Diffusion bonding-isostatic pressing strengthening composite process manufacturing method of high-temperature alloy internal flow channel heat exchange plate

Abstract

The invention relates to a diffusion bonding-isostatic pressing strengthening composite process manufacturing method for a high-temperature alloy inner runner heat exchange plate. The method comprises the steps of diffusion bonding process design, diffusion bonding die design and machining, hot forming process design, hot forming die design and machining, isostatic pressing hot strengthening process design, process parameter selection, post-treatment and the like. The method is a composite process innovative technology integrating diffusion bonding and hot isostatic pressing, and has the advantages of hot isostatic pressing and diffusion bonding; the inner channel is closed by the diffusion bonding method, so that the performance requirements of cleanliness, air tightness and the like can be met; strength strengthening is carried out through a hot isostatic pressing method, and the strength of a connection interface is improved on the basis that precise forming of the inner runner is guaranteed. Formed parts are excellent in performance, near-net forming can be achieved, the material utilization rate is high, the forming period is short, and cost is low; the method has the characteristic of designability and has remarkable advantages.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature alloy diffusion welding, and in particular to a diffusion bonding-isostatic pressing strengthening composite process manufacturing method for a high-temperature alloy inner flow channel heat exchange plate. Background Art

[0002] In order to improve the power of hypersonic aircraft, it is urgent to develop an efficient method for manufacturing engine air inlet strong precooler. High-temperature alloy components with internal flow channels can well meet the high-temperature performance requirements and the requirements of weight reduction, and have been increasingly widely used in hypersonic engines. The harsh working conditions of the engine inlet put forward dual requirements of dimensional accuracy and internal pressure strength for the high-temperature alloy internal flow channels, which brings many difficulties to the manufacture of plate-type internal flow channel components: the internal flow channel has a small cross-sectional size and a long length, and cannot be formed by conventional machining methods such as drilling; although methods such as fusion welding, brazing, and friction welding can achieve structural connection and flow channel closure, it is difficult to ensure the weld strength during the subsequent bending and forming of components; and it is difficult to prepare a filling mold that meets the shape and size of the flow channel by hot isostatic pressing powder diffusion forming, and the flow channel accuracy cannot be controlled; although 3D printing technology can form, the internal flow channel inevitably has powder particles, which cannot meet the cleanliness requirements, and its cost is also high. In addition, the alternating hot and cold working environment is enough to make most connection forming methods fail. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a diffusion bonding-isostatic pressing strengthening composite process manufacturing method for a high-temperature alloy inner flow channel heat exchange plate; the specific technical scheme is as follows:

[0004] A diffusion bonding-isostatic pressing strengthening composite process manufacturing method for a high-temperature alloy inner flow channel heat exchange plate comprises the following steps:

[0005] Step 1: Parts preparation

[0006] Two high-temperature alloy plates are prepared, and corresponding grooves are designed and processed on the welding interface according to the internal flow channel direction of the internal flow channel component;

[0007] Step 2: Diffusion bonding mold preparation

[0008] Process the corresponding concave and convex dies according to the shape of the target component;

[0009] According to the shape of the inner flow channel, the installation port of the limit module on the die is designed and processed to limit the downward pressure;

[0010] The guides and limiter modules designed and processed on the punch and die ensure the concentric assembly of the punch and die;

[0011] Step 3: Thermoforming mold preparation

[0012] The corresponding thermoforming mold is designed and processed according to the size and bending shape of the component to be formed. The male mold of the thermoforming mold is provided with a guide column, and the female mold of the thermoforming mold is provided with a guide sleeve corresponding to the guide column to ensure the mold closing during the thermoforming process;

[0013] Step 4: Assembly

[0014] Place the die flat, and fit the plates to be connected into the die. Use micro springs around to limit movement. Press the convex die on the plates to be connected, and adjust the guide mechanism to assemble the die concentrically.

