A method for preparing TiZrVNbAl alloy powder with high fine powder yield

Abstract

The application relates to a preparation method of a TiZrVNbAl alloy powder with a high fine powder yield, and belongs to the technical field of alloy powder materials. The diameter of a flow guide pipe in a gas atomization powder preparation process is designed. A high-temperature fine flow is obtained by appropriately reducing the diameter of the flow guide pipe and increasing the heating power at the bottom of a crucible; meanwhile, the geometric shape and position of a nozzle in the gas atomization powder preparation process are designed, and a ring-shaped nozzle is adopted to enhance the coupling between the flow guide pipe and the outflowing flow; the aperture of the ring-shaped nozzle is adjusted to match the diameter of the flow guide pipe, so that the resistance of the flow is reduced, and the interaction between the gas and the flow is further enhanced; the relative position and angle between the nozzle and the flow guide pipe are adjusted to realize better contact between the atomization gas and the flow, so that the gas can atomize the flow more effectively, smaller liquid drops are formed, and the fine powder rate is improved.

Description

Technical Field

[0001] The present invention relates to a method for preparing TiZrVNbAl alloy powder with a high fine powder yield, belonging to the technical field of alloy powder materials. Background Art

[0002] TiZrVNbAl alloy is a representative lightweight high-entropy alloy, which features high specific strength, excellent strength and toughness, good high-temperature stability, and outstanding corrosion resistance. These properties make it show broad application prospects in the fields of aerospace, automotive, energy, etc. To realize the preparation of high-performance complex components of TiZrVNbAl alloy, additive manufacturing technology is an effective technical approach. During the additive manufacturing process, metal powder, as the key raw material, its quality directly relates to the performance and reliability of the final component. Therefore, there are relatively high requirements for metal powder, including high sphericity, high fluidity, and high fine powder yield, etc.

[0003] However, due to the characteristics of TiZrVNbAl alloy itself, such as high melting point, large activity, and poor fluidity, the existing powder preparation technologies face certain challenges. Currently, although the traditional electrode induction gas atomization process and the emerging suspension melting water-cooled crucible gas atomization process can meet the requirements of high sphericity and high fluidity, there are still obvious deficiencies in the fine powder yield, which limits the wide application of TiZrVNbAl alloy in additive manufacturing. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing TiZrVNbAl alloy powder with a high fine powder yield. The present invention adopts the suspension melting water-cooled crucible gas atomization powder preparation process, and conducts a coupled design on the structures of the diversion tube and the nozzle in the gas atomization powder preparation process to prepare TiZrVNbAl alloy powder with a high fine powder yield.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows.

[0006] A method for preparing TiZrVNbAl alloy powder with a high fine powder yield, the method steps include:

[0007] (1) Determine the alloy composition: The chemical composition and atomic percentage of the lightweight high-entropy alloy TiZrVNbAl are Ti a Zr b V c Nb d Al e , where 25 ≤ a ≤ 60%, 5 ≤ b ≤ 30%, 5 ≤ c ≤ 20%, 10 ≤ d ≤ 25%, 0 < e ≤ 10%, and a + b + c + d + e = 100%;

[0008] (2) Pre-alloying: Weigh the metal blocks of each element according to the alloy composition and proportion and add them to the suspension melting water-cooled copper crucible. Vacuum the water-cooled copper crucible and then introduce inert gas. Melt the metal blocks in the water-cooled copper crucible. After melting, condense to obtain alloy ingots.

[0009] (3) Cold crucible melting: The alloy ingot is added back into the water-cooled copper crucible, a vacuum is drawn, and then an inert gas is introduced to heat and melt the alloy ingot. After the alloy ingot is completely melted, it is kept at 1700-1750℃, and the guide tube connected to the bottom of the water-cooled copper crucible is heated; the diameter of the guide tube is 2-5mm.

[0010] (4) Atomization powder making: After the temperature of the guide tube reaches 1700-1750℃, the atomizing gas is turned on to perform atomization powder making. The alloy melt flowing out from the bottom of the guide tube impacts and breaks into small droplets and solidifies to form powder. The atomizing nozzle is a ring structure with a nozzle outlet gap size of 0.8-1.2mm. The nozzle is aligned with the outlet of the guide tube, and the angle between the guide tube and the nozzle is 50°-60°. The atomizing gas pressure is 4-8MPa.

[0011] (5) After atomization and powdering, the powder is cooled and sieved to obtain a TiZrVNbAl alloy powder with a high fine powder yield.

