SPS diffusion welding apparatus

Abstract

The application provides an SPS diffusion welding device, and relates to the technical field of diffusion welding devices.The SPS diffusion welding device comprises a lower pressing head, an upper pressing head seat and a plurality of conductive columns, one end of the plurality of conductive columns is uniformly connected to the end face of the upper pressing head seat away from the lower pressing head, a piece to be welded is arranged between the lower pressing head and the upper pressing head seat, and the two side surfaces of the lower pressing head and at least part of the conductive columns are connected with positive and negative electrodes, respectively.Through uniformly distributing a plurality of conductive columns on the upper pressing head seat connected with the piece to be welded, the positions corresponding to the end faces of the conductive columns on the piece to be welded are welded after being electrified, the positions corresponding to the gaps between the conductive columns on the piece to be welded also have a certain current density and temperature due to the outward expansion and heat conduction of the pulse current, and the positions are also welded, the plurality of conductive columns conduct electricity respectively, so that all regions on the piece to be welded can be welded, the current on the piece to be welded is uniformly distributed, good welding of the large-size piece to be welded is achieved, and the welding quality is improved.

Description

Technical Field

[0001] This invention relates to the field of diffusion welding apparatus technology, and more specifically, to an SPS diffusion welding apparatus. Background Technology

[0002] SPS diffusion welding, also known as pulsed electric field assisted diffusion bonding, spark plasma diffusion welding, or spark plasma sintering diffusion bonding, is a highly efficient diffusion bonding method that utilizes the material's own resistance and interfacial contact resistance to rapidly heat the interface to be joined, achieving interfacial metallurgical bonding under certain pressure and time. It boasts advantages such as fast heating rate, low bonding temperature, short bonding time, and low energy consumption. The Joule heating, electroplasticity, and solid-state phase transition-induced effects during SPS diffusion welding promote plastic deformation and accelerate atomic diffusion, reducing the required bonding temperature and time, allowing for high-quality bonding of the workpieces at lower temperatures. However, when high-frequency current is used to weld workpieces through a single pressure head, electromagnetic induction leads to uneven current distribution on the bonding surface. The current density is high near the surface and low near the core, resulting in uneven distribution of Joule heating and electroplasticity effects. This leads to uneven joint structure, causing defects such as incomplete bonding and micropores in the core area of ​​large workpieces during welding. Summary of the Invention

[0003] The problem to be solved by this invention is how to improve the welding quality of SPS diffusion welding.

[0004] To address this, the present invention provides an SPS diffusion welding apparatus, comprising a lower pressure head, an upper pressure head base, and a plurality of conductive pillars. The upper pressure head base and the lower pressure head are coaxially arranged. One end of each of the conductive pillars is evenly distributed and connected to the end face of the upper pressure head base opposite to the lower pressure head. The space between the lower pressure head and the upper pressure head base is used to place the workpiece to be welded. The two opposite surfaces of the lower pressure head and at least a portion of the conductive pillars are respectively used to connect to positive and negative electrodes.

[0005] Optionally, the SPS diffusion welding apparatus further includes an upper pressure head and multiple gaskets. The upper pressure head is coaxially arranged with the upper pressure head base. The number of gaskets is the same as the number of conductive posts. One side of each of the multiple gaskets is connected to the end of the multiple conductive posts away from the upper pressure head base, and the other side is evenly distributed and connected to the end face of the upper pressure head facing the upper pressure head base. The gaskets are made of conductive or insulating materials. The two opposite surfaces of the upper pressure head and the lower pressure head are respectively used to connect to the positive and negative electrodes.

[0006] Optionally, the two sides of the gasket abut against the conductive post and the upper pressure head, respectively.

[0007] Optionally, the radial dimension of the gasket is the same as the radial dimension of the conductive post.

[0008] Optionally, the conductive material is graphite, and the insulating material is mica sheet.

[0009] Optionally, the conductive post is made of high-strength graphite.

[0010] Optionally, the conductive post is a cylinder.

[0011] Optionally, a positioning groove is provided on the side of the upper pressure head seat facing the upper pressure head, and one end of the conductive post is connected to the positioning groove.

[0012] Optionally, it also includes a pressure mechanism for pressing the upper pressure head toward the lower pressure head.

[0013] Optionally, it also includes a furnace body, wherein the lower pressure head, the upper pressure head seat, and the plurality of conductive columns are all disposed within the furnace body.

