A diffusion welding method for a heterogeneous metal composite stamping micro-channel reactor

Abstract

The application discloses a heterogeneous metal composite stamping micro-channel reactor diffusion welding method and relates to the technical field of chemical reaction engineering, and comprises the following steps: S1, stainless steel reaction channel structure preparation; S2, stamping die processing and specific metal sheet stamping; S3, channel diffusion welding; S4, post-processing and inspection; the stamping die processing and specific metal sheet stamping comprise the following steps: one, stamping die processing; two, specific metal sheet stamping. The application processes the reaction channel structure by adopting 304 stainless steel which has excellent diffusion welding performance and is low in price, then stamps the specific nickel-based high-temperature alloy sheet into the stainless steel reaction channel by using the stamping die, diffuses and welds the nickel-based high-temperature alloy sheet after stamping and the stainless steel reaction channel, thereby guaranteeing the welding quality, improving the welding qualified rate, simultaneously reducing the production cost of the micro-channel reactor and being suitable for various complex chemical reaction processes.

Description

Technical Field

[0001] This invention relates to the field of chemical reaction engineering technology, specifically to a diffusion welding method for a dissimilar metal composite stamped microchannel reactor. Background Technology

[0002] A microchannel reactor is a device that utilizes micron-level channels for chemical reactions. Its internal structure is mainly composed of micron-level channels. It has wide applications in the chemical industry, such as in the preparation of gas mixtures in the production processes of ammonia, chlorine, and formaldehyde. Diffusion welding technology is the optimal technical method for manufacturing microchannel reactors. Since microchannel reactors are used as components in chemical reactions, certain specific metal materials are required to manufacture them in some specific chemical reaction processes, depending on the characteristics of the reactants. However, the required specific metals are often expensive, have poor diffusion welding performance, or are even impossible to weld. Therefore, it is necessary to design a microchannel reactor that can guarantee welding quality and has low production costs.

[0003] The drawbacks of diffusion welding in existing microchannel reactor technologies are:

[0004] 1. Patent document KR1020140129114A discloses a method for operating a microchannel reactor and a microchannel reactor. However, the microchannel reactor has the problems of high manufacturing cost, poor diffusion welding performance or even inability to weld, and low welding quality and welding qualification rate.

[0005] 2. Patent document CN116808972A discloses a microchannel reactor and method. However, the microchannel reactor cannot maintain stable performance under high temperature, high pressure or corrosive environment, and cannot meet the requirements of a variety of complex chemical reaction processes, thus limiting its applicability.

[0006] 3. Patent document CN115533382A discloses a pre-welding treatment device for aluminum alloy microchannel heat exchangers and its diffusion welding method. This pre-welding treatment device for microchannel heat exchangers is not conducive to optimizing reaction conditions, has low reaction selectivity and product purity, and lacks scalability of diffusion welding technology, making it unable to meet the manufacturing needs of microchannel reactors of different scales and complexities.

[0007] 4. Patent document CN116689932B discloses a diffusion welding method and welding product for a microchannel heat exchanger. When the microchannel heat exchanger is used, the flow and mixing speed of the reactants in it is slow and not uniform enough, resulting in poor efficiency of heat and mass transfer, which is not conducive to achieving more precise temperature control and temperature distribution, and low production efficiency. Summary of the Invention

[0008] The purpose of this invention is to provide a diffusion welding method for a dissimilar metal composite stamped microchannel reactor to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a diffusion welding method for a dissimilar metal composite stamped microchannel reactor, comprising the following steps: S1, preparation of a stainless steel reaction channel structure; S2, processing of stamping die and stamping of a specific metal sheet; S3, diffusion welding of the channel; S4, post-processing and inspection;

[0010] The stamping die processing and specific metal sheet stamping include the following steps: 1. Stamping die processing; 2. Specific metal sheet stamping.

[0011] Preferably, the preparation of the stainless steel reaction channel structure includes the following steps: 1. Preparation of stainless steel plate; 2. Cutting and post-processing; 3. Flow channel processing; 4. Preliminary inspection.

