Titanium alloy thin-wall curved surface correcting method

Abstract

The invention relates to the field of casting, and provides a titanium alloy thin-wall curved surface shape correction method which comprises the following steps: marking a deformed part and deformation on a casting; the shape correcting tool comprises a positioning block, a lead screw and a nut, the lead screw is connected with the casting in a welded mode, the positioning block is arranged on the outer side of the lead screw in a penetrating mode, and the nut is matched with the lead screw. During shape correction, the lead screw is connected with the deformation position of the casting in a spot welding mode, after spot welding is completed, the positioning block penetrates through the lead screw to be attached to the surface of the casting, and finally the nut is used for fastening. Detecting the molded surface, and if the molded surface does not meet the requirement, adjusting the fastening degree of the nut until the molded surface meets the requirement; the casting on which the shape correcting tool is installed is annealed; and after the nut and the positioning block are detached in sequence, the lead screw is separated from the casting, and finally the lead screw is polished to be flush with the original casting. The titanium alloy thin-wall curved surface shape correction method is suitable for shape correction of local titanium alloy thin-wall curved surfaces. The tool is simple in structure and low in machining cost; and the tool is simple and convenient to mount and dismount.

Description

Technical Field

[0001] The invention relates to the field of casting, and in particular to a method for shaping a titanium alloy thin-wall curved surface. Background Art

[0002] Titanium alloys are widely used in aerospace castings due to their high specific strength and ability to maintain high mechanical properties at high temperatures. As titanium alloy castings for aerospace are developing towards thin-walled (wall thickness less than 3mm) and integrated (complex structure, special-shaped curved surface), these castings are usually prone to deformation due to their low structural strength and complex molding process. Especially in the post-processing process, repair of surface defects, internal slag inclusions, pores and other defects in castings usually requires repair welding. This process requires the use of high-temperature arc melting welding wire, which causes local overheating of the casting. In addition, during the cooling process, due to the solidification and shrinkage of the molten metal, large stress is generated, resulting in local deformation of some thin-walled curved surfaces of the casting. This deformation mode has a small area and is a curved surface, and it is difficult to accurately locate and calibrate with traditional profiling methods.

[0003] The patent with application number CN202210158944.6 in the prior art discloses a shaping and repair tool and repair method for a casing, wherein the shaping and repair tool comprises a bottom pad, a center column and a plurality of parallel slides, wherein the bottom pad is provided with a center hole and a plurality of slide grooves, and the plurality of slide grooves are radially arranged on the periphery of the center hole; the center column comprises a coaxially connected positioning part and a side thrust part; the positioning part is inserted into the center hole; the outer periphery of the side thrust part is a cone, and the small end head is connected to the positioning part; a plurality of parallel slides are respectively arranged in a plurality of slide grooves, and the inner side of the parallel slide has a first mating surface conformally adapted to the side thrust part, and the outer side has a second mating surface conformally adapted to the flow path surface of the casing, which is suitable for shaping and repairing the flow path surface under the push of the center column. Although this patent can restore the flow path surface to its original state through the above-mentioned structure, thereby realizing the correction and repair of the casing, the correction and repair tooling uses a large amount of graphite raw materials to be processed into the required shape. The processing process is complicated, the material and processing costs are high, and the tooling installation is difficult. It is suitable for large-area deformation of casting surfaces, but not suitable for local titanium alloy thin-walled surface correction.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to propose a method for profiling titanium alloy thin-walled surfaces, so as to solve the problem that the tooling for profiling and repairing titanium alloy curved surface castings in the prior art uses a large amount of graphite raw materials to be processed into the required shape, the processing process is complicated, the material and processing costs are high, and the tooling installation is difficult. It is suitable for large-area deformation of the casting surface, but not suitable for profiling of local titanium alloy thin-walled surfaces.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A titanium alloy thin-walled curved surface shaping method, the titanium alloy thin-walled curved surface shaping method comprising the following steps:

