Method for preparing titanium alloy spherical powder by warm pressure double-gradient electrode induction gas atomization and application thereof

Abstract

The application belongs to the technical field of metal powder preparation, and relates to a method for preparing titanium alloy spherical powder by using a warm-pressing double-gradient electrode induction gas atomization and application thereof. The method is innovative in adopting a multi-stage gradient process control in view of the problem of easy generation of agglomerates in the powder preparation of titanium alloy EIGA. Firstly, a steady current is established under moderate superheat, then a high superheat + high pressure main atomization section is entered to realize full fragmentation of the melt, then a cooling + high pressure maintaining section is entered to reduce the hot-state bonding of liquid drops, and finally, low pressure is used for ending and forced cooling is used to prevent sintering and agglomeration of the powder during collection. The process systematically suppresses the generation of agglomerates in the whole forming link, effectively suppresses the burning loss of Al element through accurate temperature control, and obtains high-quality powder with uniform composition, high sphericity, agglomerate rate ≤0.4%, fluidity ≤35 s / 50g, uniform element distribution, and Al segregation coefficient ≤0.035%, and is especially suitable for high-end applications such as additive manufacturing.

Description

Technical Field

[0001] This invention belongs to the field of metal powder preparation technology, and relates to the preparation of titanium alloy spherical powder, specifically to a method for preparing titanium alloy spherical powder by temperature and pressure dual gradient electrode induction gas atomization and its application. Background Technology

[0002] Titanium alloys such as TA7 (Ti-5Al-2.5Sn), TC4 (Ti-6Al-4V), TB6 (Ti-10V-2Fe-3Al), and Ti-48Al-2Cr-2Nb are important structural materials in aerospace, biomedicine, and automotive industries. Additive manufacturing technology can efficiently form various complex titanium alloy parts, but the overall performance of the finished components largely depends on the quality of the titanium alloy powder raw materials used. Electrode induction melting gas atomization (EIGA) has become one of the mainstream preparation processes for titanium alloy powders in additive manufacturing and powder metallurgy due to its advantages such as pure melting and applicability to reactive metals.

[0003] However, when preparing titanium alloy powder using the traditional EIGA process, agglomeration defects are easily generated. These defects typically occur when multiple powder particles adhere to each other in a high-temperature semi-molten or plastic state, forming rough-surfaced, irregularly shaped agglomerates. The causes of agglomeration in different grades of titanium alloys share some common patterns, but also exhibit significant differences. α-type titanium alloys such as TA7 have high melt viscosity and surface tension. Compared with alloys containing β-stabilizing elements such as TC4, their molten fluidity is weak, resulting in a stronger resistance to airflow impact and poor atomization and fragmentation effects. Although the addition of β-stabilizing elements reduces the melt viscosity of α+β type alloys such as TC4, its crystallization temperature range is widened, allowing the melt to remain in a semi-molten state over a wider temperature range, increasing the time window for droplet collision and adhesion. β-type alloys such as TB6 have a crystallization temperature range of 200~300℃. In addition, the high density of β-stabilizing elements easily leads to macroscopic segregation within the droplets, causing the droplet center of gravity to shift and intensifying the collisions between irregular powders. TiAl-based intermetallic compounds, due to their high Al content, have extremely high melt viscosity, reaching 1.5~2 times that of TC4 alloys. Furthermore, Al readily reacts with oxygen to form an Al2O3 oxide film, promoting the formation of oxide film bridging agglomerates. In addition to the inherent properties of the alloys themselves, turbulence caused by turbulent airflow within the atomization chamber is a common contributing factor. During the solidification process, droplets of different sizes and velocities collide and agglomerate due to insufficient cooling rate or intersecting trajectories, forming irregularly shaped agglomerates with coarse particles at their cores. This mechanism is common in titanium alloy systems. Furthermore, the solidified powder may also sinter and agglomerate to some extent in the collection device due to residual heat. The presence of these agglomerates severely deteriorates powder flowability and uniformity, and may create defects such as porosity and lack of fusion during printing, directly affecting the mechanical properties and reliability of the final part.

