Vacuum diffusion welding pressure plate with water cooling structure

Abstract

The application discloses a vacuum diffusion welding pressure plate with a water cooling structure, which comprises an upper plate and a lower plate, the upper plate and the lower plate are integrally formed into the welding pressure plate through sintering, a water cooling channel is arranged at the top of the lower plate, the material of the welding pressure plate is Mo-Si-B alloy, the bottom of the lower plate is provided with an array type micro-protrusion, the protrusion height is 50-80 microns, the protrusion diameter is 100-150 microns, and the center distance is 200-250 microns, and the preparation method of the welding pressure plate comprises the following steps: S1, the Mo-Si-B alloy composition is as follows in terms of atomic percentage: Mo is 10-15, Si is 8-12, B is 1-3, and the additive is 0.5-1.5 wt% ZrO2 or Y2O3 as a grain boundary strengthening phase; and S2, mechanical alloying: the Mo powder, the Si powder, the B powder, the steel powder and the additive are placed in a high-energy ball milling tank and mixed under the protection of argon gas to prepare a nanocrystalline composite powder.

Description

Technical Field

[0001] This invention relates to the field of vacuum diffusion welding plate technology, specifically a vacuum diffusion welding plate with a water-cooling structure. Background Technology

[0002] In diffusion welding, the workpiece to be welded is placed between upper and lower pressure plates. The pressure plates and workpiece are then placed together into the vacuum diffusion welding equipment. During welding, the equipment applies pressure to the pressure plates via a hydraulic mechanism, which in turn transfers the pressure to the workpiece, completing the welding process. Traditional diffusion welding equipment uses solid plate-type pressure plates, often made of molybdenum-based alloys or graphite. This has two drawbacks: First, using molybdenum-based alloys results in a rapid decrease in strength with increasing temperature, and they also exhibit creep over long periods, requiring regular calibration and repair, impacting work efficiency and posing product quality risks. Using graphite, while possessing excellent compressive strength, results in poor shear strength. During welding, shear stress can easily cause graphite to fracture, leading to the scrapping of the entire batch of products and even equipment damage. Second, after diffusion welding, the pressure plates and welded workpieces undergo a long cooling process in a vacuum environment, resulting in low production efficiency.

[0003] The existing welding plates have the following defects:

[0004] 1. Patent document CN102328153B discloses a pressure diffusion welding process and fixture for aluminum or aluminum alloys with dissimilar metals. It includes a step of surface treatment of the pre-welded surface, placing the pre-welded surfaces of the workpieces to be welded face-to-face between the upper pressure plate and lower pad of the fixture, cold pressing, placing the pressed and protected workpieces and fixture as a whole into a box-type electric furnace for heating and heat preservation pre-welding, removing the fixture after diffusion welding, hot pressing it once on a hydraulic press, and then performing diffusion welding again. This invention provides a process for pressure diffusion welding of aluminum or aluminum alloys with dissimilar metals under non-vacuum conditions using a common hydraulic press, a common box-type electric heating furnace, and fixtures, while allowing large workpieces to be welded without being limited by existing vacuum diffusion welding processes. However, the existing welding pressure plates have long cooling times and low cooling rates.

[0005] 2. Patent document CN109807455A discloses a diffusion welding fixture and a diffusion welding method for copper-nickel composite sheets. "The diffusion welding fixture includes a first graphite pressure plate, a second graphite pressure plate, and multiple positioning rods. The first graphite pressure plate has multiple first positioning holes, and its upper surface is used to place at least one copper electrode sheet and at least one nickel electrode sheet. The second graphite pressure plate is located above the first graphite pressure plate, with the copper and nickel electrode sheets positioned between the first and second graphite pressure plates. The second graphite pressure plate has multiple second positioning holes corresponding one-to-one with the multiple first positioning holes, and is used to press the copper and nickel electrode sheets together under external force. The multiple positioning rods are used to position the electrodes by passing through the corresponding first and second positioning holes. This diffusion welding fixture has a simple structure, effectively reducing the scrap rate during welding, and can simultaneously achieve large-scale diffusion welding of copper-nickel composite connecting sheets, with high reusability." However, the thermal conductivity of existing welding pressure plates is not high, affecting production speed.