[0008] S1. Confirmation of the correction part: Scan the casting to be corrected, and mark the deformation part and deformation amount on the casting;

[0009] S2. Design of the profiling tool: The profiling tool includes a positioning block, a screw rod and a nut. The screw rod is welded to the casting, the positioning block is inserted on the outside of the screw rod, and the nut is matched with the screw rod;

[0010] S3, installation of the tooling for calibration: during calibration, the screw rod is first spot-welded to the deformed position of the casting. After the spot welding is completed, the positioning block is passed through the screw rod to fit the surface of the casting, and finally the nut is used to tighten the screw rod;

[0011] S4. Confirm the deformation: Check the surface on the back of the mold or the surface of the casting. If it does not meet the requirements, adjust the tightness of the nut until the surface meets the requirements.

[0012] S5, annealing: annealing the casting installed with the calibration tooling;

[0013] S6. Tool removal: After removing the nut and positioning block in order, separate the screw rod from the casting, and finally grind it to be flush with the original casting.

[0014] The present invention provides a titanium alloy thin-walled curved surface profiling method. First, it is suitable for the profiling of local thin-walled curved surfaces. Second, the tooling structure is simple and the processing cost is low. There is no need to use a large amount of raw materials, and the tooling can be used multiple times after being dismantled, so the cost is low. Third, the installation and removal of the tooling are simple and easy to operate. Fourth, the profiling efficiency is high. After the deformation area is accurately positioned by blue light scanning, the force of the screw rod is concentrated on the deformation area, and the positioning block can ensure that the remaining areas do not change with the force of the screw rod, thereby preventing the remaining areas from being deformed during the profiling process. The profiling can achieve the expected effect once, and repeated profiling can be avoided.

[0015] Furthermore, a through hole is provided on the positioning block, which is consistent with the position of the shaping part, and the positioning block is arranged on the outer side of the screw rod through the through hole.

[0016] Furthermore, the diameter of the through hole is 4-6 mm larger than the diameter of the screw rod.

[0017] Furthermore, the number of welding points where the screw rod and the casting are connected by welding is 2 to 8.

[0018] Furthermore, in step S4, a mold surface detection plate is used to detect the mold surface on the back side of the mold or a blue light scanner is used to detect the mold surface of the casting.

[0019] Furthermore, in step S5, the casting with the proofreading block installed is placed in an annealing furnace for annealing. The material of the casting is ZTC4 titanium alloy, the annealing temperature is 700-800°C, and the holding time is 1-4 hours.

[0020] Furthermore, the wall thickness of the casting is less than 3 mm.

[0021] Furthermore, in step S6, a grinding machine or a cutting machine is used to separate the screw rod from the casting.

[0022] Furthermore, the material of the screw rod is the same as that of the casting.

[0023] Furthermore, the positioning block and the nut are made of steel or cast iron or the same material as the casting.

[0024] The present invention proposes a titanium alloy thin-walled curved surface shaping method. Compared with the prior art, the titanium alloy thin-walled curved surface shaping method of the present invention has the following beneficial effects:

[0025] 1) The titanium alloy thin-wall curved surface shaping method described in the present invention is suitable for shaping of local titanium alloy thin-wall curved surfaces.

[0026] 2) The titanium alloy thin-wall curved surface shaping method described in the present invention reduces costs: the tooling structure is simple, the processing cost is low, a large amount of raw materials does not need to be used, and the tooling can be used multiple times after being dismantled, so the cost is low.

[0027] 3) The method for shaping thin-walled curved surfaces of titanium alloys described in the present invention has high shaping efficiency: after the deformation area is accurately located by blue light scanning, the force of the screw rod is concentrated on the deformation area, and the positioning block can ensure that the remaining areas do not change with the force of the screw rod, thereby preventing the remaining areas from being deformed during the shaping process. The shaping can achieve the expected effect in one time and avoid repeated shaping.

