Non-uniform temperature field drawing and bulging integrated forming device and forming method

Abstract

The invention discloses a non-uniform temperature field drawing and bulging integrated forming device and method. The invention belongs to the field of thermoforming. The problem that the wall thickness is not uniform when a part with the large depth-diameter ratio is formed through an existing superplastic forming method is solved. The forming device comprises a high-pressure gas source storage tank, a gas source control system, a computer control system, superplastic forming equipment, a drawing and bulging integrated forming die and a to-be-formed plate, the superplastic forming equipment comprises a heating rod with the temperature independently adjusted, and different temperatures are set for the heating rod according to different forming areas; the flowing speed and the flowing direction of the material in the mold are controlled, so that the material is prevented from being stacked and too thin; the forming method provided by the invention comprises the following steps: (1) setting different temperatures for a heating rod and heating; (2) putting a to-be-formed plate after the furnace temperature of each part reaches a specified temperature; (3) the to-be-formed plate is pre-tightened, and a main cylinder is pressed downwards for pre-forming; and (4) the pressure is kept, an air source control system is ventilated, and air expansion forming is conducted.

Description

Technical Field

[0001] The invention belongs to the field of hot forming, and in particular relates to a non-uniform temperature field deep drawing and bulging integrated forming method. Background Art

[0002] As an advanced metal forming technology, superplastic forming (SPF) is widely used in aerospace, automobile manufacturing and other fields. This technology uses the extremely high ductility of certain metals or alloys under specific temperature and strain rate conditions to achieve precision forming of complex-shaped parts. With the continuous development of science and technology, the shapes of parts are becoming more and more complex, and superplastic forming has become one of the key forming technologies.

[0003] At present, superplastic forming technology is developing rapidly and has been widely used in aerospace, transportation, manufacturing, electronic products and other fields. However, for deep barrel parts with a large aspect ratio, superplastic forming has the problem of wall thickness uniformity, which seriously restricts the rapid development of superplastic forming technology. Therefore, it is particularly important to improve the wall thickness uniformity.

[0004] During the superplastic forming process, due to the uneven stress distribution, the material flow rate in the mold may vary. This difference causes the material to flow faster in some areas, forming a thinner wall thickness, while the material in other areas flows slower, resulting in a thicker wall thickness. This problem is particularly evident when forming parts with complex shapes. To achieve uniform wall thickness, mold design and process parameter control are crucial. However, due to the complexity of material flow during superplastic forming, it becomes very difficult to accurately predict and control the wall thickness of each area. In addition, factors such as friction on the mold surface and local stress concentration can also affect the fluidity of the material, resulting in uneven wall thickness. Typically, superplastic forming is performed at a low strain rate to prevent the material from breaking or generating defects during the forming process. However, longer forming times may cause changes in the material's microstructure, further affecting its fluidity and forming effect. Such microstructural changes may also cause the uniformity of the final part wall thickness to be affected. At present, the method of improving wall thickness uniformity by temperature regulation has not been widely discussed, but has the potential for further research. Summary of the invention

[0005] The present invention provides a non-uniform temperature field deep drawing and bulging integrated forming device and forming method to solve the technical problem of uneven wall thickness when forming parts with a large depth-to-diameter ratio using the existing superplastic forming method.

[0006] The technical solution of the present invention:

[0007] One of the purposes of the present invention is to provide a non-uniform temperature field drawing and bulging integrated forming device, comprising:

[0008] High-pressure gas source storage tank;

[0009] Air source control system;

[0010] Computer control system;

[0011] Superplastic forming equipment, including insulation wall, cooling water channel, host platform, inner cavity side wall, forming machine lower slide, press upper slide, heating rod, press host frame;

[0012] The integrated forming die for deep drawing and bulging comprises a forming part punch and a forming part concave die;

[0013] Sheet material to be formed.

[0014] It is further defined that the sheet material to be formed is placed between a forming part concave die and a forming part convex die, and the forming part concave die and the forming part convex die are respectively fixed on the heating platform.

[0015] It is further defined that a pressure ring and a hook are provided on the female die of the forming part, and a hook is provided on the male die of the forming part.

[0016] It is further defined that the height of the convex die of the formed part is less than the depth of the concave die of the formed part.

[0017] It is further defined that the interior of the host platform is filled with heating rods.

[0018] It is further defined that the heating rod has different temperatures through regulation of the computing control system.

[0019] It is further defined that the computer control system adjusts the temperature of each heating rod and adjusts the gas pressure loading of the gas source control system.