[0012] Preferably, the preparation steps of the stainless steel reaction channel structure are as follows: Step 1: Stainless steel plate preparation: Select 304 stainless steel for cleaning and cutting. According to the design requirements, use a precision scribing machine to scribing the flow channel lines on the 304 stainless steel plate. When scribing, it is necessary to control the scribing depth and the uniformity of the lines to ensure the quality of the flow channel; Step 2: Cutting and post-processing: Grind and polish the cut 304 stainless steel plate to remove burrs and unevenness from the cut edges. Use a cleaning agent to clean the ground and polished 304 stainless steel plate to remove surface dirt and impurities. Dry it with a dryer. The drying temperature is controlled at 110℃ and the drying time is 20 minutes; Step 3: Flow channel processing: Process the flow channel on the cleaned quartz glass. According to the scribed flow channel lines, use a laser cutting device to cut the 304 stainless steel plate into the required shape and size, controlling the shape, size and depth of the flow channel; Step 4: Preliminary inspection: Inspect the processed stainless steel reaction channel structure to check whether the shape and size of the flow channel meet the design requirements, and at the same time check the surface smoothness and transparency and other quality indicators.

[0013] Preferably, the stamping die processing steps are as follows: Based on the stainless steel reaction channel structure, CAD technology is used to design and analyze the stamping die to ensure its accuracy and reliability. 3D printing technology is used to quickly manufacture the die, with the die shrinkage rate controlled at 1%–3% and the machining allowance controlled at 5–10 mm. Wax molds and shells are prepared sequentially. After dewaxing, pure iron blocks and refined carbon-nickel alloys are selected for melting and pouring. After the molten metal solidifies, the casting is removed from the shell. The flow rate and temperature of the cooling air are controlled to ensure uniform heating of the casting throughout the cooling process. After natural cooling, a grinding machine is used to remove the casting gate and riser. Mechanical and chemical cleaning are used to clean the surface of the casting to remove sand, paint, oxides, oil, and other impurities, thus obtaining the stamping die.

[0014] Preferably, the specific metal sheet stamping further includes the following steps: Step 1: Metal sheet pretreatment: The nickel-based high-temperature alloy is cleaned with pickling solution to remove grease, oxides and other contaminants from the surface. The cleaned nickel-based high-temperature alloy surface is clean and free of impurities. The cleaned nickel-based high-temperature alloy is dried in a vacuum drying oven to remove surface moisture. The drying temperature is 80°C and the drying time is 3 minutes. Step 2: Metal sheet stamping: The pretreated nickel-based high-temperature alloy sheet is placed in a stamping die. The nickel-based high-temperature alloy sheet is stamped into the stainless steel reaction channel by the pressure of the stamping machine and the precise fit of the die, forming a tight physical contact.

[0015] Preferably, the thickness of the nickel-based high-temperature alloy sheet is 0.2 to 0.5 mm.

[0016] Preferably, the diffusion welding steps are as follows: Step 1: Diffusion welding: The nickel-based high-temperature alloy sheet and the stainless steel reaction channel structure are pressed together and placed in a vacuum diffusion welding furnace. The furnace door is closed and sealed. The vacuum diffusion welding furnace is turned on, and the diffusion welding temperature is controlled at 900-1200℃ and the pressure is controlled at 4.9-9.8MPa. Plastic deformation and high-temperature creep occur at the microscopic protrusions on the surface to achieve close contact. The atoms at the interface of the two undergo mutual diffusion to form a metallurgical bond, thereby realizing diffusion welding; Step 2: Continuous reaction and cooling: The diffusion welding time is controlled at 10-15 minutes. The contact area is further expanded through mutual diffusion of atoms, so that the surface layer molecules penetrate and fuse with each other. The entire connection interface forms a metal bond during the diffusion welding process. The material is slowly cooled to room temperature, allowing the weld between the nickel-based high-temperature alloy sheet and the stainless steel reaction channel structure to cool and solidify.

[0017] Preferably, the post-processing and inspection steps are as follows: the prepared dissimilar metal microchannel reactor is inspected to ensure that its surface quality and performance meet the requirements; the weld joints of the dissimilar metal microchannel reactor are ground and polished to remove burrs and unevenness at the weld edges; and the ground and polished dissimilar metal microchannel reactor is subjected to post-processing such as washing, drying, and heat treatment to remove residual reagents and residues.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. This invention utilizes 304 stainless steel, which boasts excellent diffusion welding performance and low cost, to fabricate the reaction channel structure. Then, a specific nickel-based high-temperature alloy sheet is stamped into the stainless steel reaction channel using a stamping die. During use, the portion of the microchannel reactor in contact with the reactants is the nickel-based high-temperature alloy sheet. Diffusion welding the stamped nickel-based high-temperature alloy sheet to the stainless steel reaction channel not only ensures welding quality and improves the welding pass rate but also reduces the production cost of the microchannel reactor. This combination allows the microchannel reactor to maintain stable performance even under high temperature, high pressure, or corrosive environments, making it suitable for various complex chemical reaction processes.

