High-efficiency and low-cost preparation method of aviation equipment reinforced part

Abstract

The invention relates to the technical field of aviation equipment structure crack repair, in particular to a high-efficiency low-cost preparation method for aviation equipment reinforced parts, which comprises the following specific steps: S1, discovering a structure crack; s2, establishing a model; s3, preliminary preparation; s4, hot isostatic pressing treatment; s5, the part is subjected to finish machining; s6, the processing performance test sample verifies whether the performance meets the requirements or not; and S7, installing and applying. According to the method, a reverse modeling method is adopted, a damaged part model is firstly constructed, a corresponding reinforced part model is established, the inspection and assembly process is reduced, the reinforced part is prepared on the plate through the laser melting deposition technology, the plate serves as a part of the part, the volume ratio of the laser melting deposition part with the high cost in the part is reduced, and the manufacturing cost is reduced. The efficiency is effectively improved; and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of aviation equipment structural crack repair, in particular to a high-efficiency and low-cost preparation method for aviation equipment reinforcement parts. Background Art

[0002] When cracks that affect flight safety appear in the fuselage structure of aviation equipment, the more mature repair method is to reinforce and repair the cracks in the fuselage by strengthening parts. At present, there are two production processes for strengthening parts. One is the traditional method, including 1) designing a reinforced corner box that is suitable for the crack location, stress conditions and structural characteristics; 2) machining the inspection parts and test assembling them according to the design drawings. Optimize the engineering drawings according to the inspection conditions; 3) Machining qualified reinforced corner boxes according to the optimized engineering drawings, and installing them for application. The process of mechanically machining the reinforced corner box is: initial processing of the plate-quenching treatment-fine processing-stress relief annealing-surface treatment. The basic time consumption is more than 20 days, with a long cycle and low efficiency, which has a great restriction on the repair cycle and a low material utilization coefficient.

[0003] In addition, patent CN 110625113 B proposes a new preparation method for reinforced parts, including: 1) discovering structural cracks; 2) drawing drawings of reinforcement parts; 3) SLA light-curing non-metallic 3D printing process to form and test parts; 4) testing and optimizing three-dimensional models; 5) SLM laser selective melting to manufacture installation parts; 6) heat treatment. However, this process also faces the problem of low efficiency. In the process of SLM laser selective melting to manufacture installation parts, the thickness of a single layer is only 0.05mm. Assuming that the height of the reinforced part is 50mm, 1000 layers need to be printed, which takes a long time. In addition, the SLM laser selective melting process generally uses 15-53μm particle size powder. The market price of powder in this particle size range is higher than that of coarser powder and corresponding material plates. The use of this method to prepare reinforced parts also faces efficiency and cost issues. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a high-efficiency and low-cost preparation method for aviation equipment reinforcement parts.

[0005] A high-efficiency and low-cost preparation method for aviation equipment reinforcement parts, the specific steps of which are as follows:

[0006] S1. Structural cracks were found;

[0007] S2. Model building: Use 3D scanning equipment to conduct reverse modeling on the crack structure, build a damaged part model, and then build a corresponding reinforced part model based on the constructed damaged part model according to the stress conditions and structural characteristics;

[0008] S3, preliminary preparation: select the surface with the largest area as the bottom surface, and cut a plate with an area and thickness larger than the reinforced part model as the substrate, laser melt deposition is performed on the substrate, and the preliminary preparation of the reinforced corner box is completed by stacking layer by layer;

[0009] S4, hot isostatic pressing treatment: hot isostatic pressing treatment is used to treat the reinforced part blank;

[0010] S5. Finish the parts by using CNC milling machine to meet the designed model size;

[0011] S6. Processing performance test specimens verify whether the performance meets the requirements:

[0012] The lower half of the sample is a plate, which is subjected to laser melting deposition using the same process as in step S3, and is subjected to hot isostatic pressing using the same process as in step S4, and is then processed into tensile specimens and fatigue specimens, and compared with the hot-rolled annealed plate specimens for performance verification. If the tensile strength and fatigue performance reach 95% of the hot-rolled annealed plate specimens, the process is deemed feasible.

[0013] S7, installation application.

[0014] The crack detection in step S1 mainly adopts three methods: visual inspection, eddy current flaw detection, and color flaw detection.