[0004] Existing technologies often reduce agglomeration by increasing atomizing gas pressure, optimizing nozzle structure, or post-processing powder, but these methods are often limited in effectiveness, increase energy consumption, or sacrifice fine powder yield to some extent. Simply increasing atomizing pressure can effectively enhance crushing kinetic energy, but it is not effective for α-type high-viscosity alloys and leads to a decrease in fine powder yield for β-type alloys. On the other hand, optimizing nozzle structure design is time-consuming and costly, and a single nozzle structure is difficult to adapt to titanium alloy raw materials with various compositions.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing titanium alloy spherical powder by temperature and pressure dual gradient electrode induction gas atomization and its application, so as to eliminate or significantly reduce the defects of gas atomization powder agglomeration.

[0007] The objective of this invention is achieved through the following technical solution: On the one hand, see Figure 1 This invention provides a method for preparing titanium alloy spherical powder by temperature and pressure dual-gradient electrode induction gas atomization, comprising the following steps: Step 1: Prepare titanium alloy rods; Step 2: Pre-treat the titanium alloy rod, then load the pre-treated titanium alloy rod into the feeding system of the EIGA equipment, and evacuate the atomization chamber to 1×10⁻⁶. -2 Below Pa, fill with protective gas to a slightly positive pressure of 0.01~0.05MPa; Step 3: Prepare target titanium alloy spherical powder using temperature and pressure dual gradient electrode induction gas atomization technology; wherein, the temperature and pressure dual gradient electrode induction gas atomization technology is to use the process of "melting and stabilizing flow → high-energy crushing → cooling and anti-sticking → gentle cooling" to intervene in different stages of agglomeration formation in order to eliminate or reduce agglomeration defects in gas atomization powder making. Step 4: After atomization, use 1300~1500 Nm 3 A high-flow-rate protective gas is used to force-cool the atomizing tower and powder collection tank for 5-15 minutes, reducing the powder temperature to <80℃ before depressurizing and removing the powder.

[0008] Specifically, in step 3, the different stages include, First stage: Start the induction coil and begin melting at the first power P1=35~45kW until the end of the bar melts and forms a stable initial liquid flow. Gradually increase the induction power to the second power P2=55~70kW, and simultaneously match the first atomizing gas pressure G1=1.5~2.5MPa. The duration of the first stage is 0.5~1min. The second stage involves increasing the induction power to a third power P3 = 90~110kW, while simultaneously increasing the atomizing gas pressure to a second atomizing gas pressure G2 = 3.5~4.5MPa. During this stage, the bar melting length is 20%~70% of the total length. The third stage: the atomizing gas pressure is maintained at the second atomizing gas pressure G2, while the induction power is reduced to the fourth power P4 = 70~85kW. During this stage, the melting length of the bar is 10%~50% of the total length. Fourth stage: Before the atomization ends, keep the induction power at the fourth power P4, reduce the atomizing gas pressure to the third atomizing gas pressure G3=1.0~1.5MPa, and complete the remaining rod atomization powder making.

[0009] Specifically, in the third stage, the induced power is gradually reduced to the target power (i.e., the fourth power) through multiple gradual reductions, with each reduction not exceeding 5kW. It is important to emphasize that this design aims to prevent a sudden and significant drop in induced power, which could cause the melt temperature to rapidly fall below the liquidus line, leading to premature solidification of the liquid flow during the breakup process and the formation of numerous irregular particles or incompletely spread particles adhering to the surface. Preferably, this application employs a gradient reduction method. This gradual reduction ensures a smooth transition in melt temperature, maintaining sufficient superheat to allow for surface tension contraction of the droplets, ensuring that the powder is fully spherical during flight, thereby reducing irregularly shaped particles and satellite-shaped powder agglomerates caused by excessively rapid solidification.

[0010] Specifically, in the fourth stage, the atomizing gas pressure is reduced to the target atomizing gas pressure (i.e., the third atomizing gas pressure) using a gradient reduction method, and the reduction value of the atomizing gas pressure in a single step does not exceed 1.0 MPa. This gradient pressure reduction maintains a gradual transition of the airflow, allowing the droplets to maintain a relatively orderly flight path in the later stages of solidification, significantly reducing the generation of flight-collision-type agglomerates caused by airflow instability. If the pressure is reduced drastically in one go, the atomizing airflow will abruptly change from a stable supersonic flow to a subsonic or turbulent flow, resulting in disordered flight trajectories of the already broken fine droplets, a sharp increase in velocity differences, and an increased probability of collisions between droplets.

[0011] Furthermore, in step 2: the feed rate of the titanium alloy bar is 30~60mm / min, and the rotational speed is 5~20r / min.

