CN114227164A - Manufacturing method for light-weight missile wing superplastic forming - Google Patents

Abstract

The invention provides a manufacturing method for light-weight elastic wing superplastic forming, and belongs to the field of superplastic forming. The invention provides a manufacturing method for lightweight missile wing superplastic forming, which solves the problems of core plate tearing, excessive thinning, low flatness of outer skin, easy occurrence of step difference, grooves and the like, and comprises the following two-layer core plate forming process steps: blanking → acid cleaning → protective glue coating, solder resist coating, sealing and welding → diffusion connection → superplastic forming → machining the appearance; the forming process of the missile wing outer skin comprises the following steps: blanking → thermoforming → machining the shape; the forming process of the missile wing core plate and the outer skin comprises the following steps: acid cleaning → sealing → diffusion bonding → machining of the shape. The method is suitable for superplastic forming/diffusion connection of a titanium alloy four-layer structure, the obtained outer skin has high surface flatness, no step difference and no groove, the R angle of the core plate has no thin neck and no tearing, and the problem of excessive thinning of the core plate is reduced.

Description

Manufacturing method for light-weight missile wing superplastic forming

Technical Field

The invention belongs to the technical field of superplastic forming, and particularly relates to a manufacturing method of lightweight missile wing superplastic forming.

Background

The original process method adopts the superplastic forming/diffusion connection of double-side skins and a core plate, wherein the double-side skins are positioned at symmetrical positions on the core plate, four-layer plates are directly subjected to diffusion connection/superplastic forming, and the process steps are as follows: blanking → acid cleaning → coating protective glue, coating solder resist, sealing → diffusion connection → superplastic forming → machining the shape. The process has the problems of easy core plate tearing, excessive thinning, low flatness of the outer skin, easy occurrence of step difference, easy occurrence of grooves and the like.

Disclosure of Invention

In view of the above, in order to solve the problems of tearing and excessive thinning of the core plate, low flatness of the outer skin, easiness in occurrence of step difference and grooves and the like, the invention provides a manufacturing method for light-weight elastic wing superplastic forming, which is suitable for titanium alloy four-layer structure superplastic forming/diffusion connection, and is used for obtaining the core plate with high surface flatness, no step difference and no groove, and the core plate has no neck and no tearing at the R angle, so that the problem of excessive thinning of the core plate is reduced.

In order to achieve the purpose, the invention adopts the following technical scheme: a manufacturing method for light-weight missile wing superplastic forming specifically comprises the following steps:

(1) and the two-layer core plate forming process comprises the following steps: blanking → acid cleaning → protective glue coating, solder resist coating, sealing and welding → diffusion connection → superplastic forming → machining the appearance;

(2) the forming process of the outer skin of the missile wing comprises the following steps: blanking → thermoforming → machining the shape;

(3) the forming process of the missile wing core plate and the outer skin comprises the following steps: acid cleaning → sealing → diffusion bonding → machining of the shape.

Furthermore, the specific method of the two-layer core plate forming process in the step (1) comprises the following steps:

s1, removing an oxide film on the surface of the raw material by adopting an acid washing or alkali washing mode, and cleaning residual acid, alkali or oil stain on the surface by using alcohol or acetone;

s2, coating protective glue and solder resist on the surface of the core plate according to the size of the designed cavity;

s3, placing the core board A and the core board B correspondingly, sealing edges and welding the periphery of the core board by adopting manual argon arc welding, and welding a vent pipe at the position of a vent groove of the core board;

s4, placing the core board into a special diffusion connection tool to perform diffusion connection of the core board A and the core board B;

and S5, loading the core plate after diffusion connection into a superplastic forming tool, and connecting the core plate pipeline with a superplastic forming machine pipeline to carry out superplastic forming.

Further, in step S2, the method for coating the protective paste and the solder resist specifically includes:

firstly, coating protective glue on the whole core plate;

marking a non-diffusion area and a vent groove on the core plate by scribing, removing protective glue in the non-diffusion area and the vent groove by using a graver, and uniformly spraying solder resist;

and thirdly, removing the rest of the protective adhesive on the core board.