[0012] Preferably, in step (1), 35% ≤ a ≤ 55%, 10 ≤ b ≤ 25%, 8 ≤ c ≤ 15%, 10 ≤ d ≤ 20%, and 1 ≤ e ≤ 7%.

[0013] Preferably, in step (2), the purity of the metal block is greater than 99%.

[0014] Preferably, in step (2), a vacuum is drawn to 5×10⁻⁶. -3 Below Pa.

[0015] Preferably, in step (2), the diameter of the guide tube is 3 to 4 mm.

[0016] Preferably, in step (3), a vacuum is drawn to 2×10⁻⁶. -2 Below Pa.

[0017] Preferably, in step (4), the nozzle outlet gap size is 0.9 to 1.0 mm.

[0018] Preferably, in step (4), the pressure of the atomizing gas is 5 to 6 MPa.

[0019] Preferably, the inert gas is argon.

[0020] A TiZrVNbAl alloy powder with high fine powder yield was prepared by the above method.

[0021] Beneficial effects

[0022] This invention provides a method for preparing TiZrVNbAl alloy powder with high fine powder yield, achieved by designing the diameter of the guide tube in the gas atomization powder preparation process. High-temperature fine fluid is obtained by appropriately reducing the diameter of the guide tube and increasing the heating power at the bottom of the crucible. Simultaneously, the geometry and position of the nozzle in the gas atomization powder preparation process are designed, employing an annular nozzle to enhance the coupling between the nozzle and the fluid flowing out of the guide tube. The orifice of the annular nozzle is adjusted to match the diameter of the guide tube, reducing fluid flow resistance and further enhancing the interaction between the gas and fluid. Adjusting the relative position and angle between the nozzle and the guide tube allows for better contact between the atomizing gas and fluid, enabling the gas to more effectively atomize the fluid, forming finer droplets and improving the fine powder yield.

[0023] This invention provides a method for preparing TiZrVNbAl alloy powder with high fine powder yield. The method involves a flow rate matching design for the guide tube and nozzle in the gas atomization powder preparation process. The pressure of the atomizing gas is adjusted to ensure a sufficiently high gas velocity for effective liquid atomization while preventing excessively large droplets. A flow control valve precisely controls the outflow velocity of the fluid within the guide tube, matching it to the atomizing gas velocity. This provides a more stable fluid flow path, reduces turbulence and instability, helps control particle size and shape, and improves the fine powder yield.

[0024] This invention provides a TiZrVNbAl alloy powder with high fine powder yield. The high temperature of the obtained high-temperature fine fluid is relatively high, and the viscosity of the liquid is relatively low. Therefore, the powder particles formed are not prone to agglomeration, which helps to obtain powder with high sphericity and increases the sphericity of the powder. Attached Figure Description

[0025] Figure 1 The TiZrVNbAl alloy powder with high fine powder yield provided in Example 1 of this invention is a method for preparing TiZrVNbAl alloy powder. 40 Zr 20 V 15 Nb 20 SEM image of Al5 alloy powder;

[0026] Figure 2 The TiZrVNbAl alloy powder with high fine powder yield provided in Example 1 of this invention is prepared by sieving Ti... 40 Zr 20 V 15 Nb 20 Laser particle size distribution diagram of Al5 alloy powder;

[0027] Figure 3Ti in the preparation method of TiZrVNbAl alloy powder with high fine powder yield provided in Embodiment 2 of the present invention 50 Zr 20 V 15 Nb 10 SEM image of Al5 alloy powder;

[0028] Figure 4 Sieved Ti in the preparation method of TiZrVNbAl alloy powder with high fine powder yield provided in Embodiment 2 of the present invention 50 Zr 20 V 15 Nb 10 Laser particle size distribution diagram of Al5 alloy powder.

[0029] Figure 5 Ti in the preparation method of TiZrVNbAl alloy powder with high fine powder yield provided in Embodiment 3 of the present invention 50 Zr 15 V 10 Nb 20 SEM image of Al5 alloy powder;

[0030] Figure 6 Sieved Ti in the preparation method of TiZrVNbAl alloy powder with high fine powder yield provided in Embodiment 3 of the present invention 50 Zr 15 V 10 Nb 20 Laser particle size distribution diagram of Al5 alloy powder. Specific embodiments

[0031] The present invention will be further described in detail below with reference to specific embodiments.

