阅读说明：本技术 一种高温合金球形粉体材料的制备方法 (Preparation method of high-temperature alloy spherical powder material ) 是由 陈傅明 王涛 唐勇 谢新宇 陈彦利 于 2021-07-09 设计创作，主要内容包括：本发明公开了一种高温合金球形粉体材料的制备方法,包括将高温合金进行预处理,真空下熔炼,加入原材料重量0.5～10.0％的WC颗粒,加入稀土化合物CeO-(2),全部呈熔融态液体后,喷惰性气体将熔融态液体破碎雾化成细小液滴,冷却和凝固形成球形粉体。(The invention discloses a preparation method of a high-temperature alloy spherical powder material, which comprises the steps of pretreating a high-temperature alloy, smelting in vacuum, adding WC particles accounting for 0.5-10.0% of the weight of the raw material, and adding a rare earth compound CeO 2 And after all the liquid is molten, spraying inert gas to break and atomize the molten liquid into fine liquid drops, and cooling and solidifying the fine liquid drops to form spherical powder.)

1. A preparation method of a high-temperature alloy spherical powder material comprises the following steps:

1) raw material treatment: removing oxide skin from high-purity high-temperature alloy, wherein the oxygen content is less than 100 ppm;

2) vacuumizing: carrying out pre-vacuum pumping treatment on the smelting chamber and the atomizing chamber, and introducing high-purity argon as protective gas;

3) smelting: placing the high-temperature alloy in a smelting chamber, heating to 1600-1750 ℃, smelting into molten liquid, adding WC powder particles, wherein the adding amount is 0.5-10.0% of the weight of the raw material of the high-temperature alloy, and after the high-temperature alloy is completely molten, starting a steady electric field and a steady magnetic field to uniformly disperse the WC particles in the alloy melt;

4) adding CeO₂: after the WC is uniformly dispersed, adding rare earth compound CeO₂The adding amount is 1.2-5.8% of the weight of the high-temperature alloy;

5) atomizing: to be CeO₂After the molten liquid is completely formed, argon is sprayed to break and atomize the falling molten liquid into fine liquid drops, and the fine liquid drops are cooled and solidified to form spherical powder.

2. The method according to claim 1, wherein the high purity in step 1) is: o <50ppm, N <10ppm, S <10ppm, H <1 ppm.

3. The method according to claim 1, wherein the vacuum treatment in the step 2) is performed under a degree of vacuum of 1X 10^-2～1×10^-1Pa。

4. The method according to claim 1, wherein in the step 2), the pressure of the gas is 0.45 to 0.85 MPa.

5. The method according to claim 1, wherein in step 3), the WC powder particles have a particle size of not more than 75 μm, preferably 20 to 45 μm, and the amount added is 5.5% by weight of the alloy raw material.

6. The method according to claim 1, wherein in step 4), CeO is added₂The addition amount is 3.0% of the weight of the high-temperature alloy.

7. The method of claim 1, wherein the argon gas has a purity of 99.99-99.999% in steps 2) and 5).

8. The method according to claim 1 or 7, wherein in the step 5), the temperature of the inert gas is controlled to be 600 ℃ to 950 ℃, and the pressure of the inert gas is 3.5MPa to 6.0 MPa.

9. The preparation method of claim 1, wherein in the step 5), the method further comprises exhausting the gas in the atomizing chamber and simultaneously supplying high-purity argon gas into the smelting chamber, wherein the gas supplying pressure is controlled to be 3.0-3.5 MPa, and the pressure difference between the smelting chamber and the atomizing chamber is kept to be 0-0.5 MPa.

10. Spherical powder material of a superalloy, characterized in that the powder is prepared by the method of preparation according to claims 1-9, the superalloy being selected from the group consisting of iron-based alloys, nickel-based alloys and cobalt-based alloys, preferably nickel-based alloys.

Technical Field

The invention belongs to the field of new materials and advanced manufacturing, and particularly relates to a high-temperature alloy spherical powder material and a preparation method thereof.

Background

The high-temperature alloy is a metal material which is prepared by adding more than ten strengthening elements such as Al, Ti, Cr, W, Mo, Ta, Re, Nb, Co and the like into iron, cobalt and nickel as the basis and can bear the high temperature of more than 600 ℃ and can work for a long time under the action of certain stress. High temperature alloys are also known as "superalloys" because they have a combination of good high temperature strength, good oxidation and corrosion resistance, good fatigue resistance, fracture toughness, and the like. The high-temperature alloy plays an important role in national defense construction and national economic development, and is an indispensable key material for advanced aeroengines, gas turbines, aerospace power propulsion systems and other high-end manufacturing.