[0015] Step 5: Diffusion Connection

[0016] After the mold is assembled as a whole, put it into a vacuum hot-pressing furnace, evacuate the vacuum to a vacuum degree of more than 10-3Pa, and heat it to 1100℃; gradually increase the pressure to 40MPa, and keep the temperature and pressure for 90 minutes; after cooling to room temperature, release the pressure and open the furnace to take out the component to be formed;

[0017] Step 6: Thermoforming

[0018] After assembling the component to be formed and the forming mold, put it into a vacuum hot pressing furnace, and evacuate the vacuum again to make the vacuum degree reach above 10Pa-3Pa to avoid surface oxidation during the forming process; heat up to 950℃ and set the minimum pressing rate;

[0019] Step 7: Pick up

[0020] Take out the components, use conventional machining methods to remove the excess material of the components to be strengthened, and dredge the internal channels to ensure balanced internal and external pressures;

[0021] Step 8: Isostatic Pressing

[0022] Fix the treated parts to be strengthened on the fixture and put them into the hot isostatic pressing furnace, heat up and keep the temperature and pressure. Under the conditions of high temperature and high pressure, the connection interface will be recrystallized, and the micro cracks will gradually heal, effectively improving the strength of the welding interface.

[0023] Step nine: Take out the component and then perform fine processing to finally form an inner flow channel component that meets the requirements.

[0024] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate, its preferred scheme is that in step one, the high-temperature alloy plate is a base plate 1 and a cover plate, and the parts to be connected are two pieces of high-temperature alloy plates, both of which are made of GH4169. The base plate is processed with grooves on the plate by wire cutting method, and the base plate and the cover plate are polished to make the surface flat and smooth.

[0025] The surfaces of the bottom plate and the cover plate are pickled to remove the oxide film, and then cleaned with ultrasonic acetone and dried; the mold surface is wiped with anhydrous ethanol as a cleaning agent, and then the solder stopper is evenly applied on the contact surface between the mold and the part; a transition assembly is used between the punch and the die, the die is laid flat, and the plate to be connected is butt-fitted into the die, and micro springs are used around to limit movement. The punch 3 is pressed on the plate to be connected, and the guide is adjusted to make the mold concentrically assembled.

[0026] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of the high-temperature alloy inner flow channel heat exchange plate has a preferred embodiment that in step 2, the material of the concave mold and the convex mold is hard graphite.

[0027] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate has a preferred embodiment that in step three, the material of the hot forming mold is high-temperature mold steel.

[0028] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate, the preferred scheme is that in step 5, the bottom plate and the cover plate are pickled to remove the oxide film before assembly, and are cleaned with ultrasonic acetone and then dried to keep the surfaces of the parts to be connected clean; anhydrous ethanol is used as a cleaning agent to wipe the surface of the mold to ensure that the contact surface is free of impurities, and then a solder stop is evenly applied on the contact surface between the mold and the part;

[0029] A transition assembly is used between the punch and the die. The die is laid flat, and the base plate and cover plate to be connected are butt-fitted into the die. Micro springs are used around to limit movement. The punch is pressed against the base plate and cover plate to be connected, and the guide is adjusted to keep the die displacement direction fixed.

[0030] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate has a preferred embodiment that, in step six, the surface of the part to be formed needs to be cleaned and solder stopper applied before assembly.

[0031] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate, the preferred scheme of which is that in step six, after the mold is closed, a five-minute holding time is designed to eliminate microcracks generated at the welding interface during the bending forming process and improve the sealing of the external boundary of the welding interface.

[0032] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate, the preferred scheme is that in step eight, the fixture is provided with a fan-shaped groove and a strip groove, the fan-shaped module is inserted into the fan-shaped groove, and the fan-shaped mold can slide in the fan-shaped groove, the long strip module is vertically correspondingly inserted into the strip groove, and the treated parts to be strengthened are correspondingly installed on the fan-shaped module and the long strip module;

[0033] After being loaded into the hot isostatic pressing furnace, the furnace temperature is raised to 1100°C, the internal pressure is increased to 120MPa, and the temperature and pressure are maintained for 3 hours, and the temperature and pressure are reduced for 2.5 hours.

[0034] The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of the high-temperature alloy inner flow channel heat exchange plate has a preferred embodiment that in step five, step six, and step eight, the vacuum degree is required to reach above 10Pa-3Pa before heating.

