A method for manufacturing ultra-high durability titanium alloy using laser additive manufacturing

Abstract

A method for manufacturing ultra-high durability titanium alloy using laser additive manufacturing, relating to the field of metal material additive manufacturing, includes the following steps: S1: loading titanium alloy powder into a powder feeding device and fixing a substrate in a forming chamber; S2: after the water and oxygen content in the forming chamber is below 50 ppm, laser forming begins, depositing the molten titanium alloy powder along a planned path to form a dense metal component; after one layer is formed, the next layer is deposited after a set time interval; S3: after deposition is complete, the deposited sample is removed from the forming chamber, the sample is cut to prepare a titanium alloy specimen, and the phase transition point T of the titanium alloy specimen is measured. β S4: Based on the phase transition point T β Based on the measurement results, the titanium alloy samples underwent a first heat treatment and a second heat treatment to obtain the final titanium alloy component. By controlling the solidification process of laser additive manufacturing and precisely matching the dual heat treatments, a titanium alloy component with good high-temperature tensile properties and excellent high-temperature creep resistance was obtained.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing of metallic materials, and in particular to an ultra-high durability titanium alloy and a laser additive manufacturing method. Background Technology

[0002] High-temperature titanium alloys mainly refer to disordered solid solution strengthened titanium alloys used in the aerospace field at temperatures above 350℃. High-temperature tensile strength and high-temperature creep rupture properties are important performance indicators. High-temperature titanium alloys are mainly near-α type and (α+β) type alloys. Currently commonly used high-temperature titanium alloys include BT36, IMI834, Ti60, Ti1100, Ti65, TC11, TA15, and TC4, but they still suffer from low high-temperature strength and poor high-temperature creep rupture properties. Taking TC11 titanium alloy as an example, its high-temperature creep rupture performance at 500℃ / 640MPa is typically less than 30 hours, severely restricting the widespread application of high-temperature titanium alloys. Therefore, there is an urgent need to develop high-performance high-temperature titanium alloys.

[0003] In patent CN112195363A, the Institute of Metal Research, Chinese Academy of Sciences, proposed a high-strength titanium alloy for use at 500–600℃ and its processing method. This method mainly involves adding TiB particles to a Ti-Al-Sn-Zr-Mo-W-Si alloy, followed by multiple upsetting and drawing deformations after alloy melting to obtain a high-performance high-temperature titanium alloy. However, the addition of TiB leads to the formation of segregated TiB2 phases in the alloy, resulting in complex alloy forming processes, unstable microstructure and properties, and low material utilization.

[0004] In patent CN115386768B, Dalian University of Technology proposed a 600℃ / 1GPa high-temperature ultra-high-strength titanium alloy and its preparation method. This method mainly involves adding refractory alloying elements such as Nb, Mo, Ta, and W to a Ti-Al-Zr-Sn-Si matrix, followed by multiple arc vacuum melting processes using electromagnetic stirring to achieve solid solution strengthening, reduce the precipitation of brittle phases at high temperatures, and improve heat resistance and strength. However, this method suffers from problems such as difficulty in controlling the smelting process, complex manufacturing procedures, and unstable microstructure and properties.

[0005] Current methods for controlling the high-temperature performance of titanium alloys primarily involve adding strengthening or solid-solution alloying elements to the original alloy matrix to increase the stability of precipitated phases and improve high-temperature properties. In recent years, laser additive manufacturing of titanium alloy materials has been gradually applied in the aerospace field, especially in high-temperature alloy engines. However, their high-temperature performance is generally lower than that of forged parts, limiting their application in aerospace. How to use laser additive manufacturing technology to prepare high-performance high-temperature titanium alloys has become one of the major challenges facing their widespread application. Summary of the Invention

[0006] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a laser additive manufacturing method for ultra-high durability titanium alloy components. Without changing the alloy element composition, the method controls the forming and solidification process of laser additive manufacturing and then precisely matches dual heat treatment to obtain titanium alloy components with good high-temperature tensile properties and excellent high-temperature durability, thus providing a reliable guarantee for the manufacturing of high-performance titanium alloy components for aerospace.