The blade is mainly made of a nickel-based high-temperature alloy material with excellent performance and high price, but the blade has the defects of cracks, corrosion, abrasion and the like due to the very harsh service environment, namely the blade is easy to be subjected to the actions of abrasion, impact, high temperature, cold and hot fatigue and the like. Damage during service of the blade will seriously affect the service life and performance of the equipment. The efficiency improvement of an aircraft engine depends to a large extent on the radial clearance between the ends of the working blades and the sealing rings or gaskets in the turbine flow path. The existing work statistical data show that the blade tip abrasion of the working blade is increased by 0.2mm, so that the service life of the working blade is shortened, and the efficiency of the engine is reduced by 1%. The laser 3D printing technology is a new technology, has strong flexibility and has obvious technical advantages in the processing quality, the manufacturing cost and the production period of the blade. Therefore, the laser 3D printing technology has important application prospect in manufacturing aviation engine blades and gas turbine blades.

The advanced western countries rely on advanced laser additive manufacturing and remanufacturing technologies, research on the laser additive manufacturing and remanufacturing technologies of key parts represented by turbine blades is earlier carried out, and the conversion process from laboratory research to engineering application is completed at present. The laser additive manufacturing and remanufacturing of domestic aviation engine blades and gas turbine blades have a large gap with foreign research, and the reason is mainly that high-performance turbine blades are manufactured by adopting nickel-based high-temperature alloy with high Al and Ti contents in the engines in service. The increase of the Al + Ti content in the alloy can improve the volume fraction and high-temperature mechanical property of a gamma' phase, but also improves the crack sensitivity of the alloy, so that the defects of easy cracks and the like are caused in the laser manufacturing and remanufacturing processes of the blade of the aero-engine, thereby restricting the manufacturing of the blade of the aero-engine and the development of the aero-industry in China.

Based on the above, the invention provides a high-temperature alloy spherical powder material and an innovative preparation method thereof, which can effectively solve the bottleneck problem.

Disclosure of Invention

In order to avoid the defects of cracks and the like easily generated when high-temperature alloy blades are manufactured by the existing laser additive manufacturing and remanufacturing technology, the invention aims to provide a novel high-temperature alloy spherical powder material for aeroengine blades and gas turbine blades and a preparation method thereof. The new material has higher melting point, can resist the high temperature of more than 1350 ℃ for a long time, has better strength and toughness, can effectively reduce the crack sensitivity of high-temperature alloy, and the blade manufactured by the material has higher mechanical property and can be more effectively applied to laser additive manufacturing and remanufacturing technologies.

To achieve the object of the present invention, the following embodiments are provided:

in one embodiment, the preparation method of the spherical high-temperature alloy powder material comprises the following steps:

1) raw material treatment: removing oxide skin from high-purity high-temperature alloy, wherein the oxygen content is less than 100 ppm;

2) vacuumizing: carrying out pre-vacuum pumping treatment on the smelting chamber and the atomizing chamber, and introducing high-purity argon as protective gas;

3) smelting: placing the high-temperature alloy in a smelting chamber, heating to 1600-1750 ℃, smelting into molten liquid, adding WC powder particles in an amount of 0.5-10.0% (preferably 5.5%) of the weight of the alloy raw material, and starting a steady electric field and a steady magnetic field after the alloy raw material is completely molten to uniformly disperse the WC particles in the alloy melt;

4) adding CeO₂：_：After the WC is uniformly dispersed, adding rare earth compound CeO₂The adding amount is 1.2-5.8% of the weight of the high-temperature alloy raw material;

5) atomizing: to be CeO₂Become completely moltenAfter the liquid is in the state, argon is sprayed to break and atomize the falling liquid in the state of melting into fine liquid drops, and the fine liquid drops are cooled and solidified to form spherical powder.

Wherein the superalloy is selected from the group consisting of an iron-based alloy, a nickel-based alloy, and a cobalt-based alloy, preferably a nickel-based alloy.

