Method for simulating and measuring phase volume fraction in additive manufacturing process

Abstract

The invention provides a method for simulating and measuring phase volume fraction change in a metal material additive manufacturing process. The method comprises the following steps: preparing a sample; mounting the sample to an experimental device; performing cyclic heat treatment on the sample to simulate an additive manufacturing process, and acquiring synchrotron radiation X-ray two-dimensional diffraction patterns of the sample at different moments; converting the two-dimensional diffraction pattern into a one-dimensional diffraction pattern; and refining the one-dimensional diffraction pattern by using a Rietveld method to obtain a change chart of the volume fraction of each phase of the sample along with time. According to the method, the heating process of a lower-layer material in the additive manufacturing process is simulated by conducting cyclic heat treatment on the material, the phase change of the material is detected through synchrotron radiation X-rays, and the complex unbalanced solid-state phase change of the lower-layer material in the additive manufacturing process of a metal material can be researched in situ; and then the additive manufacturing process is optimized in an auxiliary mode, and the alloy performance is regulated and controlled.

Description

Technical Field

[0001] The present disclosure generally relates to the field of additive manufacturing of metallic materials, and particularly to simulating the heating process of the underlying material during the additive manufacturing of metallic materials by performing cyclic heat treatment on a metallic specimen, and realizing in-situ research on the phase volume fraction during this process in combination with synchrotron X-rays. Background Art

[0002] Additive manufacturing has been applied to the production of components such as nickel-based superalloy parts. Its products have excellent surface accuracy, high forming density, and mechanical properties such as tensile strength and hardness that meet or even exceed the casting standards, and have broad application prospects in the fields of aerospace and energy power.

[0003] Compared with traditional manufacturing methods, additive manufacturing uses pre-alloyed powders with relatively uniform compositions as raw materials, and has a high cooling rate during the manufacturing process. Therefore, it is easier to produce alloys with uniform structures and fine grains. However, the ultra-high temperature gradient and cooling rate in additive manufacturing are also likely to cause cracking of the alloy, and there are also some metallurgical defects inside the alloy, which makes it difficult to fully utilize the performance improvement brought by the uniform structure and fine grains.

[0004] In the past, to address this problem, post-treatment of the finished products of additive manufacturing was often used to improve the performance. For example, Patent CN118437941A discloses a method for eliminating cracks in additive-manufactured nickel-based superalloy parts, including the following steps: (a) performing annealing heat treatment on the additive-manufactured nickel-based superalloy parts, and then performing solution heat treatment, which includes first, second, and third solution heat treatments; (b) performing hot isostatic pressing treatment. However, since this method improves the defects of the finished products afterwards, it fails to eliminate the generation of defects from the source, so the degree of performance improvement is limited.

[0005] TiAl alloys have low density, high melting point, high specific strength, good high-temperature strength, high-temperature oxidation resistance, and creep resistance. They are a kind of lightweight high-temperature structural material with broad application prospects and have been widely used in the low-pressure turbine (LPT) blades of aeroengines. However, the phase diagram of TiAl alloys is complex, and it is difficult to obtain a uniform as-cast structure. Moreover, in order to further improve the hot working performance of this alloy for application in the low-pressure turbines of civil aeroengines, researchers usually add β-phase stabilizing elements such as Nb and Mo to develop β-γ-TiAl alloys, whose phase transformation process is more complex, and it becomes particularly difficult to obtain a uniform, fine, and less segregated as-cast structure.

[0006] In view of this, the inventors of the present invention believe that the production of titanium aluminide alloys, especially high-niobium titanium aluminide alloys, by additive manufacturing processes has broad application prospects. During the additive manufacturing process, by controlling production process parameters, such as the temperature of the powder bed, the precipitation quantity and distribution of each phase are controlled to form a double gradient change in the volume fraction and elastic modulus of the precipitated phase along a preset direction, which is of profound significance for ultimately successfully achieving crack-free and low-defect production of the alloy. Therefore, studying the change in the volume fraction of phases during the additive manufacturing process is crucial for optimizing the additive manufacturing process parameters, which is conducive to accurately formulating and optimizing the production process to regulate the alloy properties.

