A method for preparing a low-oxygen-content alloy powder for metal additive

Abstract

The present application relates to the technical field of alloy powder preparation, and particularly relates to a low-oxygen-content alloy powder preparation method for metal additive manufacturing, which comprises the following steps: loading pretreated alloy raw materials into an induction melting furnace of an atomization device, heating and melting the raw materials after the melting chamber is pumped to high vacuum; after the alloy raw materials are completely melted, inert gas atomization is performed on the alloy liquid stream by using a high-pressure atomization nozzle; the alloy powder formed by atomization is collected by a cyclone separation device; the morphology characteristic index of the alloy powder is obtained to determine whether the atomization process meets preset standards, and under the condition that the atomization process does not meet the preset standards, the reason why the atomization process does not meet the preset standards is determined according to whether the alloy powder is segregated; the oxygen content in the alloy powder is detected by using an inert gas melting-thermal conductivity method, and the qualification of the alloy powder preparation is determined according to the oxygen content. The present application improves the performance consistency of the alloy powder.

Description

Technical Field

[0001] This invention relates to the field of alloy powder preparation technology, and in particular to a method for preparing low-oxygen-content alloy powder for metal additive manufacturing. Background Technology

[0002] Metal additive manufacturing technology, as a cutting-edge field in advanced manufacturing, achieves efficient forming of complex structural parts through layer-by-layer material deposition, and is widely used in high-end manufacturing fields such as aerospace, medical devices, and automobiles. Among these applications, low-oxygen-content alloy powder is a core raw material for ensuring the performance of additively manufactured parts. Oxygen, as an interstitial atom in alloys, significantly reduces the plasticity and toughness of materials. Therefore, controlling the oxygen content of powder is crucial for improving the reliability of additively manufactured parts.

[0003] Currently, the main technologies for preparing low-oxygen-content alloy powders include gas atomization, plasma rotating electrode method, and plasma atomization. Gas atomization, with its advantages of high efficiency, low cost, and narrow particle size distribution, has become the mainstream powder-making technology globally. It effectively reduces oxidation pollution by using high-pressure inert gas to break up the molten metal stream, combined with vacuum induction melting or electrode induction melting processes. Plasma atomization utilizes high-temperature plasma to melt metal wires, producing powders with high sphericity and low oxygen content. However, limited by wire cost and production capacity, it is mainly used for high-value-added materials (such as cobalt-chromium alloys).

[0004] Chinese Patent Application Publication No. CN105880612A discloses a method for preparing active metal powder for additive manufacturing. This method involves a crucible-free inert gas atomization powder preparation technique. First, the melting chamber and atomization chamber are pre-vacuumed, then argon or helium is introduced for protection. In the melting chamber, an active alloy rod is melted using a high-frequency induction coil to form a continuous alloy liquid flow. Finally, the alloy liquid flow is atomized with an inert gas using a high-pressure atomizing nozzle to produce powder. The powder is then collected by cyclone separation. This method for preparing active metal powder for additive manufacturing is advanced, flexible in production, and avoids secondary contamination as the powder does not come into contact with any other materials. It also has advantages such as good sphericity, low oxygen content, and good flowability, perfectly meeting the requirements of additive manufacturing processes.

[0005] However, the existing technology has the following problems: due to fluctuations in gas purity, it is difficult to accurately control the oxygen content of the gas entering the atomization system in actual production. Moreover, the cyclone separation process during powder collection may cause secondary pollution, making it difficult to stably control the oxygen content at an extremely low level, which in turn affects the powder quality and the performance stability of additively manufactured parts. Summary of the Invention

[0006] Therefore, the present invention provides a method for preparing low oxygen content alloy powder for metal additive manufacturing, in order to overcome the problems in the prior art that the lack of closed-loop feedback and precise traceability mechanism in the atomization process and oxygen content control leads to poor powder morphology consistency and easy exceedance of oxygen content.

[0007] To achieve the above objectives, the present invention provides a method for preparing low-oxygen content alloy powder for metal additive manufacturing, comprising:

[0008] Step S1: The pretreated alloy raw material is loaded into the induction melting furnace of the atomizing equipment. The melting chamber is evacuated to a high vacuum and the raw material is heated and melted. During the melting process, high-purity inert gas is injected into the melting chamber for protection.

[0009] Step S2: After the alloy raw materials are melted, they are vacuum degassed and refined. After refining, the alloy liquid is allowed to flow out stably through the guide pipe, and the alloy liquid is atomized with inert gas using a high-pressure atomizing nozzle.

[0010] Step S3: The atomized alloy powder is collected by a cyclone separator, and high-purity inert gas is continuously introduced for protection during the collection process.