[0032] A preparation method of TiZrVNbAl alloy powder with high fine powder yield, the method steps include:

[0033] (1) Determine the alloy composition: The alloy composition is selected from Ti, Zr, V, Nb, and Al, and the proportion of each element is set according to the alloy atomic ratio or mass ratio. The chemical composition and atomic percentage of the lightweight high-entropy alloy are Ti a Zr b V c Nb d Al e ; wherein, 25 ≤ a ≤ 60%, 5 ≤ b ≤ 30%, 5 ≤ c ≤ 20%, 10 ≤ d ≤ 25%, 0 < e ≤ 10%, and a + b + c + d + e = 100%. More preferably, 35% ≤ a ≤ 55%, 10 ≤ b ≤ 25%, 8 ≤ c ≤ 15%, 10 ≤ d ≤ 20%, 1 ≤ e ≤ 7%.

[0034] (2) Pre-alloying: Determine the required metal blocks based on the alloy composition and proportions. The purity of the metal blocks should be greater than 99%. Add the metal blocks to a suspension melting water-cooled copper crucible and evacuate to 5×10⁻⁶ mm. -3 When the pressure is below 1 Pa, argon gas is introduced into the crucible. The metal block is melted in a water-cooled copper crucible, and then condensed to obtain an alloy ingot.

[0035] (3) Cold crucible melting: Place the alloy ingot back into the water-cooled copper crucible. Evacuate the water-cooled copper crucible to a vacuum level of 2×10⁻⁶. -2 Below Pa, the ingot is then filled with inert argon gas. The alloy ingot is heated, and the flow tube connected to the bottom of the water-cooled copper crucible is preheated. After the alloy ingot is completely melted, it is held at 1700–1750°C, and the flow tube is continuously heated.

[0036] (4) Atomization and Powdering: When the temperature inside the guide tube reaches 1700–1750℃, the atomizing gas is turned on, and the pressure of the atomizing gas is set to 4–8 MPa. Argon is used as the atomizing gas, with a purity greater than or equal to 99.99%, and other impurities in the gas are less than 10 ppm. The inner diameter of the guide tube is set to 2–5 mm, the outlet gap of the annular nozzle is set to 0.8–1.2 mm, the nozzle is aligned with the guide tube, and the angle between the guide tube and the nozzle is set to 50°–60°. The alloy liquid in the crucible flows into the guide tube. The high-pressure atomizing gas released through the annular nozzle impacts the alloy molten liquid flowing out from the end of the guide tube, causing the molten liquid to break into small droplets. A flow rate matching design is implemented for both; by adjusting the pressure of the atomizing gas, the velocity of the atomizing gas is ensured to be high enough to effectively atomize the fluid. The outflow velocity of the fluid in the guide tube is precisely controlled by a flow control valve to match the flow rate of the atomizing gas, enhancing the interaction between the two.

[0037] (5) Cooling and sieving: Fine droplets solidify into spherical and subspherical particles during flight, and are then sieved to prepare metal powders of various particle sizes.

[0038] Example 1

[0039] Ti 40 Zr 20 V 15 Nb 20 The preparation of Al5 alloy spherical powder is carried out according to the following steps:

[0040] Ti alloy 40 Zr 20 V 15 Nb 20The elemental ratio in Al5 is as follows: Ti:Zr:V:Nb:Al = 4:2:1.5:2:0.5, and the purity of the metal block is ≥99%. After accurate weighing, the metal block is added to a water-cooled copper crucible, and the water-cooled copper crucible is evacuated to 5×10⁻⁶. -3 When the pressure is below Pa, argon gas is introduced into the water-cooled copper crucible.

[0041] Turn on the melting power supply and melt the metal block in the water-cooled copper crucible. After melting, condense the melt to obtain an alloy ingot. Place the alloy ingot back into the water-cooled copper crucible. Evacuate the water-cooled copper crucible to a vacuum of 2×10⁻⁶. -2 Below Pa, the ingot is then filled with inert argon gas. The alloy ingot is heated, and the flow tube connected to the bottom of the water-cooled copper crucible is preheated. After the alloy ingot is completely melted, it is held at 1750℃, and the flow tube is continuously heated.

[0042] The diameter of the guide tube is set to 3 mm, the outlet gap of the annular nozzle is set to 1.2 mm, the nozzle is aligned with the guide tube, and the angle between the guide tube and the nozzle is set to 50°. When the temperature inside the guide tube reaches 1750℃, the atomizing gas argon is turned on, and the pressure of the atomizing gas is set to 6 MPa. The molten alloy in the crucible flows into the guide tube. During atomization, the high-pressure atomizing gas released through the annular nozzle impacts the molten alloy flowing from the end of the guide tube, causing the molten alloy to break into small droplets. These fine droplets solidify into spherical and subspherical particles during flight. After the powder particles cool, they are sieved to obtain Ti particles of the desired particle size. 40 Zr 10 V 10 Nb 10 Al5 alloy spherical powder.