[0020] The second object of the present invention is to provide a method for forming using the above device, comprising:

[0021] Step 1: Fix the forming part punch and the forming part die to the host platform respectively, set different temperatures for the heating rod according to the position of the deep drawing and bulging integrated forming die and the positional relationship between the heating rod and the forming area by using a computer control system, and start heating;

[0022] Step 2: Grind the sheet to be formed, clean it and blow it dry, and put the sheet to be formed into the superplastic forming equipment after the furnace temperature at each location reaches the temperature set in step 1;

[0023] Step 3: Set the preload force of the upper slide of the press, the upper slide of the press pushes the concave die of the forming part downward, and the lower slide of the forming machine pushes the convex die of the forming part upward, so that the blank holder contacts the sheet to be formed, and the sheet to be formed is preloaded. After the furnace temperature reaches the temperature set in step 1 again, keep it warm for a period of time, and then move the upper slide of the press downward to stretch the sheet to be formed;

[0024] Step 4: The main frame of the press includes a main cylinder of the press. When the punch of the forming part contacts the blank holder ring on the concave die of the forming part, the main cylinder of the press stops moving, and the sheet to be formed is pre-tightened with a certain pre-tightening force. Then, the air source control system starts to blow air to the sheet to be formed for air expansion forming;

[0025] Step 5: After the inflation forming is completed, stop heating, cool down and take out the product.

[0026] It is further defined that the temperature range in step 1 is 860-940°C.

[0027] It is further defined that the positional relationship between the heating rod and the forming area in step 1 is: the heating rod is within the forming area and the heating rod is outside the forming area.

[0028] It is further defined that in step 1, the forming area is divided into small deformation areas on both sides, a large deformation area in the middle and a transition area in the middle. The temperature of the heating rods in the small deformation areas on both sides is set to the upper temperature of the forming interval, and the temperature of the heating rods in the large deformation area in the middle is set to the lower temperature of the forming interval.

[0029] It is further defined that in step 1, the materials of the forming part punch and the forming part die are both 2520 stainless steel.

[0030] It is further defined that the plate material to be formed in step 2 is titanium alloy.

[0031] It is further defined that the holding time in step 3 is 10 minutes.

[0032] It is further defined that in step 3, the downward movement speed of the slide block on the press is 10 to 30 mm / min.

[0033] It is further defined that the parameters of the blowing process in step 4 are: air pressure loading rate 0.001-1 MPa / min, maximum air pressure 3-5 MPa, and pressure holding time 30-60 min.

[0034] Beneficial effects of the present invention:

[0035] (1) The superplastic forming in a non-uniform temperature field of the present invention is a technology that intentionally creates temperature field differences during the superplastic forming process. This method utilizes the effect of temperature on the fluidity of the part material to optimize the quality and performance of the formed part, and has a good effect when forming complex or large-sized metal parts with a large depth-to-diameter ratio.

[0036] (2) The present invention uses a heating rod whose temperature can be independently adjusted by a computer during the superplastic forming process. Different temperatures are set according to different forming areas. By locally adjusting the temperature of the heating rod and establishing a temperature gradient, the flow speed and flow direction of the part material in the mold can be controlled. The material fluidity in the high-temperature zone is enhanced, while the material fluidity in the low-temperature zone is weakened, thereby avoiding material accumulation and excessive thinning in key areas of parts with a large depth-to-diameter ratio, and avoiding excessive thin wall thickness in the deep area of ​​the part and excessive thick wall thickness in the shallow area due to material accumulation. This is beneficial to achieving more uniform wall thickness distribution for parts with a large depth during the superplastic forming process.

[0037] (3) The present invention can reduce part forming defects. In superplastic forming, uniform material flow is the key to avoiding forming defects such as cracks and wrinkles. The present invention can reduce stress concentration caused by uneven material flow by precisely controlling the temperature distribution of each area during superplastic forming, thereby reducing or eliminating forming defects and improving the overall quality and reliability of finished parts.

[0038] (4) The present invention can improve material utilization. The non-uniform temperature field provided by the present invention can cause the part material to flow in a concentrated manner in the area that needs to be thickened, thereby reducing material waste. This method can more effectively utilize materials and reduce residual and cut waste by accurately controlling the forming temperature of each area, which has a positive impact on cost control and environmental protection of part processing and forming.

