Titanium alloy monobloc bulkhead forging method

Abstract

The present application relates to the technical field of metal plate processing, in particular to a titanium alloy integral partition frame forging method. The method comprises the following steps: S1: designing a target forging; S2: determining the radius of the bar stock; S3: determining the length of the bar stock; S4: designing the upper die and the lower die; S5: forming the target forging; and S6: forming the partition frame forging. According to the present application, the target forging is forged by using the bar stock, and the skin part and the slope part are cut after the target forging is formed. Compared with ordinary cutting and forming, the present application reduces material waste. 2. The diameter of the bar stock is selected according to the cross-sectional size of the widest position of the target forging, and the length of the bar stock is selected according to the weight of the partition frame forging, so as to accurately control the size and specifications of the bar stock, avoid material waste caused by excessive use of the bar stock, and avoid the problem that the partition frame forging after forming does not meet the design requirements due to insufficient use of the material.

Description

Technical Field

[0001] This invention relates to the field of metal sheet processing technology, specifically to a method for forging an integral titanium alloy partition frame. Background Technology

[0002] Forged bulkheads are load-bearing structural components widely used in aerospace vehicles, and are made of high-performance lightweight alloy materials (such as aluminum alloys and titanium alloys). Figure 1 A commonly used elongated forging 1 is shown, including two partition frame parts 101 and a web plate 102 connecting the two partition frame parts 101. The middle of the partition frame part is a hollow part 103, and the ends of the two partition frame parts 101 away from the web plate 102 are respectively provided with ear plates 104. This forging is mainly prepared by two methods. The first is direct processing of sheet metal. The sheet metal with the same thickness as the forging is machined to form the forging. This method can achieve the forming of the forging, but the material removal is large and the material consumption is high. The second method uses die forging, which involves first casting an ingot, then forging the ingot into a sheet metal, and finally using the sheet metal to process the partition frame forging. However, this method has the following problems: First, the process of forging the sheet metal from the ingot requires multiple forging passes, resulting in a long processing time. Furthermore, after the sheet metal is formed, its surface needs to be finished to meet flaw detection requirements, leading to significant material loss, low ingot yield, and high manufacturing costs. Second, the sheet metal has the same thickness as the partition frame forging after forming, resulting in insufficient deformation of the sheet metal during die forging, leading to compromised product quality. Third, die forging has poor stability. The positioning of the sheet metal in the die during the die forging process relies on manual placement, which is affected by the operator's skill level. Large positioning deviations can cause incomplete filling defects in the forging, leading to scrapping. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for forging an integral titanium alloy frame to reduce material loss.

[0004] The technical solution adopted by this invention to solve its technical problem is a method for forging an integral titanium alloy partition frame, which includes the following steps:

[0005] S1: Design the target forging; Based on the dimensions of the hollowed-out portion of the partition frame forging, a connecting part is set in the hollowed-out portion, and the connecting part and the partition frame portion are connected by a ramp to obtain the target forging;

[0006] S2: Determine the bar stock radius; select the widest position of the target forging and calculate the cross-sectional area S at this position. Select the bar stock area S0, where S0 = (1.3~1.7)S, then the bar stock radius...

[0007] S3: Determine the bar stock length. The bar stock length is determined according to the following formula:

[0008] M0 = (1.4 ~ 2)M

[0009]

[0010] Where M0 is the weight of the bar stock, M is the weight of the diaphragm forging, and ρ is the material density of the bar stock;

[0011] S4: Design an upper mold and a lower mold, wherein the upper mold and the lower mold are provided with a forging groove that matches the partition frame forging, a connecting groove that matches the connecting skin part, and a slope groove that matches the slope part.

[0012] S5: Forming the target forging; Heat the bar stock to the first temperature so that the core of the bar stock is warm, place the heated bar stock between the upper and lower dies, apply pressure to the upper die at least twice using a press to remove the flash, and finally form the target forging;

[0013] S6: Forming a partition frame forging involves cutting away the skin and slope portions of the target forging to ultimately form the partition frame forging.

[0014] Furthermore, in step S4, each of the connecting grooves of the lower mold is provided with a positioning groove at the bottom for use with the bar stock.