Further, in step S4, the method for diffusion bonding of the core plate a and the core plate B specifically includes:

cleaning the inner surface of a tool to ensure that the surface of the tool is clean and free of impurities, and uniformly spraying a welding stopping agent on an upper die and a lower die of the tool;

secondly, mounting the tooling on a workbench of a superplastic forming machine and fixing, placing a core plate into the tooling, connecting a core plate pipeline with an equipment pipeline, vacuumizing the core plate, and heating the tooling according to the optimal process temperature after the vacuum degree meets the requirement;

and thirdly, performing diffusion connection.

Further, in step S5, the superplastic forming method specifically includes:

firstly, designing a set of superplastic forming tools which conform to the outer surface of the missile wing, so that the appearance size of the two layers of core plates conforms to the requirement after superplastic forming;

secondly, mounting the tooling on a workbench of a superplastic forming machine and fixing, placing the core plate into the tooling, connecting a core plate pipeline and a tooling pipeline with an equipment pipeline, vacuumizing the core plate and the tooling, and heating the tooling according to the optimal process temperature after the vacuum degree meets the requirement;

thirdly, after the optimal process temperature is reached, argon is filled into the core plate, and a certain pressure (2.0MPa) is maintained;

fourthly, finishing the superplastic forming;

and fifthly, machining the outline of the core plate after the superplastic forming by adopting a machining mode, and reserving a minimum allowance.

Furthermore, the thermal forming process of the missile wing outer skin in the step (2) comprises the following specific steps:

s1, designing a thermal forming tool for the outer skin of the missile wing;

s2, carrying out hot forming on the outer skin according to the existing hot forming process;

and S3, machining the outer skin contour by adopting a machining mode, reserving a minimum allowance, and keeping the outer skin contour dimension consistent with the contour dimension of the core plate after machining.

Furthermore, the forming process of the missile wing core plate and the outer skin in the step (3) comprises the following specific steps:

s1, designing a diffusion bonding tool;

s2, fixing the core plate and the outer skin by argon arc welding, and respectively welding the core plate, the outer skin and the tooling with vent pipes;

s3, the core plate and the outer skin are placed in a tool to be fixed and placed on a superplastic forming machine, the pipeline is connected with an equipment pipeline, argon is introduced into the core plate and pressure is maintained, and the pipeline of the outer skin and the core plate is vacuumized or filled with argon;

s4, heating the tool according to the optimal process parameters and carrying out diffusion connection;

s5, machining the formed part by adopting a machining method to reach the final part shape;

and S6, adopting nondestructive testing or mechanical property testing to evaluate the quality of the formed piece.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention adopts the superplastic forming/diffusion bonding technology, which is an advanced manufacturing technology for promoting the development of the design concept of the modern aerospace structure and breaking through the traditional sheet metal forming method, and is a forming technology with low cost, high benefit and nearly no margin, and can be used for manufacturing a multilayer hollow lightweight structure, thereby achieving the purposes of reducing the structural weight and improving the structural integrity and the bearing efficiency.

(2) According to the invention, core plate diffusion connection/superplastic forming is firstly carried out, the effect of gas pressure on the interior of crystal lattices is more sufficient, the R angle is sufficient, the plate is uniformly thinned, no gap exists between the crystal lattices and the crystal lattices, the superplastic R angle tearing of the core plate is reduced, the fillet filling is improved, and the problem of excessive thinning of the core plate is reduced.

(3) The core plate and the outer skin are in diffusion connection only, the core plate has small lattice deformation, the secondary deformation of the core plate is avoided, and the problems of low flatness of the outer skin, easy occurrence of step difference and grooves are solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of a manufacturing method for light-weight missile wing superplastic forming according to the invention;

FIG. 2 is a schematic view of the process of generating the outer skin step difference and the groove; wherein (a) represents the diffusion connection of the core plate and the face plate, and the action force of vacuumizing is applied between the core plate and the face plate; (b) indicating that gas siltation is easily formed between each lattice gap of the core plate and the face plate in the diffusion bonding process; (c) indicating that the outer surface of the panel is easy to have step difference and groove due to the action of gas pressure.

