Laser deposition manufacturing method for high-temperature titanium alloy large complex aviation structural part

Abstract

The invention relates to the field of high-temperature titanium alloy additive manufacturing, in particular to a laser deposition manufacturing method for a high-temperature titanium alloy large complex aviation structural part. Carrying out partitioning treatment on the three-dimensional model of the aviation structural part blank; s2; carrying out pretreatment on the substrate; (S3); for the first deposition block, the maximum size direction is taken as the deposition direction, and the first block is deposited in the laser deposition equipment; (S4); sequentially depositing other blocks according to the method in the step 3; (S5); two adjacent forming blocks to be connected are cut, a groove is machined in the connecting position, and a certain placement angle is preset for compensating angle deformation in the connecting process; (S6); the same deposition equipment and parameters are adopted, and laser deposition connection is conducted on the two forming blocks needing to be connected; (S7); and repeating the steps 5 and 6, and connecting other blocks. The formed structural part is free of cracking and complete in structure, and the forming quality and efficiency of the high-temperature titanium alloy large complex aviation structure blank part are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of high-temperature titanium alloy additive manufacturing, and in particular relates to a laser deposition manufacturing method for large and complex aviation structural parts of high-temperature titanium alloy. Background Art

[0002] The rapid development of the aerospace industry has gradually increased the use temperature of titanium alloys from room temperature to 650°C. Currently, the titanium alloys that can be used at 650°C mainly include BT36, Ti1100 and Ti65, which can be used to manufacture engine blades and high-temperature structural parts. However, these high-temperature titanium alloys have poor process plasticity, and it is difficult to form large and complex aviation structural parts using traditional rolling and forging methods. Therefore, laser deposition manufacturing of large and complex aviation structural parts of high-temperature titanium alloys is proposed.

[0003] Laser deposition manufacturing technology is a type of additive manufacturing technology. It uses laser as a heat source to melt metal powder, combines CAD three-dimensional modeling software, and adopts a bottom-up layer-by-layer accumulation method to manufacture metal parts. This technology can achieve near-net forming of complex metal parts. Compared with traditional manufacturing processes (casting and forging), it not only shortens the production cycle but also improves the utilization rate of materials. Therefore, it has been widely used in the aerospace field. Laser deposition is a multi-physical field coupling process. The material completes melting, cooling and solidification in a short time. Therefore, the deposited parts are prone to macroscopic defects such as low dimensional accuracy and cracking. Due to the influence of its own chemical composition, high-temperature titanium alloys have worse plasticity and are more prone to cracking during the laser forming process. Especially for large and complex parts, it is difficult to ensure their perfect forming in one go.

[0004] In view of the shortcomings of the existing technology, it is necessary to propose a laser deposition manufacturing method and process for large and complex high-temperature titanium alloy aviation structural parts that can prevent cracking during their forming process. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a laser deposition manufacturing method for large and complex aviation structural parts of high-temperature titanium alloys, comprising the following steps:

[0006] Step 1: Divide the 3D model of the large and complex high-temperature titanium alloy aviation structural part blank into blocks;

[0007] Step 2: Prepare a titanium alloy substrate that meets the requirements and pre-process the substrate; import each block of the model after block processing into the laser deposition equipment to set the parameters before laser deposition;

[0008] Step 3: For the first deposited block, take the direction of its maximum dimension as the deposition direction and deposit the first block in the laser deposition equipment; when the deposition height is a multiple of 100mm, the formed part needs to be placed in a vacuum heat treatment furnace for heat treatment. After the entire block is formed, it also needs to be subjected to the same heat treatment;

[0009] Step 4: Deposit other blocks in sequence according to step 3;

[0010] Step 5: Cut the two adjacent forming blocks to be connected, process a groove at the connection, and preset a certain placement angle to compensate for the angular deformation in the connection;

[0011] Step 6: Use the same deposition equipment and parameters to perform laser deposition connection on the two forming blocks to be connected. When the deposition height at the connection is a multiple of 10 mm, place the connection piece in a vacuum heat treatment furnace for heat treatment. After the connection is completed, perform the same heat treatment on the connection piece;

[0012] Step 7: Repeat step 6 to connect other blocks until the entire blank is formed.