[0006] 3. Patent document CN106216788A discloses an electronic control grid welding fixture, "including a base, a diffusion welding block, a pressure plate, a support frame, and a control grid; the base has a central hole extending outward from the axis, and the support frame is disposed in the central hole; a groove for accommodating the control grid is formed on the bottom wall of the diffusion welding block, the diffusion welding block is fixedly disposed on the control grid, and the control grid is fixedly disposed on the support frame; the pressure plate is fixedly disposed on the diffusion welding block. This invention also proposes a welding method for an electronic control grid welding fixture, which is used for the assembly and welding of the control grid in a microwave traveling wave tube grid-controlled electron gun, realizing the full inter-diffusion and penetration of atoms on the contact surfaces between various components in a high-temperature vacuum, making the welding between the components more stable and robust." However, the existing welding pressure plate has low bending strength and toughness and is prone to creep. Summary of the Invention

[0007] The purpose of this invention is to provide a vacuum diffusion welding pressure plate with a water-cooling structure to solve the technical problems mentioned in the background art, such as long cooling time, low cooling rate, low bending strength and toughness, and easy creep of existing welding pressure plates.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a vacuum diffusion welding plate with a water-cooling structure, comprising an upper plate and a lower plate, wherein the upper plate and the lower plate are integrally formed into a welding plate by sintering, a water-cooling channel is provided on the top of the lower plate, the material of the welding plate is a Mo-Si-B alloy, and an array of micro-protrusions are provided on the bottom of the lower plate, the protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm.

[0009] Preferably, the method for preparing the welding plate includes the following steps;

[0010] The composition of S1 and Mo-Si-B alloys by atomic percentage is: Mo 10-15, Si 8-12, B 1-3, with additives of 0.5-1.5 wt% ZrO2 or Y2O3 as grain boundary strengthening phases;

[0011] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0012] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at a temperature of 20-30℃ / min to 1400-1500℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 40-50MPa and then heated to 1700-1800℃ at a temperature of 10℃ / min for 2-3 hours.

[0013] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0014] S5. Press plate forming: The sintered billet is processed into a lower plate with water cooling channels by electrical discharge machining.

[0015] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering.

[0016] Preferably, the depth of the water cooling channel is 1 / 3 to 1 / 2 of the lower plate, and the width is 0.8 to 1.2 mm.

[0017] Preferably, the alloy composition is Mo-12Si-10B-0.8Y2O3, and the molar ratio of Si / B in the alloy composition is 1.18-1.22.

[0018] Preferably, the high-energy ball mill jar adopts a stepped ball milling process, with the oxide layer coarsely ground at 350 rpm for the first 10 hours, the speed reduced to 300 rpm for the middle 10 hours to promote element diffusion, and the speed increased to 400 rpm for the last 10 hours to refine the grains.

[0019] Preferably, during the hot pressing sintering, pulse pressure is applied with a pulse frequency of 0.5-1Hz, a high-pressure phase of 50MPa maintained for 60s, and a low-pressure phase of 10MPa maintained for 30s.

[0020] Preferably, during the gradient cooling process, an Ar-H2 mixed gas containing 5 vol% H2 is introduced in the range of 1200-1000℃ to reduce the surface oxides.

[0021] Preferably, the water cooling channel adopts a three-dimensional mesh topology structure, comprising a main water channel and branch microchannels. The main water channel is 1.2 mm wide, the branch microchannels are 0.3 mm wide, the branch channels form a 45° angle with the main water channel, and the spacing density is 15-20 channels / cm. 2 .

[0022] Preferably, the composite coating is co-deposited at a MoSi2:Al2O3 mass ratio of 7:3, with a sputtering power density of 8-10 W / cm³. 2 The substrate bias voltage is -100V to -150V.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This invention utilizes a welding plate consisting of an upper plate 1 and a lower plate 2, which are integrally formed by sintering. The lower plate 2 has a water cooling channel 3 on its top. The welding plate is made of Mo-Si-B alloy. The bottom of the lower plate 2 has an array of micro-protrusions with a height of 50-80μm, a diameter of 100-150μm, and a center-to-center distance of 200-250μm. This invention achieves a significant reduction in cooling time and an increase in cooling rate of the welding plate.