[0007] In addition, synchrotron radiation X-rays have high time resolution and spatial resolution, can in-situ detect the phase transformation of materials, and then calculate the change in their phase volume fraction. Summary of the Invention

[0008] In view of the fact that in actual additive manufacturing, metal powder first melts and then solidifies. As layer upon layer of metal is deposited, the solidified metal is repeatedly heated and cooled, which is equivalent to undergoing a thermal cycle with continuously decreasing peak temperature. However, the prior art only simulates the cycle experienced by the material after solidification, and the cooling rate cannot perfectly approximate the situation in additive manufacturing, making it impossible to perfectly simulate the entire process and difficult to provide guidance for other parameters. Those skilled in the art point out that the thermal change process during the additive manufacturing process is the heating process of the solidified lower-layer material as the upper-layer material is gradually deposited layer by layer. Essentially, it is a series of thermal cycles with gradually decreasing peak temperatures, and propose that the material can be subjected to cyclic heat treatment to simulate the heating process of the lower-layer material in additive manufacturing, so as to achieve the determination of the phase volume fraction during the additive manufacturing process, and thus optimize the additive manufacturing process accordingly.

[0009] The object of the present invention is to provide a method for simulating and determining the phase volume fraction in the additive manufacturing of metal materials, so as to study the complex non-equilibrium solid-state phase transformation of the lower-layer material during the additive manufacturing process of metal materials, and further assist in optimizing the additive manufacturing process and regulating the alloy properties.

[0010] According to one aspect of the present disclosure, there is provided a method for simulating and determining the change in phase volume fraction during additive manufacturing, wherein the method includes: Step 1: Prepare a specimen; Step 2: Install the specimen on the experimental device; Step 3: Perform cyclic heat treatment on the specimen to simulate the heating process of the solidified lower-layer material during additive manufacturing, and obtain two-dimensional synchrotron radiation X-ray diffraction patterns of the specimen at different times; Step 4: Transform the two-dimensional diffraction pattern into a one-dimensional diffraction pattern. The Fit2D software can be used to transform the two-dimensional diffraction pattern into a one-dimensional diffraction pattern. Fit2D is a software tool developed by the ESRF (European Synchrotron Radiation Facility) for processing and analyzing two-dimensional X-ray diffraction data, and is widely used in the fields of materials science, physics, chemistry, etc. It can convert the two-dimensional diffraction rings into a one-dimensional diffraction pattern (intensity vs. 2θ), which is convenient for subsequent quantitative analysis (such as phase content calculation, lattice parameter determination). Step 5: Refine the one-dimensional diffraction pattern using the Rietveld method to obtain a graph of the volume fraction of each phase of the specimen changing with time.

[0011] According to an embodiment of the present disclosure, a method for simulating and determining the change in phase volume fraction during additive manufacturing is provided, wherein the cyclic heat treatment includes the following: heating the specimen to 1200 - 1350°C at a rate of 40 - 60°C / s, holding for 5 - 15 s, and then starting thermal cycling. The heating and cooling rate is 150 - 250°C / s, the peak temperature is reduced by 30 - 60°C each time, the low-temperature holding temperature is 900 - 1100°C, corresponding to the powder bed temperature of 1000°C in additive manufacturing. After cycling five times, it is rapidly cooled to room temperature.

[0012] According to an embodiment of the present disclosure, a method for simulating and determining the change in phase volume fraction during additive manufacturing is provided, wherein in step 1, the sample is a hollow sample with a diameter of 5 mm, a hole diameter of 2 mm, and a length of 10 mm; in step 2: the sample is cleaned and dried.

[0013] According to an embodiment of the present disclosure, a method for simulating and determining the change in phase volume fraction during additive manufacturing is provided, wherein in step 2, the experimental device is not particularly limited and can be any device that can achieve the technical purpose of the present invention, whether it is developed now or in the future. For example, it can be the experimental platform provided by the Institute of Materials Physics of the Helmholtz Center in Hamburg, Germany, which is used by the inventors of the present invention. It is an experimental platform assembled by a synchrotron radiation light source and many conventional experimental devices; the schematic diagram of the path of the high-energy X-ray for synchrotron radiation and the overall structure schematic diagram of the corresponding experimental device in step 3 are as Figure 8 shown. In step 3, the synchrotron radiation X-ray has an energy of 100 keV, a wavelength of 0.0124 nm, and an irradiation range of 1 mm × 1 mm.