[0012] Preferably, in step 1, the titanium alloy rod is obtained as follows: first, a titanium alloy ingot is obtained by vacuum arc melting, then the titanium alloy ingot is forged or rolled to obtain a billet, and then machined to obtain a titanium alloy rod. The diameter of the titanium alloy rod is φ50~80mm and the length is 50~600mm.

[0013] More preferably, the titanium alloy spherical powder includes, but is not limited to, one of α-type titanium alloy, α+β-type titanium alloy, β-type titanium alloy and TiAl alloy, such as TA7 powder, TC4 powder, TB6 powder or Ti-48Al-2Cr-2Nb powder.

[0014] On the other hand, the present invention provides a titanium alloy spherical powder prepared by some or all of the methods described above, wherein the titanium alloy spherical powder has an agglomeration rate of ≤0.4%, a powder yield of ≥45% with a particle size of 15~53μm, and a flowability of <40s / 50g.

[0015] Furthermore, this invention provides the application of titanium alloy spherical powders obtained by some or all of the methods described above in the preparation of additive manufacturing or powder metallurgy products, including aerospace engine components (such as compressor blades, casings, etc.), marine seawater corrosion resistant components (such as piping systems, valves, etc.), and cryogenic fuel storage containers.

[0016] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: This invention employs a temperature and pressure dual-gradient synergistic electrode induction atomization technology, which designs a complete process chain of "melting and stabilizing flow → high-energy crushing → cooling and anti-sticking → gentle cooling." It intervenes in stages of droplet formation, flight collisions, and collection and accumulation at different stages of agglomeration, systematically suppressing the generation of various agglomerates at their source. To elaborate: 1. First, a steady flow is established at a moderate superheat (first stage). Then, a high superheat + high pressure main atomization section (second stage) is entered to achieve sufficient melt fragmentation. Next, a cooling and shaping section with cooling and high pressure maintenance (third stage) is entered to reduce droplet hot adhesion. Finally, low pressure finishing (fourth stage) and forced cooling in step 4 prevent sintering and agglomeration during powder collection. This process systematically suppresses the generation of agglomerates throughout the entire formation chain, and can stably prepare high-quality titanium alloy powder with high sphericity, good flowability and extremely low agglomeration rate, which is particularly suitable for high-end applications such as additive manufacturing. 2. In particular, this invention obtains finer and more spherical initial droplets through a high superheat + high pressure main atomization section; and reduces the risk of collision and adhesion during the critical period of droplet solidification through a cooling and shaping section that combines cooling and maintaining high pressure, thereby significantly improving the sphericity and flowability of the powder while increasing the yield of fine powder. 3. In this invention, all gradient parameters—power, gas pressure, and time—can be precisely set and automatically controlled, resulting in good process repeatability and facilitating large-scale stable production. Furthermore, without relying on extremely high gas pressures (>6MPa) or complex post-processing, high-quality powder with low agglomeration rate can be directly obtained, reducing overall production costs and equipment wear. Attached Figure Description

[0017] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart of a method for preparing titanium alloy spherical powder by temperature and pressure dual gradient electrode induction gas atomization provided by the present invention; Figure 2 This is a schematic diagram of the laser particle size distribution of TA7 alloy powder in Example 1; Figure 3 The image shows the laser particle size distribution of TA7 alloy powder in Comparative Example 1. Figure 4 Here is a scanning electron microscope image of TA7 alloy powder from Example 1; Figure 5 Here is a scanning electron microscope image of TA7 alloy agglomerates from Comparative Example 1. Figure 6 The image shows the Al element composition distribution of the 15-53 μm powder of TA7 alloy in Example 1. Figure 7 The image shows the Sn element composition distribution of the 15~53μm powder of TA7 alloy in Example 1. Figure 8 This is a laser particle size distribution diagram of TC4 alloy powder from Example 2. Detailed Implementation

[0020] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses consistent with some aspects of the invention as detailed in the appended claims.