Preferably, the high purity superalloy of step 1) of the preparation method of the present invention has a purity of O<50ppm，N<10ppm,S<10ppm，H<1 ppm; the vacuum treatment in the step 2) is carried out, and the vacuum degree reaches 1 multiplied by 10^-2～1×10^{- 1}Pa, the gas pressure is 0.45-0.85 Mpa; in the step 3), the particle size range of WC powder particles is not more than 75 μm, preferably 20-45 μm, and the adding amount of the WC powder particles is 5.5% of the weight of the alloy raw material; in step 4), CeO₂The adding amount is 3.0 percent of the weight of the high-temperature nickel-based alloy raw material; in the step 2) and the step 5), the purity of the argon is 99.99-99.999%, in the step 5), the temperature of the inert gas is controlled between 600 ℃ and 950 ℃, and the pressure of the inert gas is 3.5-6.0 Mpa.

Preferably, in the preparation method of the present invention, in the step 5), the gas in the atomizing chamber is discharged, and meanwhile, the high purity argon gas is supplemented into the melting chamber, the gas supplementing pressure is controlled to be 3.0 to 3.5Mpa, and the pressure difference between the melting chamber and the atomizing chamber is maintained to be 0 to 0.5Mpa, so as to prevent the spherical powder from hollowing.

In another embodiment, the spherical powder material of the superalloy of the present invention is characterized in that the powder is prepared by the above-mentioned preparation method of the present invention, and the superalloy is selected from an iron-based alloy, a nickel-based alloy, and a cobalt-based alloy, and preferably a nickel-based alloy.

In a specific embodiment, the preparation method of the spherical high-temperature alloy powder material comprises the following steps:

1) raw material treatment: the method comprises the steps of removing surface scale, impurities and other defects of the high-temperature nickel-based alloy raw material, detecting the purity of the raw material, ensuring that chemical components meet the GB/T39251-2020 requirement, and detecting the oxygen content of the high-temperature alloy to be less than 100 ppm.

2) Vacuumizing: to the smelting chamber and the atomizing chamberPre-vacuuming to reach vacuum degree of 1 × 10^-2～1×10^-1And Pa, after the powder is qualified, filling high-purity argon into the smelting chamber and the atomizing chamber to serve as protective gas, wherein the gas pressure in the smelting chamber is 0.45-0.85 Mpa, and oxidation of the ingredients in the smelting process and the powder in the atomizing process is avoided.

3) Smelting: and starting a medium-frequency induction heating power supply, and adjusting the power of the power supply to heat the crucible to 1600-1750 ℃. Adding WC powder particles after the nickel-based alloy raw material is smelted to molten state liquid, wherein the mass of the WC powder particles is 0.5-10.0% (preferably 5.5%) of the weight of the nickel-based alloy raw material, and the particle size range of the WC powder particles is not more than 75 micrometers, preferably 20-45 micrometers. And after all the raw materials are smelted to molten state liquid, starting a steady electric field and a steady magnetic field to uniformly disperse WC particles in the nickel-based alloy melt. The magnetic field intensity and direction are adjustable, and the adjusting range is 0.05-2T; the direct current strength and direction are adjustable, and the adjusting range is 0-250A.

4) Secondary feeding: after the steady-state electric field and the steady-state magnetic field are started for 5-15 minutes, adding a rare earth compound CeO into the melt₂，CeO₂The mass of (b) is 1.2-5.8% of the weight of the nickel-based alloy raw material, and the preferable mass percentage is 3.0%. Continuously vacuumizing the smelting chamber in the smelting process until CeO is obtained₂After the liquid became completely molten, atomization was started.

5) Gas atomization: the method comprises the following steps of crushing a vertically falling metal liquid flow into fine liquid drops by using inert gas argon through a nozzle with a negative pressure drainage effect, cooling and spheroidizing solidification of the liquid drops to form powder, wherein the inert gas argon is used in the atomization process, the temperature of the argon is controlled to be 600-950 ℃, the pressure adjustable range of the argon is 3.5-6.0 Mpa, and the purity is 99.99-99.999%. And discharging gas in the atomizing chamber by adopting a 5-30 kW high-pressure fan. And high-purity argon is supplemented into the smelting chamber while exhausting, the gas supplementing pressure is controlled to be 3.0-3.5 Mpa, the pressure difference between the smelting chamber and the atomizing chamber is kept to be 0-0.5 Mpa, and the hollow powder is prevented from being formed due to overlarge pressure difference.

6) Screening and packaging: and fully cooling the powder, sieving the powder at the temperature of lower than 50 ℃ in the atmosphere of high-purity argon, and carrying out argon protection packaging on the powder with different particle size grades.