FIG. 3 is a schematic view of the core plate being excessively thinned and torn; wherein (a) shows that the core plate is in diffusion connection with the face plate under the action of internal gas pressure in the superplastic forming process of the core plate; (b) after the diffusion connection is carried out on the first contact area of the core plate and the panel, the core plate continuously deforms under the action of the internal gas pressure to cause excessive thinning and tearing; (c) the phenomenon that each crystal lattice of the core plate is excessively thinned under the action of internal gas pressure continuously is shown.

FIG. 4 is a schematic view of a diffusion bonding/superplastic forming of a core plate; wherein (a) the core plate A and the core plate B are vacuumized, and argon is introduced between the plate and the tool for protection; (b) vacuumizing the space between the plate and the tool, and filling argon into the space between the core plate A and the core plate B to perform superplastic forming; (c) the core plate superplastic forming is completed schematically.

FIG. 5 is a schematic view of a missile wing outer skin thermoforming tool;

FIG. 6 is a schematic view of a diffusion bonding tool for a core plate and an outer cover of a missile wing;

FIG. 7 is a schematic view of the diffusion bonding of the core plate to the outer skin of the missile wing; wherein argon is introduced: introducing argon gas into the superplastic formed core plate and maintaining the pressure to realize diffusion connection; deairing (evacuation): and vacuumizing the gap between the core plate and the skin.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely explained below with reference to the drawings in the embodiments of the present invention. It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict, and the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments.

First embodiment, the present embodiment will be described with reference to fig. 1 to 7.

The structural component material is TA15 titanium alloy. The thickness of the skins at the two sides is 1.0mm, and the thickness of the plate material of the core plate is 1.0 mm. The original process method adopts the superplastic forming/diffusion connection of double-side skins and a core plate, wherein the double-side skins are positioned at symmetrical positions on the core plate, four-layer plates are directly subjected to diffusion welding/superplastic forming, and the process steps are as follows: blanking → acid cleaning → coating protective glue, coating solder resist, sealing → diffusion connection → superplastic forming → machining the shape.

The process method adopted by the invention is that the operation steps are changed on the basis of the original process method, and the step-by-step operation is adopted, and the specific operation steps are as follows:

1. the two-layer core plate forming process comprises the following steps: blanking → acid cleaning → coating protective glue, coating solder resist, sealing → diffusion connection → superplastic forming → machining the shape.

2. The outer skin forming process comprises the following steps: blanking → thermoforming → machining the shape.

3. The missile wing forming process comprises the following steps: acid cleaning → seam welding → diffusion bonding → machining of the profile.

The invention adopts the superplastic forming/diffusion bonding technology, which is an advanced manufacturing technology for promoting the development of the design concept of the modern aerospace structure and breaking through the traditional sheet metal forming method, and is a forming technology with low cost, high benefit and nearly no margin, and can be used for manufacturing a multilayer hollow lightweight structure, thereby achieving the purposes of reducing the structural weight and improving the structural integrity and the bearing efficiency.

Compared with the original process method, the part obtained by the method of the invention has the advantages that firstly, the position and the size of the crystal lattice are determined by performing diffusion connection on the core plate; superplastic forming is carried out after diffusion connection, the interior of the crystal lattice is fully acted by gas pressure, the R angle is sufficient, the plate is uniformly thinned, no gap exists between the crystal lattice and the crystal lattice, superplastic R angle tearing of the core plate is reduced, fillet filling is improved, and the problem of excessive thinning of the core plate is reduced; and the core plate is in diffusion connection with the outer skin, only diffusion connection occurs, the amount of lattice deformation of the core plate is small, secondary deformation of the core plate cannot be caused, and the problems that the flatness of the outer skin is low, and step difference and grooves are easy to occur are solved.

The specific method for superplastic forming diffusion bonding of two core plates comprises the following steps (as shown in figure 4):

1. removing the oxide film on the surface of the raw material by adopting an acid washing or alkali washing mode, and cleaning residual acid, alkali, oil stain and the like on the surface by using alcohol or acetone.

2. And (4) coating a solder resist on the surface of the core plate according to the size of the designed cavity. The solder resist should be uniformly coated and suitably thin and thick.

Firstly, coating protective glue on the whole core plate;

marking a non-diffusion area and a vent groove on the core plate by scribing, removing protective glue in the non-diffusion area and the vent groove by using a graver, and uniformly spraying a solder stop agent;

and thirdly, removing the rest of the protective adhesive on the core board.