[0020] 2. This invention, through the use of stamping dies, allows for precise control of the size and shape of microchannels, ensuring the accuracy and consistency of the microchannel reactor. This helps optimize reaction conditions, improve reaction selectivity and product purity. The diffusion welding technology has good scalability, adapting to the manufacturing needs of microchannel reactors of different sizes and complexities. Due to the fast welding speed and small heat-affected zone during diffusion welding, energy can be saved and production costs reduced. The microchannel reactor, with its tiny channel size, allows for faster and more uniform flow and mixing of reactants, greatly enhancing the efficiency of heat and mass transfer. This helps achieve more precise temperature control and temperature distribution, thereby increasing yield. Attached Figure Description

[0021] Figure 1 This is a flow chart of the diffusion welding process for the microchannel reactor of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., 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 for 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. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection or a movable connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Example 1, an embodiment of the present invention: a diffusion welding method for a dissimilar metal composite stamped microchannel reactor, comprising the following steps: S1, preparation of stainless steel reaction channel structure; S2, processing of stamping die and stamping of specific metal sheet; S3, diffusion welding of channel; S4, post-processing and inspection;

[0026] The fabrication of the stainless steel reaction channel structure includes the following steps: 1. Stainless steel plate preparation: Select 304 stainless steel for cleaning and cutting. Use a precision scribing machine to etch flow channel lines onto the 304 stainless steel plate according to design requirements. During scribing, control the depth and uniformity of the lines to ensure the quality of the flow channel. 2. Cutting and post-processing: Grind and polish the cut 304 stainless steel plate to remove burrs and unevenness from the cut edges. Clean the ground and polished 304 stainless steel plate with a cleaning agent to remove surface dirt and impurities. Dry it in a dryer at 110℃ for 20 minutes. 3. Flow channel processing: Process the flow channel on the cleaned quartz glass. Use laser cutting equipment to cut the 304 stainless steel plate into the required shape and size according to the etched flow channel lines, controlling the shape, size, and depth of the flow channel. 4. Preliminary inspection: Inspect the processed stainless steel reaction channel structure to check whether the shape and size of the flow channel meet the design requirements. Also check quality indicators such as surface smoothness and transparency.

[0027] Stamping die processing and stamping of specific metal sheets include the following steps:

[0028] I. Stamping Die Processing: Based on the stainless steel reaction flow channel structure, CAD technology is used to design and analyze the stamping die to ensure its accuracy and reliability. 3D printing technology is used to quickly manufacture the die. The die shrinkage rate is controlled within 3%, and the machining allowance is controlled within 5mm. Wax pattern and shell are prepared in sequence. After dewaxing, pure metal iron blocks and refined carbon-nickel alloys are selected for melting and pouring. After the molten metal solidifies, the casting is removed from the shell. The flow rate and temperature of the cooling air are controlled to ensure that the casting is heated evenly throughout the cooling process. After natural cooling, the gate and riser of the casting are removed using a grinding machine. The sand, paint, oxides, oil and other impurities on the surface of the casting are cleaned by mechanical cleaning and chemical cleaning to obtain the stamping die.

[0029] II. Stamping of Specific Metal Sheets:

[0030] Metal sheet pretreatment: The nickel-based superalloy is cleaned with pickling solution to remove grease, oxides and other contaminants from the surface. The cleaned nickel-based superalloy surface is clean and free of impurities. The cleaned nickel-based superalloy is dried in a vacuum drying oven to remove surface moisture. The drying temperature is 80℃ and the drying time is 3 minutes.

[0031] Metal sheet stamping: The pre-treated nickel-based high-temperature alloy sheet is placed into the stamping die. Through the pressure of the stamping machine and the precise fit of the die, the nickel-based high-temperature alloy sheet is stamped into the stainless steel reaction channel to form a tight physical contact.

[0032] The thickness of the nickel-based high-temperature alloy sheet is 0.4 mm;

[0033] The diffusion welding process is as follows: 1. Diffusion welding: The nickel-based superalloy sheet and the stainless steel reaction channel structure are pressed together and placed in a vacuum diffusion welding furnace. The furnace door is closed and sealed. The vacuum diffusion welding furnace is then turned on. The diffusion welding temperature is controlled at 1200℃ and the pressure is controlled at 4.9MPa. Plastic deformation and high-temperature creep occur at the microscopic protrusions on the surface, resulting in close contact. The atoms at the interface of the two materials diffuse into each other to form a metallurgical bond, thus achieving diffusion welding. 2. Continuous reaction and cooling: The diffusion welding time is controlled at 15 minutes. The contact area further expands through atomic diffusion, allowing the surface layer molecules to penetrate and fuse with each other. The entire connection interface forms a metallic bond during the diffusion welding process. The material is then slowly cooled to room temperature, allowing the weld between the nickel-based superalloy sheet and the stainless steel reaction channel structure to cool and solidify.