[0015] Furthermore, a chamfer is provided at the connection between the positioning groove and the connecting groove.

[0016] Furthermore, in step S4, the lower mold is provided with a reference line for axial positioning of the bar stock.

[0017] Furthermore, the thickness of the connecting skin portion is H, and the thickness of the partition portion of the partition forging is H0, where H = (1 / 6 to 1 / 3)H0; the width at the widest position of the target forging is B0, the width of the connecting skin portion is B, and B / B0 ≤ 1 / 4; the slope of the ramp portion is 20 to 30°.

[0018] Furthermore, a chamfer is provided at the connection between the ramp portion and the partition frame portion.

[0019] Furthermore, in step S5, when the press applies pressure to the upper die, the initial pressing amount is 20-50% of the initial bar diameter, and the subsequent pressing amount is less than the previous pressing amount.

[0020] Furthermore, in step S3, after the length of the bar stock 8 is determined, stepped shafts are drawn out from both ends of the bar stock 8. The beneficial effects of this invention are:

[0021] 1. By designing the target forging, the target forging is forged using bar stock. After the target forging is formed, the skin and beveled parts are cut off, which reduces material waste compared to ordinary cutting and forming.

[0022] 2. By selecting the diameter of the bar stock based on the cross-sectional dimensions at the widest point of the target forging, and by selecting the length of the bar stock based on the weight of the partition frame forging, the dimensional specifications of the bar stock can be precisely controlled. This avoids material waste caused by using too much bar stock, and also avoids the problem of the formed partition frame forging not meeting the design requirements due to using too little material.

[0023] 3. By setting forging grooves matching the partition frame forging, connecting grooves matching the connecting skin, and slope grooves matching the slope section on the upper and lower dies, the target forging can be better formed during forging. Furthermore, by setting positioning grooves and datum lines during forging, better positioning of the bar stock can be ensured. After one forging operation, a protrusion will form on the bar stock. In subsequent forging operations, the protrusion and positioning grooves can cooperate to form a stable matching position. Finally, through multiple forging operations with a reasonable deformation amount, a partition frame forging with stable shape and performance is obtained. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the partition frame forging of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the target forging of the present invention;

[0026] Figure 3 It is along Figure 2 Sectional view of surface A;

[0027] Figure 4 A schematic diagram of the upper mold;

[0028] Figure 5 This is a schematic diagram of the lower mold;

[0029] Figure 6 yes Figure 5 A sectional view;

[0030] Figure 7 This is a partial view of a partition frame forging made from bar stock.

[0031] Reference numerals: 1-partition frame forging; 101-partition frame section; 102-web plate; 103-hollowed-out section; 104-ear plate; 2-target forging; 201-connecting skin section; 202-sloping section; 3-upper die; 4-lower die; 401-positioning groove; 402-datum line; 5-forging groove; 6-connecting skin groove; 7-sloping groove; 8-bar stock. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0033] like Figures 1-5 As shown, the present invention provides a method for forging an integral titanium alloy partition frame, comprising the following steps:

[0034] S1: Design target forging 2; Based on the dimensions of the hollow portion 103 of the partition frame forging 1, a connecting portion 201 is provided in the hollow portion 103. The connecting portion 201 and the partition frame portion 101 are connected by a ramp portion 202 to obtain the target forging 2; wherein, the outer contour of the connecting portion 201 can be the same as the outer contour of the hollow portion 103, and the projected area of ​​the connecting portion 201 on the horizontal plane is smaller than the projected area of ​​the hollow portion 103. The outer contour of the connecting portion 201 can also be circular. The ramp portion 202 is used to connect the connecting portion 201 and the partition frame portion 101.

[0035] S2: Determine the radius of bar stock 8; select the widest position of the target forging 2 and calculate the cross-sectional area S at this position. Select the area S0 of bar stock 8, where S0 = (1.3~1.7)S, then the radius of bar stock 8 is... Among them, such as Figure 2 As shown, the length direction of the target forging 2 is the X direction, the horizontal direction perpendicular to the X direction is the Y direction, and the direction perpendicular to both the X and Y directions is the Z direction. The two points with the longest projection of the target forging 2 on the YOZ plane are the widest positions. Taking the surface parallel to the YOZ plane as the cross-section, the area of ​​the cross-section at the widest position is S.