[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Example 1

[0022] This embodiment provides a method for preparing TA7 titanium alloy spherical powder by temperature-pressure dual-gradient electrode induction gas atomization, specifically including the following steps: Step 1: Prepare TA7 titanium alloy rods for electrode induction gas atomization, and clean and dry them. The diameter of the rods is φ50mm. Step 2: Load the TA7 alloy electrode rod into the feed system of the EIGA equipment, and evacuate the atomization chamber to reduce its pressure to 1×10⁻⁶. -2 Below Pa, fill with argon gas with a purity ≥99.999% until the micro-positive pressure reaches 0.05MPa; Step 3: Prepare TA7 titanium alloy fine spherical powder from TA7 alloy rods using a temperature-pressure dual-gradient synergistic electrode induction atomization technology; wherein the feed rate of the titanium alloy rods is 40 mm / min and the rotation speed is 20 r / min; specifically, the different stages include: First stage: Start the induction coil, adjust the first power P1 to 35kW to start melting until the end of the bar melts and forms a stable initial liquid flow, gradually increase the induction power to the second power P2=55kW, simultaneously turn on the atomizing gas and maintain the pressure G1=2.0MPa for a duration of t1=1min; Second stage: Increase the induction power to the third power P3=90kW, and at the same time increase the atomizing gas pressure to the second atomizing gas pressure G2=4.0MPa. In this stage, the melting length of the bar is 70% of the total length. The third stage: Maintain the atomizing gas pressure at the second atomizing gas pressure G2=4.0MPa, while gradually reducing the induction power to the fourth power P4=70kW. The melting length of the bar in this stage is 20% of the total length. It should be noted that the reduction from the third induction power to the fourth induction power is done in five stages, in the order of 90→85→80→75→72→70kW, and the reduction value of the induction power in a single stage does not exceed 5kW. Fourth stage: Before the atomization ends, maintain the induction power at the fourth power P4=70kW, reduce the atomizing gas pressure gradient to the third atomizing gas pressure G3=1.2MPa, and stop feeding and heating after completing the atomization of the remaining rod. It should be noted that the pressure gradient is adjusted by a gradient reduction method. The process of reducing G2 to G3 is in the order of 4.0→3.0→2.0→1.5→1.2MPa, and the reduction value of the atomizing gas pressure in a single step does not exceed 1.0MPa. Step 4: After atomization, maintain a high flow rate of argon gas to force-cool the atomization tower and powder collection tank for 10 minutes, so that the powder temperature drops to 50°C and is then depressurized and removed.

[0023] After sieving and collecting the powder, the yield of powder with a particle size of 15~53μm was 51.3% (see powder particle size distribution). Figure 2 The scanning electron microscope observation results are as follows: Figure 4 As shown in the SEM image, the powder has good sphericity. According to the image software analysis, the agglomeration rate is only 0.39%, and the Hall flowability test result is 35 s / 50g. Example 2

[0024] This embodiment provides a method for preparing TC4 titanium alloy spherical powder by temperature-pressure dual-gradient electrode induction gas atomization, specifically including the following steps: Step 1: Prepare the TC4 titanium alloy rod required for electrode induction gas atomization, and clean and dry it. The diameter of the rod is φ60mm. Step 2: Load the TC4 alloy electrode rod into the feed system of the EIGA equipment, and evacuate the atomization chamber to 1×10⁻⁶. - 2 Below Pa, fill with argon gas with a purity ≥99.999% until the micro-positive pressure reaches 0.01MPa; Step 3: Prepare TC4 titanium alloy fine spherical powder from TC4 alloy rods using a temperature-pressure dual-gradient synergistic electrode induction atomization technology; wherein the feed rate of the titanium alloy rods is 50 mm / min and the rotation speed is 10 r / min; specifically, the different stages include: First stage: Melting begins at a power of 38kW until the end of the bar melts to form a stable initial liquid flow. The induction power is then increased to 58kW. Under an atomizing gas pressure of 2.5MPa, the atomization time is t1=0.5min. Second stage: The induction power is increased to 100kW, and the atomizing gas pressure is adjusted to 3.5MPa. In this stage, the melting length of the bar is 40% of the total length. The third stage: Maintain the atomizing gas pressure at 3.5 MPa, adjust the induction power and reduce it step by step to P4=80kW. This process is divided into four reductions, decreasing the melting power sequentially from 100→95→90→85→80kW. The reduction value of the induction power in a single stage is 5kW. The melting length of the bar in this stage is 50% of the total length. Fourth stage: Maintain the induction power at 80kW, reduce the atomizing gas pressure gradient to 1.0MPa, and stop feeding and heating after completing the atomization of the remaining rod; in this stage, the process of reducing G2 to G3 is in the gradient of 3.5→2.5→1.8→1.3→1.0MPa, and the reduction value of the atomizing gas pressure in a single step does not exceed 1.0MPa; Step 4: After atomization, maintain a high flow rate of argon gas to force-cool the atomization tower and powder collection tank for 15 minutes, so that the powder temperature drops to 50°C and is then depressurized and removed.