[0013] In the step 1, based on the test and simulation analysis results, taking into account the production efficiency and forming quality, it is necessary to ensure that the size of each block after segmentation is no larger than 220 mm × 500 mm × 30 mm.

[0014] In the step 2, in order to ensure that no cracking occurs during the forming process, the thickness of the substrate is 10-12 mm.

[0015] In steps 3, 4, 6 and 7, the main technical parameters of laser deposition are:

[0016] Laser power: 5000W;

[0017] Spot diameter 5mm;

[0018] Powder feeding rate 10-20g / min;

[0019] Scanning speed 600-720mm / min;

[0020] The single layer height is 0.7-0.8mm;

[0021] Overlap rate 50%;

[0022] The scanning mode is short-edge reciprocating scanning.

[0023] In the steps 3, 4, 6 and 7, in order to improve plasticity and prevent cracking, annealing heat treatment is adopted, and its parameters are: 700°C 4h FC.

[0024] In the step 5, before the connection is made, the groove of the connection is processed into a 50° slope; and the connection is preset at a 3° placement angle to compensate for the angular deformation during the connection. Figure 2 shown.

[0025] The multiple deposition blocks involved in steps three and four can be completed simultaneously in multiple laser deposition devices to improve production efficiency.

[0026] The connection between different deposition blocks involved in steps five and six can be completed simultaneously in multiple laser deposition devices to improve production efficiency.

[0027] The advantages of the present invention compared with the prior art are:

[0028] The present invention successfully uses laser deposition to form large-scale complex aviation structural blanks made of high-temperature titanium alloy. During the laser deposition manufacturing process, the maximum size of the blocks, deposition parameters, heat treatment parameters, connection groove size, and compensation deformation during connection are obtained through experiments and theoretical analysis, which significantly improves the forming quality and efficiency of large-scale complex aviation structural blanks made of high-temperature titanium alloy. The structural parts formed by this process are free of cracks and have a complete structure. The large-scale complex high-temperature titanium alloy structural parts formed by this method can be widely used in high-temperature parts in the aviation field. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0030] Figure 2 It is a schematic diagram of the groove angle and the compensation deformation angle when two adjacent forming blocks are connected in the present invention;

[0031] Figure 3 It is a structural part of high-temperature titanium alloy in the embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the embodiments.

[0033] Forming Figure 3 The high temperature titanium alloy frame beam web blank shown has a size of 1100mm×435mm×30mm. The material used is Ti65, and its composition is

[0034] Ti-5.9Al-4Sn-3.5Zr-0.5Mo-0.3Nb-2.0Ta-0.4Si-0.8W-0.0 6C, comprising the following steps:

[0035] Step 1: Divide the 3D model of the Ti65 aviation frame beam web blank into blocks. Figure 3 The size of each of the 4 pieces shown is no larger than 500mm×220mm×30mm;

[0036] Step 2: Prepare a TA15 titanium alloy substrate with a thickness of 10 mm. Import each model into the laser deposition equipment for pre-processing and parameter setting. The laser power is 5000 W, the spot diameter is 5 mm, the powder feeding rate is 15 g / min, the scanning speed is 600 mm / min, the single layer height is 0.8 mm, the overlap rate is 50%, and the scanning mode is short-side reciprocating scanning.

[0037] Step 3: Take the direction of the largest overall dimension of the first block as the deposition direction and perform laser deposition forming. When the deposition height is a multiple of 100 mm, the formed part needs to be placed in a vacuum heat treatment furnace for heat treatment; after the entire block is formed, it must also be subjected to the same heat treatment.

[0038] Step 4: Deposit other blocks in sequence according to the method and process of step 3.

[0039] Step 5: Cut the blocks 1 and 2 to be connected so that the connection is a 50° bevel and preset a 3° placement angle to compensate for the angular deformation in the connection, such as Figure 2 shown.

[0040] Step 6: Use the same deposition equipment and parameters to connect the forming blocks 1 and 2 by laser deposition. When the deposition height at the connection is a multiple of 10 mm, the connection piece needs to be placed in a vacuum heat treatment furnace for heat treatment. After the connection is completed, the connection block 1 is formed, and the same heat treatment is also performed on it. The heat treatment parameters are: 700℃4h FC.