[0034] The post-processing and inspection steps are as follows: The prepared dissimilar metal microchannel reactor is inspected to ensure that its surface quality and performance meet the requirements. The weld joints of the dissimilar metal microchannel reactor are ground and polished to remove burrs and unevenness at the weld edges. The dissimilar metal microchannel reactor after grinding and polishing is washed, dried, and heat-treated to remove residual reagents and residues.

[0035] Example 2, an embodiment of the present invention: a diffusion welding method for a dissimilar metal composite stamped microchannel reactor, comprising the following steps: S1, preparation of stainless steel reaction channel structure; S2, processing of stamping die and stamping of specific metal sheet; S3, diffusion welding of channel; S4, post-processing and inspection;

[0036] The fabrication of the stainless steel reaction channel structure includes the following steps: 1. Stainless steel plate preparation: Select 304 stainless steel for cleaning and cutting. Use a precision scribing machine to etch flow channel lines onto the 304 stainless steel plate according to design requirements. During scribing, control the depth and uniformity of the lines to ensure the quality of the flow channel. 2. Cutting and post-processing: Grind and polish the cut 304 stainless steel plate to remove burrs and unevenness from the cut edges. Clean the ground and polished 304 stainless steel plate with a cleaning agent to remove surface dirt and impurities. Dry it in a dryer at 110℃ for 20 minutes. 3. Flow channel processing: Process the flow channel on the cleaned quartz glass. Use laser cutting equipment to cut the 304 stainless steel plate into the required shape and size according to the etched flow channel lines, controlling the shape, size, and depth of the flow channel. 4. Preliminary inspection: Inspect the processed stainless steel reaction channel structure to check whether the shape and size of the flow channel meet the design requirements. Also check quality indicators such as surface smoothness and transparency.

[0037] Stamping die processing and stamping of specific metal sheets include the following steps:

[0038] I. Stamping Die Processing: Based on the stainless steel reaction flow channel structure, CAD technology is used to design and analyze the stamping die to ensure its accuracy and reliability. 3D printing technology is used to quickly manufacture the die. The die shrinkage rate is controlled within 3%, and the machining allowance is controlled within 5mm. Wax pattern and shell are prepared in sequence. After dewaxing, pure metal iron blocks and refined carbon-nickel alloys are selected for melting and pouring. After the molten metal solidifies, the casting is removed from the shell. The flow rate and temperature of the cooling air are controlled to ensure that the casting is heated evenly throughout the cooling process. After natural cooling, the gate and riser of the casting are removed using a grinding machine. The sand, paint, oxides, oil and other impurities on the surface of the casting are cleaned by mechanical cleaning and chemical cleaning to obtain the stamping die.

[0039] II. Stamping of Specific Metal Sheets:

[0040] Metal sheet pretreatment: The nickel-based superalloy is cleaned with pickling solution to remove grease, oxides and other contaminants from the surface. The cleaned nickel-based superalloy surface is clean and free of impurities. The cleaned nickel-based superalloy is dried in a vacuum drying oven to remove surface moisture. The drying temperature is 80℃ and the drying time is 3 minutes.

[0041] Metal sheet stamping: The pre-treated nickel-based high-temperature alloy sheet is placed into the stamping die. Through the pressure of the stamping machine and the precise fit of the die, the nickel-based high-temperature alloy sheet is stamped into the stainless steel reaction channel to form a tight physical contact.

[0042] The thickness of the nickel-based high-temperature alloy sheet is 0.2 mm;

[0043] The diffusion welding process is as follows: 1. Diffusion welding: The nickel-based superalloy sheet and the stainless steel reaction channel structure are pressed together and placed in a vacuum diffusion welding furnace. The furnace door is closed and sealed. The vacuum diffusion welding furnace is then turned on. The diffusion welding temperature is controlled at 1200℃ and the pressure is controlled at 4.9MPa. Plastic deformation and high-temperature creep occur at the microscopic protrusions on the surface, resulting in close contact. The atoms at the interface of the two materials diffuse into each other to form a metallurgical bond, thus achieving diffusion welding. 2. Continuous reaction and cooling: The diffusion welding time is controlled at 15 minutes. The contact area further expands through atomic diffusion, allowing the surface layer molecules to penetrate and fuse with each other. The entire connection interface forms a metallic bond during the diffusion welding process. The material is then slowly cooled to room temperature, allowing the weld between the nickel-based superalloy sheet and the stainless steel reaction channel structure to cool and solidify.