[0039] (5) The present invention can shorten the forming time of parts and improve production efficiency. Conventional superplastic forming often requires maintaining a uniform high temperature throughout the workpiece to maintain the superplasticity of the material, while the non-uniform temperature field of the present invention can achieve the same effect through local heating. This method can significantly shorten the heating time and improve production efficiency without sacrificing the forming quality.

[0040] (6) The forming method provided by the present invention has strong adaptability. The non-uniform temperature field superplastic forming provides a high degree of flexibility and can adjust the temperature distribution according to different forming requirements to meet the forming requirements of various complex parts. It has broad application prospects in the fields of aerospace, automobiles and high-precision manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the non-uniform temperature field stretching and bulging integrated forming in Example 1;

[0042] Figure 2 It is a three-dimensional image of the formed part of Example 1;

[0043] Figure 3 A schematic diagram showing the principle of a method for decomposing the air pressure loading curve obtained by the Marc software in Example 1 into an input air source control system;

[0044] Figure 4 for Figure 1 A magnified view of the integrated deep-drawing and bulging forming die when it is working in a non-uniform temperature field;

[0045] Figure 5 This is a cross-sectional view of the parts formed in Example 1;

[0046] Figure 6 It is a cross-sectional view of the part formed in Comparative Example 1;

[0047] Figure 7 It is a comparison curve of the wall thickness uniformity of the parts formed by Example 1 and Comparative Example 1;

[0048] Figure 8 The instability performance comparison curve of the parts formed by Example 1 and Comparative Example 1;

[0049] Among them, 1. High-pressure gas source storage tank; 2. Gas source control system; 3. Computer control system; 4. Insulation wall; 5. Cooling water channel; 6. Main machine platform; 7. Inner cavity side wall; 8. Lower slide of forming machine; 9. Forming part punch; 10. Forming part die; 10-1. Binder; 11. Plate to be formed; 12. Upper slide of press; 13. Heating rod; 14. Main machine frame of press; 15. Hook; 16. Temperature zone A (high temperature zone); 17. Temperature zone B (transition zone); 18. Temperature zone C (low temperature zone); 19. Temperature zone D (transition zone); 20. Temperature zone E (high temperature zone); 21. Temperature zone F (low temperature zone). DETAILED DESCRIPTION

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0052] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0053] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, and methods used are conventional materials, reagents, and methods in the art, unless otherwise specified, and can be obtained by those skilled in the art through commercial channels.

[0054] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0055] Example 1

[0056] This embodiment provides a non-uniform temperature field stretching and bulging integrated forming device, the device structure and forming process are as follows Figure 1 , Figure 4 As shown, the device comprises:

[0057] High-pressure gas source storage tank 1;

[0058] Gas source control system 2;

[0059] Computer control system 3;

[0060] The superplastic forming equipment includes a heat preservation wall 4, a cooling water channel 5, a main machine platform 6, an inner cavity side wall 7, a lower slide block 8 of a forming machine, an upper slide block 12 of a press machine, a heating rod 13, and a main machine frame 14 of a press machine;

[0061] The integrated drawing and bulging forming die comprises a forming part punch 9 and a forming part die 10;

[0062] The sheet material 11 to be formed.

[0063] like Figure 1 and Figure 4 As shown, the sheet 11 to be formed is placed between the forming part die 10 and the forming part punch 9, the height of the forming part punch 9 is less than the depth of the forming part die 10, both the forming part punch 9 and the forming part die 10 are provided with hooks 15, and the forming part die 10 is also provided with a pressure ring 10-1, the deep drawing and bulging integrated forming mold moves up and down through the hooks 15, the main engine platform 6 is filled with heating rods 13, the main engine platform 6 is heated by the heating rods 13, the main engine platform 6 heats the deep drawing and bulging integrated forming mold, and the deep drawing and bulging integrated forming mold heats the sheet 11 to be formed, the heating rods 13 can be adjusted by the computer control system 3 to have different temperatures, and the specific temperature setting is determined according to different forming areas; in addition to adjusting the temperature of each heating rod 13, the computer control system 3 can also adjust the loading curve of the air source control system 2; the area on the lower side of the insulation wall 4 and the inner side of the inner cavity side wall 7 is the furnace body part in the superplastic forming equipment.

