A 3D printing method for TA15 titanium alloy aerospace components

Abstract

This invention relates to a 3D printing method for TA15 titanium alloy aerospace components, comprising the following steps: obtaining TA15 titanium alloy blanks by passing forged TA15 alloy wire through an electron beam filament forming device; subsequently, subjecting the TA15 titanium alloy blanks to double hot isostatic pressing treatment to obtain TA15 titanium alloy aerospace components; after the above treatment, grinding and polishing the TA15 titanium alloy aerospace components to obtain finished TA15 titanium alloy aerospace components; the preparation process of this invention is completed in a vacuum environment, the components are less prone to introducing impurities, have fewer defects and higher density, and the wire has high melting efficiency and relatively safe storage and transportation, greatly reducing the processing cost of titanium alloy components; after the double hot isostatic pressing treatment of the TA15 titanium alloy aerospace components in this invention, the α-strip width increases and a gradient oxygen-permeable layer is formed on the surface of the components, significantly improving the fatigue performance of the TA15 titanium alloy aerospace components.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy additive manufacturing technology, and in particular to a 3D printing method for TA15 titanium alloy aerospace components. Background Technology

[0002] Titanium alloys are widely used in aerospace, marine, medical, and chemical industries due to their high specific strength, low density, good thermal stability, and high-temperature strength. However, their high processing costs, narrow processing window, and complex forging processes severely limit their widespread application.

[0003] Electron beam filament rapid prototyping is a type of metal 3D printing technology. It is based on a vacuum environment, using a high-energy electron beam to melt the metal surface and the fed metal filament, while moving along a path planned by CAD, stacking layer by layer to finally form the desired metal component.

[0004] Commonly used aerospace components are manufactured using traditional forging techniques, with a smaller portion using 3D printing. Traditional forging is costly, while 3D printing, although cost-effective, suffers from extremely high cooling rates during the forming process. This results in titanium alloy aerospace components produced using electron beam fusion rapid prototyping technology exhibiting a fine lath-like microstructure, often leading to lower fatigue performance. Since aerospace components are subjected to alternating loads during long-term use, fatigue failure is a primary mode of component failure. Therefore, the fatigue life of a component largely determines its service life. This severely limits the application of electron beam fusion rapid prototyping technology in the aerospace field. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a 3D printing method for TA15 titanium alloy aerospace components, which can significantly improve the fatigue performance of the components.

[0006] This invention is achieved using the following technical solution:

[0007] A 3D printing method for TA15 titanium alloy aerospace components includes the following steps:

[0008] The forged TA15 alloy wire is processed by an electron beam wire forming equipment to obtain TA15 titanium alloy billet, and then the TA15 titanium alloy billet is subjected to double hot isostatic pressing treatment to obtain TA15 titanium alloy aerospace components.

[0009] After the above processing is completed, the TA15 titanium alloy aerospace component is ground and polished to obtain the finished TA15 titanium alloy aerospace component.

[0010] As a further explanation of the invention, the forging process of the TA15 alloy wire includes the following steps:

[0011] Select TA15 alloy and determine the phase transformation point T of TA15 alloy. β After the TA15 alloy ingot is rolled at 50-150°C above the phase transformation point, it is upsetting and drawing twice at 20-80°C above the phase transformation point. Then, it is drawn and precision forged at 10-100°C below the phase transformation point. The resulting precision forged bar is drawn into wire at 400-700°C. After peeling and pickling, TA15 alloy wire is obtained.

[0012] As a further explanation of the invention, the process parameters of the forged TA15 alloy wire in the electron beam wire forming equipment are as follows: electron beam acceleration voltage is 60kV; beam current is 30mA~100mA; feed wire diameter is 2.0mm; feed rate is 10mm / s~30mm / s; and deposit thickness is 4.0mm~8.0mm.

