A CVD method gas flow distribution device

Abstract

The application relates to a CVD airflow distribution device, which comprises a reaction chamber, an air inlet device, a fixing device and an air outlet device. The reaction chamber is provided with an outer chamber wall and an inner chamber wall, a plurality of through holes are uniformly arranged on the inner chamber wall, one end of the outer chamber wall is in a sealing shape, the other end is provided with an opening, the two ends of the inner chamber wall are arranged at the two ends of the outer chamber wall, the air inlet device is provided with a support and an air inlet pipe, the support is arranged on the outer chamber wall, one end of the air inlet pipe penetrates through the support and is communicated with the outer chamber wall, the fixing device is arranged on the inner chamber wall, a groove is arranged on the end surface of the fixing device, the air outlet device is arranged on the end of the outer chamber wall provided with the opening, and the air outlet device is provided with an air outlet hole. Through the structure, the reaction atmosphere can be effectively distributed to the surface of the test rod, the uniformity of the atmosphere in the process of forming the aluminide permeation layer on the test rod is guaranteed, and the problems of poor thickness and composition consistency of the permeation layer formed on the surface of the test rod are solved.

Description

Technical Field

[0001] This invention relates to the field of infiltration technology, and more specifically to a CVD airflow distribution device. Background Technology

[0002] CVD (Continuous Chemical Deposition) is currently the most advanced technology for preparing aluminide diffusion layers. It employs directional pipeline transport and strictly controls the flow rate of the reaction atmosphere through the action of a carrier gas. By controlling parameters such as reaction temperature, composition, concentration, and pressure of the source gas, the microstructure and composition of the aluminide diffusion layer can be easily controlled, thereby altering its mechanical properties and corrosion and oxidation resistance. Since the microstructure and composition of the diffusion layer are affected by the concentration of the reaction atmosphere, improving the consistency of the atmosphere concentration becomes crucial to ensuring uniform diffusion layer thickness, intact microstructure, and controllable composition on the sample surface.

[0003] Currently, the preparation of the surface infiltration layer on test specimens is carried out directly in an infiltration chamber. Specifically, a certain amount of atmosphere is introduced into a pipeline. The atmosphere is first directionally introduced into the material rack within the reaction vessel (temperature > 1000℃), and then exits through small holes on the rack into the infiltration chamber containing the sample, where it reacts with the sample surface to form the infiltration layer. During this operation, the airflow moves from bottom to top. Because the surface of the test specimen to be infiltrated is cylindrical, the atmosphere is more abundant on the surface of the specimen directly opposite the inlet of the infiltration chamber, resulting in differences in the thickness and composition of the infiltration layer at different locations on the specimen. Summary of the Invention

[0004] This invention provides a CVD gas flow distribution device that can effectively distribute the reaction atmosphere to the surface of the test rod, thereby ensuring the uniformity of the atmosphere during the formation of the aluminide diffusion layer on the test rod and solving the problems of poor consistency in the thickness and composition of the diffusion layer formed on the surface of the existing test rods.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] The reaction chamber has an outer wall and an inner wall. The inner wall has multiple through holes evenly distributed. One end of the outer wall is sealed, and the other end is open. The outer wall is fitted over the inner wall. The air inlet device has a support and an air inlet pipe. The support is installed on the outer wall of the chamber, and one end of the air inlet pipe passes through the support and connects to the outer wall of the chamber. The fixing device is installed on the inner wall of the chamber, and the end face of the fixing device has a groove. The air outlet device is installed at the opening position of the outer wall of the chamber, and the air outlet device has an air outlet hole.