[0015] The step S2 uses a three-dimensional scanning device, such as an industrial-grade handheld three-dimensional scanner, to perform a fine scan of the local structure with cracks, collect its structural features and generate corresponding point cloud data, and use UG, CATIA and other three-dimensional modeling tools to extract the corresponding assembly surface of the damaged structure digital model, and perform thickening processing. The thickness should make the strength of the reinforced part 1.5 times that of the original structure, generate the corresponding reinforced part basic model, and then generate the final model of the reinforced part after performing detail processing such as chamfering.

[0016] The area and thickness of step S3 are specifically greater than or equal to 2 mm in length and width directions of the length and width of the corresponding surface of the reinforced part model.

[0017] The specific preparation steps of step S3 are as follows: before the substrate is clad, the surface oxide layer is removed by mechanical grinding, and then the oil impurities on the surface are removed by acetone.

[0018] The plate material of the substrate is TA15 titanium alloy plate, and the plate thickness is greater than or equal to the thickness of the reinforcement part 2mm.

[0019] The powder material of the substrate is TA15 titanium alloy powder, and the powder particle size is 53-150 μm.

[0020] The cladding process of step S3 is as follows: laser power 1100 W, scanning speed 10 mm / s, powder feeding rate 4.3 g / min, each layer height is set to 0.8 mm, and argon protection flow rate 4 L / min.

[0021] The hot isostatic pressing process of step S4 is as follows: the temperature is set between 700 and 750° C., the pressure is set between 170 and 200 MPa, and the time is set between 2 and 6 hours.

[0022] The step S6 requires laser cladding on the TA15 plate to prepare a sample blank, wherein the lower half of the sample blank is the plate and the upper half is the cladding forming part.

[0023] The beneficial effect of the present invention is as follows: the present invention adopts the reverse modeling method to first construct a damaged part model, and then, according to the stress conditions and structural characteristics, a corresponding reinforced part model is established corresponding to the constructed damaged part model, thereby reducing the inspection and assembly process, effectively improving efficiency and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Figure 1 It is a schematic diagram of the substrate structure of the present invention;

[0026] Figure 2 It is a schematic diagram of laser cladding forming of the present invention;

[0027] Figure 3 It is a schematic diagram of the finished parts of the present invention. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below.

[0029] like Figures 1 to 3 As shown, a high-efficiency and low-cost preparation method for aviation equipment reinforcement parts, the specific steps are as follows:

[0030] S1. Structural cracks were found;

[0031] S2. Model building: Use 3D scanning equipment to conduct reverse modeling on the crack structure, build a damaged part model, and then build a corresponding reinforced part model based on the constructed damaged part model according to the stress conditions and structural characteristics;

[0032] S3, preliminary preparation: select the surface with the largest area as the bottom surface, and cut a plate with an area and thickness larger than the reinforced part model as the substrate, laser melt deposition is performed on the substrate, and the preliminary preparation of the reinforced corner box is completed by stacking layer by layer;

[0033] S4, hot isostatic pressing treatment: hot isostatic pressing treatment is used to treat the reinforced part blank;

[0034] S5. Finish the parts by using CNC milling machine to meet the designed model size;

[0035] S6. Processing performance test specimens verify whether the performance meets the requirements:

[0036] The lower half of the sample is a plate, which is subjected to laser melting deposition using the same process as in step S3, and is subjected to hot isostatic pressing using the same process as in step S4, and is then processed into tensile specimens and fatigue specimens, and compared with the hot-rolled annealed plate specimens for performance verification. If the tensile strength and fatigue performance reach 95% of the hot-rolled annealed plate specimens, the process is deemed feasible.

[0037] Specifically, the mechanical properties of the comparison samples processed from TA15 hot-rolled annealed plates are compared, and the performance of the performance test samples is equivalent to that of the comparison samples;

[0038] S7, installation application.

[0039] The present invention adopts the reverse modeling method to first construct a damaged part model, and then establish a corresponding reinforced part model according to the stress conditions and structural characteristics of the damaged part model, thereby reducing the inspection and assembly process, effectively improving efficiency and reducing costs.

[0040] The crack detection in step S1 mainly adopts three methods: visual inspection, eddy current flaw detection, and color flaw detection.