[0007] The technical solution provided in this application is as follows:

[0008] A laser additive manufacturing method for ultra-high durability titanium alloys includes:

[0009] S1: Load titanium alloy powder into the powder feeding device and fix the substrate in the forming chamber.

[0010] S2: When the water and oxygen content in the forming chamber is lower than 50ppm, the titanium alloy powder is fed into the laser processing head to start the titanium alloy laser additive forming, and the molten titanium alloy powder is deposited along the planned path to form a dense metal component.

[0011] After one layer is formed, the next layer is deposited after a set time interval.

[0012] S3: After deposition is complete, the deposited sample is removed from the forming chamber, cut to prepare a titanium alloy specimen, and the phase transformation point T of the titanium alloy specimen is determined. β ;

[0013] S4: Based on the phase transition point T β Based on the measurement results, the titanium alloy sample was subjected to a first heat treatment and a second heat treatment to obtain the final titanium alloy component.

[0014] In step S2, the laser additive manufacturing process parameters during deposition are as follows: laser scanning power of 2.6–4.0 kW, scanning rate of 800–1200 mm / s, spot diameter of 1–3 mm, powder feeding rate of 15–25 g / min, overlap spacing of 55%–65%, and layer thickness of 1.0–1.5 mm.

[0015] By controlling the process parameters of laser additive manufacturing, the energy density of the titanium alloy deposition zone can be controlled to be no less than 55–67 J / mm². 2 With an overlap rate of 55%–65%, the cooling rate at the leading edge of the solid-liquid molten pool interface is 10. 4 ~10 5 K / s was used to prepare thin sheet structures with a layer height of 1.0–1.5 mm, a volume fraction of 100%, a width of 0.55–0.86 μm, and a dislocation density greater than 102. -20.5 m -2 The titanium alloy sample is used for the subsequent formation of elongated primary α-type titanium alloys. P Phase and αS The phase provides the driving force.

[0016] The first heat treatment includes: heating the deposited sample at a rate of 25–35 °C / min to (T β -60)~(T β -30℃, hold at that temperature for 4-6 hours, and control the cooling rate of the sample to be no less than 55℃ / s to cool to room temperature; after the first heat treatment is completed, perform the second heat treatment; the second heat treatment is specifically as follows: heat the sample at 15-25℃ / min to (T β -300)~(T β Keep the sample at -200℃ for 6 to 8 hours, and control the cooling rate of the sample to be no less than 50℃ / s to cool to room temperature.

[0017] By setting the first and second heat treatments, this can avoid the formation of elongated α-rays. P The coarsening of both the α-phase and α-s phase is relatively high, resulting in a microstructure with a volume fraction of 42%–52% and a width not exceeding 5.58 μm. P A phase with a volume fraction of 48%–58% and a width not exceeding 10.64 μm. s A special biphasic structure.

[0018] In step S2, the time is set to 40-50 minutes.

[0019] In step S1, the titanium alloy powder has a particle size of 65–280 μm and an oxygen content of not less than 0.13 wt.%.

[0020] In step S1, the [Al] equivalent in the titanium alloy powder is in the range of 1.6 to 7.5.

[0021] In step S1, the purity of argon gas in the forming chamber is not less than 99.99%.

[0022] In step S3, the phase transition point T β Measurement accuracy within (T) β Within ±5)℃.

[0023] An ultra-high durability titanium alloy is prepared by any of the laser additive manufacturing methods described above.

[0024] This invention proposes a laser additive manufacturing method for ultra-high durability titanium alloy components. The main idea is to obtain a dislocation density greater than 10 by controlling the solidification process. -20.5 m -2 The sample contained 100% by volume and 0.55–0.86 μm in width, forming ultrafine lamellar structures. Based on this deposited sample, precise dual heat treatment was applied to obtain α-lamellae with a volume fraction of 42%–52% and a width not exceeding 5.58 μm.P A phase with a volume fraction of 48%–58% and a width not exceeding 10.64 μm. S A special two-phase structure was used to obtain ultra-high persistence laser additive manufacturing titanium alloy components.