[0025] 2. This invention achieves a significant improvement in the thermal conductivity of the welded pressure plate by installing a water-cooling channel 3 with a depth of 1 / 3 to 1 / 2 of the lower plate 2 and a width of 0.8 to 1.2 mm. The alloy composition is Mo-12Si-10B-0.8Y2O3, and the molar ratio of Si / B in the alloy composition is 1.18 to 1.22. The high-energy ball mill jar adopts a stepped ball milling method. The oxide layer is coarsely ground at 350 rpm for the first 10 hours, the speed is reduced to 300 rpm for the middle 10 hours to promote element diffusion, and the speed is increased to 400 rpm for the last 10 hours to refine the grains.

[0026] 3. This invention achieves a significant improvement in the bending strength and toughness of the welded plate by installing a pulse pressure during hot pressing sintering, with a pulse frequency of 0.5-1Hz, a high-pressure phase of 50MPa maintained for 60s, a low-pressure phase of 10MPa maintained for 30s, and during the gradient cooling process, an Ar-H2 mixed gas containing 5vol%H2 is introduced in the 1200-1000℃ range to reduce surface oxides. The water cooling channel 3 adopts a three-dimensional mesh topology structure. Attached Figure Description

[0027] Figure 1 This is a front view structural diagram of the present invention;

[0028] Figure 2 This is a schematic representation of the experimental data of the present invention.

[0029] In the diagram: 1. Upper plate; 2. Lower plate; 3. Water cooling channel. Detailed Implementation

[0030] 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.

[0031] 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.

[0032] 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, 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 this according to the specific circumstances.

[0033] Example 1: Please refer to Figure 1 and Figure 2 The present invention provides an embodiment of a vacuum diffusion welding plate with a water-cooling structure, comprising an upper plate 1 and a lower plate 2, wherein the upper plate 1 and the lower plate 2 are integrally formed by sintering to form a welding plate, a water-cooling channel 3 is provided on the top of the lower plate 2, the material of the welding plate is a Mo-Si-B alloy, and an array of micro protrusions are provided on the bottom of the lower plate 2, wherein the protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm;

[0034] The preparation method of this welding plate includes the following steps;

[0035] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 0.5wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0036] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0037] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 20℃ / min to 1400℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 40MPa and then heated to 1700℃ at 10℃ / min for 3 hours.

[0038] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0039] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0040] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering;

[0041] The water-cooling channel 3 has a depth of 1 / 3 to 1 / 2 of the lower plate 2 and a width of 0.8-1.2 mm. Its alloy composition is Mo-12Si-10B-0.8Y2O3, with a Si / B molar ratio of 1.18-1.22. A stepped ball mill is used in the high-energy ball mill jar. For the first 10 hours, the oxide layer is coarsely ground at 350 rpm. For the middle 10 hours, the speed is reduced to 300 rpm to promote element diffusion. For the last 10 hours, the speed is increased to 400 rpm to refine the grains. During hot pressing sintering, pulsed pressure is applied, with a pulse frequency... The frequency is 0.5-1Hz, the high-pressure phase is 50MPa maintained for 60s, and the low-pressure phase is 10MPa maintained for 30s. During the gradient cooling process, an Ar-H2 mixed gas containing 5 vol% H2 is introduced in the 1200-1000℃ range to reduce surface oxides. The water cooling channel 3 adopts a three-dimensional mesh topology structure, which includes a main water channel and branch microchannels. The main water channel is 1.2mm wide, the branch microchannels are 0.3mm wide, the branch channels are at a 45° angle to the main water channel, and the spacing density is 15-20 channels / cm.2 The composite coating was co-deposited at a mass ratio of MoSi2:Al2O3 of 7:3, with a sputtering power density of 8-10 W / cm³. 2 The substrate bias voltage is -100V to -150V. When using it, connect the welding plate to the water cooling circulation system of the vacuum diffusion welding equipment. After the diffusion welding is completed, turn on the water cooling circulation of the plate to cool it down.