[0014] Compared with the prior art, the beneficial effects of the SPS diffusion welding apparatus of the present invention are:

[0015] This invention uses a lower pressure head and an upper pressure head base as structures that directly contact the workpieces to be welded. Two workpieces, for example, a first workpiece and a second workpiece, are positioned between the lower pressure head and the upper pressure head base. Multiple conductive posts are evenly distributed on the end face of the upper pressure head base away from the lower pressure head. The end face of the lower pressure head away from the upper pressure head base is electrically connected to the negative terminal of the power supply, and the end faces of the conductive posts away from the upper pressure head base can be electrically connected to the positive terminal of the power supply. After energization, the positions on the workpieces corresponding to the ends of the conductive posts are welded. Because the pulse current slightly expands outwards, the positions corresponding to the gaps between the conductive posts on the workpieces also have a certain current density and temperature due to the outward expansion of the current and heat conduction. It can also be welded. Multiple conductive pillars conduct electricity separately, so that all areas on the workpiece can be welded. The current on the workpiece is evenly distributed, which can achieve good welding of large-sized workpieces, improve welding quality, and avoid defects such as uneven current density distribution and incomplete welding of the core area of ​​the workpiece caused by the skin effect when welding large-sized test pieces with a single pressure head. In addition, multiple conductive pillars can be selectively connected to the positive terminal of the power supply, which makes it easy to weld the areas on the workpiece that need to be welded according to the actual welding requirements, thereby improving welding quality. For example, when only the center position of the workpiece needs to be welded, only the conductive pillar located in the center of the upper pressure head seat can be energized. Attached Figure Description

[0016] Figure 1 This is one of the structural schematic diagrams of the SPS diffusion welding apparatus according to an embodiment of the present invention;

[0017] Figure 2This is a second schematic diagram of the SPS diffusion welding apparatus according to an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures:

[0019] 1-Lower pressure head; 2-First workpiece to be welded; 3-Second workpiece to be welded; 4-Upper pressure head seat; 5-Conductive post; 6-Gasket; 7-Upper pressure head. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] It should be noted that in the description of this invention, the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "top," "bottom," "front," "back," "inner," and "outer" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention. They are not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention.

[0022] 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 at least one of that feature.

[0023] Furthermore, although specific embodiments have been described herein, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features herein can be combined in ways not used as described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other embodiments.

[0024] To solve the above problems, such as Figure 1 and Figure 2 As shown, the present invention provides an SPS diffusion welding apparatus, including a lower pressure head 1, an upper pressure head seat 4, and a plurality of conductive posts 5. The upper pressure head seat 4 and the lower pressure head 1 are coaxially arranged. One end of the plurality of conductive posts 5 is evenly distributed and connected to the end face of the upper pressure head seat 4 opposite to the lower pressure head 1. The lower pressure head 1 and the upper pressure head seat 4 are used to place the workpiece to be welded. The two opposite sides of the lower pressure head 1 and at least a portion of the conductive posts 5 are respectively used to connect to positive and negative electrodes.

[0025] In this embodiment, by setting a lower pressure head 1 and an upper pressure head seat 4 as structures that directly contact the workpieces to be welded, two workpieces to be welded, such as a first workpiece 2 and a second workpiece 3, are placed between the lower pressure head 1 and the upper pressure head seat 4. Multiple conductive posts 5 are evenly distributed on the end face of the upper pressure head seat 4 away from the lower pressure head 1. The end face of the lower pressure head 1 away from the upper pressure head seat 4 is electrically connected to the negative terminal of the power supply, and the end faces of the conductive posts 5 away from the upper pressure head seat 4 can be electrically connected to the positive terminal of the power supply. After energizing, the positions on the workpieces to be welded corresponding to the end faces of the conductive posts 5 are welded. Because the pulse current will slightly expand outwards, the positions corresponding to the gaps between the conductive posts 5 on the workpieces to be welded also have a certain effect due to the outward expansion of the current and heat conduction. Under constant current density and temperature, welding can also be achieved. Multiple conductive pillars 5 conduct electricity separately, allowing all areas on the workpiece to be welded to be welded. The current on the workpiece is evenly distributed, achieving good welding of large-sized workpieces, improving welding quality, and avoiding defects such as uneven current density distribution and incomplete welding of the core area of ​​the workpiece caused by the skin effect when welding large-sized test pieces with a single pressure head. In addition, multiple conductive pillars 5 can be selectively connected to the positive terminal of the power supply, making it convenient to weld the areas on the workpiece that need to be welded according to the actual welding requirements, thus improving welding quality. For example, when only the center position of the workpiece needs to be welded, only the conductive pillar 5 located at the center of the upper pressure head seat 4 can be energized.