[0025] In summary, this application includes at least the following beneficial technical effects:

[0026] First, by "precise control of solidification during laser additive manufacturing + precise control of α-phase coarsening in titanium alloy sheets", long strips of α-phase with a volume fraction of no more than 42% and a width of no more than 5.58 μm were obtained. P A phase with a volume fraction not exceeding 58% and a width not exceeding 10.64 μm. S A special two-phase microstructure. This microstructure exhibits α-phase... (The sentence appears to be incomplete and requires further context.) P The semi-coherent interface of the phase / αs phase is well matched, and the long strip α P Phase and α S The phase can be synchronously coordinated to increase the resistance of titanium alloy to high-temperature tensile deformation and improve the high-temperature tensile properties of titanium alloy (Table 1).

[0027] Second, during high-temperature sustained deformation, α P Phase / α S The phase interface was stable, and no slip bands or protrusions formed. Meanwhile, dislocations slipped to α. P Phase / α S The semi-coherent phase interface forms a pile-up and dislocation network, which increases the resistance to high-temperature crack propagation, thus significantly improving the high-temperature creep performance (Table 1).

[0028] Third, without changing the composition of the titanium alloy, this method enables the forming of ultra-high persistence laser additive manufacturing titanium alloy components, providing a new approach for the preparation of high-temperature titanium alloys (Table 1). Attached Figure Description

[0029] Figure 1 Special dual-phase microstructure of TC11 titanium alloy for laser additive manufacturing 1;

[0030] Figure 2 Special biphase microstructure of TC11 titanium alloy for laser additive manufacturing 2. Detailed Implementation

[0031] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0032] First, load titanium alloy powder with a particle size of 65-280μm into the powder feeder. The oxygen content of the powder must be greater than 0.13wt%. Fix the substrate on the forming chamber worktable with sufficient argon gas. The purity of argon gas in the forming chamber must be no less than 99.999%.

[0033] Second, when the water and oxygen content in the forming chamber is below 50 ppm, the titanium alloy powder in the powder feeder is fed into the laser processing head to start titanium alloy laser additive forming. The molten powder is deposited along the planned path to form a dense metal component. After one layer is formed, the next layer is deposited after an interval of 40 to 50 minutes.

[0034] The laser additive manufacturing process parameters during deposition are as follows: laser scanning power of 2.6–4.0 kW, scanning rate of 800–1200 mm / s, spot diameter of 1–3 mm, powder feed rate of 15–25 g / min, overlap spacing of 55%–65%, layer thickness of 1.0–1.5 mm, and dislocation density greater than 10. -20.5 m -2 The titanium alloy sample contained 100% by volume thin sheet structure with a width of 0.55 to 0.86 μm.

[0035] Third, after the forming process is complete, the deposited sample is removed from the forming chamber, and the deposited sample and substrate are separated using wire cutting to prepare a 10mm×10mm×5mm sample. The phase transition point T of the sample is then determined using a DSC device. β ;

[0036] Fourth, based on the phase transition point T β Based on the measurement results, the deposited sample was placed in a heat treatment furnace for double heat treatment to obtain the final titanium alloy component.

[0037] The dual heat treatment consists of a first heat treatment and a second heat treatment; the first heat treatment specifically involves heating the deposited sample at a rate of 25–35 °C / min to (T β -60)~(T β -30℃, hold at that temperature for 4-6 hours, and control the cooling rate of the sample to be no less than 55℃ / s to cool to room temperature; after the first heat treatment is completed, perform the second heat treatment; the second heat treatment is specifically as follows: heat the sample at 15-25℃ / min to (T β -300)~(T β Keep the sample at -200℃ for 6 to 8 hours, and control the cooling rate of the sample to be no less than 50℃ / s to cool to room temperature.

[0038] The titanium alloys used in the following examples are all TC11 titanium alloys with an [Al] equivalent of 3.5.