[0011] Step S4: Observe the morphology of the alloy powder using a scanning electron microscope and measure the particle size distribution of the alloy powder using a laser particle size analyzer. Obtain the morphology characteristic index of the alloy powder to determine whether the atomization process meets the preset standard. If the atomization process does not meet the preset standard, determine the reason why the atomization process does not meet the preset standard based on whether there is segregation in the alloy powder.

[0012] Step S5: Under the condition that the atomization process meets the preset standard, the oxygen content in the alloy powder is detected by the inert gas melting-thermal conductivity method. The qualification of the alloy powder preparation is determined according to the oxygen content. Under the condition that it is unqualified, the refining and degassing time is increased according to the oxygen content exceeding the standard rate.

[0013] Furthermore, the morphology characteristic index of the alloy powder is determined by the average sphericity and average particle size of the alloy powder.

[0014] Furthermore, the process of determining whether the atomization process meets the preset standards based on the morphological characteristic index of the alloy powder includes:

[0015] Compare the morphological feature index with the preset index;

[0016] The atomization process is determined to be non-compliant with the preset standard based on the condition that the morphology characteristic index is less than the preset index, and the reason for non-compliance with the preset standard is determined based on whether there is segregation in the alloy powder.

[0017] The atomization process is determined to meet the preset standard based on the condition that the morphological characteristic index is greater than or equal to the preset index, and the qualification of the alloy powder preparation is determined based on the oxygen content.

[0018] Furthermore, the reasons why the atomization process does not meet the preset standards are determined based on whether there is segregation in the alloy powder.

[0019] If segregation exists, the reason why the atomization process does not meet the preset standard will be further determined based on the type of segregation.

[0020] If there is no segregation, the reason why the atomization process does not meet the preset standard is that the atomization parameters are not up to standard, and the atomization parameters are adjusted according to the specific manifestation of the morphological characteristics.

[0021] Furthermore, the process of determining the segregation type includes:

[0022] Several samples of different particle size ranges were selected from the same batch of powder.

[0023] The chemical composition of each sample was determined using inductively coupled plasma atomic emission spectrometry.

[0024] If there is a systematic difference in the content of the same element among different particle size ranges, it is determined that there is component segregation.

[0025] When there is no component segregation, each sample powder is made into a metallographic sample and observed using a scanning electron microscope and an energy dispersive spectroscopy instrument.

[0026] If an element-enriched or depleted region is observed inside a single powder particle, or if the element distribution map shows uneven light and dark stripes or clumps, then intraparticle segregation is determined to exist.

[0027] Furthermore, the atomization parameters are adjusted according to the specific manifestations of the morphological characteristics, including:

[0028] If the average sphericity is less than the preset sphericity, the superheating temperature of the alloy liquid flow is increased according to the difference between the preset sphericity and the average sphericity.

[0029] If the average particle size is greater than or equal to the preset particle size, the atomizing gas pressure is increased based on the difference between the average particle size and the preset particle size.

[0030] Furthermore, the qualification of the alloy powder preparation is determined based on the oxygen content, among which,

[0031] If the oxygen content is less than the preset oxygen content, the alloy powder preparation is deemed qualified.

[0032] If the oxygen content is greater than or equal to the preset oxygen content, the alloy powder preparation is deemed unqualified, and the refining and degassing time is increased according to the oxygen content exceedance rate, wherein the oxygen content exceedance rate = (oxygen content - preset oxygen content) / preset oxygen content.

[0033] Furthermore, the reasons why the atomization process does not meet the preset standards are determined based on the segregation type, among which,

[0034] If the segregation type is component segregation, the reason why the atomization process does not meet the preset standard is that the alloy liquid flow after melting is uneven, and the speed of electromagnetic stirring during melting should be increased.

[0035] If the segregation type is intraparticle segregation, the reason why the atomization process does not meet the preset standard is that the cooling rate during the atomization process is not up to standard, and the flow rate of the atomizing gas is increased according to the segregation coefficient.

[0036] Furthermore, several adjustment methods are provided for the flow rate of the atomized gas, and each adjustment method has a different adjustment range for the flow rate of the atomized gas.

[0037] Compared with existing technologies, the beneficial effects of this invention lie in its establishment of a three-level quality evaluation system—"morphology characteristic index - segregation analysis - oxygen content detection"—achieving closed-loop control throughout the entire process from atomization to finished product testing. Compared to traditional open-loop production processes, this invention can accurately locate process defects based on real-time detection data and specifically adjust key process indicators such as atomization parameters and refining time. This effectively solves problems such as uneven powder morphology and excessive oxygen content caused by fluctuations in process parameters, significantly improving the consistency and stability of product quality.

[0038] Furthermore, by introducing a segregation type identification mechanism, this invention can accurately distinguish between different types of defects such as "component segregation" and "intragranular segregation," and trace their origins to specific process steps such as "uniform alloy liquid flow" and "substandard cooling rate." This refined fault diagnosis mechanism overcomes the limitations of existing technologies that rely on experience-based trial and error, making process adjustments more targeted and scientific, greatly shortening the process optimization cycle, and improving production efficiency.

