduction welding, and the upper end of the sintering tube is connected to the The inside of the furnace body is interconnected, and the stacked sintering of tungsten bars may lead to uneven sintering temperature distribution, especially the tungsten bars in the stacked area may be insufficiently heated or overheated, affecting the sintering quality. The sintering is carried out through an independent sintering tube structure, and the tungsten bars are heated evenly, which solves the problem of low sintering density of tungsten bars and is not prone to defects. The heating efficiency of the stacked sintering structure may be reduced because the heat needs to penetrate multiple layers of tungsten bars to be evenly distributed. The sintering is carried out through a sintering tube structure that outsources each tungsten bar, and the tungsten bars are evenly distributed, which reduces the sintering time and reduces production costs.

[0008] The assembly base is in the shape of a disc-type boss seat, and the center of the assembly base is circularly protruding with a boss, and the surface of the boss is aligned with the sintering tube and provided with a plug-in seat, and the outer side of the boss is annularly equidistantly provided with guide posts, and the guide posts are vertically arranged on the upper surface of the assembly base, and the shape of the support slide is a center disk, and the outer surface of the support slide is annularly equidistantly provided with guide holes, and the middle part of the support slide is provided with a plurality of support holes corresponding to the sintering tube, and the inner side of the support hole is provided with a tungsten bar, and the shape of the guide post is cylindrical, and the outer side of the guide post is provided with a support slide in a sliding plug-in manner, and the lower end of the guide post is externally provided with a guide plate. The side is provided with a locking thread, the inner side of the guide column is protruding with a spring pressure pin, and a supporting slide plate is provided above the spring pressure pin. The stacking and sintering of tungsten bars requires more complex operating technology and parameter control, and after the stacking and sintering of the tungsten bars, the post-sintering processing may be more complicated, such as cutting, grinding, etc., which will increase the difficulty and cost of subsequent processes. Through the structure of the assembly base directly assembled from the bottom, the loading can be conveniently and quickly carried out externally, effectively avoiding the breakage of the tungsten bars caused by loading, improving the problem of bending during the sintering process, avoiding the processing of subsequent processing steps, and improving the yield rate of tungsten bars.

[0009] Beneficial effects:

[0010] The heating uniformity of the tungsten bar during the sintering process is improved, and the adhesion caused by accumulation is eliminated, thereby improving the quality of the finished tungsten bar. It can effectively increase the sintering density of the tungsten bar and improve the problem of bending during the sintering process.

[0011] The stacked sintering of tungsten bars may lead to uneven sintering temperature distribution, especially the tungsten bars in the stacked area may be underheated or overheated, affecting the sintering quality. By sintering through an independent sintering tube structure, the tungsten bars are heated evenly, solving the problem of low sintering density of the tungsten bars and not prone to defects.

[0012] The stacked sintering structure may reduce the heating efficiency because the heat needs to penetrate multiple layers of tungsten bars to be evenly distributed. By sintering with a sintering tube structure that outsources each tungsten bar, the tungsten bars are evenly distributed, which reduces the sintering time and production costs.

[0013] The stacking and sintering of tungsten bars requires more complex operating techniques and parameter control. After the stacking and sintering of tungsten bars, the post-sintering processing may be more complicated, such as cutting, grinding, etc., which will increase the difficulty and cost of subsequent processes. Through the assembly base, the structure of the assembly is directly assembled from the bottom, and the loading can be conveniently and quickly carried out externally, which effectively avoids the breakage of tungsten bars caused by loading, improves the problem of bending during sintering, avoids the processing of subsequent processing steps, and improves the yield rate of tungsten bars. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the assembly of a sintering furnace for medium frequency sintering of tungsten bars;

[0015] Figure 2 This is a bottom view of a sintering furnace for medium frequency sintering of tungsten bars;

[0016] Figure 3 This is a top view of the internal structure of a sintering furnace for medium frequency sintering of tungsten bars;

[0017] Figure 4 This is a schematic diagram of the interior of a sintering furnace for medium frequency sintering of tungsten bars;

[0018] Figure 5 It is a loading base for the sintering furnace used for medium frequency sintering of tungsten bars.

[0019] In the figure; 1, furnace body, 2, middle partition, 3, sintering tube, 4, assembly base, 5, supporting slide plate, 6, guide column, 7, tungsten bar. DETAILED DESCRIPTION

[0020] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0021] Furnace body 1, middle partition plate 2, sintering tube 3, assembly base 4, supporting slide plate 5, guide column 6, tungsten bar 7.