[0014] According to an embodiment of the present disclosure, a method for simulating and determining the change in phase volume fraction during additive manufacturing is provided, wherein in step 3, the synchrotron radiation X-ray penetrates the specimen and is collected by the image acquisition system after exiting, and a picture is taken every 0.1 s.

[0015] According to an embodiment of the present disclosure, a method for simulating and measuring the change in phase volume fraction during the additive manufacturing process is provided, wherein step 5 includes: Step 5-1: Perform whole-spectrum fitting on the one-dimensional diffraction pattern using the Rietveld method to obtain the volume fraction of each phase of the specimen; Step 5-2: Superimpose the volume fractions of each phase of the specimen at different times and plot a graph of the change in the volume fraction of each phase of the specimen over time.

[0016] According to a preferred embodiment of the present disclosure, a method for simulating and measuring the change in phase volume fraction during the additive manufacturing process is provided, wherein the cyclic heat treatment includes the following: Heat the specimen to 1300 °C at a rate of 50 °C / s, hold for 10 s, then start the thermal cycle. The heating and cooling rate is 200 °C / s, the peak temperature is reduced by 50 °C each time, the low-temperature holding temperature is 1000 °C, corresponding to the powder bed temperature of 1000 °C in additive manufacturing. After five cycles, quickly cool to room temperature.

[0017] According to a preferred embodiment of the present disclosure, a method for measuring the change in phase volume fraction during the additive manufacturing process is provided, wherein the cyclic heat treatment includes the following: Heat the specimen to 1300 °C at a rate of 50 °C / s, hold for 10 s, then start the thermal cycle. The heating and cooling rate is 200 °C / s, the peak temperature is reduced by 50 °C each time, the low-temperature holding temperature is 700 °C, corresponding to the powder bed temperature of 700 °C in additive manufacturing. After five cycles, quickly cool to room temperature.

[0018] According to a preferred embodiment of the present disclosure, a method for simulating and measuring the change in phase volume fraction during the additive manufacturing process is provided, wherein the composition of the specimen is a Ti-(43-47)Al-(7-10)Nb alloy. However, the present invention is not limited thereto. Considering that in recent years, trace alloying elements including but not limited to W, B, Mo, V, Ta, Y, and Mn can be added to the high-niobium titanium-aluminum alloy to promote grain refinement and tissue uniformity, so as to improve the phase distribution and thus improve the mechanical properties such as toughness of the high-niobium titanium-aluminum alloy. Therefore, the present invention is also applicable to alloys containing but not limited to the above-mentioned additive elements. For example, the content of W can be 0-1 at.%, further preferably 0.5 at.%; the content of B can be 0-0.5 at.%, further preferably 0.2 at.%; the content of Mo can be 0-3 at.%, further preferably 2 at.%; the content of V can be 0-3 at.%, further preferably 2 at.%; the content of Ta can be 0-1 at.%, further preferably 0.5 at.%; the content of Y can be 0-0.5 at.%, further preferably 0.2 at.%; the content of Mn can be 0-2 at.%, further preferably 1.0 at.%.

[0019] According to a preferred embodiment of the present disclosure, a method for simulating and determining the change of phase volume fraction during the additive manufacturing process is provided, wherein the composition of the specimen is Ti-46Al-9Nb alloy.

[0020] According to one aspect of the present invention, a method for additive manufacturing of a titanium-aluminum alloy is provided, characterized in that the additive manufacturing process, such as but not limited to the powder bed temperature during the additive manufacturing process, is obtained by analyzing the change of the volume fraction of each phase in the titanium-aluminum alloy over time obtained by the method according to any one of claims 1 to 9, and can be 950 to 1050 °C, corresponding to the powder bed temperature in additive manufacturing being 950 to 1050 °C.

[0021] According to a preferred embodiment of the present disclosure, the powder bed temperature is 1000 °C, and the composition of the titanium-aluminum alloy used for the additive manufacturing is Ti-46Al-9Nb alloy.

