CN114346396A - A kind of double-layer flap wall plate superplastic forming diffusion connection die and method - Google Patents

Abstract

The invention provides a superplastic forming diffusion bonding die and a superplastic forming diffusion bonding method for a double-layer flap wall plate, which aim to realize the superplastic forming/diffusion bonding process of the double-layer flap wall plate at one time through a set of tooling. Compared with the existing processing technology, a set of tooling can be saved, and the processing cost is greatly reduced; in addition, the superplastic forming/diffusion bonding process can be completed by heating the part once, so that the mechanical property of the material can be improved; finally, one set of die is adopted for one-step forming, so that the product processing period can be obviously shortened, and the production efficiency is improved.

Description

A kind of double-layer flap wall plate superplastic forming diffusion connection die and method

technical field

The invention belongs to the field of precision plastic processing, and relates to a superplastic forming/diffusion connection mold and method for a double-layered flap wall plate.

Background technique

In recent years, with the continuous improvement of the performance of aerospace vehicles, integration and lightweight have become the development trend of aerospace parts. The titanium alloy multi-layer structure is hollow inside, which can maximize the lightweight of the aircraft. For the multi-layer structure of titanium alloy, it is difficult to achieve forming by conventional processing methods, and the superplastic forming/diffusion bonding technology of titanium alloy can realize the overall near-net shape of the multi-layer structure. For titanium alloy double-layer flap wall panels, due to the limitation of ventilation and sealing conditions during forming, it is usually necessary to separate diffusion joining and superplastic forming processes. That is to say, firstly use the diffusion connection mold and carry out the diffusion connection of the double-layer board separately. Before that, it is necessary to spray the solder resist on the cap rib of the non-diffusion connection of the slab; then place the diffused slab in the cap rib superplastic forming mold Superplastic forming of cap ribs. This method can realize the forming of the titanium alloy double-layer port wall plate, but separate superplastic forming and diffusion joining need to design and manufacture two sets of tooling, which increases the cost. In addition, forming in two times will increase the processing cycle and reduce production efficiency. In particular, the mechanical properties of titanium alloys can be significantly degraded after two thermal cycles.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention: the present invention provides a superplastic forming diffusion connection die and method for a double-layer flap wall plate, which can realize the superplastic forming/diffusion connection of the double-layer flap wall plate at one time through a set of tooling process. Compared with the existing processing technology, it can save a set of tooling and greatly reduce the processing cost; in addition, the parts only need to be heated once to complete the superplastic forming/diffusion joining process, which can improve the mechanical properties of the material; finally, a set of One-time forming of the mold can significantly shorten the product processing cycle and improve production efficiency.

The technical scheme adopted in the present invention is: a superplastic forming diffusion connection mold for a double-layer mouth cover wall plate, comprising an upper mold, an inflatable tube, an inflatable hole, a sealing stem, a cavity, a lower mold, and a pressing block;

Among them, the cavity is located on the lower surface of the upper mold, and the end of each cavity is provided with an inflatable hole, and all the inflatable holes are communicated with the inflatable pipe outside the mold, which is used for the injection of the double-layer mouth cover wall into the cavity when forming. Introduce high-pressure inert gas (2-3Mpa); a sealing stem is arranged around the cavity on the lower surface of the upper mold. When the mold is pressed down, the sealing stem, the double-layer slab and the cavity of the upper mold form a closed cavity. After the high-pressure inert gas is introduced into the inflation pipe, the diffusion connection of the double-layer slab is realized by maintaining the pressure;

A groove is arranged on the lower die, and when the double-layer slab is installed on the lower die, the ventilation block and the ventilation pipe of the double-layered slab are placed in the groove of the lower die correspondingly and compacted with a compact.