[0007] The beneficial effects of this invention are as follows: When the test rod is placed on the fixing device of the reaction chamber, the reaction atmosphere is evenly distributed during the formation of the aluminide diffusion layer using chemical vapor deposition (CVD). The reaction atmosphere enters the outer wall of the chamber through the air inlet device, and then flows to the surface of the test rod through the through-holes in the inner wall of the chamber to form a uniform diffusion layer. Because small holes are evenly arranged radially on the inner wall of the chamber, the reaction atmosphere is evenly distributed from one end of the test rod to the other side onto the test rod surface, ensuring effective distribution of the reaction atmosphere to the test rod surface. This reduces the difference in diffusion layer between the top and bottom areas of the test rod, as well as the difference in diffusion layer along the length direction, thus ensuring the uniformity of the atmosphere during the formation of the aluminide diffusion layer on the test rod.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the inner wall of the cavity has multiple rows of through holes, each row having multiple through holes, and the arc angle between two adjacent rows of through holes on the inner wall of the cavity is 36 degrees.

[0010] The beneficial effect of adopting the above-mentioned further scheme is that small holes are evenly arranged radially on the inner wall of the chamber, and the through holes are opened with the axis of the inner wall of the chamber as the axis. The arc angle between two adjacent rows of through holes is 36 degrees. The reaction atmosphere is evenly distributed from one end of the test rod to the other side of the test rod to the surface of the test rod, ensuring that the reaction atmosphere is effectively distributed to the surface of the test rod, reducing the difference in diffusion layer between the top area and the bottom area of ​​the test rod and in the length direction, and ensuring the uniformity of the atmosphere during the formation of the aluminide diffusion layer on the test rod.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Furthermore, the diameter of the outer wall of the cavity is larger than the diameter of the inner wall of the cavity.

[0013] The beneficial effect of adopting the above-mentioned further scheme is that the diameter of the outer wall of the chamber is larger than the diameter of the inner wall of the chamber, so that the reaction atmosphere enters the outer wall of the chamber through the air inlet device, and then flows to the surface of the test rod through the uniformly opened through holes in the inner wall of the chamber to form a uniform infiltration layer.

[0014] Based on the above technical solution, the present invention can be further improved as follows.

[0015] Furthermore, the outer wall of the cavity is welded and fixed to the inner wall of the cavity.

[0016] The beneficial effect of adopting the above-mentioned further solution is that the outer wall of the chamber and the inner wall of the chamber are fixed by integral welding, which ensures that the reaction atmosphere does not leak out at high temperature and avoids danger caused by gas leakage.

[0017] Based on the above technical solution, the present invention can be further improved as follows.

[0018] Furthermore, the opening is provided with an internal thread, and the air outlet device has an external thread that matches the internal thread. The air outlet device is installed in conjunction with the outer wall of the chamber.

[0019] The beneficial effect of adopting the above-mentioned further solution is that the airflow distribution device assembled by the threaded method avoids the quality risk that the lid may be blown open due to excessive airflow.

[0020] Based on the above technical solution, the present invention can be further improved as follows.

[0021] Furthermore, the air outlet device has three air outlets.

[0022] The beneficial effects of adopting the above-mentioned further scheme are that the air outlet device has three air outlets. The middle air outlet allows the incoming airflow to converge from the through hole to the center, thereby improving the coverage of the test bar by the airflow. The air outlets on both sides ensure the dispersion of the airflow and improve the uniformity of the atmosphere when placed between the three test bars. Ensuring uniform airflow distribution, with the three air outlets being uniform in the upper, middle, and lower regions along the longitudinal direction, guarantees the flow field properties of the airflow.

[0023] Based on the above technical solution, the present invention can be further improved as follows.

[0024] Furthermore, the fixing device has two sets, and each set of fixing devices has multiple grooves on its end face. The two sets of fixing devices are respectively fixedly installed at both ends of the inner wall of the cavity, and the grooves of the two sets of fixing devices correspond one-to-one.

[0025] The beneficial effect of adopting the above-mentioned further solution is that the two sets of fixing devices are respectively fixedly installed at both ends of the inner wall of the chamber, and the grooves opened in the two sets of fixing devices correspond to each other, so that the two ends of the test rod can be placed into the corresponding two grooves to fix the test rod. This avoids the rolling of the test rod during the infiltration layer preparation process and prevents the test rods from contacting or bumping against each other.

[0026] Based on the above technical solution, the present invention can be further improved as follows.

[0027] Furthermore, the corresponding grooves are fitted with clearances at both ends of the test bar.