[0028] 4) The titanium alloy thin-wall curved surface correction method described in the present invention is easy to operate: the tooling design and machining are simple, and the installation of the tooling does not require the use of other hydraulic tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of a shaping tool for a titanium alloy thin-walled curved surface shaping method described in an embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 1. Positioning block; 11. Through hole; 2. Screw rod; 3. Nut; 4. Casting. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The descriptions of "first", "second", etc. mentioned in the embodiments of the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0033] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Example 1

[0034] In the prior art, the tooling for shaping and repairing curved surface castings of titanium alloys uses a large amount of graphite raw materials to be processed into the desired shape. The processing process is complicated, the material and processing costs are high, and the tooling is difficult to install. It is suitable for large-area deformation of casting surfaces, but not suitable for shaping local thin-walled surfaces.

[0035] In order to solve the above technical problems, this embodiment provides a titanium alloy thin-walled curved surface shaping method, and the titanium alloy thin-walled curved surface shaping method comprises the following steps:

[0036] S1. Confirming the shape correction part: Scan the casting 4 to be shaped, and mark the deformation part and deformation amount on the casting 4;

[0037] Step S1 is specifically as follows: use a blue light 3D scanning device to scan the casting 4 to be calibrated, perform high-precision fitting of the scanned point data cloud with the theoretical 3D model, perform fine-tuning according to the benchmark, perform 3D comparison after qualified adjustment, and mark the deformed part and deformation amount on the casting 4.

[0038] S2. Proofing tool design: Proofing tool is set according to the three-dimensional model. Proofing tool includes positioning block 1, screw rod 2 and nut 3. The screw rod 2 is connected to the casting 4 by welding. The positioning block 1 is passed through the outside of the screw rod 2. The nut 3 matches the screw rod 2.

[0039] S3, installation of the tooling for calibration: during calibration, the screw rod 2 is first spot-welded to the deformed position of the casting 4, and the deformed position and the screw rod are cleaned before spot welding to avoid defects during spot welding; after the spot welding is completed, the positioning block 1 is passed through the screw rod 2 and fits the surface of the casting 4, and finally the nut 3 is used to tighten;

[0040] S4. Confirm the deformation: Check the profile on the back of the mold. If it does not meet the requirements, adjust the tightness of the nut 3 until the profile meets the requirements.

[0041] Step S4 is specifically as follows: after tightening is completed, the surface on the back of the mold is inspected using a surface inspection plate or the surface of the casting 4 is inspected using a blue light scanner. If it does not meet the requirements, the tightening degree of the nut 3 is adjusted until the surface meets the requirements.

[0042] S5, annealing: annealing the casting 4 installed with the calibration tooling, and the annealing temperature needs to be determined according to the material of the casting 4;

[0043] S6, tooling removal: After removing the nut 3 and the positioning block 1 in sequence, separate the screw rod 2 from the casting 4, and finally grind the remaining welding points until they are flush with the original casting 4.

[0044] In a titanium alloy thin-walled surface profiling method of the present embodiment, steps S1 to S6 are interrelated and inseparable, and play multiple roles: 1. It is suitable for profiling of local titanium alloy thin-walled surfaces; 2. The tooling structure is simple, the processing cost is low, and there is no need to use a large amount of raw materials. The tooling can be used many times after being removed, and the cost is low; 3. The installation and removal of the tooling are easy to operate; 4. The profiling efficiency is high. After the deformation area is accurately located by blue light scanning, the force of the screw rod 2 is concentrated on the deformation area, and the positioning block 1 can ensure that the remaining areas do not change with the force of the screw rod 2, thereby preventing the remaining areas from deforming during the profiling process. The profiling can achieve the expected effect once, avoiding repeated profiling.

[0045] The present invention provides a method for designing a profiling tool and a method for profiling a local thin-walled curved surface using the tool. The method can accurately locate the deformed area caused by the repair welding of a thin-walled casting and can correct the deformed part to a qualified range at one time.