[0036] S3: Determine the length of bar stock 8. The length of bar stock 8 is determined according to the following formula:

[0037] M0 = (1.4 ~ 2)M

[0038]

[0039] Where M0 is the weight of bar stock 8, M is the weight of partition frame forging 1, and ρ is the material density of bar stock 8; it should be noted that the length of bar stock 8 must be less than the length of partition frame forging 1 and greater than the farthest distance between the two hollow parts 103.

[0040] S4: Design an upper mold 3 and a lower mold 4. The upper mold 3 and the lower mold 4 are provided with a forging groove 5 that matches the partition frame forging 1, a connecting groove 6 that matches the connecting part 201, and a ramp groove 7 that matches the ramp part 202. The forging groove 5 includes three parts: the ear plate 104 part, the partition frame part 101 part, and the web plate 102 part, which are used to form the partition frame forging 1. The connecting groove 6 is used to form the connecting part 201, and the ramp groove 7 is used to form the ramp part 202.

[0041] S5: Forming the target forging 2; heating the bar stock 8 to a first temperature to bring the core of the bar stock 8 to a warm temperature, placing the heated bar stock 8 between the upper die 3 and the lower die 4, applying pressure to the upper die 3 at least twice using a press to remove flash, and finally forming the target forging 2; wherein, for two-phase region titanium alloy forging, the first temperature is T β -50℃~T β -30℃, T β The β phase transformation temperature of the titanium alloy is used to fill the forging groove 5, the connecting groove 6 and the inclined groove 7 by the press, which utilizes the fluidity of the high-heat metal.

[0042] S6: Form the partition frame forging 1 by cutting and removing the skin portion 201 and the slope portion 202 of the target forging 2, and finally forming the partition frame forging 1.

[0043] To prevent the bar stock 8 from moving between the upper die 3 and the lower die 4, further see... Figure 5 and Figure 6 In step S4, each of the connecting grooves 6 of the lower mold 4 is provided with a positioning groove 401 at its bottom for use with the bar stock 8. The positioning groove 401 is an arc groove located in the middle of the connecting groove. The diameter of the arc groove is larger than the diameter of the bar stock 8. For example, if the diameter of the bar stock 8 is 400 mm, the diameter of the arc groove is 405 mm. The central angle of the arc groove must be less than 180°; preferably 30°, 45°, and 60°. The axes of the positioning grooves 401 on the two connecting grooves 6 are coaxial. In use, the bar stock 8 is placed in the positioning groove 401 to achieve radial positioning of the bar stock 8.

[0044] To prevent the sharp corners at the connection point between the positioning groove 401 and the connecting groove 6 from scratching the bar stock 8, a chamfer is further provided at the connection between the positioning groove 401 and the connecting groove 6. The radius of the chamfer is R = 60~120mm.

[0045] To avoid uneven material usage at both ends of the partition frame 101, further see... Figure 5 In step S4, the lower die 4 is provided with a reference line 402 for axial positioning of the bar stock 8. The distance from the reference line 402 to the center line of the web portion of the forging groove 5 is half that of the bar stock 8. During use, one end of the bar stock 8 is aligned with the reference line 402.

[0046] Further, see Figure 3 The thickness of the connecting portion 201 is H, and the thickness of the partition portion 101 of the partition forging 1 is H0, where H = (1 / 6 to 1 / 3)H0; the width at the widest position of the target forging 2 is B0, and the width of the connecting portion 201 is B, where B / B0 ≤ 1 / 4; the slope of the ramp portion 202 is 20 to 30°. A smaller H value results in less cross-sectional loss but a larger forming load, while a larger H value results in greater cross-sectional loss but a smaller forming load. Therefore, H = (1 / 6 to 1 / 3)H0 is selected. The width at the widest position of the forging, B0, must satisfy B / B0 ≤ 1 / 4. Similarly, a smaller B helps reduce the forming load, but more material is wasted at the connecting portion 201. The slope α of the ramp 202 is used in the later stage of deformation to make the metal thicken on a slope, so as to avoid the metal being too thin from becoming unstable at the edge and forming folds. The slope should be between 20 and 30°. If the slope α is too small, it will not play a role in guiding the flow, and if the slope α is too large, it will lead to metal waste.