[0022] According to a preferred embodiment of the present disclosure, the specimen is prepared through the following process: Melting the master alloy, weighing the raw materials according to the determined target composition of the titanium-aluminum alloy, and melting the weighed raw materials to prepare the master alloy; Gas atomization for powder making, subjecting the master alloy to gas atomization for powder making to prepare alloy powder; Filling the alloy powder into a titanium can for hot isostatic pressing to prepare the titanium-aluminum alloy, wherein the hot isostatic pressing can be, for example, holding at 1000 to 1300 °C for 1 to 4 h under 150 to 200 MPa, for example, obtaining the sample required for this experiment by hot isostatic pressing at 190 MPa and 1270 °C for 2 h.

[0023] According to a preferred embodiment of the present disclosure, the Rietveld method in step 5 is a refinement technique for analyzing X-ray or neutron diffraction data of polycrystalline materials. This method establishes a crystal structure model, calculates the theoretical diffraction pattern, and refines the parameters by the least squares method to obtain the crystal structure information matching the experimental data, and can also perform orientation analysis of the phase ratio to obtain the volume fraction of each phase.

[0024] In an alternative embodiment, in step 5-1, the GSAS-II software is used to refine the one-dimensional diffraction pattern of the specimen. The specific operations are as follows: Collect the crystal structure information of each phase, which is usually saved in a 'cif' file; Initialize the instrument parameters and calibrate the instrument parameters with a LaB6 standard sample; Create a new project in GSAS-II, import the experimental data, and import the instrument parameter file; Import the '.cif' files of the three phases in sequence through the 'Add Phase' function to ensure that the unit cell parameters and space groups of each phase are correct; Select the background function as the Chebyschev polynomial, with the order usually being 6-8, and check the background parameter refinement; Refine the unit cell parameters (a, b, c) of each phase to improve the peak position alignment; Check the refinement of the phase fractions and limit the sum of the three phases to 1, and then refine; Check the residual factors (Rwp, Rp) and the goodness of fit (GoF, i.e., χ²). The ideal values are: Rwp < 10%, GoF ≈ 1-2; Export the refined result table, including the content of each phase, unit cell parameters, R factors, etc.

[0025] Technical effects The beneficial effects of the present invention are reflected in: Simulating the thermal process changes of the underlying material of the titanium-aluminum alloy during the additive manufacturing process, using synchrotron radiation X-rays to characterize the specimen information in real time, measuring the real-time changes in the volume fractions of each phase of the specimen, providing sufficient basis for the phase transformation research of materials under complex heating conditions in additive manufacturing, and formulating an optimized additive manufacturing plan for titanium-aluminum alloys. Description of the drawings

[0026] By describing the embodiments of the present disclosure in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present disclosure will become more apparent. The drawings are used to provide a further understanding of the embodiments of the present disclosure, and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the present disclosure and do not constitute a limitation to the present disclosure. In the drawings, the same reference numerals generally represent the same components or steps.

[0027] Figure 1 It is a schematic flow chart of a method for simulating and measuring the phase volume fraction in additive manufacturing; Figure 2 It shows a temperature change diagram of the cyclic heat treatment of the specimen by simulated additive manufacturing according to Embodiment 1 of the present invention; Figure 3 It shows a diagram of the change of the volume fraction of each phase in the specimen over time according to Embodiment 1 of the present invention; Figure 4 It shows a temperature change diagram of the cyclic heat treatment of the specimen by simulated additive manufacturing according to Embodiment 2 of the present invention; Figure 5 It shows a diagram of the change of the volume fraction of each phase in the specimen over time according to Embodiment 2 of the present invention; Figure 6 Two-dimensional synchrotron X-ray diffraction pattern of the specimen at a certain moment; Figure 7 is Figure 6 One-dimensional synchrotron X-ray diffraction pattern at a certain moment described in; Figure 8 Schematic diagram of the path of synchrotron X-rays used in the present invention. Specific implementation mode

[0028] Hereinafter, exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all embodiments of the present disclosure. It should be understood that the present disclosure is not limited by the exemplary embodiments described herein.

[0029] Exemplary method To facilitate understanding of the technical key points of the present invention, the implementation scheme of the present invention will be described in detail below in conjunction with embodiments and the accompanying drawings.

[0030] It should be noted that the alloy used in this embodiment is Ti-46Al-9Nb alloy. Example 1

[0031] According to Figure 1 shown, perform the following steps.