[0043] Ti prepared by this method 40 Zr 20 V 15 Nb 20 Al5 powder morphology as follows Figure 1 As shown, the powder morphology is spherical, and after sieving, the powder particle size distribution is as follows. Figure 2 As shown, the powder has a D10 of 9.191 μm, a D50 of 13.940 μm, and a D90 of 20.980 μm, exhibiting a high fine powder ratio, which meets the powder particle size requirements for additive manufacturing processes.

[0044] Example 2

[0045] Ti 50 Zr 20 V 15 Nb 10 The preparation of Al5 alloy spherical powder is carried out according to the following steps:

[0046] Ti alloy50 Zr 20 V 15 Nb 10 The elemental ratio in Al5 is as follows: Ti:Zr:V:Nb:Al = 5:2:1.5:1:0.5, and the purity of the metal block is ≥99%. After accurate weighing, the metal block is added to the suspension melting water-cooled copper crucible in the suspension melting chamber. The suspension melting chamber is then evacuated to 5 × 10⁻⁶. -3 When the pressure is below Pa, argon gas is introduced into the suspension melting chamber.

[0047] Turn on the melting power supply and melt the metal block in the water-cooled copper crucible. After melting, condense the melt to obtain an alloy ingot. Place the alloy ingot back into the water-cooled copper crucible. Evacuate the water-cooled copper crucible to a vacuum of 2×10⁻⁶. -2 Below Pa, the ingot is then filled with inert argon gas. The alloy ingot is heated, and the flow tube connected to the bottom of the water-cooled copper crucible is preheated. After the alloy ingot is completely melted, it is held at 1700℃, and the flow tube is continuously heated.

[0048] The guide tube diameter is set to 4 mm, the outlet gap of the annular nozzle is set to 1.0 mm, the nozzle is aligned with the guide tube, and the angle between the guide tube and the nozzle is set to 55°. When the temperature inside the guide tube reaches 1700℃, the atomizing gas argon is turned on, and the pressure of the atomizing gas is set to 4 MPa. The molten alloy in the crucible flows into the guide tube. During atomization, the high-pressure atomizing gas released through the annular nozzle impacts the molten alloy flowing from the end of the guide tube, causing the molten alloy to break into small droplets. These fine droplets solidify into spherical and subspherical particles during flight. After the powder particles cool, they are sieved to obtain Ti particles of the desired particle size. 50 Zr 20 V 15 Nb 10 Al5 alloy spherical powder.

[0049] Ti prepared by this method 50 Zr 20 V 15 Nb 10 Al5 powder morphology as follows Figure 3 As shown, the powder morphology is spherical, and after sieving, the powder particle size distribution is as follows. Figure 4 As shown, the powder has a D10 of 14.921 μm, a D50 of 24.840 μm, and a D90 of 41.941 μm. It exhibits a high fineness ratio, meeting the powder particle size requirements for additive manufacturing processes.

[0050] Example 3

[0051] Ti 50 Zr 15 V 10 Nb20 The preparation of Al5 alloy spherical powder is carried out according to the following steps:

[0052] Ti alloy 50 Zr 15 V 10 Nb 20 The elemental ratio in Al5 is as follows: Ti:Zr:V:Nb:Al = 5:1.5:1:2:0.5, and the purity of the metal block is ≥99%. After accurate weighing, the metal block is added to the suspension melting water-cooled copper crucible in the suspension melting chamber. The suspension melting chamber is then evacuated to 5 × 10⁻⁶. -3 When the pressure is below Pa, argon gas is introduced into the suspension melting chamber.

[0053] Turn on the melting power supply and melt the metal block in the water-cooled copper crucible. After melting, condense the melt to obtain an alloy ingot. Place the alloy ingot back into the water-cooled copper crucible. Evacuate the water-cooled copper crucible to a vacuum of 2×10⁻⁶. -2 Below Pa, the ingot is then filled with inert argon gas. The alloy ingot is heated, and the flow tube connected to the bottom of the water-cooled copper crucible is preheated. After the alloy ingot is completely melted, it is held at 1700℃, and the flow tube is continuously heated.