[0044] The post-processing and inspection steps are as follows: The prepared dissimilar metal microchannel reactor is inspected to ensure that its surface quality and performance meet the requirements. The weld joints of the dissimilar metal microchannel reactor are ground and polished to remove burrs and unevenness at the weld edges. The dissimilar metal microchannel reactor after grinding and polishing is washed, dried, and heat-treated to remove residual reagents and residues.

[0045] Example 3, an embodiment of the present invention: a diffusion welding method for a dissimilar metal composite stamped microchannel reactor, comprising the following steps: S1, preparation of stainless steel reaction channel structure; S2, channel diffusion welding; S3, post-processing and inspection;

[0046] The fabrication of the stainless steel reaction channel structure includes the following steps: 1. Stainless steel plate preparation: Select 304 stainless steel for cleaning and cutting. Use a precision scribing machine to etch flow channel lines onto the 304 stainless steel plate according to design requirements. During scribing, control the depth and uniformity of the lines to ensure the quality of the flow channel. 2. Cutting and post-processing: Grind and polish the cut 304 stainless steel plate to remove burrs and unevenness from the cut edges. Clean the ground and polished 304 stainless steel plate with a cleaning agent to remove surface dirt and impurities. Dry it in a dryer at 110℃ for 20 minutes. 3. Flow channel processing: Process the flow channel on the cleaned quartz glass. Use laser cutting equipment to cut the 304 stainless steel plate into the required shape and size according to the etched flow channel lines, controlling the shape, size, and depth of the flow channel. 4. Preliminary inspection: Inspect the processed stainless steel reaction channel structure to check whether the shape and size of the flow channel meet the design requirements. Also check quality indicators such as surface smoothness and transparency.

[0047] The thickness of the nickel-based high-temperature alloy sheet is 0.2 mm;

[0048] The diffusion welding process is as follows: 1. Diffusion welding: The nickel-based superalloy sheet and the stainless steel reaction channel structure are pressed together and placed in a vacuum diffusion welding furnace. The furnace door is closed and sealed. The vacuum diffusion welding furnace is then turned on. The diffusion welding temperature is controlled at 1200℃ and the pressure is controlled at 4.9MPa. Plastic deformation and high-temperature creep occur at the microscopic protrusions on the surface, resulting in close contact. The atoms at the interface of the two materials diffuse into each other to form a metallurgical bond, thus achieving diffusion welding. 2. Continuous reaction and cooling: The diffusion welding time is controlled at 15 minutes. The contact area further expands through atomic diffusion, allowing the surface layer molecules to penetrate and fuse with each other. The entire connection interface forms a metallic bond during the diffusion welding process. The material is then slowly cooled to room temperature, allowing the weld between the nickel-based superalloy sheet and the stainless steel reaction channel structure to cool and solidify.

[0049] The post-processing and inspection steps are as follows: The prepared dissimilar metal microchannel reactor is inspected to ensure that its surface quality and performance meet the requirements. The weld joints of the dissimilar metal microchannel reactor are ground and polished to remove burrs and unevenness at the weld edges. The dissimilar metal microchannel reactor after grinding and polishing is washed, dried, and heat-treated to remove residual reagents and residues.

[0050] Comparative Example 1, the present invention provides a comparative example comprising the following steps: S1, preparation of a stainless steel reaction channel structure; S2, processing of a stamping die and stamping of a specific metal sheet; S3, channel diffusion welding; S4, post-processing and inspection;

[0051] The fabrication of the stainless steel reaction channel structure includes the following steps: 1. Aluminum alloy plate preparation: Select an aluminum alloy plate for cleaning and cutting. Use a precision scribing machine to etch the flow channel lines onto the aluminum alloy plate according to design requirements. During scribing, control the depth and uniformity of the lines to ensure the quality of the flow channel. 2. Cutting and post-processing: Grind and polish the cut aluminum alloy plate to remove burrs and unevenness from the cut edges. Clean the ground and polished aluminum alloy plate with a cleaning agent to remove surface dirt and impurities. Dry it in a dryer at 110℃ for 20 minutes. 3. Flow channel processing: Process the flow channel on the cleaned quartz glass. Use laser cutting equipment to cut the aluminum alloy plate into the required shape and size according to the etched flow channel lines, controlling the shape, size, and depth of the flow channel. 4. Preliminary inspection: Inspect the processed aluminum alloy reaction channel structure to check whether the shape and size of the flow channel meet the design requirements. Also check quality indicators such as surface smoothness and transparency.