[0042] Example 2: Please refer to Figure 1 and Figure 2 The present invention provides an embodiment of a vacuum diffusion welding plate with a water-cooling structure, comprising an upper plate 1 and a lower plate 2, wherein the upper plate 1 and the lower plate 2 are integrally formed by sintering to form a welding plate, a water-cooling channel 3 is provided on the top of the lower plate 2, the material of the welding plate is a Mo-Si-B alloy, and an array of micro protrusions are provided on the bottom of the lower plate 2, wherein the protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm;

[0043] The preparation method of this welding plate includes the following steps;

[0044] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 0.8wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0045] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0046] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 24℃ / min to 1440℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 440MPa and then heated to 1740℃ at 10℃ / min for 3 hours.

[0047] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0048] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0049] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering;

[0050] The water-cooling channel 3 has a depth of 1 / 3 to 1 / 2 of the lower plate 2 and a width of 0.8-1.2 mm. Its alloy composition is Mo-12Si-10B-0.8Y2O3, with a Si / B molar ratio of 1.18-1.22. A stepped ball mill is used in the high-energy ball mill jar. For the first 10 hours, the oxide layer is coarsely ground at 350 rpm. For the middle 10 hours, the speed is reduced to 300 rpm to promote element diffusion. For the last 10 hours, the speed is increased to 400 rpm to refine the grains. During hot pressing sintering, pulsed pressure is applied, with a pulse frequency... The frequency is 0.5-1Hz, the high-pressure phase is 50MPa maintained for 60s, and the low-pressure phase is 10MPa maintained for 30s. During the gradient cooling process, an Ar-H2 mixed gas containing 5 vol% H2 is introduced in the 1200-1000℃ range to reduce surface oxides. The water cooling channel 3 adopts a three-dimensional mesh topology structure, which includes a main water channel and branch microchannels. The main water channel is 1.2mm wide, the branch microchannels are 0.3mm wide, the branch channels are at a 45° angle to the main water channel, and the spacing density is 15-20 channels / cm. 2 The composite coating was co-deposited at a mass ratio of MoSi2:Al2O3 of 7:3, with a sputtering power density of 8-10 W / cm³. 2 The substrate bias voltage is -100V to -150V. When using it, connect the welding plate to the water cooling circulation system of the vacuum diffusion welding equipment. After the diffusion welding is completed, turn on the water cooling circulation of the plate to cool it down.

[0051] Example 3: Please refer to Figure 1 and Figure 2 The present invention provides an embodiment of a vacuum diffusion welding plate with a water-cooling structure, comprising an upper plate 1 and a lower plate 2, wherein the upper plate 1 and the lower plate 2 are integrally formed by sintering to form a welding plate, a water-cooling channel 3 is provided on the top of the lower plate 2, the material of the welding plate is a Mo-Si-B alloy, and an array of micro protrusions are provided on the bottom of the lower plate 2, wherein the protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm;

[0052] The preparation method of this welding plate includes the following steps;

[0053] The composition of S1, Mo-Si-B alloy by atomic percentage is: Mo 10-15, Si 8-12, B 1-3, with 1wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0054] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0055] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 26℃ / min to 1460℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 46MPa and then heated to 1760℃ at 10℃ / min for 2.5 hours.

[0056] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0057] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0058] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering;