[0054] The diameter of the guide tube is set to 5 mm, the outlet gap of the annular nozzle is set to 0.8 mm, the nozzle is aligned with the guide tube, and the angle between the guide tube and the nozzle is set to 55°. When the temperature inside the guide tube reaches 1700℃, the atomizing gas argon is turned on, and the pressure of the atomizing gas is set to 4 MPa. The molten alloy in the crucible flows into the guide tube. During atomization, the high-pressure atomizing gas released through the annular nozzle impacts the molten alloy flowing from the end of the guide tube, causing the molten alloy to break into small droplets. These fine droplets solidify into spherical and subspherical particles during flight. After the powder particles cool, they are sieved to obtain Ti particles of the desired particle size. 50 Zr 15 V 10 Nb 20 Al5 alloy spherical powder.

[0055] Ti prepared by this method 50 Zr 15 V 10 Nb 20 Al5 powder morphology as follows Figure 5 As shown, the powder morphology is spherical, and after sieving, the powder particle size distribution is as follows. Figure 6 As shown, the powder has a D10 of 17.623 μm, a D50 of 30.377 μm, and a D90 of 53.077 μm. It exhibits excellent fineness, meeting the powder particle size requirements for additive manufacturing processes.

[0056] In summary, the invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered to be within the protection scope of this invention.

Claims

1. A method for producing a TiZrVNbAl alloy powder with a high fine powder yield, characterized by: The method steps include: (1) Determine the alloy composition: the chemical composition and atomic percentage of lightweight high-entropy alloy TiZrVNbAl is Ti a Zr b V c Nb d Al e Wherein, 25≤a≤60%, 5≤b≤30%, 5≤c≤20%, 10≤d≤25%, 0<e≤10%, and a+b+c+d+e=100%. (2) Pre-alloying: according to the alloy composition and proportion, the metal blocks of each element are weighed and then added into a water-cooled copper crucible for suspension smelting, the water-cooled copper crucible is vacuumized, then inert gas is introduced, the metal blocks are melted in the water-cooled copper crucible, and then condensed after melting to obtain alloy ingots; (3) Cold crucible smelting: the alloy ingots are re-added into the water-cooled copper crucible, vacuumized, then inert gas is introduced, the alloy ingots are heated and melted, when the alloy ingots are completely melted, the temperature is kept at 1700-1750℃, and the flow guide pipe connected to the bottom of the water-cooled copper crucible is heated; wherein the diameter of the flow guide pipe is 2-5mm; (4) Atomization powdering: after the temperature of the flow guide pipe reaches 1700-1750℃, the atomization gas is opened for atomization powdering, the alloy melt flowing out from the bottom of the flow guide pipe is broken into small droplets and solidified to form powder; wherein the atomization nozzle is annular structure, the size of the nozzle outlet gap is 0.8-1.2mm, the nozzle is aligned with the outlet of the flow guide pipe, and the angle between the flow guide pipe and the nozzle is 50-60°, the atomization gas pressure is 4-8MPa; (5) After the atomization powdering is completed, cooling and screening are performed to obtain a TiZrVNbAl alloy powder with high fine powder yield.

2. A method of producing a high fines yield TiZrVNbAl alloy powder according to claim 1, characterized in that: In step (1), 35%≤a≤55%, 10≤b≤25%, 8≤c≤15%, 10≤d≤20%, and 1≤e≤7%.

3. A method of producing a high fines yield TiZrVNbAl alloy powder as claimed in claim 1, characterized by: In step (2), the purity of the metal blocks is greater than 99%.

4. A method of producing a high fines yield TiZrVNbAl alloy powder as claimed in claim 1, characterized by: In step (2), the vacuum is drawn to 5 x 10 -3 Pa or below.

5. A process for the production of a high fines yield TiZrVNbAl alloy powder as claimed in claim 1 or 3 or 4, characterized in that: In step (2), the diameter of the flow guide pipe is 3-4mm.

6. A method of producing a high fines yield TiZrVNbAl alloy powder as claimed in claim 1, characterized by: In step (3), the vacuum is drawn to 2 x 10 -2 Pa or below.

7. A method of producing a high fines yield TiZrVNbAl alloy powder as claimed in claim 1, characterized by: In step (4), the size of the nozzle outlet gap is 0.9-1.0mm.

8. A method of producing a high fines yield TiZrVNbAl alloy powder as claimed in claim 1 or 7, characterised by: In step (4), the atomization gas pressure is 5-6MPa.

9. A method of producing a high fines yield TiZrVNbAl alloy powder as claimed in claim 1, characterized by: The inert gas is argon.

10. A high fines yield TiZrVNbAl alloy powder characterized by: Prepared by the method of any one of claims 1-9.

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