3. The core board A and the core board B are correspondingly placed, edge sealing welding is carried out on the periphery of the core board by adopting manual argon arc welding (sealing welding is not carried out at the position of the vent groove), and the vent pipe is welded at the position of the vent groove of the core board.

4. And placing the core board into a special diffusion connection tool to perform diffusion connection of the core board A and the core board B.

Cleaning the inner surface of a tool to ensure that the surface of the tool is clean and free of impurities, and uniformly spraying a welding stopping agent on an upper die and a lower die of the tool;

secondly, mounting the tooling on a workbench of a superplastic forming machine and fixing, placing the core plate into the tooling (placing according to a tooling limit position), connecting a core plate pipeline with an equipment pipeline, vacuumizing the core plate firstly, and heating the tooling according to an optimal process temperature after the vacuum degree meets the requirement (continuously vacuumizing in the heating process and finishing diffusion connection);

and thirdly, performing diffusion connection.

5. And (4) loading the core plate subjected to diffusion connection into a superplastic forming tool, and connecting the core plate pipeline with the pipeline of the overspeed forming machine to perform superplastic forming.

Firstly, designing a set of superplastic forming tools which conform to the outer shape surface of the missile wing (the thickness of upper and lower outer skins is reduced), so that the external dimensions of the two layers of core plates conform to the requirements after superplastic forming;

secondly, mounting the tooling on a workbench of a superplastic forming machine and fixing, placing the core plate into the tooling (placing according to a tooling limit position), connecting a core plate pipeline and a tooling pipeline with an equipment pipeline, vacuumizing the core plate and the tooling at first, and heating the tooling according to an optimal process temperature after the vacuum degree meets the requirement (the tooling pipeline continuously maintains a vacuumizing state);

thirdly, after the optimal process temperature is reached, argon is filled into the core plate, and a certain pressure (2.0MPa) is maintained;

fourthly, finishing the superplastic forming;

and fifthly, machining the outline of the core plate after the superplastic forming by adopting a machining mode, and reserving a minimum allowance.

Secondly, a thermal forming process of the missile wing outer skin comprises the following steps:

1. and designing a thermal forming tool for the missile wing outer skin (shown in figure 5).

2. The outer skin is thermoformed according to the existing thermoforming process.

3. And (4) machining the outer skin contour by adopting a machining mode, and reserving a minimum allowance (the outer contour dimension is consistent with the outer contour dimension of the core plate after machining).

Thirdly, diffusion connection is carried out between the core plate and the outer skin

1. A diffusion bonding tool was designed (as shown in fig. 6).

2. And (3) fixing the core plate and the outer skin by argon arc welding edge sealing, and welding the core plate, the outer skin and the tooling with the vent pipe.

3. And (3) placing the core plate and the outer skin into a tool, fixing the core plate and the outer skin, placing the core plate and the outer skin on a superplastic forming machine, and connecting a pipeline with an equipment pipeline. Argon is introduced into the core plate, the pressure is maintained, and the outer skin and core plate pipelines are vacuumized or filled with argon.

4. And heating the tool according to the optimal process parameters and performing diffusion connection.

5. And (4) machining the formed part by adopting a machining method to achieve the final part shape.

6. And evaluating the quality of the formed part by adopting modes such as nondestructive testing, mechanical property testing and the like.

The embodiments of the invention disclosed above are intended merely to aid in the explanation of the invention. The examples are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention.

Claims (7)

1. A manufacturing method for light-weight missile wing superplastic forming is characterized in that: the method specifically comprises the following steps:

(1) and the two-layer core plate forming process comprises the following steps: blanking → acid cleaning → protective glue coating, solder resist coating, sealing and welding → diffusion connection → superplastic forming → machining the appearance;

(2) the forming process of the outer skin of the missile wing comprises the following steps: blanking → thermoforming → machining the shape;

(3) the forming process of the missile wing core plate and the outer skin comprises the following steps: acid cleaning → sealing → diffusion bonding → machining of the shape.