[0041] The step S2 uses a three-dimensional scanning device, such as an industrial-grade handheld three-dimensional scanner, to perform a fine scan of the local structure with cracks, collect its structural features and generate corresponding point cloud data, and use UG, CATIA and other three-dimensional modeling tools to extract the corresponding assembly surface of the damaged structure digital model, and perform thickening processing. The thickness should make the strength of the reinforced part 1.5 times that of the original structure, generate the corresponding reinforced part basic model, and then generate the final model of the reinforced part after performing detail processing such as chamfering.

[0042] Based on the point cloud data and the DesignX reverse modeling tool, reverse modeling is performed to generate a digital model of the damaged structure. According to the characteristics of the damaged structure, the surfaces that need to be assembled with reinforced parts are determined, and then processed in conjunction with UG, CATIA and other 3D modeling tools.

[0043] The area and thickness of step S3 are specifically greater than or equal to 2 mm in length and width directions of the length and width of the corresponding surface of the reinforced part model.

[0044] The specific preparation steps of step S3 are as follows: before the substrate is clad, the surface oxide layer is removed by mechanical grinding, and then the oil impurities on the surface are removed by acetone.

[0045] The plate material of the substrate is TA15 titanium alloy plate, and the plate thickness is greater than or equal to the thickness of the reinforcement part 2mm.

[0046] The specific preparation steps of step S3 are as follows: before the substrate is clad, the surface oxide layer is removed by mechanical grinding, and then the oil impurities on the surface are removed by acetone.

[0047] The plate material of the substrate is TA15 titanium alloy plate, the thickness of the plate is 2 mm greater than the thickness of the reinforced part, the plate is used as the substrate, laser melting and deposition are performed on the substrate, and the substrate is also a part of the part, which reduces the area of ​​laser melting and deposition. The price of titanium alloy plate is much lower than that of powder, which effectively improves efficiency and reduces costs.

[0048] The powder material of the substrate is TA15 titanium alloy powder with a powder particle size of 53 to 150 μm. The LMD laser melting deposition process is used, and the single-layer height is 0.7 to 1.1 mm, which is 14 to 22 times the single-layer height of 0.05 mm of the SLM laser selective melting process. The single-piece forming time is reduced by more than 10 times, greatly improving the efficiency. In addition, the price of 53 to 150 μm powder selected by the LMD laser melting deposition process is also lower than that of 15 to 53 μm powder selected by the SLM laser selective melting process.

[0049] The cladding process of step S3 is as follows: laser power 1100 W, scanning speed 10 mm / s, powder feeding rate 4.3 g / min, each layer height is set to 0.8 mm, and argon protection flow rate 4 L / min.

[0050] The hot isostatic pressing process of step S4 is as follows: the temperature is set between 700 and 750°C, the pressure is set between 170 and 200 MPa, and the time is set between 2 and 6 hours. The advantage is that the treatment temperature is lower than the TA15 conventional annealing heat treatment or hot isostatic pressing temperature of 800 to 900°C, and 170 to 200 MPa ultra-high pressure treatment is used. The lower temperature avoids the growth of the laser cladding forming fast cooling structure caused by heat treatment, and higher strength can be obtained. At the same time, ultra-high pressure treatment can close pores at a lower temperature, reduce defects, and improve the comprehensive mechanical properties of the treated parts.

[0051] The hot isostatic pressing process is used as a post-treatment process to effectively eliminate the defects caused by the LMD laser melting deposition process, reduce the residual stress, and regulate the structure, so that the mechanical properties are equivalent to those of hot-rolled annealed plates.

[0052] The step S6 requires laser cladding on the TA15 plate to prepare a sample blank, wherein the lower half of the sample blank is the plate and the upper half is the cladding forming part.

[0053] Specific steps of performance testing

[0054] Test pieces are prepared to verify the repair effect. The test pieces include laser cladding formed parts and comparison parts.

[0055] The method for making laser cladding formed parts is to prepare a sample blank by laser cladding on a TA15 plate, wherein the lower half of the sample blank is the plate and the upper half is the cladding forming part. The hot isostatic pressing process is a temperature of 750°C and a pressure of 180 MPa. The sample blank is then processed into a tensile specimen and a fatigue specimen.