[0039] Example 1

[0040] like Figure 1 and Figure 2 As shown, a laser additive manufacturing method for ultra-high durability titanium alloy components includes the following steps:

[0041] First, load titanium alloy powder with a particle size of 65μm into the powder feeder. The oxygen content of the powder must be greater than 0.13wt%. Fix the substrate on the forming chamber worktable with sufficient argon gas. The purity of argon gas in the forming chamber must be no less than 99.999%.

[0042] Second, when the water and oxygen content in the forming chamber is lower than 50 ppm, the titanium alloy powder in the powder feeder is fed into the laser processing head to start the titanium alloy laser additive forming. The molten powder is deposited along the planned path to form a dense metal component. After one layer is formed, the next layer is deposited after a 40-minute interval.

[0043] During deposition, the laser additive manufacturing forming parameters were: laser scanning power of 2.6kW, scanning rate of 800mm / s, spot diameter of 1mm, powder feed rate of 15g / min, and overlap spacing of 55%, resulting in a layer height of 1.0mm and a dislocation density of 102. -19 m -2 The titanium alloy sample contained a 100% volume fraction of sheet-like microstructure with a width of 0.55 μm.

[0044] Third, after the forming is completed, the deposited sample is taken out from the forming chamber, and the deposited sample and the substrate are separated by wire cutting to prepare a 10mm×10mm×5mm sample. The phase transition point of the sample is determined to be 990℃ using DSC equipment.

[0045] Fourth, based on the phase transition point T β The measurement results showed that the deposited sample was placed in a heat treatment furnace for double heat treatment. The double heat treatment consisted of a first heat treatment and a second heat treatment. The first heat treatment was as follows: the deposited sample was heated to 930℃ at a rate of 25℃ / min, held at that temperature for 6 hours, and then cooled to room temperature at a rate of 65℃ / s. After the first heat treatment was completed, the second heat treatment was performed. The second heat treatment was as follows: the sample was heated to 690℃ at a rate of 15℃ / min, held at that temperature for 6 hours, and then cooled to room temperature at a rate of 55℃ / s.

[0046] Example 2

[0047] like Figure 1 and Figure 2 As shown, taking TC11 titanium alloy as an example, a laser additive manufacturing method for ultra-high durability titanium alloy components includes the following steps:

[0048] First, load titanium alloy powder with a particle size of 280μm into the powder feeder. The oxygen content of the powder must be greater than 0.13wt%. Fix the substrate on the forming chamber worktable with sufficient argon gas. The purity of argon gas in the forming chamber must be no less than 99.999%.

[0049] Second, when the water and oxygen content in the forming chamber is below 50 ppm, the titanium alloy powder in the powder feeder is fed into the laser processing head to start the titanium alloy laser additive forming. The molten powder is deposited along the planned path to form a dense metal component. After one layer is formed, the next layer is deposited after a 50-minute interval.

[0050] During deposition, the laser additive manufacturing parameters were as follows: laser scanning power of 4.0 kW, scanning rate of 1200 mm / s, spot diameter of 3 mm, powder feed rate of 25 g / min, and overlap spacing of 65%. This resulted in a layer height of 1.5 mm and a dislocation density of 102. -20 m -2 The titanium alloy sample contained a 100% volume fraction of sheet-like microstructure with a width of 0.76 μm.

[0051] Third, after the forming is completed, the deposited sample is taken out from the forming chamber, and the deposited sample and the substrate are separated by wire cutting to prepare a 10mm×10mm×5mm sample. The phase transition point of the sample is determined to be 980℃ using DSC equipment.

[0052] Fourth, based on the phase transition point T β The measurement results showed that the deposited sample was placed in a heat treatment furnace for double heat treatment. The double heat treatment consisted of a first heat treatment and a second heat treatment. The first heat treatment was as follows: the deposited sample was heated to 940℃ at a rate of 35℃ / min, held at that temperature for 4 hours, and then cooled to room temperature at a rate of 60℃ / s. After the first heat treatment was completed, the second heat treatment was performed. The second heat treatment was as follows: the sample was heated to 780℃ at a rate of 25℃ / min, held at that temperature for 8 hours, and then cooled to room temperature at a rate of 55℃ / s.