The method for superplastic forming diffusion connection of double-layer flap wall plates using the described mould comprises the following steps:

Step 1. Make a double-layer board solder resist pattern;

Step 2: Weld the double-layer board by sealing the edge, and weld the ventilation block and the ventilation pipe;

Step 3. Install the welded double-layer slab on the lower mold, place the ventilation block and the ventilation pipe in the groove of the lower mold, and compress the ventilation pipe with a compact; finally close the upper mold; heat the mold to titanium The superplastic forming diffusion bonding temperature of the alloy;

Step 4. After the mold reaches the superplastic forming diffusion bonding temperature of the titanium alloy, mechanical pressure is applied to the upper mold, so that the sealing stem, the double-layer slab and the upper mold cavity form a closed cavity; Gas, maintain pressure within a set period of time to achieve diffusion connection in the non-cap rib area of the double-layer plate;

Step 5. Superplastic forming of the cap rib layer: unloading the air pressure in the inflation pipe, at the same time injecting high-pressure inert gas into the vent pipe of the lower die, and maintaining the pressure within a set period of time, so as to realize the superplastic forming of the cap rib layer; After the cap rib is completely molded, the air pressure in the vent pipe is unloaded and the temperature is lowered to realize the superplastic forming diffusion connection of the double-layer mouth cover wall plate.

The specific method of the first step is as follows: laser cutting the titanium alloy double-layer sheet, wherein the lower sheet corresponds to the cap rib layer to cut holes corresponding to the ventilation blocks; after the double-layer sheet is pickled, take the upper sheet Make the solder resist pattern of the cap rib layer, in which the parts corresponding to the cap rib layer are sprayed with solder resist, and the rest of the parts should not be sprayed with solder resist.

The specific method of step 2 is:

Align the double-layer boards and weld the edges by manual argon arc welding; weld the ventilation block and the ventilation pipe to the position of the small hole reserved on the back of the cap rib layer by manual argon arc welding; check the ventilation block after the welding is completed , snorkel and air tightness of double slab.

In step 3, the superplastic forming diffusion bonding temperature of the titanium alloy is 920-930°C.

In step 4, the pressure is maintained for 2 hours.

In step 5, the pressure is maintained for 2 hours; the air pressure in the snorkel is unloaded and the temperature is lowered below 300 degrees Celsius.

The beneficial effects of the present invention compared with the prior art are:

Compared with the existing processing technology, the invention can realize the superplastic forming/diffusion joining process of the double-layered flap wall plate at one time with one set of tooling, saves a set of tooling and greatly reduces the processing cost.

According to the invention, the superplastic forming/diffusion joining process of the double-layer flap wall plate can be completed by only one heating, and the mechanical properties of the material can be improved.

The present invention adopts the one-time forming method of a set of molds, which can significantly shorten the product processing cycle and improve the production efficiency.

Description of drawings

Fig. 1 is the superplastic forming/diffusion connection mould diagram of the double-layer mouth cover wall plate;

Fig. 2 is the superplastic forming/diffusion connection lower die and assembly drawing of the double-layer mouth cover wall plate;

Figure 3 is a structural diagram of a double-layer mouth cover wall plate;

FIG. 4 is a schematic diagram of the solder resist pattern corresponding to the cap rib layer of the upper board.

Detailed ways

In order to reduce the cost of the titanium alloy double-layer port wall panel and improve the processing efficiency and material performance, the present invention proposes a superplastic forming/diffusion connection method for the double-layer port panel panel, which can be realized at one time by a set of tooling. Superplastic forming/diffusion joining process of double-layer flap panels.

Aiming at the superplastic forming/expansion connection process of the double-layered flap wall plate, the present invention proposes a set of mold forming method at one time.

A superplastic forming diffusion connection mold for a double-layer flap wall plate includes an upper mold 1, an inflatable tube 2, an inflatable hole 3, a sealing stem 4, a cavity 5, a lower mold 6, and a pressing block 7, as shown in Figure 1. Among them, the cavity 5 is located in the upper mold 1, and the end of each cavity 5 is provided with an inflatable hole 3, and all the inflatable holes 3 are communicated with the inflatable tube 2 outside the mold, which is used for the cavity when the double-layer mouth cover wall is formed. High-pressure inert gas (the pressure range is 2-3Mpa) is introduced into 5 to realize the diffusion connection between the double-layer plates; the inflatable hole 3 is arranged at the end of each cavity 5 and can also be used for gas during superplastic forming. of discharge. The upper mold 1 is provided with a sealing stem 4. When the mold is pressed down, the sealing stem 4, the slab and the cavity 5 of the upper mold form a closed cavity. Diffusion bonding of layer slabs.