[0059] The water-cooling channel 3 has a depth of 1 / 3 to 1 / 2 of the lower plate 2 and a width of 0.8-1.2 mm. Its alloy composition is Mo-12Si-10B-0.8Y2O3, with a Si / B molar ratio of 1.18-1.22. A stepped ball mill is used in the high-energy ball mill jar. For the first 10 hours, the oxide layer is coarsely ground at 350 rpm. For the middle 10 hours, the speed is reduced to 300 rpm to promote element diffusion. For the last 10 hours, the speed is increased to 400 rpm to refine the grains. During hot pressing sintering, pulsed pressure is applied, with a pulse frequency... The frequency is 0.5-1Hz, the high-pressure phase is 50MPa maintained for 60s, and the low-pressure phase is 10MPa maintained for 30s. During the gradient cooling process, an Ar-H2 mixed gas containing 5 vol% H2 is introduced in the 1200-1000℃ range to reduce surface oxides. The water cooling channel 3 adopts a three-dimensional mesh topology structure, which includes a main water channel and branch microchannels. The main water channel is 1.2mm wide, the branch microchannels are 0.3mm wide, the branch channels are at a 45° angle to the main water channel, and the spacing density is 15-20 channels / cm. 2 The composite coating was co-deposited at a mass ratio of MoSi2:Al2O3 of 7:3, with a sputtering power density of 8-10 W / cm³. 2The substrate bias voltage is -100V to -150V. When using it, connect the welding plate to the water cooling circulation system of the vacuum diffusion welding equipment. After the diffusion welding is completed, turn on the water cooling circulation of the plate to cool it down.

[0060] Example 4: Please refer to Figure 1 and Figure 2 The present invention provides an embodiment of a vacuum diffusion welding plate with a water-cooling structure, comprising an upper plate 1 and a lower plate 2, wherein the upper plate 1 and the lower plate 2 are integrally formed by sintering to form a welding plate, a water-cooling channel 3 is provided on the top of the lower plate 2, the material of the welding plate is a Mo-Si-B alloy, and an array of micro protrusions are provided on the bottom of the lower plate 2, wherein the protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm;

[0061] The preparation method of this welding plate includes the following steps;

[0062] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 1.2wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0063] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0064] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 28℃ / min to 1480℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 48MPa and then heated to 1780℃ at 10℃ / min for 3 hours.

[0065] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0066] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0067] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering;

[0068] The water-cooling channel 3 has a depth of 1 / 3 to 1 / 2 of the lower plate 2 and a width of 0.8-1.2 mm. Its alloy composition is Mo-12Si-10B-0.8Y2O3, with a Si / B molar ratio of 1.18-1.22. A stepped ball mill is used in the high-energy ball mill jar. For the first 10 hours, the oxide layer is coarsely ground at 350 rpm. For the middle 10 hours, the speed is reduced to 300 rpm to promote element diffusion. For the last 10 hours, the speed is increased to 400 rpm to refine the grains. During hot pressing sintering, pulsed pressure is applied, with a pulse frequency... The frequency is 0.5-1Hz, the high-pressure phase is 50MPa maintained for 60s, and the low-pressure phase is 10MPa maintained for 30s. During the gradient cooling process, an Ar-H2 mixed gas containing 5 vol% H2 is introduced in the 1200-1000℃ range to reduce surface oxides. The water cooling channel 3 adopts a three-dimensional mesh topology structure, which includes a main water channel and branch microchannels. The main water channel is 1.2mm wide, the branch microchannels are 0.3mm wide, the branch channels are at a 45° angle to the main water channel, and the spacing density is 15-20 channels / cm. 2 The composite coating was co-deposited at a mass ratio of MoSi2:Al2O3 of 7:3, with a sputtering power density of 8-10 W / cm³. 2 The substrate bias voltage is -100V to -150V. When using it, connect the welding plate to the water cooling circulation system of the vacuum diffusion welding equipment. After the diffusion welding is completed, turn on the water cooling circulation of the plate to cool it down.

[0069] Example 5: Please refer to Figure 1 and Figure 2 The present invention provides an embodiment of a vacuum diffusion welding plate with a water-cooling structure, comprising an upper plate 1 and a lower plate 2, wherein the upper plate 1 and the lower plate 2 are integrally formed by sintering to form a welding plate, a water-cooling channel 3 is provided on the top of the lower plate 2, the material of the welding plate is a Mo-Si-B alloy, and an array of micro protrusions are provided on the bottom of the lower plate 2, wherein the protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm;

[0070] The preparation method of this welding plate includes the following steps;

[0071] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 1.5wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0072] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0073] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 30℃ / min to 1500℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 50MPa and then heated to 1800℃ at 10℃ / min for 3 hours.