[0052] Stamping die processing and stamping of specific metal sheets include the following steps:

[0053] I. Stamping Die Processing: Based on the aluminum alloy reaction flow channel structure, CAD technology is used to design and analyze the stamping die to ensure its accuracy and reliability. 3D printing technology is used to quickly manufacture the die. The die shrinkage rate is controlled within 3%, and the machining allowance is controlled within 5mm. Wax pattern and shell are prepared in sequence. After dewaxing, pure metal iron blocks and refined carbon-nickel alloy are selected for melting and pouring. After the molten metal solidifies, the casting is removed from the shell. The flow rate and temperature of the cooling air are controlled to ensure that the casting is heated evenly throughout the cooling process. After natural cooling, the gate and riser of the casting are removed using a grinding machine. The sand, paint, oxides, oil and other impurities on the surface of the casting are cleaned by mechanical cleaning and chemical cleaning to obtain the stamping die.

[0054] II. Stamping of Specific Metal Sheets:

[0055] Metal sheet pretreatment: The nickel-based superalloy is cleaned with pickling solution to remove grease, oxides and other contaminants from the surface. The cleaned nickel-based superalloy surface is clean and free of impurities. The cleaned nickel-based superalloy is dried in a vacuum drying oven to remove surface moisture. The drying temperature is 80℃ and the drying time is 3 minutes.

[0056] Metal sheet stamping: The pre-treated nickel-based high-temperature alloy sheet is placed into the stamping die. Through the pressure of the stamping machine and the precise fit of the die, the nickel-based high-temperature alloy sheet is stamped into the stainless steel reaction channel to form a tight physical contact.

[0057] The thickness of the nickel-based high-temperature alloy sheet is 0.2 mm;

[0058] The diffusion welding process is as follows: 1. Diffusion welding: The nickel-based superalloy sheet and the aluminum alloy reaction channel structure are pressed together and placed in a vacuum diffusion welding furnace. The furnace door is closed and sealed. The vacuum diffusion welding furnace is then turned on. The diffusion welding temperature is controlled at 1200℃ and the pressure is controlled at 4.9MPa. Plastic deformation and high-temperature creep occur at the microscopic protrusions on the surface, resulting in close contact. The atoms at the interface of the two materials diffuse into each other to form a metallurgical bond, thus achieving diffusion welding. 2. Continuous reaction and cooling: The diffusion welding time is controlled at 15 minutes. The contact area further expands through atomic diffusion, allowing the surface layer molecules to penetrate and fuse with each other. The entire connection interface forms a metallic bond during the diffusion welding process. The material is then slowly cooled to room temperature, allowing the weld between the nickel-based superalloy sheet and the aluminum alloy reaction channel structure to cool and solidify.

[0059] The post-processing and inspection steps are as follows: The prepared dissimilar metal microchannel reactor is inspected to ensure that its surface quality and performance meet the requirements. The weld joints of the dissimilar metal microchannel reactor are ground and polished to remove burrs and unevenness at the weld edges. The dissimilar metal microchannel reactor after grinding and polishing is washed, dried, and heat-treated to remove residual reagents and residues.

[0060] Comparative Example 2, a comparative example provided by the present invention, includes the following steps: S1, preparation of a stainless steel reaction channel structure; S2, channel diffusion welding; S3, post-processing and inspection;

[0061] The fabrication of the stainless steel reaction channel structure includes the following steps: 1. Aluminum alloy plate preparation: Select an aluminum alloy plate for cleaning and cutting. Use a precision scribing machine to etch the flow channel lines onto the aluminum alloy plate according to design requirements. During scribing, control the depth and uniformity of the lines to ensure the quality of the flow channel. 2. Cutting and post-processing: Grind and polish the cut aluminum alloy plate to remove burrs and unevenness from the cut edges. Clean the ground and polished aluminum alloy plate with a cleaning agent to remove surface dirt and impurities. Dry it in a dryer at 110℃ for 20 minutes. 3. Flow channel processing: Process the flow channel on the cleaned quartz glass. Use laser cutting equipment to cut the aluminum alloy plate into the required shape and size according to the etched flow channel lines, controlling the shape, size, and depth of the flow channel. 4. Preliminary inspection: Inspect the processed aluminum alloy reaction channel structure to check whether the shape and size of the flow channel meet the design requirements. Also check quality indicators such as surface smoothness and transparency.