[0025] After sieving and collecting the powder, the yield of powder with a particle size of 15~53μm was 56.7% (see powder particle size distribution). Figure 8 Scanning electron microscopy showed that the powder had good sphericity, and image analysis software showed that the agglomeration rate was only 0.26%, with a Hall flowability test result of 32 s / 50g. Example 3

[0026] This embodiment provides a method for preparing TB6 titanium alloy spherical powder by temperature-pressure dual-gradient electrode induction gas atomization, specifically including the following steps: Step 1: Prepare TB6 titanium alloy rods for electrode induction gas atomization, and clean and dry them. The diameter of the rods is φ80mm. Step 2: Load the TB6 alloy electrode rod into the feed system of the EIGA equipment, and evacuate the atomization chamber to 1×10⁻⁶. - 2 Below Pa, fill with argon gas with a purity ≥99.999% until the micro-positive pressure reaches 0.03MPa; Step 3: Prepare TB6 titanium alloy fine spherical powder from TB6 alloy rods using a temperature-pressure dual-gradient synergistic electrode induction atomization technology; wherein the feed rate of the titanium alloy rods is 60 mm / min and the rotational speed is 15 r / min; specifically, the different stages include: First stage: Melting begins at a power of 40kW until the end of the bar melts to form a stable initial liquid flow. The induction power is then increased to 65kW. Under an atomizing gas pressure of 2.2MPa, the atomization time is t1=0.75min. Second stage: The induction power is increased to 100kW, and the atomizing gas pressure is adjusted to 4.2MPa. In this stage, the melting length of the bar is 30% of the total length. Third stage: Maintain the atomizing gas pressure at 4.2 MPa, adjust the induction power and reduce it step by step to P4 = 80 kW. The method of reducing the induction power in this process is the same as in Example 2. In this stage, the melting length of the bar is 50% of the total length. Fourth stage: Maintain the induction power at 80kW, reduce the atomizing gas pressure gradient to 1.2MPa, and stop feeding and heating after completing the atomization of the remaining rod; in this stage, the process of reducing G2 to G3 follows the gradient of 4.2→3.2→2.5→1.9→1.4→1.2MPa, and the reduction value of the atomizing gas pressure in a single step does not exceed 1.0MPa; Step 4: After atomization, maintain a high flow rate of argon gas to force-cool the atomization tower and powder collection tank for 13 minutes, so that the powder temperature drops to 50°C and is then depressurized and removed.

[0027] After sieving and collecting the powder, the yield of powder with a particle size of 15~53μm was 50.3%. Scanning electron microscopy showed that the powder had good sphericity. Image analysis software showed that the agglomeration rate was only 0.21%, and the Hall flowability test result was 33 s / 50g. Example 4

[0028] This embodiment provides a method for preparing Ti-48Al-2Cr-2Nb titanium alloy spherical powder by temperature-pressure dual-gradient electrode induction gas atomization, specifically including the following steps: Step 1: Prepare Ti-48Al-2Cr-2Nb titanium alloy rods for electrode induction gas atomization, and clean and dry them. The diameter of the rods is φ55mm. Step 2: Load the Ti-48Al-2Cr-2Nb alloy electrode rod into the feed system of the EIGA equipment, and evacuate the atomization chamber to 1×10⁻⁶. -2 Below Pa, fill with argon gas with a purity ≥99.999% until the micro-positive pressure reaches 0.02MPa; Step 3: Fine spherical Ti-48Al-2Cr-2Nb titanium alloy powder is prepared from Ti-48Al-2Cr-2Nb alloy rods using a temperature-pressure dual-gradient synergistic electrode induction atomization technology; wherein the feed rate of the titanium alloy rods is 30 mm / min and the rotational speed is 5 r / min; specifically, the different stages include: First stage: starting the melting process with a power of 45kW until the end of the bar melts to form a stable initial liquid flow, then increasing the induction power to 70kW, with an atomizing gas pressure of 1.5MPa and an atomization time of t1=1min; Second stage: The induction power is increased to 110kW, and the atomizing gas pressure is adjusted to 4.5MPa. In this stage, the melting length of the bar is 20% of the total length. The third stage: Maintain the atomizing gas pressure at 4.5 MPa, adjust the induction power and reduce it step by step to P4=85kW. This process is reduced in five stages, decreasing the melting power sequentially from 110→105→100→95→90→85kW. The reduction in induction power in a single stage is 5kW. The melting length of the bar in this stage is 50% of the total length. Fourth stage: Maintain the induction power at 85kW, reduce the atomizing gas pressure gradient to 1.5MPa, and stop feeding and heating after completing the atomization of the remaining rod; in this stage, the process of reducing G2 to G3 is carried out in the gradient manner of 4.5→3.5→2.7→2.0→1.5MPa, and the reduction value of the atomizing gas pressure in a single step does not exceed 1.0MPa; Step 4: After atomization, maintain a high flow rate of argon gas to force-cool the atomization tower and powder collection tank for 15 minutes, so that the powder temperature drops to 50°C and is then depressurized and removed.