[0013] As a further explanation of the invention, the TA15 titanium alloy billet undergoes a double hot isostatic pressing process as follows:

[0014] The TA15 titanium alloy billet is subjected to a first hot isostatic pressing at 10°C to 100°C above the phase transformation point, with a pressure of 90MPa to 150MPa. After holding at this temperature and pressure under argon atmosphere for 2 to 6 hours, it is furnace cooled to room temperature. During this process, the width of the α-strips of the TA15 titanium alloy aerospace component increases. Then, a second hot isostatic pressing is performed at 500°C to 600°C, with a pressure of 1MPa to 10MPa. After holding at this temperature and pressure under an oxygen atmosphere for 8 to 20 hours, it is air cooled. A gradient oxygen-permeable layer is formed on the surface of the TA15 titanium alloy aerospace component.

[0015] As a further explanation of the invention, the surface oxide layer of the TA15 titanium alloy aerospace component is ground and polished to obtain a finished TA15 titanium alloy aerospace component that retains a gradient oxygen-permeable layer.

[0016] As a further illustration of the invention, the process of preparing TA15 titanium alloy aerospace components using the electron beam filament forming equipment is completed in a vacuum environment.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] 1. Compared with traditional manufacturing processes, the present invention uses 3D printing technology, which not only eliminates mold costs and saves materials to the maximum extent, but also has great advantages in electron beam filament rapid prototyping technology. Since the preparation process is completed in a vacuum environment, the components are less likely to introduce impurities, have fewer defects, and have higher density. At the same time, its filament has high melting efficiency and relatively safe storage and transportation, which greatly reduces the processing cost of titanium alloy aerospace components.

[0019] 2. In this invention, after the TA15 titanium alloy aerospace component undergoes double hot isostatic pressing treatment, the width of the α-strip increases, and a gradient oxygen-permeable layer is formed on the surface of the component, thereby significantly improving the fatigue performance of the TA15 titanium alloy aerospace component. Attached Figure Description

[0020] The invention will be further described below with reference to the accompanying drawings:

[0021] Figure 1 The microstructure of the TA15 titanium alloy aerospace component before double hot isostatic pressing in this embodiment of the invention;

[0022] Figure 2 The microstructure of the TA15 titanium alloy aerospace component after double hot isostatic pressing in the embodiments of the present invention;

[0023] Figure 3 The results of Micro-CT testing of TA15 titanium alloy aerospace components after double hot isostatic pressing in this embodiment of the invention are shown. Detailed Implementation

[0024] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0026] Example 1:

[0027] The TA15 alloy used in this embodiment has the composition of Ti-6.52Al-2.06Zr-1.05Mo-1.05V, and its phase transformation point T β It is 998℃.

[0028] like Figure 1-3 As shown, a 3D printing method for TA15 titanium alloy aerospace components includes the following steps:

[0029] Step 1, Forging of TA15 alloy wire:

[0030] TA15 alloy ingots were subjected to billet preparation and two-stage upsetting and drawing deformation on an 8000T forging mill. The billet preparation temperature was 1100℃, the first upsetting and drawing deformation temperature was 1048℃, and the second upsetting and drawing deformation temperature was 1028℃. The resulting billet was then drawn on a 2500T forging mill at a drawing temperature of 948℃ to obtain a Ф150mm bar. The bar was then precision forged on a 1000T precision forging mill at the same forging temperature as the drawing temperature of 948℃ to obtain a Ф50mm precision forged bar. After grinding, the precision forged bar was drawn at 500℃, peeled, and pickled to obtain a Ф2mm TA15 alloy wire.

[0031] Step 2, Fabrication of TA15 titanium alloy aerospace components:

[0032] TA15 titanium alloy aerospace components were prepared using an electron beam filament forming equipment of model ZD60-60. The forming process parameters were as follows: electron beam accelerating voltage was 60kV; beam current was 50mA; feed wire diameter was 2.0mm; feed rate was 18mm / s; and the deposit thickness was approximately 6.0mm.