[0056] The comparison piece is made of TA15 hot-rolled annealed sheet, with an annealing temperature of 850℃ and an annealing time of 4h. The TA15 hot-rolled annealed sheet is processed into tensile specimens and fatigue properties.

[0057] The tensile strengths of laser cladding parts are 1020Pa, 1028MPa and 1023MPa respectively.

[0058] The tensile strengths of the comparison pieces are 1018MPa, 1025MPa and 1022MPa respectively.

[0059] The fatigue test load is 370MPa, the stress concentration factor Kt is 2.5, and the stress ratio is 0.1.

[0060] The fatigue lives of laser cladding parts are 249327, 184863, and 329102 respectively.

[0061] By comparison, the fatigue life of the parts is 387183, 192250, and 219998.

[0062] The performance of the laser cladding formed parts is basically equivalent to that of the comparison parts, which shows that the process method is feasible.

[0063] 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 high-efficiency and low-cost method for preparing reinforced parts for aviation equipment, characterized in that: The specific steps are as follows: S1. Structural cracks were found; S2. Model building: Use 3D scanning equipment to conduct reverse modeling on the crack structure, build a damaged part model, and then build a corresponding reinforced part model based on the constructed damaged part model according to the stress conditions and structural characteristics; S3, preliminary preparation: select the surface with the largest area as the bottom surface, and cut a plate with an area and thickness larger than the reinforced part model as the substrate, laser melt deposition is performed on the substrate, and the preliminary preparation of the reinforced corner box is completed by stacking layer by layer; S4, hot isostatic pressing treatment: hot isostatic pressing treatment is used to treat the reinforced part blank; S5. Finish the parts by using CNC milling machine to meet the designed model size; S6. Processing performance test specimens verify whether the performance meets the requirements: The lower half of the sample is a plate, which is subjected to laser melting deposition using the same process as in step S3, and is subjected to hot isostatic pressing using the same process as in step S4, and is then processed into tensile specimens and fatigue specimens, and compared with the hot-rolled annealed plate specimens for performance verification. If the tensile strength and fatigue performance reach 95% of the hot-rolled annealed plate specimens, the process is deemed feasible. S7, installation application.

2. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 1, characterized in that: The crack detection in step S1 mainly adopts three methods: visual inspection, eddy current flaw detection, and color flaw detection.

3. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 1, characterized in that: The step S2 uses a three-dimensional scanning device, such as an industrial-grade handheld three-dimensional scanner, to perform a fine scan of the local structure with cracks, collect its structural features and generate corresponding point cloud data, and use UG, CATIA and other three-dimensional modeling tools to extract the corresponding assembly surface of the damaged structure digital model, and perform thickening processing. The thickness should make the strength of the reinforced part 1.5 times that of the original structure, generate the corresponding reinforced part basic model, and then generate the final model of the reinforced part after performing detail processing such as chamfering.

4. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 1, characterized in that: The area and thickness of step S3 are specifically greater than or equal to 2 mm in length and width directions of the length and width of the corresponding surface of the reinforced part model.

5. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 4, characterized in that: The specific preparation steps of step S3 are as follows: before the substrate is clad, the surface oxide layer is removed by mechanical grinding, and then the oil impurities on the surface are removed by acetone.

6. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 5, characterized in that: The plate material of the substrate is TA15 titanium alloy plate, and the plate thickness is greater than or equal to the thickness of the reinforcement part 2mm.

7. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 6, characterized in that: The powder material of the substrate is TA15 titanium alloy powder, and the powder particle size is 53-150 μm.

8. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 5, characterized in that: The cladding process of step S3 is as follows: laser power 1100 W, scanning speed 10 mm / s, powder feeding rate 4.3 g / min, each layer height is set to 0.8 mm, and argon protection flow rate 4 L / min.

9. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 1, characterized in that: The hot isostatic pressing process of step S4 is as follows: the temperature is set between 700 and 750° C., the pressure is set between 170 and 200 MPa, and the time is set between 2 and 6 hours.

10. The high-efficiency and low-cost method for preparing aviation equipment reinforcement parts according to claim 1, characterized in that: The step S6 requires laser cladding on the TA15 plate to prepare a sample blank, wherein the lower half of the sample blank is the plate and the upper half is the cladding forming part.

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