[0047] To make the connection between the ramp portion 202 and the partition frame portion 101 smoother, a chamfer is provided at the connection between the ramp portion 202 and the partition frame portion 101, wherein the radius of the chamfer R = 60~120mm.

[0048] Furthermore, in step S5, when the press applies pressure to the upper die 3, the initial reduction is 20-60% of the initial bar stock 8 diameter, and the subsequent reduction is less than the previous reduction. Specifically, the initial reduction for titanium alloy should be between 20-50%. However, since the connecting groove 6 first applies pressure to the bar stock 8 when the upper die 3 applies pressure to the lower die 4, and the connecting groove 6 and the bar stock 8 ultimately form the connecting portion 201, which needs to be removed later, the initial reduction during the first pressure application can exceed 50%. See Figure 7, where the shaded area represents the forming area of ​​the partition frame 101. When the initial reduction is 60% of the initial bar stock 8 diameter, the reduction in the shaded area is less than 50%, thus ensuring the quality of the partition frame 101 while reducing the number of pressure applications.

[0049] When the length of the ear plate 104 is greater than one-quarter of the overall length of the partition frame 101 and the web plate 102, in order to ensure that the metal can flow better to the end of the ear plate 104 during the forging process, in step S3, after the length of the bar stock 8 is determined, stepped shafts are drawn out at both ends of the bar stock 8.

[0050] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for forging an integral titanium alloy partition frame, characterized in that, Includes the following steps: S1: Design the target forging (2); Based on the dimensions of the hollow part (103) of the partition frame forging (1), a connecting part (201) is set in the hollow part (103), and the connecting part (201) and the partition frame part (101) are connected by a ramp part (202) to obtain the target forging (2); The thickness of the connecting part (201) is H, and the thickness of the partition frame part (101) of the partition frame forging (1) is H0, where H = (1 / 6~1 / 3)H0; The width at the widest position of the target forging (2) is B0, and the width of the connecting part (201) is B, B / B0≤1 / 4; The slope of the ramp part (202) is 20~30°; S2: Determine the radius of the bar stock (8); Select the widest position of the target forging (2) and calculate the cross-sectional area S at this position. Select the area S0 of the bar stock (8), where S0 = (1.3~1.7)S. Then the radius R0 of the bar stock (8) = ; S3: Determine the length L0 of the bar stock (8); The length L0 of the bar stock (8) is determined according to the following formula: M0 = (1.4~2)M; L0= ； Where M0 is the weight of the bar stock (8), M is the weight of the diaphragm forging (1), and ρ is the material density of the bar stock (8); S4: Design an upper mold (3) and a lower mold (4); the upper mold (3) and the lower mold (4) are provided with a forging groove (5) matching the partition frame forging (1), a connecting groove (6) matching the connecting part (201), and a ramp groove (7) matching the ramp part (202); the bottom of each connecting groove (6) of the lower mold (4) is provided with a positioning groove (401) for use with the bar stock (8); the lower mold (4) is provided with a reference line (402) for axial positioning of the bar stock (8). S5: Form the target forging (2); heat the bar stock (8) to the first temperature so that the core of the bar stock (8) is warm, place the heated bar stock (8) between the upper die (3) and the lower die (4), apply pressure to the upper die (3) at least twice using a press, when the press applies pressure to the upper die (3), the initial pressing amount is 20~60% of the initial bar stock (8) diameter, and the next pressing amount is less than the previous pressing amount; remove the flash, and finally form the target forging (2). S6: Form a partition frame forging (1); cut off the skin part (201) and the slope part (202) of the target forging (2) to finally form a partition frame forging (1).

2. The method for forging a titanium alloy integral partition frame as described in claim 1, characterized in that, The positioning groove (401) and the connecting groove (6) are chamfered at the connection point.

3. The method for forging a titanium alloy integral partition frame as described in claim 1, characterized in that, The connection between the ramp portion (202) and the partition portion (101) is provided with a chamfer.

4. The method for forging a titanium alloy integral partition frame as described in claim 1, characterized in that, In step S3, after the length of the bar (8) is determined, stepped shafts are drawn out at both ends of the bar (8).

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