[0064] The method for forming using the above-mentioned device provided in this embodiment includes:

[0065] Step 1: Close the furnace door of the superplastic forming equipment, fix the forming part punch 9 and the forming part die 10 to the main machine platform respectively, the forming part punch 9 and the forming part die 10 are made of 2520 stainless steel, and use the computer control system 3 to set different temperatures for the heating rod 13 according to the mold placement position and the positional relationship between the heating rod and the forming area. The temperature setting rules are as follows: the heating rod 13 is divided into inside the forming area and outside the forming area. The position where the sheet 11 to be formed is formed is the forming area. The range covered by the heating rod 13 in the horizontal direction of the forming area indicates that the heating rod 13 is in the forming area. The range covered by the heating rod 13 in the horizontal direction of the forming area and being outside the range covered by the heating rod 13 in the horizontal direction of the forming area and being at both ends of the forming area indicates that the heating rod 13 is outside the forming area. The temperature of the heating rod 13 not in the forming area is uniformly set to the lowest temperature of the forming interval temperature of the sheet 11 to be formed. The sheet material in this embodiment is TC4 high-temperature titanium alloy, so the temperature of the heating rod 13 not in the forming area is set to 860°C. This area is Figure 3 21 (temperature zone F) in the figure can also be called the low temperature zone; for the forming area, it can be divided into small deformation areas on both sides, a large deformation area in the middle and a transition area in the middle. The positions of the small deformation areas on both sides are: the parts within the forming area and close to the left and right sides of the formed part, that is, Figure 3 16 (temperature zone A) and 20 (temperature zone E) in the figure, the temperature of the heating rod 13 in the small deformation zones on both sides is set to the upper temperature of the forming interval 940°C, the small deformation zones on both sides can also be called high temperature zones, and the position of the middle large deformation zone is: the part within the forming zone and located in the middle of the formed part (the part with the largest deformation), that is, Figure 3 18 (temperature zone C), the temperature of the heating rod 13 in the middle large deformation zone is set to the lower temperature of the forming interval 860°C. This zone can also be called the low temperature zone. The middle transition zone is the transition temperature field naturally formed between the small deformation zones on both sides and the middle large deformation zone, that is, Figure 3 In 17 (temperature zone B) and 19 (temperature zone D), it should be noted that: Figure 3 This is to better illustrate the situation of the mold in the non-uniform temperature field and how the temperature areas of the non-uniform temperature field are divided. Figure 3 The arc line on the die 10 of the formed part is the contour line of the concave part. Figure 3 This is to explain the temperature setting rules of the heating rod 13, and does not represent Figure 3 It is a schematic diagram of the process of step 1, in which forming has not yet begun;

[0066] Step 2: Clean the sheet 11 to be formed. The sheet material is TC4 high-temperature titanium alloy. Polish the impurities on the surface of the TC4 high-temperature titanium alloy, clean it with 100% alcohol, blow it dry and set it aside. In the process of cleaning the sheet 11 to be formed, be sure to ensure that the sheet is smooth and pollution-free to avoid stress concentration during deformation. After the furnace temperature in each part of the superplastic forming equipment furnace reaches the set temperature in step 1, open the furnace door and put in the sheet 11 to be formed;

[0067] Step 3: Set the preload force of the upper slide 12 of the press, and make the upper slide 12 of the press push the forming part die 10 downward, and the lower slide 8 of the forming machine push the forming part die 9 upward, so that the blank holder 10-1 contacts the sheet 11 to be formed, and preloads the sheet 11 to be formed for hot stretching preforming. The Marc software is used to simulate the preload force of 1t according to the size of the sheet 11 to be formed (length 400mm, width 160mm). Since the furnace door is opened in step 2, the temperature will drop. Therefore, after the furnace temperature reaches the set temperature in step 1 again, it is kept warm for ten minutes, and the upper slide 12 of the press moves downward at a speed of 10mm / min to stretch the sheet 11 to be formed.

[0068] Step 4: After the punch 9 of the formed part contacts the blank holder 10-1 on the die 10 of the formed part, the main cylinder of the press stops moving, and the slide 12 on the press pre-tightens the sheet 11 to be formed with a pre-tightening force of 1t (the calculation method of the pre-tightening force is the same as that of step 3). At this time, the part of the sheet 11 to be formed that has not reached the die 10 of the formed part is blown to fit by the subsequent air source. After pre-tightening, the computer control system 3 divides the air pressure loading curve into the smallest adjustment interval according to the finite element simulation results, and assigns the descending command to the air source control system 2. The air source control system 2 loads and starts blowing for air bulging. The air pressure loading rate is 0.1MPa / min. After loading to the maximum air pressure of 2MPa, the pressure is maintained for 30 minutes.

[0069] Step 5: After the inflation forming is completed, stop heating, cool down and take out the product.