[0035] Compared with the prior art, the present invention has the following beneficial technical effects:

[0036] The present invention proposes an isostatic pressing strengthening composite process forming method, which has the characteristics of high weld strength of the diffusion bonding process and strong controllability of the forming process, and also has the advantages of the hot isostatic pressing process to promote material densification and strengthen the parent material and the connection interface, thereby ensuring the precise forming of channel components with large bending radius, and can also be promoted and applied to other parts of high-temperature alloys or other materials with internal characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the external shape of a typical high-temperature alloy inner flow channel component formed by an isostatic pressing strengthening composite process manufacturing method;

[0038] Figure 2 A schematic diagram of the internal flow channel of a typical high-temperature alloy internal flow channel component formed by an isostatic pressing strengthening composite process manufacturing method;

[0039] Figure 3 This is a schematic diagram of the diffusion connection mold;

[0040] Figure 4 It is a schematic diagram of the hot forming mold;

[0041] Figure 5 Schematic diagram of the fixture for isostatic pressing process.

[0042] In the figure: 1-base plate, 2-cover plate, 3-die, 4-punch, 5-guide, 6-punch of thermoforming mold, 7-die of thermoforming mold, 8-guide column, 9-guide sleeve, 10-clamp, 11-limiting module, 12-fan-shaped module, 13-long strip module. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1-5 The present invention is described in detail, but the protection scope of the present invention is not limited by the accompanying drawings.

[0044] A diffusion bonding-isostatic pressing strengthening composite process manufacturing method for a high-temperature alloy inner flow channel heat exchange plate comprises the following steps:

[0045] Step 1: Parts preparation

[0046] Two high-temperature alloy plates are prepared, and corresponding grooves are designed and processed on the welding interface according to the internal flow channel direction of the internal flow channel component;

[0047] Step 2: Diffusion bonding mold preparation

[0048] Processing corresponding concave mold 3 and convex mold 4 according to the shape of the target component;

[0049] According to the shape of the inner flow channel, the installation opening of the limit module 11 on the die is designed and processed to limit the downward pressure;

[0050] The guide 5 and the limit module 11 designed and processed on the punch 3 and the die 4 ensure the concentric assembly of the punch 3 and the die 4;

[0051] Step 3: Thermoforming mold preparation

[0052] The corresponding thermoforming mold is designed and processed according to the size and bending shape of the component to be formed. A guide column 8 is provided on the male mold 6 of the thermoforming mold, and a guide sleeve 9 corresponding to the guide column is provided on the female mold 7 of the thermoforming mold to ensure mold closing during the thermoforming process;

[0053] Step 4: Assembly

[0054] Place the die flat, and fit the plates to be connected into the die. Use micro springs around to limit movement. Press the convex die on the plates to be connected, and adjust the guide mechanism to assemble the die concentrically.

[0055] Step 5: Diffusion Connection

[0056] After the mold is assembled as a whole, put it into a vacuum hot-pressing furnace, evacuate the vacuum to a vacuum degree of more than 10-3Pa, and heat it to 1100℃; gradually increase the pressure to 40MPa, and keep the temperature and pressure for 90 minutes; after cooling to room temperature, release the pressure and open the furnace to take out the component to be formed;

[0057] Step 6: Thermoforming

[0058] After assembling the component to be formed and the forming mold, put it into a vacuum hot pressing furnace, and evacuate the vacuum again to make the vacuum degree reach above 10Pa-3Pa to avoid surface oxidation during the forming process; heat up to 950℃ and set the minimum pressing rate;

[0059] Step 7: Pick up

[0060] Take out the components, use conventional machining methods to remove the excess material of the components to be strengthened, and dredge the internal channels to ensure balanced internal and external pressures;

[0061] Step 8: Isostatic Pressing

[0062] The treated parts to be strengthened are fixed on the fixture 10 and placed in a hot isostatic pressing furnace, and the temperature is increased and the temperature and pressure are maintained. Under the conditions of high temperature and high pressure, recrystallization occurs at the connection interface, and microcracks are gradually healed, effectively improving the strength of the welding interface;

[0063] Step nine: Take out the component and then perform fine processing to finally form an inner flow channel component that meets the requirements.