[0074] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0075] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0076] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering;

[0077] The water-cooling channel 3 has a depth of 1 / 3 to 1 / 2 of the lower plate 2 and a width of 0.8-1.2 mm. Its alloy composition is Mo-12Si-10B-0.8Y2O3, with a Si / B molar ratio of 1.18-1.22. A stepped ball mill is used in the high-energy ball mill jar. For the first 10 hours, the oxide layer is coarsely ground at 350 rpm. For the middle 10 hours, the speed is reduced to 300 rpm to promote element diffusion. For the last 10 hours, the speed is increased to 400 rpm to refine the grains. During hot pressing sintering, pulsed pressure is applied, with a pulse frequency... The frequency is 0.5-1Hz, the high-pressure phase is 50MPa maintained for 60s, and the low-pressure phase is 10MPa maintained for 30s. During the gradient cooling process, an Ar-H2 mixed gas containing 5 vol% H2 is introduced in the 1200-1000℃ range to reduce surface oxides. The water cooling channel 3 adopts a three-dimensional mesh topology structure, which includes a main water channel and branch microchannels. The main water channel is 1.2mm wide, the branch microchannels are 0.3mm wide, the branch channels are at a 45° angle to the main water channel, and the spacing density is 15-20 channels / cm. 2 The composite coating was co-deposited at a mass ratio of MoSi2:Al2O3 of 7:3, with a sputtering power density of 8-10 W / cm³. 2The substrate bias voltage is -100V to -150V. When using it, connect the welding plate to the water cooling circulation system of the vacuum diffusion welding equipment. After the diffusion welding is completed, turn on the water cooling circulation of the plate to cool it down.

[0078] Comparative experiment:

[0079] The difference between Comparative Example 1 and Example 1 is that;

[0080] It includes an upper plate 1 and a lower plate 2. The upper plate 1 and the lower plate 2 are sintered together to form a welding plate. A water cooling channel 3 is opened on the top of the lower plate 2. The material of the welding plate is Mo-Si-B alloy. The bottom of the lower plate 2 is provided with an array of micro protrusions with a protrusion height of 50-80μm, a protrusion diameter of 100-150μm, and a center-to-center spacing of 200-250μm.

[0081] The preparation method of this welding plate includes the following steps;

[0082] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 0.5wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0083] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0084] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 20℃ / min to 1400℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 40MPa and then heated to 1700℃ at 10℃ / min for 3 hours.

[0085] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0086] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0087] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering.

[0088] The difference between Comparative Example 1 and Example 2 is that;

[0089] It includes an upper plate 1 and a lower plate 2. The upper plate 1 and the lower plate 2 are sintered together to form a welding plate. A water cooling channel 3 is opened on the top of the lower plate 2. The material of the welding plate is Mo-Si-B alloy. The bottom of the lower plate 2 is provided with an array of micro protrusions with a protrusion height of 50-80μm, a protrusion diameter of 100-150μm, and a center-to-center spacing of 200-250μm.

[0090] The preparation method of this welding plate includes the following steps;

[0091] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 0.8wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0092] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0093] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 24℃ / min to 1440℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 440MPa and then heated to 1740℃ at 10℃ / min for 3 hours.

[0094] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0095] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0096] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering.

[0097] The difference between Comparative Example 1 and Example 3 is that;

[0098] It includes an upper plate 1 and a lower plate 2. The upper plate 1 and the lower plate 2 are sintered together to form a welding plate. A water cooling channel 3 is opened on the top of the lower plate 2. The material of the welding plate is Mo-Si-B alloy. The bottom of the lower plate 2 is provided with an array of micro protrusions with a protrusion height of 50-80μm, a protrusion diameter of 100-150μm, and a center-to-center spacing of 200-250μm.

[0099] The preparation method of this welding plate includes the following steps;

[0100] The composition of S1, Mo-Si-B alloy by atomic percentage is: Mo 10-15, Si 8-12, B 1-3, with 1wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0101] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0102] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 26℃ / min to 1460℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 46MPa and then heated to 1760℃ at 10℃ / min for 2.5 hours.

[0103] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0104] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0105] S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering.