[0033] First, a first-stage thermostatic pressing was performed at a pressure of 120 MPa and a temperature of 1030 °C. After holding at this temperature and pressure for 4 hours under argon protection, the furnace was cooled. The resulting microstructure is as follows: Figure 1 As shown, the α-slat width of the TA15 titanium alloy aerospace component is increased, and then a second hot isostatic pressing is performed under a pressure of 5 MPa and a temperature of 550℃. After holding at this temperature and pressure for 12 hours in an oxygen atmosphere, it is air-cooled. Its microstructure is as follows. Figure 2 As shown, a gradient oxygen-permeable layer is formed on the surface of its TA15 titanium alloy aerospace component.

[0034] Step 3, Preparation of finished TA15 titanium alloy aerospace components:

[0035] The surface oxide layer of the TA15 titanium alloy aerospace component was ground and polished to obtain a finished TA15 titanium alloy aerospace component retaining a gradient oxygen-permeable layer. Micro-CT (microcomputed tomography) testing revealed no obvious internal defects. Figure 3 As shown;

[0036] Table 1 shows the fatigue limits of the components before and after hot isostatic pressing in Example 1:

[0037] Table 1. Fatigue limits of components before and after hot isostatic pressing in Example 1.

[0038]

[0039] Note: As can be seen from the table above, the 3D printed TA15 titanium alloy aerospace components prepared by this invention have excellent room temperature and high temperature fatigue properties.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A 3D printing method for TA15 titanium alloy aerospace components, characterized in that, Includes the following steps: The forged TA15 alloy wire is processed by an electron beam wire forming equipment to obtain TA15 titanium alloy billet, and then the TA15 titanium alloy billet is subjected to double hot isostatic pressing treatment to obtain TA15 titanium alloy aerospace components. After the above processing is completed, the TA15 titanium alloy aerospace component is ground and polished to obtain the finished TA15 titanium alloy aerospace component. The TA15 titanium alloy billet undergoes a double hot isostatic pressing process as follows: The TA15 titanium alloy billet is subjected to a first hot isostatic pressing at 10°C to 100°C above the phase transformation point, with a pressure of 90 MPa to 150 MPa. After holding at this temperature and pressure under argon atmosphere for 2 to 6 hours, it is furnace cooled to room temperature. During this process, the width of the α-strips of the TA15 titanium alloy aerospace component increases. Then, a second hot isostatic pressing is performed at 500°C to 600°C, with a pressure of 1 MPa to 10 MPa. After holding at this temperature and pressure under an oxygen atmosphere for 8 to 20 hours, it is air cooled. A gradient oxygen-permeable layer is formed on the surface of the TA15 titanium alloy aerospace component.

2. The 3D printing method for TA15 titanium alloy aerospace components as described in claim 1, characterized in that, The forging process of the TA15 alloy wire includes the following steps: Select TA15 alloy and determine the phase transformation point T of TA15 alloy. β After the TA15 alloy ingot is rolled at 50~150℃ above the phase transformation point, it is upsetting and drawing twice at 20~80℃ above the phase transformation point. Then it is drawn and precision forged at 10~100℃ below the phase transformation point. The resulting precision forged bar is drawn at 400~700℃ and then peeled and pickled to obtain TA15 alloy wire.

3. The 3D printing method for TA15 titanium alloy aerospace components as described in claim 2, characterized in that, The process parameters for the forged TA15 alloy wire in the electron beam wire forming equipment are as follows: electron beam acceleration voltage is 60 kV; beam current is 30mA ~ 100 mA; feed wire diameter is 2.0 mm; feed rate is 10 mm / s ~ 30 mm / s; and deposit thickness is 4.0 mm ~ 8.0 mm.

4. The 3D printing method for TA15 titanium alloy aerospace components as described in claim 1, characterized in that, The surface oxide layer of the TA15 titanium alloy aerospace component is ground and polished to obtain the finished TA15 titanium alloy aerospace component with a gradient oxygen-permeable layer.

5. The 3D printing method for TA15 titanium alloy aerospace components as described in claim 4, characterized in that, The electron beam filament forming equipment is used to prepare TA15 titanium alloy aerospace components in a vacuum environment.

Images