[0029] After sieving and collecting the powder, the yield of powder with a particle size of 15~53μm was 45.8%. Scanning electron microscopy showed that the powder had good sphericity. Image analysis software showed that the agglomeration rate was only 0.31%, and the Hall flowability test result was 36 s / 50g. Comparative Example 1

[0030] Based on Example 1, the difference between this comparative example and Example 1 is that this comparative example uses a single temperature and pressure process for atomization powder preparation, specifically including the following steps: Step 1: Prepare TA7 titanium alloy rods for electrode induction gas atomization, and clean and dry them. The diameter of the rods is φ50mm. Step 2: Clean and dry the surface of the TA7 alloy electrode rod, load the rod into the feed system of the EIGA equipment, and evacuate the atomization chamber to 1×10⁻⁶. -2 Below Pa, fill with argon gas with a purity ≥99.999% until the micro-positive pressure reaches 0.05MPa; Step 3: Start the induction coil, adjust the first power P1 to 90kW to start melting, turn on and maintain the atomizing gas pressure at 3.0MPa, and stop feeding and heating after the bar is atomized; Step 4: After atomization, allow the powder to cool naturally to 50°C and then release the pressure before removing it. Comparative Example 2

[0031] Based on Example 2, the difference between this comparative example and Example 2 is that this comparative example uses a single temperature and pressure process for atomization powder preparation, specifically including the following steps: Step 1: Prepare TC4 titanium alloy rods for electrode induction gas atomization, and clean and dry them. The diameter of the rods is φ60mm. Step 2: Clean and dry the surface of the TC4 alloy electrode rod, load the rod into the feed system of the EIGA equipment, and evacuate the atomization chamber to 1×10⁻⁶. -2 Below Pa, fill with argon gas with a purity ≥99.999% until the micro-positive pressure reaches 0.01MPa; Step 3: Start the induction coil, adjust the first power P1 to 90kW to start melting, turn on and maintain the atomizing gas pressure at 3.0MPa, and stop feeding and heating after the bar is atomized; Step 4: After atomization, maintain a high flow rate of argon gas to force-cool the atomization tower and powder collection tank for 10 minutes. Once the powder temperature drops to 50°C, release the pressure and remove the powder.

[0032] To further verify the effectiveness of the technical solution provided by this invention, the properties of the titanium alloy powders prepared in Examples 1-4 and Comparative Examples 1-2 were tested, and the test results are shown in Table 1: Table 1

[0033] As shown in Table 1, combined with Figure 3 It can be seen that the TA7 alloy powder prepared in Comparative Example 1 has a relatively coarse particle size, with the maximum particle size ranging from 143.9 μm (see Comparative Example 1). Figure 2 The particle size increased to 260.8 μm, indicating the formation of more agglomerated powder particles. See also... Figures 4-5As shown, the titanium alloy powder prepared using the method of this invention has a significantly reduced proportion of agglomerated powder, effectively solving the problem of agglomerated powder adhesion. Combined with... Figures 6-7 This invention also optimizes particle size distribution and flowability, achieving a maximum yield of 56.7% for fine powder with a particle size of 15-53 μm, and reducing flowability to below 35 s / 50g. This significantly optimizes powder performance, reduces powder costs for the SLM process, and demonstrates good industrial application value. Furthermore, EDS analysis of the powder shows uniform distribution of Al and Sn / Nb elements, with no abnormal element loss, volatilization, or component segregation.