[0032] Step 1: Prepare the specimen: Cut the alloy into a hollow sample with a diameter of 5 mm, a hole diameter of 2 mm, and a length of 10 mm, and clean and dry it with alcohol: Step 2: Install the specimen on the experimental device; Step 3: Simulate additive manufacturing to perform cyclic heat treatment on the specimen to obtain two-dimensional synchrotron X-ray diffraction patterns of the specimen at different moments; Heat the specimen to 1300 °C at a rate of 50 °C / s, hold for 10 s, and then start thermal cycling. The heating and cooling rate is 200 °C / s, the peak temperature is reduced by 50 °C each time, and the low-temperature holding temperature is 1000 °C, corresponding to the powder bed temperature of 1000 °C in additive manufacturing. After cycling five times, quickly cool to room temperature, see Figure 2 ; Step 4: Use Fit2D software to transform the two-dimensional diffraction pattern into a one-dimensional diffraction pattern; Step 5: Use the Rietveld method to perform full-profile fitting on the one-dimensional diffraction pattern to obtain the volume fraction of each phase of the specimen at each moment, superimpose the volume fractions of each phase of the specimen at different moments, and draw a graph of the change of the volume fraction of each phase of the specimen with time, see Figure 3 . Example 2

[0033] According to Figure 1 shown, perform the following steps.

[0034] Step 1: Prepare the specimen: Cut the alloy into a hollow sample with a diameter of 5 mm, a hole diameter of 2 mm, and a length of 10 mm. After cleaning with alcohol, dry it: Step 2: Install the specimen onto the experimental device; Step 3: Simulate additive manufacturing to perform cyclic heat treatment on the specimen to obtain two-dimensional synchrotron X-ray diffraction patterns of the specimen at different times; Heat the specimen to 1300 °C at a rate of 50 °C / s, hold for 10 s, and then start thermal cycling. The heating and cooling rates are 200 °C / s, the peak temperature is reduced by 50 °C each time, the low-temperature holding temperature is 700 °C, corresponding to the powder bed temperature of 700 °C in additive manufacturing. After cycling five times, quickly cool it to room temperature. See Figure 4 ; Step 4: Use Fit2D software to transform the two-dimensional diffraction pattern into a one-dimensional diffraction pattern; Step 5: Use the Rietveld method to perform full-profile fitting on the one-dimensional diffraction pattern to obtain the volume fractions of each phase of the specimen at different times. Superimpose the volume fractions of each phase of the specimen at different times and plot the variation of the volume fractions of each phase of the specimen with time. See Figure 5 。

[0035] As can be seen from the above embodiments, the present invention can realize the characterization of the real-time change of the volume fractions of each phase of the specimen, thereby helping to understand the solid-state phase transformation of the solidified lower-layer material during repeated rapid heating and cooling in additive manufacturing, so as to optimize the additive manufacturing process.

[0036] As can be seen from Comparative Example 1 and Example 2, for Example 1, the α2 / α phase volume fraction continuously decreases before reaching the low-temperature holding temperature, and during the low-temperature holding stage, the phase fraction continues to decrease, and the phase transformation can still proceed. For Example 2, the α2 / α phase volume fraction has almost stopped decreasing before reaching the low-temperature holding temperature, remains almost unchanged during the low-temperature holding stage, the phase transformation rate drops sharply, and when heating starts from low temperature after the low-temperature holding ends, the α2 / α phase volume fraction is still higher than the thermodynamic equilibrium, so it first decreases and then increases. Therefore, it can be seen that the phase transformation proceeds more fully when the low-temperature holding temperature is 1000 °C.

[0037] It can be seen that the phase transformation proceeds more fully when the low-temperature holding temperature is 1000 °C, which is beneficial to ensuring the uniformity of the internal structure of the material and reducing the generation of defects and internal stresses. Therefore, the inventor of the present invention proposes that when additive manufacturing Ti-46Al-9Nb alloy, the powder bed temperature can be maintained at about 1000 °C.

[0038] The basic principles of the present disclosure have been described above in connection with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are merely examples and not limitations. It cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present disclosure. Additionally, the specific details disclosed above are for illustrative and easy-to-understand purposes only, and not for limitation. These details do not limit the present disclosure to necessarily implementing with the above specific details.