The high-temperature alloy spherical material of the invention is doped with WC/CeO₂The composite alterant, and the content and the grain diameter are optimized, so that the dispersion strengthening and fine grain strengthening effects of the high-temperature alloy matrix are realized, and the wear resistance and the toughness of the coating are synergistically improved.

The invention adopts a steady-state electromagnetic composite field assisted vacuum induction melting gas atomization method, accurately regulates and controls the distribution state of a hard phase in a melt, improves the uniformity of the structure and the performance of the high-temperature alloy, and provides a new technical path for preparing the high-temperature alloy with high wear resistance, high toughness and uniform performance.

The preparation method of the invention adopts the sequence of secondary feeding to effectively avoid CeO₂Evaporation of CeO₂The alterant can increase the number of heterogeneous nucleation particles in the high-temperature alloy melt, further refine the matrix crystal grains after solidification, and obviously improve the impact toughness.

The high-temperature alloy spherical powder material and the preparation method thereof have the beneficial effects that:

compared with the existing material or technology, the preparation method of the invention utilizes the component design and the trace element regulation of the high-temperature alloy material, adopts the secondary feeding method, and adds WC/CeO with a certain mass percentage₂The composite modifier optimizes the content, particle size and other formulas of the composite modifier, and utilizes a steady-state electromagnetic composite field assisted vacuum induction melting gas atomization technology to prepare the high-temperature alloy spherical powder material, so that fine matrix crystal grains (the size of the crystal grains is 2-20 mu m) and a large number of reinforced hard phases can be obtained, and the high-temperature alloy spherical powder material with high wear resistance, high toughness and excellent mechanical properties, particularly the high-temperature nickel alloy spherical powder material, can be easily prepared.

Drawings

FIG. 1 is a microscopic morphology diagram of the high temperature alloy spherical powder material of the present invention;

FIG. 2 is a diagram of a blade made of the superalloy spherical powder material of the present invention;

FIG. 3 is a density chart of a blade prepared by using the high-temperature alloy spherical powder material of the invention;

FIG. 4 is a microstructure diagram of a blade prepared by using the high-temperature alloy spherical powder material of the invention;

FIG. 5 is a diagram of the mechanical properties of a blade prepared from the high-temperature alloy spherical powder material of the invention.

Detailed Description

The following further illustrates and helps to understand the spirit of the present invention in connection with the representative examples, but not to limit the scope of the present invention in any way.

The argon used in the following examples and comparative examples is high purity argon having a purity of 99.99% to 99.999%, and the alloy raw material used is a high temperature nickel alloy raw material having purity indexes of O <50ppm, N <10ppm, S <10ppm, and H <1 ppm.

Example 1:

preparation of high-temperature nickel alloy spherical powder material

The preparation process comprises the following steps:

1. raw material treatment: the method comprises the steps of removing surface oxide skin, impurities and other defects of the high-temperature nickel alloy raw material, detecting the purity of the raw material (O <50ppm, N <10ppm, S <10ppm and H <1ppm), ensuring that chemical components meet the requirements of GB/T39251-2020, and detecting the oxygen content of the high-temperature nickel alloy to be less than 10 ppm.

2. Vacuumizing: pre-vacuumizing the smelting chamber and atomizing chamber to 6X 10 vacuum degree^-2And Pa, after the powder is qualified, filling high-purity argon into the smelting chamber and the atomizing chamber to serve as protective gas, wherein the gas pressure in the smelting chamber is 0.65-0.85 Mpa, and oxidation of the ingredients in the smelting process and the powder in the atomizing process is avoided.

3. Smelting: and starting a medium-frequency induction heating power supply, and adjusting the power of the power supply to heat the crucible to 1700-1750 ℃. And adding WC powder particles after the high-temperature alloy raw material is smelted to molten state liquid, wherein the adding amount of the WC powder particles is preferably 5.5% of the mass of the nickel alloy raw material, and the preferable particle size range of the WC powder particles is 30-40 μm. And after all the raw materials are smelted to molten state liquid, starting a steady electric field and a steady magnetic field to uniformly disperse WC particles in the nickel-based alloy melt. The magnetic field intensity and direction are adjustable, and the adjusting range is 0.15-2T; the direct current strength and direction are adjustable, and the adjusting range is 200-250A.