[0053] Example 3

[0054] like Figure 1 and Figure 2 As shown, taking TC11 titanium alloy as an example, a laser additive manufacturing method for ultra-high durability titanium alloy components includes the following steps:

[0055] First, load titanium alloy powder with a particle size of 200μm into the powder feeder. The oxygen content of the powder must be greater than 0.13wt%. Fix the substrate on the forming chamber worktable with sufficient argon gas. The purity of argon gas in the forming chamber must be no less than 99.999%.

[0056] Second, when the water and oxygen content in the forming chamber is lower than 50 ppm, the titanium alloy powder in the powder feeder is fed into the laser processing head to start titanium alloy laser additive forming. The molten powder is deposited along the planned path to form a dense metal component. After one layer is formed, the next layer is deposited after an interval of 45 minutes.

[0057] During deposition, the laser additive manufacturing parameters were as follows: laser scanning power of 3.5 kW, scanning rate of 1000 mm / s, spot diameter of 2 mm, powder feed rate of 20 g / min, and overlap spacing of 60%. A layer with a height of 1.0 mm and a dislocation density of 10⁻⁶ was obtained. -19.7 m -2 The titanium alloy sample contained a 100% volume fraction of sheet-like microstructure with a width of 0.65 μm.

[0058] Third, after the forming is completed, the deposited sample is taken out from the forming chamber, and the deposited sample and the substrate are separated by wire cutting to prepare a 10mm×10mm×5mm sample. The phase transition point of the sample is determined to be 985℃ using DSC equipment.

[0059] Fourth, based on the phase transition point T β The measurement results showed that the deposited sample was placed in a heat treatment furnace for double heat treatment. The double heat treatment consisted of a first heat treatment and a second heat treatment. The first heat treatment was as follows: the deposited sample was heated to 955℃ at a rate of 30℃ / min, held at that temperature for 5 hours, and then cooled to room temperature at a rate of 62℃ / s. After the first heat treatment was completed, the second heat treatment was performed. The second heat treatment was as follows: the sample was heated to 755℃ at a rate of 20℃ / min, held at that temperature for 7 hours, and then cooled to room temperature at a rate of 54℃ / s.

[0060] Example 4

[0061] The difference from Example 1 is that the process parameters for laser additive manufacturing are different in the second step.

[0062] The laser additive manufacturing parameters were: laser scanning power of 3.7kW, scanning rate of 1050mm / s, spot diameter of 3mm, powder feed rate of 22g / min, and overlap spacing of 58%. The resulting material had a layer height of 1.3mm and a dislocation density of 102. - 20.2 m -2 The titanium alloy sample contained a 100% volume fraction of sheet-like structures with a width of 0.78 μm.

[0063] The temperature for subsequent double heat treatment is determined based on the phase transition point of the sample.

[0064] Example 5

[0065] The difference from Example 1 is that the process parameters for laser additive manufacturing are different in the second step.

[0066] The laser additive manufacturing parameters were as follows: laser scanning power of 2.9 kW, scanning rate of 1120 mm / s, spot diameter of 1.1 mm, powder feed rate of 19 g / min, and overlap spacing of 57%. The resulting material had a layer height of 1.3 mm and a dislocation density of 102. -19.8 m -2 The titanium alloy sample contained a 100% volume fraction of sheet-like microstructure with a width of 0.76 μm.

[0067] The temperature for subsequent double heat treatment is determined based on the phase transition point of the sample.

[0068] Example 6

[0069] The difference from Example 1 is that in the second step, the interval time is 42 minutes.

[0070] The temperature for subsequent double heat treatment is determined based on the phase transition point of the sample.

[0071] Example 7

[0072] The difference from Example 1 is that in the second step, the interval time is 49 minutes.