[0039] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any way. Words such as "including", "comprising", "having", etc. are open-ended terms, meaning "including but not limited to", and can be used interchangeably with each other. The word "or" and "and" used herein refer to the word "and / or", and can be used interchangeably with it, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to", and can be used interchangeably with it.

[0040] It should also be noted that in the devices, equipment, and methods of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present disclosure.

[0041] In this document, modifiers without quantifiers such as "first", "second", etc. are intended to distinguish different elements / components / circuits / modules / devices / steps, rather than to emphasize order, positional relationship, importance, priority, etc. In contrast, modifiers with quantifiers such as "the first", "the second", etc. can be used to emphasize the order, positional relationship, importance, priority, etc. of different elements / components / circuits / modules / devices / steps.

[0042] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

[0043] The above description has been given for purposes of illustration and description. In addition, this description does not intend to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions, and sub-combinations thereof.

Claims

1. A method for determining the change in phase volume fraction during additive manufacturing, characterized in that: The method comprises: Step 1: Prepare the sample; Step 2: Install the sample into the experimental device; Step 3: performing cyclic heat treatment on the sample to simulate the heating process of the lower layer of solidified material in the additive manufacturing process, and obtaining synchrotron radiation X-ray two-dimensional diffraction patterns of the sample at different times; Step 4: transforming the two-dimensional diffraction pattern into a one-dimensional diffraction pattern; Step 5: Use the Rietveld method to refine the one-dimensional diffraction pattern to obtain a graph showing the volume fraction of each phase of the sample changing with time.

2. The method according to claim 1, characterized in that The cyclic heat treatment includes the following steps: heating the sample to 1200-1350°C at a rate of 40-60°C / s, keeping the temperature for 5-15s, and then starting a thermal cycle with a heating and cooling rate of 150-250°C / s, reducing the peak temperature by 30-60°C each time, and keeping the low temperature at 900-1100°C. After 3-6 cycles, the sample is rapidly cooled to room temperature.

3. The method according to claim 1, characterized in that The synchrotron radiation X-ray energy in step 3 is 100 keV, the wavelength is 0.0124 nm, and the irradiation range is 1 mm×1 mm.

4. The method according to claim 1, characterized in that: The synchrotron radiation X-rays in step 3 penetrate the sample and are collected by the image acquisition system after being emitted, with a picture being taken every 0.1s.

5. The method according to claim 1, characterized in that: The step 5 comprises: Step 5-1: using the Rietveld method to perform full spectrum fitting on the one-dimensional diffraction pattern to obtain the volume fraction of each phase of the sample; Step 5-2: Superimpose the volume fractions of the various phases of the sample at different times, and draw a graph showing the changes in the volume fractions of the various phases of the sample over time.

6. The method according to claim 2, characterized in that The cyclic heat treatment includes the following: heating the sample to 1300°C at a rate of 50°C / s, keeping it warm for 10s, and then starting a thermal cycle with a heating and cooling rate of 200°C / s, reducing the peak temperature by 50°C each time, and a low-temperature holding temperature of 1000°C, corresponding to a powder bed temperature of 1000°C in additive manufacturing. After five cycles, the sample is rapidly cooled to room temperature.

7. The method according to claim 2, characterized in that The cyclic heat treatment includes the following: heating the sample to 1300°C at a rate of 50°C / s, keeping it warm for 10s, then starting a thermal cycle, with a heating and cooling rate of 200°C / s, the peak temperature decreasing by 50°C each time, the low-temperature holding temperature being 700°C, corresponding to a powder bed temperature of 700°C in additive manufacturing, and rapidly cooling to room temperature after five cycles.

8. The method according to claim 1, characterized in that The composition of the sample is Ti-(43-47)Al-(7-10)Nb alloy.

9. The method according to claim 1, characterized in that: The composition of the sample is Ti-46Al-9Nb alloy.

10. A method for additive manufacturing of titanium aluminum alloy, characterized in that: The powder bed temperature during the additive manufacturing process is obtained by changing the volume fraction of each phase in the titanium aluminum alloy obtained by the method as described in any one of claims 1 to 9 over time, and is 950 to 1050°C. The titanium aluminum alloy component used for the additive manufacturing is Ti-46Al-9Nb alloy.

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