[0070] Figure 2 This is a three-dimensional diagram of the part formed in this embodiment. It can be seen from the figure that the deformation of the part is small at both ends and large in the middle. It is a thin-walled part with a large diameter reduction ratio (large depth-to-diameter ratio part), and its shape conforms to the law of parts formed in a non-uniform temperature field.

[0071] Figure 5This is a cross-sectional view of the part formed in this embodiment. It can be seen from the figure that the wall thickness of the part is uniform, which shows that the present invention uses hot stretching pre-forming to bring the sheet material into the cavity composed of the forming part punch 9 and the forming part die 10, which improves the uniformity of the wall thickness of the formed part to a certain extent. Combined with the non-uniform temperature field, high temperature is used in the small deformation area to promote deformation, and low temperature is used in the large deformation area to weaken deformation. Finally, the material deformation tends to be average, which greatly improves the uniformity of the wall thickness of the formed part.

[0072] The wall thickness distribution curve of the formed part in this embodiment is as follows: Figure 7 As shown in the red curve in the middle, it can be seen that the wall thickness of each point of the part formed using a non-uniform temperature field is not much different, and the wall thickness can be considered to be uniform.

[0073] The instability performance curve of the formed part in this embodiment is as follows: Figure 8 As shown in the black curve, it can be seen that the instability strength of the parts formed using the non-uniform temperature field is as high as 37MPa, indicating that it has good ability to resist deformation.

[0074] Comparative Example 1

[0075] This comparative example adopts a uniform temperature field to perform superplastic forming to prepare parts. The components have the same structure, shape, and function as those in Example 1. For example, the forming part punch, the upper slide block of the press, etc. mentioned in this comparative example can be considered as the same components as the forming part punch 9, the upper slide block 12 of the press, etc. in the embodiment. The specific steps are as follows:

[0076] Step 1: Close the furnace door of the superplastic forming equipment, fix the forming part punch and the forming part die to the main machine platform respectively, the forming part punch and the forming part die are made of 2520 stainless steel, set the furnace temperature to 920℃, and start heating.

[0077] Step 2: Clean the sheet to be formed. The sheet material is TC4 high-temperature titanium alloy. Grind away impurities on the surface of the TC4 high-temperature titanium alloy, clean it with 100% alcohol, blow it dry and set it aside. In the process of cleaning the sheet to be formed, be sure to ensure that the sheet is smooth and pollution-free to avoid stress concentration during deformation. After the furnace temperature of the superplastic forming equipment reaches 920°C set in step 1, open the furnace door and put in the sheet to be formed;

[0078] Step 3: Set the preload force of the upper slide of the press, and make the upper slide of the press push the concave die of the forming part downward, and the lower slide of the forming machine push the convex die of the forming part upward, so that the blank holder contacts the sheet to be formed, and preloads the sheet to be formed for hot stretching preforming. The Marc software is used to simulate the preload force of 1t according to the size of the sheet to be formed (length 400mm, width 160mm). Since the furnace door is opened in step 2, the temperature will drop. Therefore, after the furnace temperature reaches 920℃ in step 1 again, it is kept warm for ten minutes, and the upper slide of the press moves downward at a speed of 10mm / min to stretch the sheet to be formed.

[0079] Step 4: After the punch of the formed part contacts the blank holder on the die of the formed part, the main cylinder of the press stops moving, and the slide on the press preloads the sheet to be formed with a preload force of 1t (the calculation method of the preload force is the same as that of step 3). At this time, the part of the sheet to be formed that has not reached the die of the formed part is blown to fit by the subsequent air source. After preloading, the computer control system segments the air pressure loading curve into the smallest adjustment interval according to the finite element simulation results, and assigns the descending command to the air source control system. The air source control system loads and starts blowing for air bulging. The air pressure loading rate is 0.1MPa / min. After loading to the maximum air pressure of 2MPa, the pressure is maintained for 30 minutes.

[0080] Step 5: After the inflation forming is completed, stop heating, cool down and take out the product.

[0081] Figure 6 For thin-walled parts with a large diameter reduction ratio (large depth-to-diameter ratio parts) formed using a uniform temperature field, it can be seen that compared with the parts prepared using a non-uniform temperature field in Example 1, the wall thickness uniformity of the parts prepared in the comparative example is worse than that in Example 1, indicating that the wall thickness uniformity of the parts formed by the non-uniform temperature field is greatly improved compared to the parts formed by the uniform temperature field.