[0022] like Figure 1 , 2, 3, 4, 5 as shown;

[0023] A sintering furnace for medium frequency sintering of tungsten bars 7, the furnace body 1 of the sintering furnace is in the shape of a cylindrical cavity, a plurality of sintering tubes 3 are arranged vertically and plug-inly on the inner side of the furnace body 1, a plurality of sintering tubes 3 are arranged in an array at equal distances, the sintering tubes 3 and the furnace body 1 are connected to each other by heat conduction, a middle partition plate 2 is arranged through the middle of the sintering tube 3, the shape of the sintering tube 3 is a conductive round tube, the bottom end of the sintering tube 3 is flush with the bottom surface of the furnace body 1, an assembly base 4 is arranged below the furnace body 1, the assembly base 4 is connected to the bottom surface of the furnace body 1 by a guide column 6, and the assembly base A supporting slide plate 5 is provided between the upper surface of the seat 4 and the bottom surface of the furnace body 1. A plurality of plug-in seats are provided on the upper surface of the assembly base 4 in alignment with the sintering tubes 3. A tungsten bar 7 is provided on the plug-in seat and vertically penetrates the supporting slide plate 5. The outer edge surface of the supporting slide plate 5 is connected to the guide column 6 by plugging and sliding. The furnace body 1 is a hollow cylindrical cavity. An arc furnace cover is provided in a sealed manner at one end of the furnace body 1. A plurality of connecting holes are provided in an array at equal distances on the surface of the other end of the furnace body 1. A guide flange is provided on the outer side of one end of the connecting hole of the furnace body 1. A central flange is provided in the middle of the inner side of the furnace body 1. The partition 2 is provided with a sintering tube 3 in a fixed plug-in manner inside the connecting hole. The shape of the sintering tube 3 is a through-hole type round tube. The material of the sintering tube 3 is the same as that of the furnace body 1. The bottom end of the sintering tube 3 is connected to the furnace body 1 by heat conduction welding. The middle outer side of the sintering tube 3 is connected to the middle partition 2 by heat conduction welding. The upper end of the sintering tube 3 is mutually conductive with the inside of the furnace body 1. The assembly base 4 is in the shape of a disc-type boss seat. The center of the assembly base 4 is circularly protruding and provided with a boss. The surface of the boss is aligned one by one with a plug-in seat, and the outer side of the boss is annularly equidistantly provided with a guide The connecting column 6 is vertically arranged on the upper surface of the assembly base 4. The support slide plate 5 is in the shape of a circular center disk. The outer surface of the support slide plate 5 is annularly and equidistantly provided with connecting holes. The middle part of the support slide plate 5 is provided with a plurality of supporting holes corresponding to the sintering tube 3. A tungsten bar 7 is provided on the inner side of the supporting hole. The shape of the connecting column 6 is cylindrical. The outer side of the connecting column 6 is provided with a supporting slide plate 5 in a sliding and plug-in manner. A locking thread is provided on the outer side of the lower end of the connecting column 6. A spring pressure pin is protruding from the inner side of the connecting column 6. The support slide plate 5 is provided above the spring pressure pin.

[0024] Implementation examples;

[0025] Before sintering, first insert the tungsten bar 7 to be sintered vertically through the support slide plate 5 onto the assembly base 4. After the preparation of the tungsten bar 7 is completed, align the guide column 6 on the assembly base 4 with the guide hole on the outside of the furnace body 1 and insert it to complete the positioning. Then, directly push the assembly base 4 upward and push the tungsten bar 7 directly into the sintering tube 3 in the furnace body 1. When the support slide plate 5 contacts the bottom surface of the furnace body 1, the support slide plate 5 will press the spring pressure pin on the guide column 6 downward, thereby moving the support slide plate 5 downward to complete the supporting function of the support slide plate 5. Finally, after the assembly base 4 is fixed to the bottom surface of the furnace body 1, the guide column 6 is locked and fixed with bolts to complete the assembly of the tungsten bar 7 in the furnace body 1.

[0026] At this time, each tungsten bar 7 is vertically inserted into each sintering tube 3, thereby ensuring uniform sintering.