[0073] The temperature for subsequent double heat treatment is determined based on the phase transition point of the sample.

[0074] Example 8

[0075] The difference from Example 1 is that the conditions for the double heat treatment are different in the fourth step.

[0076] The dual heat treatment consists of a first heat treatment and a second heat treatment. The first heat treatment is as follows: the deposited sample is heated to 955℃ at a rate of 22℃ / min, held at that temperature for 5.5h, and then cooled to room temperature at a rate of 59℃ / s. After the first heat treatment is completed, the second heat treatment is performed. The second heat treatment is as follows: the sample is heated to 720℃ at a rate of 23℃ / min, held at that temperature for 7.5h, and then cooled to room temperature at a rate of 58℃ / s.

[0077] Example 9

[0078] The difference from Example 1 is that the conditions for the double heat treatment are different in the fourth step.

[0079] The dual heat treatment consists of a first heat treatment and a second heat treatment. The first heat treatment is as follows: the deposited sample is heated to 945℃ at 31℃ / min, held at that temperature for 4.6h, and then cooled to room temperature at a controlled cooling rate of 63℃ / s. After the first heat treatment is completed, the second heat treatment is performed. The second heat treatment is as follows: the sample is heated to 725℃ at 24℃ / min, held at that temperature for 6.5h, and then cooled to room temperature at a controlled cooling rate of 60℃ / s.

[0080] Comparative Example

[0081] The difference between the comparative example and Example 1 is the method of heat treatment in the fifth step, which is as follows:

[0082] Based on the phase transformation point measurement results, the sample was placed in a heat treatment furnace for special heat treatment to obtain the final titanium alloy component. The special heat treatment was divided into a first heat treatment and a second heat treatment. The first heat treatment was as follows: the sample was heated to 900℃ at a rate of 10℃ / min and held for 2 hours. The sample was then removed and cooled to room temperature at a controlled cooling rate of 56℃ / s. After the first heat treatment was completed, the second heat treatment was performed. Specifically, the sample was heated to 600℃ at a rate of 30℃ / min and held for 4 hours. The sample was then removed and cooled to room temperature at a controlled cooling rate of 50℃ / s.

[0083] The microstructure of the sedimentary samples obtained in the comparative model was observed to obtain... Figure 1 The microstructure of the titanium alloy obtained in Example 1 was observed, and the results were obtained. Figure 2 The titanium alloys obtained in the above embodiments and comparative examples were subjected to high-temperature tensile properties (tensile strength Rm and elongation A) at 500℃ and high-temperature creep rupture properties (time τ) at 500℃ / 640MPa. The test results are shown in Table 1.

[0084] As shown in Table 1, Figure 1 and Figure 2 As shown, the comparative sample has a two-phase microstructure (primary α-phase). P Phase + fine α S The high-temperature tensile properties of the sample exceeded the standard, while the high-temperature creep rupture properties reached the standard level. After adopting this invention, the sample obtained a special two-phase structure (long strips of primary α-phase). P Phase + medium-sized α S (phase), long strip of nascent α P Phase and α S The phase can form a large number of dislocation networks and interface barriers, which can improve the resistance to high-temperature crack propagation and obtain excellent high-temperature tensile properties and high-temperature creep properties.

[0085] Table 1 Comparison of tensile properties at 500℃ and creep rupture properties at 500℃ / 640MPa for laser additively manufactured TC11 titanium alloy components

[0086]

[0087]

[0088] In step S2, when the laser power is too low (less than 2.6kW), the scanning rate is too low (less than 800mm / min), and the powder feed rate is too low (less than 15g / min), the laser additive manufacturing process generates excessive heat and a high cooling rate, which easily leads to the formation of martensitic structures and causes cracking of the titanium alloy components. When the laser power is too high (greater than 4.0kW), the scanning rate is too high (greater than 1200mm / min), and the powder feed rate is too high (greater than 25g / min), the laser additive manufacturing process generates insufficient heat, resulting in coarse, thin lamellar structures and dislocation densities below 10. -20.5 m -2 The titanium alloy samples could not provide sufficient driving force for subsequent heat treatment microstructure and property control, and could not obtain the biphase microstructure required for ultra-high temperature tensile and ultra-high temperature creep.