[0082] The wall thickness distribution curve of the formed part in this embodiment is as follows: Figure 7 As shown in the black curve, it can be seen that the wall thickness of some points of the parts formed using a uniform temperature field differs by 0.15 mm, and the wall thickness is obviously uneven, indicating that the wall thickness uniformity of the parts formed using a uniform temperature field is poor.

[0083] The instability performance curve of the formed parts in this comparative example is as follows Figure 8 As shown in the red curve, it can be seen that the maximum instability strength of the parts formed using a uniform temperature field is only 30MPa, which is a certain gap compared to the instability strength of the parts formed using a non-uniform temperature field, indicating that the ability to resist deformation is not as good as that of the parts formed using a non-uniform temperature field.

[0084] Although the present invention has been disclosed as above in the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A non-uniform temperature field stretching and bulging integrated forming device, characterized in that: The forming device comprises: High-pressure gas source storage tank (1); Air source control system (2); Computer control system (3); Superplastic forming equipment, the superplastic forming equipment comprising a heat-insulating wall (4), a cooling water channel (5), a main machine platform (6), an inner cavity side wall (7), a lower slider of a forming machine (8), an upper slider of a press machine (12), a heating rod (13), and a main machine frame of a press machine (14); A deep-drawing and bulging integrated forming die, wherein the deep-drawing and bulging integrated forming die comprises a forming part male die (9) and a forming part female die (10); A sheet to be formed (11); The sheet material (11) to be formed is placed between a forming piece male die (9) and a forming piece female die (10); The drawing and bulging integrated forming die is fixed on the host platform (6).

2. The forming device according to claim 1, characterized in that: The forming part concave die (10) is provided with a blank holder (10-1) and a hook (15), and the forming part convex die (9) is provided with a hook (15); The height of the forming part convex die (9) is smaller than the depth of the forming part concave die (10).

3. The forming device according to claim 1, characterized in that: The interior of the host platform (6) is filled with heating rods (13).

4. The forming device according to claim 1, characterized in that: The computer control system (3) adjusts the temperature of each heating rod (13) and adjusts the air pressure loading of the air source control system (2).

5. A forming method using the forming device according to claim 1, characterized in that: include: Step 1: fix the forming part convex die (9) and the forming part concave die (10) to the host platform (6) respectively, set different temperatures for the heating rod (13) according to the position of the deep drawing and bulging integrated forming die and the positional relationship between the heating rod (13) and the forming area by using the computer control system (3), and start heating; Step 2: Grind the sheet to be formed (11), clean and blow dry, and put the sheet to be formed (11) into the superplastic forming equipment after the furnace temperature reaches the temperature set in step 1; Step 3: setting the preload force of the upper slide block (12) of the press, the upper slide block (12) of the press pushes the forming part die (10) downward, and the lower slide block (8) of the press pushes the forming part die (9) upward, so that the blank holder (10-1) contacts the sheet to be formed (11), preloads the sheet to be formed (11), and keeps the temperature for a period of time after the temperature reaches the temperature set in step 1 again, and then moves the upper slide block (12) of the press downward to stretch the sheet to be formed (11); Step 4: The main frame (14) of the press machine includes a main cylinder of the press machine. When the punch (9) of the formed part contacts the blank holder (10-1) on the die (10) of the formed part, the main cylinder of the press machine stops moving and pre-tightens the sheet (11) to be formed with a certain pre-tightening force. Then, the air source control system (2) starts blowing air to the sheet (11) to be formed for air expansion forming. Step 5: After the inflation forming is completed, stop heating, cool down and take out the product.

6. The forming method according to claim 5, characterized in that: The temperature in step 1 ranges from 860 to 940°C.

7. The forming method according to claim 5, characterized in that: In step 1, the forming area is divided into two small deformation areas on both sides, a large deformation area in the middle and a transition area in the middle; The temperature of the heating rod (13) in the small deformation areas on both sides is set as the upper temperature of the forming interval, and the temperature of the heating rod (13) in the middle large deformation area is set as the lower temperature of the forming interval.

8. The forming method according to claim 5, characterized in that: In the step 1, the materials of the forming part male die (9) and the forming part female die (10) are both 2520 stainless steel; In step 2, the material of the plate (11) to be formed is titanium alloy.

9. The forming method according to claim 5, characterized in that: In step 3, the downward movement speed of the slide block (12) on the press is 10 to 30 mm / min.

10. The forming method according to claim 5, characterized in that: The parameters of the blowing process in step 4 are: air pressure loading rate is 0.001-1 MPa / min, maximum air pressure is 3-5 MPa, and pressure holding time is 30-60 min.

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