[0046] Specifically, a through hole 11 is provided on the positioning block 1 and is located in the same position as the shaping part. The positioning block 1 is arranged on the outer side of the screw rod 2 through the through hole 11 .

[0047] Specifically, in order to avoid the position of the welding point, the diameter of the through hole 11 is 4-6 mm larger than the diameter of the screw rod 2 .

[0048] More specifically, in this embodiment, the diameter of the through hole 11 is 5 mm larger than the diameter of the screw rod 2 .

[0049] Specifically, the projection area of ​​the positioning block 1 on the casting 4 is more than three times the area of ​​the deformation position.

[0050] More specifically, in this embodiment, the projection area of ​​the positioning block 1 on the casting 4 is 4 times the area of ​​the deformation position.

[0051] Specifically, the number of welding points for connecting the screw rod 2 and the casting 4 by welding is 2 to 8, which is determined according to the area of ​​the deformed part.

[0052] More specifically, in this embodiment, the screw rod 2 and the casting 4 are connected by welding at 6 welding points.

[0053] Specifically, in step S4, a profile detection plate is used to detect the profile on the back side of the proofreading.

[0054] Specifically, in step S5, the casting with the proofreading block installed is placed in an annealing furnace for annealing. The material of the casting 4 is ZTC4 titanium alloy, the annealing temperature is 700-800°C, and the holding time is 1-4 hours.

[0055] More specifically, in this embodiment, the material of the casting 4 is ZTC4 titanium alloy, the annealing temperature is 750° C., and the holding time is 2.5 h.

[0056] Specifically, the wall thickness of the casting 4 is less than 3 mm, and the titanium alloy thin-wall curved surface shaping method is suitable for thin-wall curved surface shaping with a wall thickness of less than 3 mm.

[0057] More specifically, in this embodiment, the wall thickness of the casting 4 is 2 mm.

[0058] Specifically, in step S6, a grinding machine or a cutting machine is used to separate the screw rod 2 from the casting 4.

[0059] More specifically, in this embodiment, a grinding machine is used to separate the screw rod 2 from the casting 4 .

[0060] Specifically, the material of the screw rod 2 is the same as that of the casting 4 .

[0061] Specifically, the positioning block 1 and the nut 3 are made of steel or cast iron or the same material as the casting 4 .

[0062] More specifically, in this embodiment, the material of the casting 4 is ZTC4 titanium alloy, and the material of the screw rod 2, the screw rod 2, the positioning block 1, and the nut 3 are all ZTC4 titanium alloy.

[0063] Specifically, if multiple parts of the same casting 4 are deformed, multiple toolings can be installed on the deformed parts to achieve the purpose of simultaneous correction.

[0064] When multiple deformation areas are close to each other, the same positioning tool can be used to design multiple holes according to the deformation areas, and multiple nuts 3 and screw rods 2 can be used for correction. When designing, it should be noted that there should be no interference between the nuts 3.

[0065] In a titanium alloy thin-walled surface profiling method of the present embodiment, steps S1 to S6 are interrelated and inseparable, and play multiple roles: 1. It is suitable for profiling of local thin-walled surfaces; 2. The tooling structure is simple, the processing cost is low, and there is no need to use a large amount of raw materials. The tooling can be used many times after being removed, and the cost is low; 3. The installation and removal of the tooling are easy to operate; 4. The profiling efficiency is high. After the deformation area is accurately located by blue light scanning, the force of the screw rod 2 is concentrated in the deformation area, and the positioning block 1 can ensure that the remaining areas do not change with the force of the screw rod 2, thereby preventing the remaining areas from deforming during the profiling process. The profiling can achieve the expected effect once, avoiding repeated profiling. Example 2

[0066] In this embodiment, different from the embodiment 1, specifically, step S4 is: inspecting the surface of the casting 4, and if it does not meet the requirements, adjusting the tightness of the nut 3 until the surface meets the requirements.