[0041] Step 7: Cut the forming blocks 3 and 4 to be connected so that the connection is a 50° bevel and preset a 3° placement angle to compensate for the angular deformation in the connection, such as Figure 2 shown.

[0042] Step 8: Use the same deposition equipment and parameters to connect the blocks 3 and 4 by laser deposition. When the deposition height at the connection is a multiple of 10 mm, the connection piece needs to be placed in a vacuum heat treatment furnace for heat treatment. After the connection is completed, the connection block 2 is formed, and the same heat treatment is also performed on it. The heat treatment parameters are: 700℃4h FC.

[0043] Step 9: Repeat steps 7 and 8 for connecting blocks 1 and 2 to complete the final Figure 3 The forming of the Ti65 frame beam web blank is shown.

[0044] By adopting the method and process of the present invention, the Ti65 frame beam web blank after laser deposition block forming and then connection has a complete structure without cracking.

[0045] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A laser deposition manufacturing method for large and complex aviation structural parts of high-temperature titanium alloy, characterized by: Here are the steps: Step 1: Divide the 3D model of the large and complex high-temperature titanium alloy aviation structural part blank into blocks; Step 2: Prepare a titanium alloy substrate that meets the requirements and pre-treat the substrate; import each model into the laser deposition equipment and set the parameters before laser deposition; Step 3: For the first deposited block, take the direction of its maximum dimension as the deposition direction and deposit the first block in the laser deposition equipment; when the deposition height is a multiple of 100 mm, the formed part needs to be placed in a vacuum heat treatment furnace for heat treatment; after the entire block is formed, it also needs to be subjected to the same heat treatment; Step 4: Deposit other blocks in sequence according to step 3; Step 5: Cut the two adjacent forming blocks to be connected, process a groove at the connection, and preset a certain placement angle to compensate for the angular deformation in the connection; Step 6: Use the same deposition equipment and parameters to perform laser deposition connection on the two forming blocks to be connected. When the deposition height at the connection is a multiple of 10 mm, place the connection piece in a vacuum heat treatment furnace for heat treatment. After the connection is completed, perform the same heat treatment on the connection piece. Step 7: Repeat steps 5 and 6 to connect other blocks until all forming blocks are connected to form the desired blank.

2. The laser deposition manufacturing method for large and complex aviation structural parts of high-temperature titanium alloy according to claim 1 is characterized in that: In the step 1, based on the test and simulation analysis results, taking into account the production efficiency and forming quality, the size of each block after segmentation is no larger than 220 mm×500 mm×30 mm.

3. The laser deposition manufacturing method for large and complex aviation structural parts made of high-temperature titanium alloy according to claim 1 is characterized in that: In the step 2, the thickness of the substrate is 10-12 mm.

4. The laser deposition manufacturing method for large and complex aviation structural parts made of high-temperature titanium alloy according to claim 1 is characterized in that: In steps 3, 4, 6 and 7, the laser deposition parameters are: Laser power: 5000W; Spot diameter 5mm; Powder feeding rate 10-20g / min; Scanning speed 600-720mm / min; The single layer height is 0.7-0.8mm; Overlap rate 50%; The scanning mode is short-edge reciprocating scanning.

5. The laser deposition manufacturing method for large and complex aviation structural parts made of high-temperature titanium alloy according to claim 1, characterized in that: In the steps 3, 4, 6 and 7, annealing heat treatment is adopted, and the parameters are: 700° C. 4h FC.

6. The laser deposition manufacturing method for large and complex aviation structural parts made of high-temperature titanium alloy according to claim 1 is characterized in that: In the step 5, before connecting the parts to be connected, the groove at the connection is processed into a 50° slope; and the parts to be connected are preset at a placement angle of 3° to compensate for the angular deformation during the connection.

7. The laser deposition manufacturing method for large and complex aviation structural parts made of high-temperature titanium alloy according to claim 1 is characterized in that: The multiple deposition blocks involved in steps three and four can be completed synchronously in multiple laser deposition devices.

8. The laser deposition manufacturing method for large and complex aviation structural parts made of high-temperature titanium alloy according to claim 1 is characterized in that: The connection between different deposition blocks involved in steps five and six can be completed synchronously in multiple laser deposition devices.

Images