[0027] The specific sintering steps are as follows;

[0028] a. First, raise the temperature to 800-950°C for 2-3 hours, and keep the hydrogen at 15-18;

[0029] b. Keep the temperature at 800-950°C for 2 hours and keep the hydrogen at 15-18;

[0030] c. Raise the temperature to 1700-1950°C for 6 hours, and keep the hydrogen at 15-18;

[0031] d. Keep the temperature at 1700-1950°C for 2 hours and the hydrogen at 15-18;

[0032] e. Raise the temperature to 1950-2160°C for 4 hours, and keep the hydrogen at 12-14;

[0033] f. Keep the temperature at 1950-2160°C for 1.5 hours and the hydrogen at 12-14;

[0034] g. High temperature cooling, reduce the temperature to 1550-1800℃ for 1 hour, and keep the hydrogen at 8-12;

[0035] h. Cool down to room temperature, reduce the temperature to 1550-1800℃ for 18h, and keep the hydrogen at 8-12;

[0036] The diameter of the tungsten bar before sintering is 19mm~20mm, the length is 850mm~910mm, and the sintering temperature is 1950℃~2160℃. Under the conditions of this device, the sintering density of the tungsten bar is 18.40g / cm2~18.70g / cm2, which is significantly improved compared to the sintering density of about 17.46g / cm2 of tungsten bars using a stacking method; and the straightness of the sintered tungsten bar is also improved.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A sintering furnace for medium frequency sintering of tungsten bars, the furnace body of the sintering furnace is in the shape of a cylindrical cavity, characterized in that: The inner side of the furnace body is provided with a plurality of sintering tubes in a vertical plug-in manner, and the sintering tube array is provided with a plurality of equidistant ones, the sintering tube and the furnace body are thermally connected to each other, a middle partition is provided through the middle of the sintering tube, the sintering tube is in the shape of a conductive round tube, the bottom end of the sintering tube is flush with the bottom surface of the furnace body, an assembly base is provided under the furnace body, the assembly base is conductively connected to the bottom surface of the furnace body through a guiding column, a supporting slide is provided between the upper surface of the assembly base and the bottom surface of the furnace body, a plurality of plug-in seats are provided on the upper surface of the assembly base aligned with the sintering tubes, a tungsten bar is provided on the plug-in seat which vertically penetrates the supporting slide, and the outer edge surface of the supporting slide is plug-in and slidably connected to the guiding column.

2. The sintering furnace for medium frequency sintered tungsten bars according to claim 1, characterized in that: The furnace body is a hollow cylindrical cavity, one end of the furnace body is sealed with an arc-shaped furnace cover, the other end of the furnace body is arrayed with a plurality of connection holes at equal distances, a guide flange is provided on the outside of one end of the connection hole of the furnace body, a middle partition is transversely fixed in the middle of the inner side of the furnace body, and a sintering tube is fixedly inserted inside the connection hole.

3. The sintering furnace for medium frequency sintering of tungsten bars according to claim 1, characterized in that: The sintering tube is in the shape of a through-hole round tube. The material of the sintering tube is the same as that of the furnace body. The bottom end of the sintering tube is connected to the furnace body by heat conduction welding, the outer middle part of the sintering tube is connected to the middle partition by heat conduction welding, and the upper end of the sintering tube is connected to the inside of the furnace body.

4. The sintering furnace for medium frequency sintering of tungsten bars according to claim 1, characterized in that: The assembly base is in the shape of a disc-type boss seat, and a boss is protruding from the center of the assembly base in a circular manner. A plug-in seat is provided on the surface of the boss in alignment with the sintering tube, and guide columns are provided in an annular manner equidistantly on the outer side of the boss. The guide columns are vertically arranged on the upper surface of the assembly base.

5. The sintering furnace for medium frequency sintering of tungsten bars according to claim 1, characterized in that: The support slide is in the shape of a circular center disk, and guide holes are equidistantly arranged in an annular manner on the outer surface of the support slide. A plurality of support holes are arranged in the middle of the support slide corresponding to the sintering tubes, and tungsten bars are arranged inside the support holes.

6. The sintering furnace for medium frequency sintering of tungsten bars according to claim 1, characterized in that: The guide column is cylindrical in shape, a support slide is slidably inserted on the outside of the guide column, a locking thread is provided on the outside of the lower end of the guide column, a spring pressure pin is protruding on the inner side of the guide column, and a support slide is provided above the spring pressure pin.

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