[0067] More specifically, in step S4, the surface of the casting 4 is inspected using blue light scanning.

[0068] The diameter of the through hole 11 is 4 mm larger than the diameter of the screw rod 2 .

[0069] The projection area of ​​the positioning block 1 on the casting 4 is 5 times the area of ​​the deformation position.

[0070] More specifically, in this embodiment, the screw rod 2 and the casting 4 are connected by welding at 8 welding points.

[0071] In step S5, the annealing temperature is 700° C. and the holding time is 4 hours.

[0072] The wall thickness of the casting 4 is 1.5 mm.

[0073] The positioning block 1 and the nut 3 are made of steel.

[0074] In step S6 , the screw rod 2 and the casting 4 are separated using a cutting machine. Example 3

[0075] In this embodiment, different from the first embodiment, the diameter of the through hole 11 is 6 mm larger than the diameter of the screw rod 2 .

[0076] The projection area of ​​the positioning block 1 on the casting 4 is 3.5 times the area of ​​the deformation position.

[0077] More specifically, in this embodiment, the screw rod 2 and the casting 4 are connected by welding at two welding points.

[0078] In step S5, the annealing temperature is 800°C and the holding time is 1 hour.

[0079] The wall thickness of the casting 4 is 2.5 mm.

[0080] The positioning block 1 and the nut 3 are made of cast iron.

[0081] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for shaping a titanium alloy thin-walled curved surface, characterized in that: The titanium alloy thin-wall curved surface shaping method comprises the following steps: S1. Confirming the shape correction part: scanning the casting (4) to be shaped correction, and marking the deformation part and deformation amount on the casting (4); S2. Design of the profiling tool: The profiling tool comprises a positioning block (1), a screw rod (2) and a nut (3), wherein the screw rod (2) is welded to the casting (4), the positioning block (1) is inserted into the outside of the screw rod (2), and the nut (3) is matched with the screw rod (2); S3, installation of the shaping tool: during shaping, the screw rod (2) is first connected to the deformed position of the casting (4) by spot welding. After the spot welding is completed, the positioning block (1) is passed through the screw rod (2) and fits the surface of the casting (4), and finally the nut (3) is used to tighten the screw rod (2). S4. Confirm the deformation: Check the surface on the back of the mold or the surface of the casting. If it does not meet the requirements, adjust the tightness of the nut (3) until the surface meets the requirements. S5, annealing: annealing the casting (4) installed with the shaping tooling; S6. Tool removal: After removing the nut (3) and the positioning block (1) in order, separate the screw rod (2) from the casting (4), and finally grind them until they are flush with the original casting (4).

2. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: A through hole (11) is provided on the positioning block (1) and is located in the same position as the shaping part. The positioning block (1) is arranged on the outside of the screw rod (2) through the through hole (11).

3. A titanium alloy thin-wall curved surface correction method according to claim 2, characterized in that: The diameter of the through hole (11) is 4-6 mm larger than the diameter of the screw rod (2).

4. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: The number of welding points at which the screw rod (2) and the casting (4) are connected by welding is 2 to 8.

5. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: In step S4, the mold surface on the back side of the mold is inspected using a mold surface inspection plate or the mold surface of the casting is inspected using a blue light scanner.

6. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: In step S5, the casting with the correction block installed is placed in an annealing furnace for annealing. The material of the casting (4) is ZTC4 titanium alloy, the annealing temperature is 700-800°C, and the holding time is 1-4 hours.

7. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: The wall thickness of the casting (4) is less than 3 mm.

8. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: In step S6, a grinding machine or a cutting machine is used to separate the screw rod (2) from the casting (4).

9. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: The material of the screw rod (2) is the same as that of the casting (4).

10. A titanium alloy thin-wall curved surface correction method according to claim 1, characterized in that: The positioning block (1) and the nut (3) are made of steel or cast iron or are made of the same material as the casting (4).

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