[0106] The difference between Comparative Example 1 and Example 4 is that;

[0107] It includes an upper plate 1 and a lower plate 2. The upper plate 1 and the lower plate 2 are sintered together to form a welding plate. A water cooling channel 3 is opened on the top of the lower plate 2. The material of the welding plate is Mo-Si-B alloy. The bottom of the lower plate 2 is provided with an array of micro protrusions with a protrusion height of 50-80μm, a protrusion diameter of 100-150μm, and a center-to-center spacing of 200-250μm.

[0108] The preparation method of this welding plate includes the following steps;

[0109] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 1.2wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0110] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0111] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 28℃ / min to 1480℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 48MPa and then heated to 1780℃ at 10℃ / min for 3 hours.

[0112] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0113] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0114] The difference between Comparative Example 1 and Example 5 is that;

[0115] It includes an upper plate 1 and a lower plate 2. The upper plate 1 and the lower plate 2 are sintered together to form a welding plate. A water cooling channel 3 is opened on the top of the lower plate 2. The material of the welding plate is Mo-Si-B alloy. The bottom of the lower plate 2 is provided with an array of micro protrusions with a protrusion height of 50-80μm, a protrusion diameter of 100-150μm, and a center-to-center spacing of 200-250μm.

[0116] The preparation method of this welding plate includes the following steps;

[0117] The composition of the S1, Mo-Si-B alloy, by atomic percentage, is: Mo 10-15, Si 8-12, B 1-3, with 1.5wt% ZrO2 or Y2O3 as the grain boundary strengthening phase.

[0118] S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm-15μm, the particle size of Si powder is 5μm-8μm and the particle size of B powder is 3μm-6μm.

[0119] S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at 30℃ / min to 1500℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 50MPa and then heated to 1800℃ at 10℃ / min for 3 hours.

[0120] S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2% to 99.2% and an average grain size of 5μm to 9μm.

[0121] S5. Press plate forming: The sintered billet is processed into a lower plate 2 with water cooling channels 3 by electrical discharge machining.

[0122] The welding plates of Embodiments 1, 2, 3, 4, and 5 of the present invention were compared with a conventional welding plate (Comparative Example 1) by conducting 800°C cooling time tests, 800°C thermal conductivity tests, and room temperature bending strength tests, respectively. The values ​​were calculated and statistically analyzed, and the results are shown in Table 1.

[0123] Example 1 1.6h 85％ 860Mpa Example 2 1.4h 89％ 865Mpa Example 3 1.5h 90％ 870Mpa Example 4 1.6h 86％ 875Mpa Example 5 1.5h 87％ 880Mpa Comparative Example 1 2h 60％ 750Mpa

[0124] As can be seen from the data in Table 1, the cooling times of the welding plates in Examples 1, 2, 3, 4 and 5 of the present invention are 1.6, 1.4, 1.5, 1.6 and 1.5 respectively, which are significantly higher than the cooling time of the welding plate in Comparative Example 1. Therefore, it can be seen that the cooling time of the welding plate of the present invention is significantly reduced and the cooling rate is improved.

[0125] As can be seen from the data in Table 1, the thermal conductivity of the welding plates in Examples 1, 2, 3, 4 and 5 of the present invention is 85, 89, 90, 86 and 87 respectively, which is significantly higher than that of the welding plate in Comparative Example 1. Therefore, it is shown that the thermal conductivity of the welding plate of the present invention is significantly improved.

[0126] As can be seen from the data in Table 1, the bending strength of the welded pressure plates in Examples 1, 2, 3, 4 and 5 of the present invention is 860, 865, 870, 875 and 880 respectively, which is significantly higher than the bending strength of the welded pressure plate in Comparative Example 1. Therefore, it is shown that the bending strength and toughness of the welded pressure plate of the present invention are significantly improved.