[0026] Specifically, there are seven conductive posts 5, six of which are arranged in a regular hexagon and the remaining one is located at the center of the regular hexagon; the positive and negative electrodes can also be interchanged, the pressure head 1 is electrically connected to the positive terminal of the power supply, and the conductive posts are electrically connected to the negative terminal of the power supply.

[0027] Optionally, such as Figure 1 and Figure 2 As shown, the SPS diffusion welding device also includes an upper pressure head 7 and multiple gaskets 6. The upper pressure head 7 is coaxially arranged with the upper pressure head base 4. The number of gaskets 6 is the same as the number of conductive posts 5. One side of each of the multiple gaskets 6 is connected to one end of each of the multiple conductive posts 5 away from the upper pressure head base 4, and the other side is evenly distributed and connected to the end face of the upper pressure head 7 facing the upper pressure head base 4. The gaskets 6 are made of conductive or insulating materials. The two opposite surfaces of the upper pressure head 7 and the lower pressure head 1 are respectively used to connect to the positive and negative electrodes.

[0028] In this embodiment, an upper pressure head 7 and multiple gaskets 6 are provided. The number of gaskets 6 is the same as the number of conductive posts 5. Each conductive post 5 has a gasket 6 connected to the end away from the upper pressure head seat 4. The upper pressure head 7 and the upper pressure head seat 4 are coaxially arranged. The upper pressure head 7 covers the multiple gaskets 6. The end of the upper pressure head 7 away from the gaskets 6 is electrically connected to the positive terminal of the power supply. The upper pressure head 7 is provided above the multiple conductive posts 5. By pressing the upper pressure head 7, two parts to be welded, the upper pressure head seat 4, and the conductive posts 5 are squeezed together. Each conductive post 5... The uniform force distribution improves welding quality. The gasket 6 can be made of conductive or insulating material. When the gasket 6 between the conductive post 5 and the upper pressure head 7 is a conductive gasket, the area on the workpiece corresponding to the conductive post 5 will be welded after the upper pressure head 7 is energized. When the gasket 6 between the conductive post 5 and the upper pressure head 7 is an insulating gasket, the area on the workpiece corresponding to the conductive post 5 cannot be welded after the upper pressure head 7 is energized. The insulating or conductive gasket can be selected according to the actual welding requirements, making it convenient to weld the workpiece according to the actual welding needs.

[0029] Optionally, the two sides of the gasket 6 abut against the conductive post 5 and the upper pressure head 7, respectively.

[0030] In this embodiment, both ends of the gasket 6 are in contact with the conductive post 5 and the upper pressure head 7, which facilitates the replacement of the gasket 6 with an insulating gasket or a conductive gasket as needed.

[0031] Optionally, such as Figure 2 As shown, the radial dimension of the gasket 6 is the same as the radial dimension of the conductive post 5.

[0032] In this embodiment, the radial dimension of the gasket 6 is set to be the same as that of the conductive post 5, so that the gasket 6 can completely isolate the conductive post 5 from the upper pressure head 7, and avoid the situation where the corresponding conductive post 5 is still conductive when an insulating gasket is used.

[0033] Optionally, the conductive material is graphite, and the insulating material is mica sheet.

[0034] In this embodiment, by setting the material of the conductive pad to graphite and the material of the insulating pad to mica, when energized, the conductive pad can guide the current from the upper pressure head 7 to the conductive post 5, thereby completing the welding of the workpiece to be welded. The insulating pad can block the upper pressure head 7 and the conductive post 5, so that the conductive post 5 connected to the insulating pad is not energized, which facilitates welding of the workpiece to be welded according to the actual welding requirements.

[0035] Optionally, the conductive post 5 is made of high-strength graphite.

[0036] In this embodiment, the conductive post 5 is made of high-strength graphite, which is resistant to high temperatures, corrosion, and has a low resistivity and strong conductivity, facilitating the flow of current through the conductive post 5 for welding the workpiece.

[0037] Optionally, such as Figure 1 and Figure 2 As shown, the conductive post 5 is a cylinder.

[0038] In this embodiment, by setting the conductive post 5 as a cylinder with a circular end face, and the circular shape being a centrally symmetrical structure, it is easier for the current passing through the conductive post 5 to flow evenly on the surface of the workpiece to be welded and to the periphery of the conductive post 5, so that the current distribution is more uniform and the welding quality is improved.