4. Secondary feeding: after the steady-state electric field and the steady-state magnetic field are started for 10-15 minutes, adding a rare earth compound CeO into the melt₂，CeO₂The amount of (b) is preferably 3.0% by mass of the nickel alloy raw material. Continuously vacuumizing the smelting chamber in the smelting process until CeO is obtained₂After the liquid became completely molten, atomization was started.

5. Gas atomization: the method comprises the following steps of crushing and atomizing a vertically falling metal liquid flow into fine liquid drops by using high-purity argon through a nozzle with a negative pressure drainage effect, cooling and spheroidizing solidification of the liquid drops to form powder, wherein the temperature of the argon used in the atomization process is controlled between 600 ℃ and 850 ℃, the pressure adjustable range of the argon is 4.5-6.0 Mpa, and the purity of the argon is 99.99-99.999%. And discharging gas in the atomizing chamber by adopting a 15-30 kW high-pressure fan. And (3) exhausting and simultaneously supplementing high-purity argon gas into the smelting chamber, controlling the gas supplementing pressure to be 3.0-3.5 Mpa, ensuring that the pressure difference between the smelting chamber and the atomizing chamber is kept at 0-0.5 Mpa, and preventing overlarge pressure difference from forming hollow powder to obtain the spherical powder material. The powder was photographed by a scanning electron microscope, and as a result, as shown in FIG. 1, the particles were spherical, and the average size D50 of the spherical particles was 37.5. mu.m.

6. Screening and packaging: and fully cooling the powder, sieving the powder at the temperature of lower than 50 ℃ in the atmosphere of high-purity argon, and carrying out high-purity argon protection packaging on the powder with different particle size grades.

Comparative example 1:

a method for developing and preparing a novel high-temperature alloy spherical powder material comprises the following steps:

1. raw material treatment: the method comprises the steps of removing surface oxide skin, impurities and other defects of the high-temperature alloy raw material, detecting the purity of the raw material, ensuring that chemical components meet the requirements of GB/T39251-2020, and detecting the oxygen content of the high-temperature alloy to be less than 100 ppm.

2. Vacuumizing: pre-vacuumizing the smelting chamber and atomizing chamber to 1X 10^-1Pa, after the pressure is qualified, high-purity argon is filled into the smelting chamber and the atomizing chamber to be used as protective gas, the gas pressure in the smelting chamber is 0.45-0.65 Mpa, and the situation that the ingredients are not mixed in the smelting process and are not mixed in the atomizing chamber is avoidedOxidation of the powder during atomization.

3. Smelting: and starting a medium-frequency induction heating power supply, and adjusting the power of the power supply to heat the crucible to 1600-1700 ℃. Adding WC powder particles after the nickel-based alloy raw material is smelted to molten liquid, wherein the mass of the WC powder particles is 10.0% of that of the nickel alloy raw material, and the particle size range of the WC powder particles is 40-75 mu m. And after all the raw materials are smelted to molten state liquid, starting a steady electric field and a steady magnetic field to uniformly disperse WC particles in the nickel-based alloy melt. The magnetic field intensity and direction are adjustable, and the adjusting range is 0.05-0.15T; the direct current strength and direction are adjustable, and the adjusting range is 150-200A.

4. Secondary feeding: after the steady-state electric field and the steady-state magnetic field are started for 5-10 minutes, adding a rare earth compound CeO into the melt₂，CeO₂The mass of (b) was 1.5% of the mass of the nickel alloy raw material. Continuously vacuumizing the smelting chamber in the smelting process until CeO is obtained₂After the liquid became completely molten, atomization was started.

5. Gas atomization: the method comprises the following steps of crushing a vertically falling metal liquid flow into fine liquid drops by using high-purity argon through a nozzle with a negative pressure drainage effect, cooling and spheroidizing and solidifying the liquid drops to form powder, controlling the temperature of the high-purity argon used in the atomization process to be 450-600 ℃, controlling the pressure adjustable range of the high-purity argon to be 3.0-4.5 Mpa, and controlling the purity of the high-purity argon to be 99.99-99.999%. And discharging gas in the atomizing chamber by adopting a 10-15 kW high-pressure fan. And high-purity argon is supplemented into the smelting chamber while exhausting, the gas supplementing pressure is controlled to be 2.5-3.0 Mpa, the pressure difference between the smelting chamber and the atomizing chamber is kept to be 0.5-1.5 Mpa, and the hollow powder is prevented from being formed due to overlarge pressure difference.