[0062] The thickness of the nickel-based high-temperature alloy sheet is 0.2 mm;

[0063] The diffusion welding process is as follows: 1. Diffusion welding: The nickel-based superalloy sheet and the aluminum alloy reaction channel structure are pressed together and placed in a vacuum diffusion welding furnace. The furnace door is closed and sealed. The vacuum diffusion welding furnace is then turned on. The diffusion welding temperature is controlled at 1200℃ and the pressure is controlled at 4.9MPa. Plastic deformation and high-temperature creep occur at the microscopic protrusions on the surface, resulting in close contact. The atoms at the interface of the two materials diffuse into each other to form a metallurgical bond, thus achieving diffusion welding. 2. Continuous reaction and cooling: The diffusion welding time is controlled at 15 minutes. The contact area further expands through atomic diffusion, allowing the surface layer molecules to penetrate and fuse with each other. The entire connection interface forms a metallic bond during the diffusion welding process. The material is then slowly cooled to room temperature, allowing the weld between the nickel-based superalloy sheet and the aluminum alloy reaction channel structure to cool and solidify.

[0064] The post-processing and inspection steps are as follows: The prepared dissimilar metal microchannel reactor is inspected to ensure that its surface quality and performance meet the requirements. The weld joints of the dissimilar metal microchannel reactor are ground and polished to remove burrs and unevenness at the weld edges. The dissimilar metal microchannel reactor after grinding and polishing is washed, dried, and heat-treated to remove residual reagents and residues.

[0065] Performance testing:

[0066] 1. Welding qualification rate inspection: The quality of diffusion welding is intuitively judged by tensile strength value and metallographic structure results, and the corresponding welding qualification rate is calculated based on the welding quality.

[0067] 2. Product purity: Gas chromatography is used to separate the components in the product by chromatography and measure their content to determine the purity of the product. It has high resolution and sensitivity and can detect trace impurities, thus realizing the detection of product purity.

[0068] 3. High-temperature stability: Using an infrared thermometer to monitor the temperature in the microchannel reactor in real time can ensure that the reaction takes place within a suitable temperature range and observe whether there are any temperature anomalies or fluctuations in the reactor under high-temperature conditions. Pressure changes inside the microchannel reactor are continuously monitored by a pressure sensor, as high temperatures may cause the internal pressure of the reactor to rise.

[0069] The test data for each embodiment under the same test conditions are shown in Table 1.

[0070] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 reactor material 304 stainless steel 304 stainless steel 304 stainless steel aluminum alloy aluminum alloy Specific metals Nickel-based superalloy Nickel-based superalloy Nickel-based superalloy Nickel-based superalloy Nickel-based superalloy Die stamping yes yes no yes no Welding pass rate % 95 95 75 85 60 Product purity % 85 80 60 62 40 Performance at high temperatures Stablize Stablize Unstable Stablize Unstable

[0071] Table 1

[0072] As shown in Table 1, the microchannel reactor produced by using 304 stainless steel, which has excellent diffusion welding performance and low cost, to process the reaction channel structure and then using a stamping die to press a specific nickel-based high-temperature alloy sheet into the stainless steel reaction channel has better welding quality. Compared with Example 3 and Comparative Example 2, which did not use a stamping die, the welding qualification rate was significantly improved, and the production cost of the microchannel reactor was reduced. The microchannel reactor in Comparative Example 1 can still maintain stable performance under high temperature and high pressure environment, and is suitable for a variety of complex chemical reaction processes, with higher reaction selectivity and product purity.