[0064] In step 1, the high-temperature alloy plates are a base plate 1 and a cover plate 2, and the parts to be connected are two pieces of high-temperature alloy plates, both of which are made of GH4169. The base plate 1 is processed with grooves on the plate using a wire cutting method, and the base plate and the cover plate are polished to make the surface flat and smooth.

[0065] The surfaces of the bottom plate 1 and the cover plate 2 are pickled to remove the oxide film, and then cleaned with ultrasonic acetone and dried; the mold surface is wiped with anhydrous ethanol as a cleaning agent, and then the solder stopper is evenly applied on the contact surface between the mold and the part; a transition assembly is used between the punch 3 and the die 4, the die 4 is laid flat, the plate to be connected is butt-fitted into the die 4, and micro springs are used around to limit movement. The punch 3 is pressed on the plate to be connected, and the guide 5 is adjusted to make the mold concentrically assembled.

[0066] In step 2, the materials of the concave mold and the convex mold are hard graphite.

[0067] In step three, the material of the hot forming mold is high temperature mold steel.

[0068] In step 5, the bottom plate 1 and the cover plate 2 are pickled to remove the oxide film before assembly, and then cleaned with ultrasonic acetone and dried to keep the surfaces of the parts to be connected clean; anhydrous ethanol is used as a cleaning agent to wipe the surface of the mold to ensure that there are no impurities on the contact surface, and then solder stop is evenly applied on the contact surface between the mold and the parts;

[0069] A transition assembly is used between the punch 3 and the die 4. The die 4 is laid flat, and the base plate 1 and the cover plate 2 to be connected are butt-fitted into the die 4. Micro springs are used around to limit movement. The punch 3 is pressed on the base plate 1 and the cover plate 2 to be connected, and the guide 5 is adjusted to make the mold keep the displacement direction of the mold fixed.

[0070] In step six, the surface of the formed parts needs to be cleaned and solder stopper applied before assembly.

[0071] In step six, after the mold is closed, a five-minute holding time is designed to eliminate microcracks generated at the welding interface during the bending process and improve the sealing of the external boundary of the welding interface.

[0072] In step eight, the fixture 10 is provided with a fan-shaped groove and a strip-shaped groove, the fan-shaped module 12 is inserted into the fan-shaped groove, and the fan-shaped mold can slide in the fan-shaped groove, the strip module 13 is vertically inserted into the strip groove, and the treated parts to be strengthened are correspondingly mounted on the fan-shaped module 12 and the strip module 13;

[0073] After being loaded into the hot isostatic pressing furnace, the furnace temperature is raised to 1100°C, the internal pressure is increased to 120MPa, and the temperature and pressure are maintained for 3 hours, and the temperature and pressure are reduced for 2.5 hours.

[0074] In step 5, step 6 and step 8, the vacuum degree is required to reach above 10Pa-3Pa before heating.