[0089] In step S4, when the first heat treatment temperature is below (T) β At -60℃ and a holding time of less than 4 hours, the fine, thin sheet-like structure of the sample coarsens and transforms into coarse, thin sheet-like structure, making it impossible to form long, primary α-filaments. P Phase; when the first heat treatment temperature is higher than (T) β When the temperature is -30℃ and the holding time is higher than 6 hours, the fine lamellar structure of the sample transforms into a coarse lamellar structure; when the second heat treatment temperature is lower than (T... β At -300℃, if the holding temperature is below 6h, the sample cannot form a medium-sized αs phase, and the high-temperature tensile properties and high-temperature creep rupture properties of the sample meet the standard requirements; when the second heat treatment temperature is higher than (T... β At -200℃, the holding time is higher than 8 hours, and the sample forms an ultra-large α-size. S The phase, the high-temperature tensile properties and high-temperature creep properties of the specimens were lower than the standard requirements. The 10 samples obtained through this application... -20.5 m -2 Titanium alloy samples, after being subjected to special coupled heat treatment, can yield titanium alloy components with good high-temperature tensile properties and excellent high-temperature creep properties.

[0090] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

[0091] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

Claims

1. A method for laser additive manufacturing of titanium alloys, characterized in that, include: S1: Load titanium alloy powder into the powder feeding device and fix the substrate in the forming chamber; S2: When the water and oxygen content in the forming chamber is lower than 50ppm, titanium alloy powder is fed into the laser processing head to start titanium alloy laser additive forming. The molten titanium alloy powder is deposited along the planned path to form a dense metal component. After one layer is formed, the next layer is deposited after a set time interval. The laser additive manufacturing process parameters during deposition are as follows: laser scanning power of 2.6–4.0 kW, scanning rate of 800–1200 mm / s, spot diameter of 1–3 mm, powder feed rate of 15–25 g / min, and overlap spacing of 55%–65%. S3: After the deposition is completed, the deposition-formed sample is taken out from the forming chamber, the sample is cut to prepare a titanium alloy test piece, and the phase transition point T of the titanium alloy test piece is measured β ; S4: depending on phase transition point T β The measurement results, the first heat treatment and the second heat treatment are performed on the titanium alloy sample to obtain the final titanium alloy component; The first heat treatment comprises: heating the as-deposited sample to (T β -60)~(T β -30)℃ at a rate of 25~35℃ / min, keeping for 4~6h, and controlling the cooling rate of the sample to be not less than 55℃ / s to cool to room temperature; after the first heat treatment, the second heat treatment is performed; the second heat treatment specifically comprises: heating the sample to (T β -300)~(T β -200)℃ at a rate of 15~25℃ / min, keeping for 6~8h, and controlling the cooling rate of the sample to be not less than 50℃ / s to cool to room temperature; In step S2, the height of the single-layer deposition layer obtained by laser additive manufacturing during deposition is 1.0~1.5mm; In step S2, laser additive manufacturing during deposition yields a dislocation density greater than 10. -20.5 m -2 The titanium alloy sample contained a sheet structure with a volume fraction of 100% and a width of 0.55~0.80µm. In step S2, the time is set to 40-50 minutes; In step S1, the particle size of the titanium alloy powder is 65–280 µm. In step S1, the oxygen content of the titanium alloy powder is not less than 0.13 wt.%.

2. The method for laser additive manufacturing of titanium alloys according to claim 1, characterized in that: In step S1, the [Al] equivalent in the titanium alloy powder is in the range of 1.6 to 7.

5.

3. The method for laser additive manufacturing of titanium alloys according to claim 1, characterized in that: In step S1, the purity of argon gas in the forming chamber is not less than 99.99%.

4. A titanium alloy, characterized in that: The titanium alloy was prepared using the laser additive manufacturing method described in any one of claims 1-3.

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