Since the upper mold 1 needs to form a closed cavity to meet the requirements of diffusion connection, in this method, the superplastic forming ventilation device is arranged on the lower mold 6 . In the method of the present invention, the double-layer slab is used for air intake on the back of the cap rib layer 8, and the back air intake structure adopts the combination of ventilation block 9 and ventilation pipe 10, as shown in FIG. 2 . The lower mold 6 of the mold is provided with a pressing block 7 . After the double-layer slab is sealed and welded, the ventilation block 9 and the ventilation pipe 10 of the double-layered slab are placed in the groove of the lower mold 6 and compacted with the pressing block 7 .

In the present invention, when the double-layer mouth cover wall plate is subjected to superplastic forming/diffusion connection, after the double-layer slab is sprayed with a solder resist pattern and sealed and welded, the ventilation block 9 and the through hole are welded at the back small holes of the corresponding cap rib layer 8. trachea 10, and ensure the air tightness of the interior of the cavity, the ventilation block 9 and the ventilation tube 10. After the welding is completed, install the double-layer slab on the lower mold 6. At this time, the ventilation block 9 and the ventilation pipe 10 should be placed in the groove of the lower mold 6, and the ventilation pipe 10 should be compacted with the pressing block 7; finally, the upper mold is closed. 1.

When the mold is heated to the temperature of superplastic forming/diffusion bonding of titanium alloy, mechanical pressure is applied to the upper mold 1, so that the sealing stem 4, the slab and the upper mold cavity 5 form a closed cavity; Inert gas, pressurized to achieve diffusion bonding in the non-cap rib area of the double-layer plate.

After the diffusion connection is completed, the air pressure in the inflation pipe 2 is unloaded, and at the same time, a high-pressure inert gas is introduced into the ventilation pipe 10 of the lower mold 6 to maintain the pressure to realize the superplastic forming of the cap rib layer 8 .

After the cap rib is completely molded, the air pressure in the vent pipe 10 is unloaded and the temperature is lowered to realize the superplastic forming/diffusion connection of the double-layer flap wall plate.

This example provides a superplastic forming/diffusion joining method for a double-layer mouth cover wall; the part is a hollow cap rib structure, which is processed by the double-layer superplastic forming/diffusion joining method, and the non-cap rib part is a double-layer plate. Diffusion connection, the cap rib part is superplastic formed. The structure diagram is shown in Figure 3.

Example:

The specific method steps of this example are as follows:

Cut the material to make a double-layer board solder resist pattern. The titanium alloy double-layer sheet is laser cut, and the lower sheet corresponding to the cap rib layer 8 is cut with small holes corresponding to the ventilation block 9 . After the double-layer board is pickled, take the upper board to make the solder resist pattern of the cap rib layer 8, in which the parts corresponding to the cap rib layer 8 are sprayed with solder resist, and the rest of the parts should not be sprayed with solder resist. As shown in Figure 4.

Edge-sealing and welding the double-layer board, welding the ventilation block 9 and the ventilation pipe 10: after the preparation of the solder resist pattern of the cap rib, align the double-layer board and perform edge sealing welding by manual argon arc welding; then connect the ventilation block 9 to the ventilation pipe. 10 Use manual argon arc welding to weld to the small hole reserved on the back. After the welding is completed, check the air tightness of the ventilation block, the ventilation pipe 10 and the double slab.

Mold heating. Install the welded double-layer slab on the lower mold 6. At this time, the ventilation block 9 and the ventilation pipe 10 should be placed in the groove of the lower mold 6, and the ventilation pipe 10 should be compacted with the pressing block 7; finally, the upper mold is closed. 1; Raise the temperature of the mold to the superplastic forming/diffusion bonding temperature of the titanium alloy at 920-930°C.

Diffusion connection of double-layer plates: After the mold reaches temperature, apply a mechanical pressure of 4MPa to the upper mold 1, so that the sealing stem 4, the slab and the upper mold cavity 5 form a closed cavity; Argon, maintained for 2 hours to achieve diffusion bonding in the non-cap rib area of the double-layer plate.

Superplastic forming of cap rib layers. After the diffusion connection is completed, the air pressure in the inflation pipe 2 is unloaded, and 2MPa high-pressure argon gas is introduced into the ventilation pipe 10 of the lower mold 6 at the same time, and the pressure is maintained for 2 hours to realize the superplastic forming of the cap rib layer 8 . After the cap rib is completely molded, the air pressure in the vent pipe 10 is unloaded and the temperature is lowered to below 300°C, so as to realize the superplastic forming/diffusion connection of the double-layer mouth cover wall plate.