[0028] The beneficial effect of adopting the above-mentioned further scheme is that the corresponding grooves fit with the end faces of both ends of the test rod with a clearance. This improves the coverage of the airflow on the test rod, ensures that the reaction atmosphere is effectively distributed to the surface of the test rod, reduces the difference in diffusion layer between the top and bottom areas of the test rod and along the length direction, and ensures the uniformity of the atmosphere during the formation of the aluminide diffusion layer on the test rod.

[0029] Based on the above technical solution, the present invention can be further improved as follows.

[0030] Furthermore, the fixing device is welded and fixed to the inner wall of the cavity.

[0031] The beneficial effects of adopting the above-mentioned further solution are that the fixing device is welded and fixed to the inner wall of the cavity, ensuring the stability of the fixing device and the stability of the test rod within the fixing device. This avoids the rolling of the test rod during the infiltration layer preparation process and prevents the test rods from contacting or bumping against each other.

[0032] Based on the above technical solution, the present invention can be further improved as follows.

[0033] Furthermore, the reaction chamber, air inlet device, fixing device, and air outlet device are all made of GH3044.

[0034] The beneficial effect of adopting the above-mentioned further scheme is that the material selected for the reaction chamber, air inlet device, fixing device, and air outlet device is GH3044. GH3044 is a solution-strengthened nickel-based anti-oxidation alloy with a solution treatment temperature of 1120-1160℃, and has excellent oxidation resistance and good stamping and welding process performance. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of a CVD airflow distribution device according to the present invention;

[0036] Figure 2 This is a partial structural schematic diagram of a CVD airflow distribution device according to the present invention;

[0037] Figure 3 This is a front sectional view of a CVD airflow distribution device according to the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the air outlet device and the inner wall of the cavity of the present invention.

[0039] The components represented by each number in the attached diagram are listed below: 110 - Reaction chamber; 112 - Inner wall of the chamber; 1121 - Through hole; 113 - Outer wall of the chamber; 1131 - Opening; 1133 - Internal thread; 130 - Air inlet device; 131 - Support; 133 - Air inlet pipe; 150 - Fixing device; 151 - Groove; 170 - Air outlet device; 171 - Air outlet hole; 173 - External thread. Detailed Implementation

[0040] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0041] Example 1

[0042] like Figure 1-4As shown, the reaction chamber 110 has an outer wall 113 and an inner wall 112. The inner wall 112 has a plurality of through holes 1121 evenly distributed. One end of the outer wall 113 is sealed, and the other end has an opening 1131. The outer wall 113 is fitted over the inner wall 112. The air inlet device 130 has a support 131 and an air inlet pipe 133. The support 131 is installed on the outer wall 113. One end of the air inlet pipe 133 passes through the support 131 and communicates with the outer wall 113. The fixing device 150 is installed on the inner wall 112. The end face of the fixing device 150 has a groove 151. The air outlet device 170 is installed at the opening 1131 of the outer wall 113. The air outlet device 170 has an air outlet hole 171.

[0043] Specifically, the test rod is placed on the fixing device 150 of the reaction chamber 110. The reaction atmosphere enters the outer wall 113 of the chamber through the air inlet device 130, and then flows to the surface of the test rod through the through hole 1121 of the inner wall 112 of the chamber to form a uniform permeation layer. Then, the uniformity and dispersion of the atmosphere at the outlet position are improved through the air outlet 171.

[0044] like Figure 1-4 As shown, the inner wall 112 of the cavity has multiple rows of through holes 1121, each row of through holes 1121 has multiple holes, and the arc angle of two adjacent rows of through holes 1121 on the inner wall 112 of the cavity is 36 degrees.

[0045] Specifically, in this embodiment, the through holes 1121 are rotatably opened around the axis of the inner wall 112 of the chamber, and the arc angle between two adjacent rows of through holes 1121 is 36 degrees. This ensures that the reaction atmosphere is evenly distributed on the surface of the test rod from one end to the other. To ensure the flow rate of the reaction atmosphere into the reaction chamber 110, the arc angle between two adjacent rows of through holes 1121 can be less than 36 degrees, or the diameter of the through holes 1121 can be increased.