6. Screening and packaging: and fully cooling the powder, sieving the powder at the temperature of lower than 50 ℃ in the atmosphere of high-purity argon, and carrying out high-purity argon protection packaging on the powder with different particle size grades.

Comparative example 2:

a method for developing and preparing a novel high-temperature alloy spherical powder material comprises the following steps:

1. raw material treatment: the method comprises the steps of removing surface oxide skin, impurities and other defects of the high-temperature alloy raw material, detecting the purity of the raw material, ensuring that chemical components meet the GB/T39251-2020 requirement, and detecting the oxygen content of the high-temperature alloy to be less than 10 ppm.

2. Vacuumizing: pre-vacuumizing the smelting chamber and atomizing chamber to 6X 10 vacuum degree^-2And Pa, after the powder is qualified, filling high-purity argon into the smelting chamber and the atomizing chamber to serve as protective gas, wherein the gas pressure in the smelting chamber is 0.65-0.85 Mpa, and oxidation of the ingredients in the smelting process and the powder in the atomizing process is avoided.

3. Smelting: and starting a medium-frequency induction heating power supply, and adjusting the power of the power supply to heat the crucible to 1700-1750 ℃. After the high-temperature alloy raw material is smelted to molten state liquid, WC powder particles and a rare earth compound CeO are added simultaneously₂. The mass of WC powder particles is 5.5% of the mass of the nickel alloy raw material, the preferable particle size range of the WC powder particles is 30-40 mu m, and CeO₂The mass of the nickel alloy is 3.0 percent of the mass of the nickel alloy raw material. And after all the raw materials are smelted to molten state liquid, starting a steady electric field and a steady magnetic field to uniformly disperse WC particles in the nickel-based alloy melt. The magnetic field intensity and direction are adjustable, and the adjusting range is 0.15-2T; the direct current strength and direction are adjustable, and the adjusting range is 200-250A.

4. Gas atomization: the method comprises the following steps of crushing a vertically falling metal liquid flow into fine liquid drops by using high-purity argon through a nozzle with a negative pressure drainage effect, cooling and spheroidizing and solidifying the liquid drops to form powder, controlling the temperature of the high-purity argon used in the atomization process to be between 600 and 850 ℃, controlling the pressure adjustable range of the high-purity argon to be 4.5 to 6.0Mpa, and controlling the purity of the high-purity argon to be 99.99 to 99.999 percent. And discharging gas in the atomizing chamber by adopting a 15-30 kW high-pressure fan. And high-purity argon is supplemented into the smelting chamber while exhausting, the gas supplementing pressure is controlled to be 3.0-3.5 Mpa, the pressure difference between the smelting chamber and the atomizing chamber is kept to be 0-0.5 Mpa, and the hollow powder is prevented from being formed due to overlarge pressure difference.

5. Screening and packaging: and fully cooling the powder, sieving the powder at the temperature of lower than 50 ℃ in the atmosphere of high-purity argon, and carrying out high-purity argon protection packaging on the powder with different particle size grades.

Comparative example 3:

a method for developing and preparing a novel high-temperature alloy spherical powder material comprises the following steps:

1. raw material treatment: the method comprises the steps of removing surface oxide skin, impurities and other defects of the high-temperature alloy raw material, detecting the purity of the raw material, ensuring that chemical components meet the GB/T39251-2020 requirement, and detecting the oxygen content of the high-temperature alloy to be less than 10 ppm.

2. Vacuumizing: pre-vacuumizing the smelting chamber and atomizing chamber to 6X 10 vacuum degree^-2And Pa, after the powder is qualified, filling high-purity argon into the smelting chamber and the atomizing chamber to serve as protective gas, wherein the gas pressure in the smelting chamber is 0.65-0.85 Mpa, and oxidation of the ingredients in the smelting process and the powder in the atomizing process is avoided.

3. Smelting: and starting a medium-frequency induction heating power supply, and adjusting the power of the power supply to heat the crucible to 1700-1750 ℃. And after the high-temperature alloy raw material is smelted to molten state liquid, adding WC powder particles, wherein the mass of the WC powder particles is 5.5% of that of the nickel alloy raw material, and the preferable particle size range of the WC powder particles is 30-40 mu m. And after all the raw materials are smelted to molten state liquid, starting a steady electric field and a steady magnetic field to uniformly disperse WC particles in the nickel-based alloy melt. The magnetic field intensity and direction are adjustable, and the adjusting range is 0.15-2T; the direct current strength and direction are adjustable, and the adjusting range is 200-250A.