[0127] 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 for preparing a vacuum diffusion welding pressure plate with a water-cooling structure, characterized in that, The vacuum diffusion welding plate includes an upper plate (1) and a lower plate (2). The upper plate (1) and the lower plate (2) are integrally formed by sintering to form a welding plate. A water cooling channel (3) is provided on the top of the lower plate (2). The material of the welding plate is Mo-Si-B alloy. An array of micro protrusions is provided on the bottom of the lower plate (2). The protrusion height is 50-80μm, the protrusion diameter is 100-150μm, and the center spacing is 200-250μm. The preparation method of this welding plate includes the following steps; The composition of S1 and Mo-Si-B alloys by atomic percentage is: Mo 10-15, Si 8-12, B 1-3, with additives of 0.5-1.5wt% ZrO2 or Y2O3 as grain boundary strengthening phases; S2. Mechanical alloying: Mo powder, Si powder, B powder, steel powder and additives are placed in a high-energy ball mill jar and mixed under argon protection. The ball-to-powder ratio of Mo powder, Si powder, B powder and steel powder is 10-15:

1. The rotation speed of the high-energy ball mill jar is 300-400 rpm and the ball milling time is 20-40 hours to obtain nanocrystalline composite powder. The particle size of Mo powder is 10μm~15μm, the particle size of Si powder is 5μm~8μm and the particle size of B powder is 3μm~6μm. S3. Hot pressing sintering: The composite powder is loaded into a graphite mold and pre-sintered in a vacuum hot press furnace at a temperature of 20-30℃ / min to 1400-1500℃ for 1 hour. Then, the vacuum hot press furnace is pressurized to 40-50MPa and then heated to 1700-1800℃ at a temperature of 10℃ / min for 2-3 hours. S4. Gradient cooling: Cool to 1200℃ at 15℃ / min, then slowly cool to below 800℃ at 5℃ / min to obtain a sintered blank with a density of 98.2%~99.2% and an average grain size of 5μm~9μm; S5, Press plate forming: The sintered blank is processed into a lower plate (2) with water cooling channel (3) by electric spark cutting. S6. Surface strengthening: A 2-5 μm thick MoSi2-Al2O3 composite coating is deposited on the working surface of the welding plate by magnetron sputtering.

2. The method for preparing a vacuum diffusion welding pressure plate with a water-cooled structure according to claim 1, characterized in that: The depth of the water cooling channel (3) is 1 / 3 to 1 / 2 of the lower plate (2), and the width is 0.8 to 1.2 mm.

3. The method for preparing a vacuum diffusion welding pressure plate with a water-cooled structure according to claim 1, characterized in that: The alloy composition is Mo-12Si-10B-0.8Y2O3, and the molar ratio of Si / B in the alloy composition is 1.18-1.

22.

4. The method for preparing a vacuum diffusion welding pressure plate with a water-cooled structure according to claim 1, characterized in that: The high-energy ball mill jar adopts a stepped ball milling process. For the first 10 hours, the oxide layer is coarsely ground at 350 rpm. For the middle 10 hours, the speed is reduced to 300 rpm to promote element diffusion. For the last 10 hours, the speed is increased to 400 rpm to refine the grains.

5. The method for preparing a vacuum diffusion welding pressure plate with a water-cooling structure according to claim 1, characterized in that: During the hot pressing sintering process, pulse pressure is applied with a pulse frequency of 0.5-1Hz. The high-pressure phase is maintained at 50MPa for 60s, and the low-pressure phase is maintained at 10MPa for 30s.

6. The method for preparing a vacuum diffusion welding pressure plate with a water-cooled structure according to claim 1, characterized in that: During the gradient cooling process, a mixture of Ar and H2 containing 5 vol% H2 is introduced into the 1200-1000℃ range to reduce the surface oxides.

7. The method for preparing a vacuum diffusion welding pressure plate with a water-cooled structure according to claim 2, characterized in that: The water cooling channel (3) adopts a three-dimensional mesh topology structure. The water cooling channel (3) includes a main water channel and branch micro channels. The main water channel is 1.2 mm wide and the branch micro channels are 0.3 mm wide. The branch channels are at a 45° angle to the main water channel and the spacing density is 15-20 channels / cm².

8. The method for preparing a vacuum diffusion welding pressure plate with a water-cooled structure according to claim 1, characterized in that: The composite coating is co-deposited at a mass ratio of MoSi2:Al2O3 of 7:3, with a sputtering power density of 8-10 W / cm² and a substrate bias of -100V to -150V.

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