[0046] like Figure 1-4 As shown, the diameter of the outer wall 113 of the cavity is larger than the diameter of the inner wall 112 of the cavity.

[0047] Specifically, the diameter of the outer wall 113 of the chamber is larger than the diameter of the inner wall 112 of the chamber. There is a gap between the outer wall 113 and the inner wall 112 of the chamber. After the reaction atmosphere enters the outer wall 113 of the chamber, it will be evenly dispersed on the outer wall 113 of the chamber. Then, it will flow through the through hole 1121 of the inner wall 112 of the chamber to the surface of the test rod to form a uniform infiltration layer.

[0048] like Figure 1-4 As shown, the outer wall 113 of the cavity is welded and fixed to the inner wall 112 of the cavity.

[0049] Specifically, the outer wall 113 of the cavity and the inner wall 112 of the cavity are integrally welded together, with the weld being 100% full weld.

[0050] like Figure 1-4 As shown, the opening 1131 is provided with an internal thread 1133, and the air outlet device 170 has an external thread 173 that is adapted to the internal thread. The air outlet device 170 is installed in conjunction with the outer wall 113 of the chamber.

[0051] Specifically, during use, the reaction chamber 110 is separated from the gas outlet device 170, and then both ends of the test rod are placed in the corresponding grooves 151 of the two sets of fixing devices 150. Then the reaction chamber 110 and the gas outlet device 170 are screwed together.

[0052] like Figure 1-4 As shown, the air outlet device 170 has three air outlets 171.

[0053] Specifically, the air outlet device 170 has three air outlets 171. The middle air outlet 171 allows the incoming airflow to converge from the through hole 1121 to the center, while the two side air outlets 171 ensure airflow dispersion. This ensures uniform airflow distribution. The three air outlets 171 are uniform in the upper, middle, and lower regions along the longitudinal direction, which guarantees the flow field of the airflow.

[0054] like Figure 1-4 As shown, the fixing device 150 has two sets, and each set of fixing devices 150 has multiple grooves 151 on its end face. The two sets of fixing devices 150 are respectively fixedly installed at both ends of the inner wall 112 of the cavity, and the grooves 151 of the two sets of fixing devices 150 correspond one-to-one.

[0055] Specifically, by placing the two sets of fixing devices 150 with the grooves 151 facing each other, the two ends of the test rod can be placed into the corresponding grooves 151.

[0056] like Figure 1-4 As shown, the corresponding grooves 151 are fitted with the end faces at both ends of the test bar with clearance.

[0057] Specifically, the groove 151 is clearance-fitted with the end faces of both ends of the test bar, which makes it easy to place both ends of the test bar into the corresponding groove 151, or to remove them from the groove 151.

[0058] like Figure 1-4 As shown, the fixing device 150 is welded and fixed to the inner wall 112 of the cavity.

[0059] Specifically, the fixing device 150 is welded and fixed to the inner wall 112 of the cavity to ensure the stability of the fixing device 150 and the stability of the test rod within the fixing device 150. This prevents the test rod from rolling during the infiltration layer preparation process and prevents the test rods from contacting or bumping against each other.

[0060] like Figure 1-4As shown, the materials of the reaction chamber 110, the air inlet device 130, the fixing device 150 and the air outlet device 170 are all GH3044.

[0061] Specifically, GH3044 is a solution-strengthened nickel-based anti-oxidation alloy with a solution treatment temperature of 1120-1160℃. It has excellent oxidation resistance and good stamping and welding process performance.