4. Gas atomization: the method comprises the following steps of crushing a vertically falling metal liquid flow into fine liquid drops by using high-purity argon through a nozzle with a negative pressure drainage effect, cooling and spheroidizing and solidifying the liquid drops to form powder, controlling the temperature of the high-purity argon used in the atomization process to be between 600 and 850 ℃, controlling the pressure adjustable range of the high-purity argon to be 4.5 to 6.0Mpa, and controlling the purity to be 99.99 to 99.999 percent. And discharging gas in the atomizing chamber by adopting a 15-30 kW high-pressure fan. And high-purity argon is supplemented into the smelting chamber while exhausting, the gas supplementing pressure is controlled to be 3.0-3.5 Mpa, the pressure difference between the smelting chamber and the atomizing chamber is kept to be 0-0.5 Mpa, and the hollow powder is prevented from being formed due to overlarge pressure difference.

5. Screening and packaging: and fully cooling the powder, sieving the powder at the temperature of lower than 50 ℃ in the atmosphere of high-purity argon, and carrying out high-purity argon protection packaging on the powder with different particle size grades.

Comparative example 4:

a method for developing and preparing a novel high-temperature alloy spherical powder material comprises the following steps:

1. raw material treatment: the method comprises the steps of removing surface oxide skin, impurities and other defects of the high-temperature alloy raw material, detecting the purity of the raw material, ensuring that chemical components meet the GB/T39251-2020 requirement, and detecting the oxygen content of the high-temperature alloy to be less than 10 ppm.

2. Vacuumizing: pre-vacuumizing the smelting chamber and atomizing chamber to 6X 10 vacuum degree^-2And Pa, after the powder is qualified, filling high-purity argon into the smelting chamber and the atomizing chamber to serve as protective gas, wherein the gas pressure in the smelting chamber is 0.65-0.85 Mpa, and oxidation of the ingredients in the smelting process and the powder in the atomizing process is avoided.

3. Smelting: and starting a medium-frequency induction heating power supply, and adjusting the power of the power supply to heat the crucible to 1700-1750 ℃. After the high-temperature alloy raw material is smelted to molten state liquid, adding rare earth compound CeO₂，CeO₂The mass of (b) was 3.0% of the mass of the nickel alloy raw material. After all raw materials are smelted to molten state liquid, starting a steady-state electric field and a steady-state magnetic field, wherein the magnetic field intensity and direction are adjustable, and the adjusting range is 0.15-2T; the direct current strength and direction are adjustable, and the adjusting range is 200-250A.

4. Gas atomization: the method comprises the following steps of crushing a vertically falling metal liquid flow into fine liquid drops by using high-purity argon through a nozzle with a negative pressure drainage effect, cooling and spheroidizing and solidifying the liquid drops to form powder, controlling the temperature of the high-purity argon used in the atomization process to be between 600 and 850 ℃, controlling the pressure adjustable range of the high-purity argon to be 4.5 to 6.0Mpa, and controlling the purity of the high-purity argon to be 99.99 to 99.999 percent. And discharging gas in the atomizing chamber by adopting a 15-30 kW high-pressure fan. And high-purity argon is supplemented into the smelting chamber while exhausting, the gas supplementing pressure is controlled to be 3.0-3.5 Mpa, the pressure difference between the smelting chamber and the atomizing chamber is kept to be 0-0.5 Mpa, and the hollow powder is prevented from being formed due to overlarge pressure difference.

5. Screening and packaging: and fully cooling the powder, sieving the powder at the temperature of lower than 50 ℃ in the atmosphere of high-purity argon, and carrying out high-purity argon protection packaging on the powder with different particle size grades.

According to GB/T39251-2020 additive manufacturing metal powder performance characterization method, the performance of the powder prepared in the preferred embodiment and the comparative embodiment is compared, and the chemical composition, carbon and oxygen content, particle size, sphericity, fluidity, apparent density and tap density of the two powders are compared with emphasis. The powder chemical composition analysis method was carried out according to the regulation of GB/T4698. The oxygen and carbon contents of the powder should be in accordance with the GB/T14265-1993 standard. The median diameters D50 and D10, D90 of the powders were measured according to the specification of GB-T19077.1-2008. The sphericity of the powder was measured by using digital Image analysis software (Image-Pro-Plus), and the flow of the conventional factory powder was measured according to ASTM B213-2017. The bulk density of the powder was determined according to GB/T1479.1-2011. Respectively taking the powder prepared in the preferred embodiment and the powder prepared in the comparative embodiment as raw materials, printing a metal sample by adopting selective laser melting forming equipment, and carrying out a normal-temperature tensile property test according to the GB/T228.1-2010 standard. The performance index and tensile property ratio of the powders prepared in the preferred examples and comparative examples are shown in Table 1.