The parts of the present invention that are not described in detail belong to the well-known technology of those skilled in the art.

Claims (7)

1. a double-layer mouth cover wall plate superplastic forming diffusion connection mould, is characterized in that, comprises upper mould (1), inflatable tube (2), inflatable hole (3), sealing stem (4), cavity (5) ), lower die (6), pressing block (7); Wherein, the cavity (5) is located on the lower surface of the upper mold (1), the end of each cavity (5) is provided with an inflatable hole (3), and all the inflatable holes (3) are connected to the inflatable pipes ( 2) Connected, used for feeding high-pressure inert gas into the cavity (5) when forming the double-layer mouth cover wall plate; sealing stems (4) are arranged around the cavity (5) on the lower surface of the upper mold (1), When the mold is pressed down, the sealing stem (4), the double-layer slab and the cavity (5) of the upper mold form a closed cavity, and the double-layer slab is realized by maintaining the pressure after the high-pressure inert gas is introduced into the inflation tube (2). diffusion junction; A groove is provided on the lower die (6), and when the double-layer slab is installed on the lower die (6), the ventilation block (9) and the ventilation pipe (10) of the double-layered slab are correspondingly placed in the groove of the lower die (6). The inside is compacted with the pressing block (7). 2. use the mould as claimed in claim 1 to carry out the method for double-layer flap wall plate superplastic forming diffusion connection, is characterized in that, comprises the steps as follows: Step 1. Make a double-layer board solder resist pattern; Step 2: Welding the double-layer board by sealing the edge, and welding the ventilation block (9) and the ventilation pipe (10); Step 3: Install the welded double-layer slab on the lower mold (6), place the ventilation block (9) and the ventilation pipe (10) in the groove of the lower mold (6) correspondingly, and press with the pressing block (7). solid air pipe (10); finally closing the upper mold (1); heating the mold to the superplastic forming diffusion bonding temperature of titanium alloy; Step 4. After the mold reaches the superplastic forming diffusion bonding temperature of the titanium alloy, mechanical pressure is applied to the upper mold (1), so that the sealing stem (4), the double-layer slab and the upper mold cavity (5) form a closed cavity At the same time, high-pressure inert gas is introduced into the inflation pipe (2), and the pressure is maintained within a set time period, so as to realize the diffusion connection of the non-cap rib area of the double-layer plate; Step 5. Superplastic forming of the cap rib layer (8): unloading the air pressure in the inflation tube (2), and at the same time feeding high-pressure inert gas into the vent tube (10) of the lower die (6), within a set time period maintaining pressure to realize superplastic forming of the cap rib layer (8); after the cap rib is completely attached to the mold, unload the air pressure in the vent pipe (10) and cool down, so as to realize the superplastic forming diffusion connection of the double-layer mouth cover wall plate . 3. The method for superplastic forming diffusion connection of double-layer mouth cover wall plate according to claim 2, it is characterized in that, the concrete method of described step 1 is: laser cutting titanium alloy double-layer sheet, wherein the lower sheet corresponds to Cut out the holes corresponding to the ventilation block (9) at the part of the cap rib layer (8); after the double-layer board is pickled, take the upper board to make the solder resist pattern of the cap rib layer (8), wherein the cap rib layer ( 8) The corresponding parts should be sprayed with solder resist, and the rest of the parts should not be sprayed with solder resist. 4. the method for superplastic forming diffusion connection of double-layer mouth cover wall plate according to claim 3, is characterized in that, the concrete method of step 2 is: Align the double-layer boards and perform edge-sealing welding by manual argon arc welding; weld the ventilation block (9) and the ventilation pipe (10) to the small space reserved on the back of the cap rib layer (8) by manual argon arc welding. Hole location; check the air tightness of the ventilation block (9), the ventilation pipe (10) and the double-layer slab after the welding is completed. 5 . The method for superplastic forming diffusion joining of double-layered flap wall plates according to claim 4 , wherein in step 3, the temperature of superplastic forming diffusion joining of titanium alloy is 920-930° C. 6 . 6 . The method for superplastic forming diffusion connection of double-layer flap wall panels according to claim 5 , wherein the pressure is maintained for 2 hours in step 4. 7 . 7. The method for superplastic forming diffusion connection of double-layer port cover wall plates according to claim 6, characterized in that, in step 5, the pressure is maintained for 2 hours;

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