[0034] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0035] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for preparing titanium alloy spherical powder by temperature-pressure dual-gradient electrode induction gas atomization, characterized in that, Includes the following steps: Step 1: Prepare titanium alloy rods; Step 2: Pre-treat the titanium alloy rod, then load the pre-treated titanium alloy rod into the feeding system of the EIGA equipment, and evacuate the atomization chamber to reduce its pressure to 1×10⁻⁶. -2 Below Pa, fill with protective gas until the slight positive pressure reaches 0.01~0.05MPa; Step 3: Prepare target titanium alloy spherical powder using temperature and pressure dual gradient electrode induction gas atomization technology; wherein, the temperature and pressure dual gradient electrode induction gas atomization technology is to use the process of "melting and stabilizing flow → high-energy crushing → cooling and anti-sticking → gentle cooling" to intervene in different stages of agglomeration formation in order to eliminate or reduce agglomeration defects in gas atomization powder making. Step 4: After atomization, use high-flow protective gas to force-cool the atomization tower and powder collection tank for 5-15 minutes, and then depressurize and remove the powder after the temperature drops to <80℃.

2. The method for preparing titanium alloy spherical powder by temperature and pressure dual-gradient electrode induction gas atomization according to claim 1, characterized in that, Step 3, specifically includes the following different stages: First stage: Start the induction coil and begin melting at the first power P1=35~45kW until the end of the bar melts to form a stable initial liquid flow. Gradually increase the induction power to the second power P2=55~70kW, and simultaneously match the first atomizing gas pressure G1=1.5~2.5MPa. The duration of the first stage is 0.5~1min. The second stage involves increasing the induction power to a third power P3 = 90~110kW, while simultaneously increasing the atomizing gas pressure to a second atomizing gas pressure G2 = 3.5~4.5MPa. During this stage, the bar melting length is 20%~70% of the total length. The third stage: the atomizing gas pressure is maintained at the second atomizing gas pressure G2, while the induction power is reduced to the fourth power P4 = 70~85kW. During this stage, the bar melting length is 10%~50% of the total length. Fourth stage: Before the atomization ends, keep the induction power at the fourth power P4, reduce the atomizing gas pressure to the third atomizing gas pressure G3=1.0~1.5MPa, and complete the remaining rod atomization powder making.

3. The method for preparing titanium alloy spherical powder by temperature-pressure dual-gradient electrode induction gas atomization according to claim 2, characterized in that, In the third stage, the inductive power is gradually reduced to the fourth power through multiple slow reductions, and the reduction value of the inductive power in a single step does not exceed 5kW.

4. The method for preparing titanium alloy spherical powder by temperature and pressure dual-gradient electrode induction gas atomization according to claim 2, characterized in that, In the fourth stage, the atomizing gas pressure is reduced to the third atomizing gas pressure in a gradient manner, and the reduction value of the atomizing gas pressure in a single step does not exceed 1.0 MPa.

5. The method for preparing titanium alloy spherical powder by temperature and pressure dual-gradient electrode induction gas atomization according to claim 2, characterized in that, In step 2: the feed rate of the titanium alloy bar is 30~60mm / min, and the rotational speed is 5~20r / min.

6. The method for preparing titanium alloy spherical powder by temperature and pressure dual-gradient electrode induction gas atomization according to claim 1, characterized in that, In step 1, the titanium alloy rod is obtained in the following way: First, a titanium alloy ingot is obtained by vacuum arc melting. Then, the titanium alloy ingot is forged or rolled to obtain a billet. Finally, it is machined to obtain a titanium alloy bar. The diameter of the titanium alloy bar is φ50~80mm and the length is 50~600mm.

7. The method for preparing titanium alloy spherical powder by temperature and pressure dual-gradient electrode induction gas atomization according to claim 1, characterized in that, The titanium alloy spherical powder includes one of α-type titanium alloy, α+β-type titanium alloy, β-type titanium alloy, and TiAl alloy.

8. A titanium alloy spherical powder prepared by the method according to any one of claims 1 to 7, characterized in that, The titanium alloy spherical powder has an agglomeration rate of ≤0.4%, a powder yield of ≥45% with a particle size of 15~53μm, and a flowability of <40 s / 50g.

9. The use of titanium alloy spherical powder obtained by the method according to any one of claims 1 to 7 in the preparation of additive manufacturing or powder metallurgy products.

10. The application according to claim 9, characterized in that, The products include aerospace engine components, marine seawater corrosion-resistant components, and cryogenic fuel storage containers.

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