Table 1 comparison of the properties of the powders prepared in example 1 and in the comparative example

From a comparative analysis of the properties of the powders in Table 1, it can be seen that CeO is present in the powder prepared by the process of the invention (example 1)₂The burning loss is less, and the content fluctuation is relatively stable. The carbon-oxygen content, granularity, sphericity, fluidity, apparent density and other indexes of the powder are more excellent. With addition of WC and CeO only₂The purpose of the invention can be realized only by adding the two components separately, and the technical problem to be solved by the invention is solved. Therefore, the preparation method of the novel high-temperature alloy spherical powder material is obtained and realized through optimization and comparative verification of a large number of process conditions. The above examples and comparative examplesThe embodiments are also only partial representative examples of process conditions optimization.

The laser additive manufacturing process comprises (1) vacuumizing a molding cavity, introducing high-purity argon to prevent powder oxidation, and preheating a substrate to 180 ℃ to reduce deformation and cracking of the molded part; (2) a powder feeding cylinder mechanism in the powder paving system feeds powder into the forming chamber; (3) starting a laser source in a light source system, expanding the laser beam through a dichroic mirror after the laser beam passes through a laser control mechanism, and enabling the laser beam to enter a scanning vibrating mirror, and focusing the laser beam output by the scanning vibrating mirror through a focusing lens to perform two-dimensional scanning and forming on powder in a forming chamber; (4) and after single-layer scanning forming, the substrate is descended by one layer of height, and the previous step is repeated until the three-dimensional part forming is realized. The nickel-base superalloy blade prepared by the method is shown in figure 2. The relative densities of the laser-printed products of the powder materials prepared in example 1 and comparative example were measured at least three times using a high-precision multifunctional solid densitometer, and the results of the relative densities were averaged and shown in fig. 3. The crack distribution and the crack size are detected by adopting an X-ray and CT detection system for Nikon Metrology industry, the test principle is that a micro-focus source generates radiation and penetrates through a sample, a digital flat panel detector collects the X-ray penetrating through the sample, different gray gradients are formed according to different materials and geometric shapes, and therefore the distribution characteristics and the sizes of defects such as internal cracks are obtained. The crack detection results are shown in table 2. A metallographic sample is cut along the deposition direction of a laser additive manufacturing sample piece by linear cutting, fine ground by using metallographic abrasive paper, and finally polished on polishing cloth, and the molten pool morphology and the microstructure of the powder material laser printing piece prepared in the preferred embodiment are observed by using an optical microscope (Zeiss, Axio scope. ai), as shown in fig. 4. Preparing a mechanical property test sample according to the GB/T228.1-2010 standard, and carrying out tensile property test on an electronic universal tester. Polishing the surface of the sample to eliminate the influence of surface inclusions on a test result, and measuring the geometric dimension of the sample by using a vernier caliper; (2) opening test software, selecting a test method and inputting sample information; (3) keeping the sample in a vertical clamping state, and selecting the stretching speed to be 0.5 mm/min; (4) the test was started until the specimen broke. Samples under each parameter were tested three times and the average was taken as the final result. The mechanical property test results are shown in fig. 5 and table 2, respectively.

TABLE 2 comparison of mechanical Properties of laser-printed products of powdered materials prepared in example 1 and comparative example

As can be seen from the comparison of the mechanical properties of the laser-printed powder materials in Table 2, the quality of the blade manufactured by the powder material of example 1 is significantly improved, the defects such as cracks are significantly reduced, and the mechanical properties are improved, compared with the blades manufactured by the powder materials of comparative examples 1 to 4. Therefore, the spherical powder material prepared by the preparation method disclosed by the invention meets the requirements of aviation engine blades and gas turbine blades on high mechanical properties through the verification of a laser additive manufacturing process, and has a good technical application prospect.

Finally, it is noted that the above preferred embodiment, example 1, is provided only to illustrate the technical solution of the present invention and not to limit it, and although the present invention has been described in detail by the above preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention defined by the claims.