Claims

1. A diffusion bonding-isostatic pressing strengthening composite process manufacturing method for a high-temperature alloy inner flow channel heat exchange plate, characterized in that: The steps include: Step 1: Parts preparation Two high-temperature alloy plates are prepared, and corresponding grooves are designed and processed on the welding interface according to the internal flow channel direction of the internal flow channel component; Step 2: Diffusion bonding mold preparation Process the corresponding concave and convex dies according to the shape of the target component; According to the shape of the inner flow channel, the installation port of the limit module on the die is designed and processed to limit the downward pressure; The guides and limiter modules designed and processed on the punch and die ensure the concentric assembly of the punch and die; Step 3: Thermoforming mold preparation The corresponding thermoforming mold is designed and processed according to the size and bending shape of the component to be formed. The male mold of the thermoforming mold is provided with a guide column, and the female mold of the thermoforming mold is provided with a guide sleeve corresponding to the guide column to ensure the mold closing during the thermoforming process; Step 4: Assembly Place the die flat, and fit the plates to be connected into the die. Use micro springs around to limit movement. Press the convex die on the plates to be connected, and adjust the guide mechanism to assemble the die concentrically. Step 5: Diffusion Connection After the mold is assembled as a whole, put it into a vacuum hot-pressing furnace, evacuate the vacuum to a vacuum degree of 10Pa-3Pa or above, and heat it to 1100°C; gradually increase the pressure to 40MPa, and keep the temperature and pressure for 90 minutes; after cooling to room temperature, release the pressure and open the furnace to take out the component to be formed; Step 6: Thermoforming After assembling the component to be formed and the forming mold, put it into a vacuum hot pressing furnace, and evacuate the vacuum again to make the vacuum degree reach above 10Pa-3Pa to avoid surface oxidation during the forming process; heat up to 950℃ and set the minimum pressing rate; Step 7: Pick up Take out the components, use conventional machining methods to remove the excess material of the components to be strengthened, and dredge the internal channels to ensure balanced internal and external pressures; Step 8: Isostatic Pressing Fix the treated parts to be strengthened on the fixture and put them into the hot isostatic pressing furnace, heat up and keep the temperature and pressure. Under the conditions of high temperature and high pressure, the connection interface will be recrystallized, and the micro cracks will gradually heal, effectively improving the strength of the welding interface. Step nine: Take out the component and then perform fine processing to finally form an inner flow channel component that meets the requirements.

2. The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step one, the high-temperature alloy plates are a base plate and a cover plate, and the parts to be connected are two pieces of high-temperature alloy plates, both of which are made of GH4169. The base plate is processed with grooves on the plate using a wire cutting method, and the base plate and the cover plate are polished to make the surface flat and smooth. The surfaces of the base plate and the cover plate are pickled to remove the oxide film, cleaned with ultrasonic acetone and then dried; the mold surface is wiped with anhydrous ethanol as a cleaning agent, and then the solder stopper is evenly applied on the contact surface between the mold and the part; a transition assembly is used between the punch and the die, the die is laid flat, the plates to be connected are butt-fitted into the die, miniature springs are used around to limit movement, the punch is pressed on the plates to be connected, and the guide is adjusted to make the mold concentrically assembled.

3. The diffusion bonding-isostatic pressing composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step 2, the materials of the concave mold and the convex mold are hard graphite.

4. The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step three, the material of the hot forming mold is high temperature mold steel.

5. The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step 5, the bottom plate and the cover plate 2 are pickled to remove the oxide film before assembly, and then cleaned with ultrasonic acetone and dried to keep the surfaces of the parts to be connected clean; anhydrous ethanol is used as a cleaning agent to wipe the surface of the mold to ensure that there are no impurities on the contact surface, and then solder stop is evenly applied on the contact surface between the mold and the parts; A transition assembly is used between the punch and the die. The die is laid flat, and the base plate and cover plate to be connected are butt-fitted into the die. Micro springs are used around to limit movement. The punch is pressed against the base plate and cover plate to be connected, and the guide is adjusted to keep the die displacement direction fixed.

6. The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step six, the surface of the formed parts needs to be cleaned and solder stopper applied before assembly.

7. The laser deposition repair method for TC4 titanium alloy straightening blades according to claim 1 is characterized in that: In step six, after the mold is closed, a five-minute holding time is designed to eliminate microcracks generated at the welding interface during the bending process and improve the sealing of the external boundary of the welding interface.

8. The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step eight, the fixture 10 is provided with a fan-shaped groove and a strip-shaped groove, the fan-shaped module is inserted into the fan-shaped groove, and the fan-shaped mold can slide in the fan-shaped groove, the strip module is vertically correspondingly inserted into the strip groove, and the processed parts to be strengthened are correspondingly installed on the fan-shaped module and the strip module; After being loaded into the hot isostatic pressing furnace, the furnace temperature is raised to 1100°C, the internal pressure is increased to 120MPa, and the temperature and pressure are maintained for 3 hours, and the temperature and pressure are reduced for 2.5 hours.

9. The diffusion bonding-isostatic pressing strengthening composite process manufacturing method of a high-temperature alloy inner flow channel heat exchange plate according to claim 1, characterized in that: In step 5, step 6 and step 8, the vacuum degree is required to reach above 10Pa-3Pa before heating.

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