[0062] The beneficial effects of this embodiment are as follows: the test rod is placed on the fixing device 150 of the reaction chamber 110 and fixed. This avoids the test rod rolling during the diffusion layer preparation process and prevents the test rods from contacting or bumping against each other. By uniformly distributing the airflow of the reaction atmosphere during the formation of the aluminide diffusion layer using chemical vapor deposition (CVD), the reaction atmosphere enters the outer wall 113 of the chamber through the air inlet device 130, and then flows to the surface of the test rod through the through holes 1121 of the inner wall 112 of the chamber to form a uniform diffusion layer. Because small holes are uniformly arranged radially on the inner wall 112 of the chamber, the reaction atmosphere is uniformly distributed from one end of the test rod to the other side of the test rod surface, ensuring that the reaction atmosphere is effectively distributed to the surface of the test rod, reducing the difference in diffusion layer between the top and bottom areas of the test rod and in the length direction, and ensuring the uniformity of the atmosphere during the formation of the aluminide diffusion layer on the test rod. Meanwhile, the three air outlets 171 of the air outlet device 170 allow the incoming airflow to converge from the through hole 1121 towards the center, thereby increasing the coverage of the test bar by the airflow. The two side air outlets 171 ensure airflow dispersion and, when placed between the three test bars, improve atmosphere uniformity. Ensuring uniform airflow distribution, the three air outlets 171 are uniform in the upper, middle, and lower regions along the longitudinal direction, thus guaranteeing the flow field of the airflow.

[0063] The working process of this embodiment is as follows: The gas outlet device 170 and the reaction chamber 110 are separated. The test rod is placed on the fixing device 150 of the reaction chamber 110. Then, the gas outlet device 170 and the reaction chamber 110 are tightened and fixed by threaded connection. The reaction atmosphere enters the outer wall 113 of the chamber through the gas inlet pipe 133 and is evenly dispersed on the outer wall 113. Then, it flows through the through hole 1121 of the inner wall 112 of the chamber to the surface of the test rod to form a uniform permeation layer. Then, when the airflow is too large, the airflow is dispersed through the gas outlet hole 171.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0065] 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 at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0066] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0068] 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] 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 CVD airflow distribution device, characterized in that, The device includes a reaction chamber (110), an air inlet device (130), a fixing device (150), and an air outlet device (170). The reaction chamber (110) has an outer wall (113) and an inner wall (112). The inner wall (112) has a plurality of through holes (1121) evenly distributed on it. One end of the outer wall (113) is sealed, and the other end has an opening (1131). The outer wall (113) is fitted over the inner wall (112). The air inlet device (130) has a support (131) and... An air inlet pipe (133) is provided. The support (131) is installed on the outer wall of the cavity (113). One end of the air inlet pipe (133) passes through the support (131) and communicates with the outer wall of the cavity (113). The fixing device (150) is installed in the inner wall of the cavity (112). The end face of the fixing device (150) is provided with a groove (151). The air outlet device (170) is installed at the opening (1131) of the outer wall of the cavity (113). The air outlet device (170) is provided with an air outlet hole (171). The opening (1131) is provided with an internal thread (1133), and the air outlet device (170) has an external thread (173) that is adapted to the internal thread (1133). The air outlet device (170) is installed in conjunction with the outer wall (113) of the cavity. The air outlet device (170) has three air outlet holes (171). The fixing device (150) has two sets, and each set of the fixing device (150) has multiple grooves (151) on its end face. The two sets of fixing devices (150) are respectively fixedly installed at both ends of the inner wall (112) of the cavity, and the grooves (151) of the two sets of fixing devices (150) correspond one-to-one; the corresponding grooves (151) are clearance-fitted with the end faces of both ends of the test rod. The inner wall of the cavity (112) has multiple rows of through holes (1121), each row of through holes (1121) has multiple holes, and the arc angle of two adjacent rows of through holes (1121) on the inner wall of the cavity (112) is 36 degrees.

2. The CVD airflow distribution device according to claim 1, characterized in that, The diameter of the outer wall (113) of the cavity is larger than the diameter of the inner wall (112) of the cavity.

3. The CVD airflow distribution device according to claim 2, characterized in that, The outer wall of the cavity (113) is welded and fixed to the inner wall of the cavity (112).

4. The CVD airflow distribution device according to claim 1, characterized in that, The fixing device (150) is welded and fixed to the inner wall (112) of the cavity.

5. A CVD airflow distribution device according to claim 1, characterized in that, The reaction chamber (110), the air inlet device (130), the fixing device (150), and the air outlet device (170) are all made of GH3044.

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