[0039] Specifically, the conductive post 5 can also be a quadrangular prism, triangular prism, or other structure. The structure of the conductive post 5 only needs to be able to support the upper pressure head seat 4 and the upper pressure head 7, and no specific limitation is made here.

[0040] Optionally, the upper pressure head seat 4 has a positioning groove on the side facing the upper pressure head 7, and one end of the conductive post 5 is connected to the positioning groove.

[0041] In this embodiment, multiple positioning grooves are opened on the side of the upper pressure head seat 4 facing the upper pressure head 7. The size of the positioning grooves corresponds to the size of the conductive post 5, and the number and position of the positioning grooves correspond to the number and position of the conductive post 5. The positioning grooves facilitate the connection of the conductive post 5 to the upper pressure head seat 4 and prevent the conductive post 5 from being displaced.

[0042] Optionally, it also includes a pressure mechanism for pressing the upper pressure head 7 toward the lower pressure head 1.

[0043] In this embodiment, by setting a pressure mechanism, such as a hydraulic cylinder, the pressure mechanism can press on the upper pressure head 7, pressing the upper pressure head 7 in the direction of the lower pressure head 1, squeezing the two parts to be welded, the upper pressure head seat 4, and the conductive post 5 together, so that the force on each conductive post 5 is evenly distributed, thereby improving the welding quality.

[0044] Optionally, it also includes a furnace body, wherein the lower pressure head 1, the upper pressure head seat 4, and the plurality of conductive posts 5 are all disposed within the furnace body.

[0045] In this embodiment, the lower pressure head 1, the upper pressure head seat 4, and multiple conductive pillars 5 are installed inside the furnace body and welded into the furnace chamber. The furnace body isolates the operator from the current, preventing injury to the operator.

[0046] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An SPS diffusion welding apparatus, characterized in that, It includes a lower pressure head (1), an upper pressure head seat (4) and a plurality of conductive posts (5). The upper pressure head seat (4) and the lower pressure head (1) are coaxially arranged. One end of the plurality of conductive posts (5) is evenly distributed and connected to the end face of the upper pressure head seat (4) away from the lower pressure head (1). The lower pressure head (1) and the upper pressure head seat (4) are used to place the workpiece to be welded. The two opposite sides of the lower pressure head (1) and at least some of the conductive posts (5) are respectively used to connect to the positive and negative electrodes. The SPS diffusion welding device also includes an upper pressure head (7) and multiple gaskets (6). The upper pressure head (7) is coaxially arranged with the upper pressure head base (4). The number of gaskets (6) is the same as the number of conductive posts (5). One side of each of the multiple gaskets (6) is connected to one end of each of the multiple conductive posts (5) away from the upper pressure head base (4), and the other side is evenly distributed and connected to the end face of the upper pressure head (7) facing the upper pressure head base (4). The gaskets (6) are made of conductive or insulating materials. The two opposite surfaces of the upper pressure head (7) and the lower pressure head (1) are respectively used to connect to the positive and negative electrodes.

2. The SPS diffusion welding apparatus according to claim 1, characterized in that, The two sides of the gasket (6) abut against the conductive post (5) and the upper pressure head (7), respectively.

3. The SPS diffusion welding apparatus according to claim 1, characterized in that, The radial dimension of the gasket (6) is the same as the radial dimension of the conductive post (5).

4. The SPS diffusion welding apparatus according to claim 1, characterized in that, The conductive material is graphite, and the insulating material is mica sheet.

5. The SPS diffusion welding apparatus according to claim 1, characterized in that, The conductive pillar (5) is made of high-strength graphite.

6. The SPS diffusion welding apparatus according to claim 1, characterized in that, The conductive post (5) is a cylinder.

7. The SPS diffusion welding apparatus according to claim 1, characterized in that, The upper pressure head seat (4) has a positioning groove on the side facing the upper pressure head (7), and one end of the conductive post (5) is connected to the positioning groove.

8. The SPS diffusion welding apparatus according to claim 1, characterized in that, It also includes a pressure mechanism for pressing the upper pressure head (7) toward the lower pressure head (1).

9. The SPS diffusion welding apparatus according to claim 1, characterized in that, It also includes a furnace body, and the lower pressure head (1), the upper pressure head seat (4) and the plurality of conductive columns (5) are all disposed in the furnace body.

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