[0073] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method of diffusion bonding a dissimilar metal composite stamped microchannel reactor, characterized by: It comprises the following steps; S1, stainless steel reaction channel structure preparation; S2, stamping die processing and specific metal sheet stamping; S3, channel diffusion welding; S4, post-processing and inspection; The stamping die processing and specific metal sheet stamping comprises the following steps: one, stamping die processing; two, specific metal sheet stamping; The stamping die processing step is as follows: according to the stainless steel reaction runner structure, CAD technology is used for stamping die design and analysis to ensure the accuracy and reliability of the die, 3D printing technology is used to quickly manufacture the die, the die shrinkage rate is controlled at 1%~3%, the machining allowance is controlled at 5~10mm, wax mold and shell preparation are carried out in turn, after dewaxing treatment, pure metal iron block and refined carbon nickel alloy are selected for melting and pouring, after the metal liquid solidifies, the casting is taken out from the shell, the flow rate and temperature of the cooling air are controlled to ensure that the casting is uniformly heated during the whole cooling process, after natural cooling, the casting sprue and riser are removed using a grinding machine, the sand particles, paint, oxides, oil stains and impurities on the surface of the casting are cleaned through mechanical cleaning and chemical cleaning to obtain the stamping die; The specific metal sheet stamping further comprises the following steps: step (1) metal sheet pretreatment: using pickling solution to clean the nickel-based high-temperature alloy to remove the surface grease, oxides and other pollution impurities, the cleaned nickel-based high-temperature alloy surface is clean and impurity-free, a vacuum drying oven is used to dry the cleaned nickel-based high-temperature alloy to remove the surface moisture, the drying temperature is 80℃, and the drying time is 3min; step (2) metal sheet stamping: the pretreated nickel-based high-temperature alloy sheet is put into the stamping die, the nickel-based high-temperature alloy sheet is stamped into the stainless steel reaction channel through the pressure of the stamping machine and the accurate cooperation of the die to form a close physical contact; The channel diffusion welding step is as follows: step (1) diffusion welding: the nickel-based high-temperature alloy sheet and the stainless steel reaction channel structure are tightly pressed together and placed in a vacuum diffusion welding furnace, the furnace door is closed and sealed, the vacuum diffusion welding furnace is started, the diffusion welding temperature is controlled at 900~1200℃, the pressure is controlled at 4.9~9.8MPa, plastic deformation and high temperature creep occur at the surface micro convex position to achieve close contact, atoms at the contact interface of the two occur mutual diffusion to form metallurgical bonding to realize diffusion welding; step (2) continuous reaction and cooling: the diffusion welding time is controlled at 10~15min, the contact area is further expanded through mutual atomic diffusion, the surface layer molecules penetrate and fuse with each other, the whole connection interface forms a metal bond, and the diffusion welding process is completed, slow cooling makes it cool to room temperature naturally, and the nickel-based high-temperature alloy sheet and the stainless steel reaction channel structure are cooled and shaped at the welding position.

2. A method of diffusion bonding a dissimilar metal composite stamped microchannel reactor according to claim 1, wherein: The stainless steel reaction channel structure preparation comprises the following steps: one, stainless steel plate preparation; two, cutting and post-processing; three, runner processing; four, preliminary inspection.

3. A method of diffusion bonding a dissimilar metal composite stamped microchannel reactor according to claim 2, wherein: The stainless steel reaction channel structure preparation steps are as follows: step (1) stainless steel plate preparation: select 304 stainless steel for cleaning and cutting, use a precision scribing machine to draw flow channel lines on the 304 stainless steel plate according to design requirements, and control the depth of drawing and the uniformity of lines to ensure the quality of the flow channel; step (2) cutting and post-processing: grinding and polishing the cut 304 stainless steel plate to remove burrs and unevenness on the cutting edge, using a cleaning agent to clean the ground and polished 304 stainless steel plate to remove surface dirt and impurities, drying with a drying machine, drying temperature control at 110 DEG C, drying time for 20 min; step (3) flow channel processing: flow channel processing on the cleaned quartz glass, using laser cutting equipment to cut the 304 stainless steel plate into the required shape and size according to the drawn flow channel lines, controlling the shape, size and depth of the flow channel; step (4) preliminary inspection: detecting the processed stainless steel reaction channel structure, checking whether the shape and size of the flow channel meet the design requirements, and checking the surface smoothness and transparency quality indicators.

4. The method of diffusion bonding a heterogeneous metal composite stamped microchannel reactor of claim 1, wherein: The nickel-based superalloy sheet has a thickness of 0.2-0.5 mm.

5. The method of diffusion bonding a heterogeneous metal composite stamped microchannel reactor of claim 1, wherein: The post-processing and inspection steps are as follows: checking the prepared heterogeneous metal micro-channel reactor to ensure that its surface quality and performance meet the requirements, grinding and polishing the welded part of the heterogeneous metal micro-channel reactor to remove burrs and unevenness on the welding edge, and washing, drying and heat treating the ground and polished heterogeneous metal micro-channel reactor for post-processing to remove residual reagents and residues.

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