2. The manufacturing method of light-weight missile wing superplastic forming according to claim 1, characterized in that: the specific method of the two-layer core plate forming process in the step (1) comprises the following steps:

s1, removing an oxide film on the surface of the raw material by adopting an acid washing or alkali washing mode, and cleaning residual acid, alkali or oil stain on the surface by using alcohol or acetone;

s2, coating protective glue and solder resist on the surface of the core plate according to the size of the designed cavity;

s3, placing the core board A and the core board B correspondingly, sealing edges and welding the periphery of the core board by adopting manual argon arc welding, and welding a vent pipe at the position of a vent groove of the core board;

s4, placing the core board into a special diffusion welding tool to perform diffusion connection of the core board A and the core board B;

and S5, loading the core plate after diffusion connection into a superplastic forming tool, and connecting the core plate pipeline with a superplastic forming machine pipeline to carry out superplastic forming.

3. The manufacturing method of the lightweight missile wing superplastic forming according to claim 2, comprising the steps of: in step S2, the method for coating the protective glue and the solder resist specifically includes:

firstly, coating protective glue on the whole core plate;

marking a non-diffusion area and a vent groove on the core plate by scribing, removing protective glue in the non-diffusion area and the vent groove by using a graver, and uniformly spraying solder resist;

and thirdly, removing the rest of the protective adhesive on the core board.

4. The manufacturing method of the lightweight missile wing superplastic forming according to claim 2, comprising the steps of: in step S4, the method for diffusion bonding of core plate a and core plate B specifically includes:

cleaning the inner surface of a tool to ensure that the surface of the tool is clean and free of impurities, and uniformly spraying a welding stopping agent on an upper die and a lower die of the tool;

secondly, mounting the tooling on a workbench of a superplastic forming machine and fixing, placing a core plate into the tooling, connecting a core plate pipeline with an equipment pipeline, vacuumizing the core plate, and heating the tooling according to the optimal process temperature after the vacuum degree meets the requirement;

and thirdly, performing diffusion connection.

5. The manufacturing method of the lightweight missile wing superplastic forming according to claim 2, comprising the steps of: in step S5, the superplastic forming method specifically includes:

firstly, designing a set of superplastic tooling conforming to the outer surface of the missile wing, so that the external dimension of the two layers of core plates conforms to the requirement after superplastic forming;

secondly, mounting the tooling on a workbench of a superplastic forming machine and fixing, placing the core plate into the tooling, connecting a core plate pipeline and a tooling pipeline with an equipment pipeline, vacuumizing the core plate and the tooling, and heating the tooling according to the optimal process temperature after the vacuum degree meets the requirement;

thirdly, after the optimal process temperature is reached, argon is filled into the core plate and certain pressure is maintained;

fourthly, finishing the superplastic forming;

and fifthly, machining the outline of the core plate after the superplastic forming by adopting a machining mode, and reserving a minimum allowance.

6. The manufacturing method of light-weight missile wing superplastic forming according to claim 1, characterized in that: the thermal forming process of the missile wing outer skin in the step (2) comprises the following specific steps:

s1, designing a thermal forming tool for the outer skin of the missile wing;

s2, carrying out hot forming on the outer skin according to the existing hot forming process;

and S3, machining the outer skin contour by adopting a machining mode, reserving a minimum allowance, and keeping the outer skin contour dimension consistent with the contour dimension of the core plate after machining.

7. The manufacturing method of light-weight missile wing superplastic forming according to claim 1, characterized in that: the forming process of the missile wing core plate and the outer skin in the step (3) comprises the following specific steps:

s1, designing a diffusion bonding tool;

s2, fixing the core plate and the outer skin by argon arc welding, and welding the core plate, the outer skin and the tooling with the vent pipe;

s3, the core plate and the outer skin are placed in a tool to be fixed and placed on a superplastic forming machine, the pipeline is connected with an equipment pipeline, argon is introduced into the core plate and pressure is maintained, and the pipeline of the outer skin and the core plate is vacuumized or filled with argon;

s4, heating the tool according to the optimal process parameters and carrying out diffusion connection;

s5, machining the formed part by adopting a machining method to reach the final part shape;

and S6, adopting nondestructive testing or mechanical property testing to evaluate the quality of the formed piece.

Images