[0039] Furthermore, this invention incorporates quantitative indicators such as morphology characteristic index, oxygen content exceedance rate, and segregation coefficient into the process control process and establishes corresponding mathematical relationship models. By calculating parameters such as average sphericity difference, particle size difference, and oxygen content exceedance rate, precise quantitative adjustments to key parameters such as superheating temperature, atomization pressure, and refining time are achieved. This avoids the subjectivity and uncertainty of traditional methods that rely on operator experience, thereby improving the reliability of process control.

[0040] Furthermore, this invention constructs a multi-layered gas protection system covering the entire process by introducing high-purity inert gas during the smelting process, using high-purity inert gas as the atomization medium during the atomization process, and continuously introducing protective gas during the collection process. Combined with vacuum degassing refining technology and a dynamic adjustment mechanism for refining time based on the oxygen content exceedance rate, this system forms a multi-level barrier and active removal of oxygen content, providing a solid guarantee for the stable preparation of low-oxygen-content alloy powders. Attached Figure Description

[0041] Figure 1 This is a flowchart of a method for preparing low-oxygen content alloy powder for metal additive manufacturing according to an embodiment of the present invention;

[0042] Figure 2 This is a flowchart illustrating how an embodiment of the present invention determines whether the atomization process meets a preset standard based on the morphological characteristic index of alloy powder.

[0043] Figure 3 This is a flowchart illustrating how the atomization process fails to meet a preset standard based on the presence or absence of segregation in the alloy powder, as described in an embodiment of the present invention.

[0044] Figure 4 This is a flowchart illustrating how the quality of alloy powder preparation is determined based on oxygen content, according to an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0046] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0047] It should be noted that the data in this embodiment are all derived from a comprehensive analysis and evaluation of historical test data and corresponding historical test results from the three months prior to this test. Those skilled in the art will understand that the determination of the above-mentioned parameters for any single item in this invention can be achieved by selecting the value with the highest percentage based on the data distribution as the preset standard parameter, using weighted summation to obtain the value as the preset standard parameter, substituting each historical data point into a specific formula and using the value obtained from that formula as the preset standard parameter, or other selection methods, as long as the invention can clearly define different specific situations in the single-item judgment process through the obtained values.

[0048] Please see Figures 1 to 4The flowcharts shown are respectively: a flowchart of the method for preparing low-oxygen content alloy powder for metal additive manufacturing according to an embodiment of the present invention; a flowchart of determining whether the atomization process meets the preset standard based on the morphology characteristic index of the alloy powder according to an embodiment of the present invention; a flowchart of determining the reason why the atomization process does not meet the preset standard based on whether there is segregation in the alloy powder according to an embodiment of the present invention; and a flowchart of determining the qualification of alloy powder preparation based on oxygen content according to an embodiment of the present invention.

[0049] The present invention provides a method for preparing low-oxygen content alloy powder for metal additive manufacturing, comprising:

[0050] Step S1: The pretreated alloy raw material is loaded into the induction melting furnace of the atomizing equipment. The melting chamber is evacuated to a high vacuum and the raw material is heated and melted. During the melting process, high-purity inert gas is injected into the melting chamber for protection.

[0051] Step S2: After the alloy raw materials are melted, they are vacuum degassed and refined. After refining, the alloy liquid is allowed to flow out stably through the guide pipe, and the alloy liquid is atomized with inert gas using a high-pressure atomizing nozzle.

[0052] Step S3: The atomized alloy powder is collected by a cyclone separator, and high-purity inert gas is continuously introduced for protection during the collection process.

[0053] Step S4: Observe the morphology of the alloy powder using a scanning electron microscope and measure the particle size distribution of the alloy powder using a laser particle size analyzer. Obtain the morphology characteristic index of the alloy powder to determine whether the atomization process meets the preset standard. If the atomization process does not meet the preset standard, determine the reason why the atomization process does not meet the preset standard based on whether there is segregation in the alloy powder.

[0054] Step S5: Under the condition that the atomization process meets the preset standard, the oxygen content in the alloy powder is detected by the inert gas melting-thermal conductivity method. The qualification of the alloy powder preparation is determined according to the oxygen content. Under the condition that it is unqualified, the refining and degassing time is increased according to the oxygen content exceeding the standard rate.

[0055] Specifically, the pretreatment of the alloy raw materials in step S1 includes surface cleaning (such as pickling and ultrasonic cleaning) and drying to remove oil, oxides and moisture, thereby reducing the source of oxygen and hydrogen.

[0056] Specifically, the high-purity inert gas is argon or helium that has undergone multi-stage purification, and its purity is not less than 99.999%.

[0057] Specifically, the morphology characteristic index of the alloy powder is determined by the average sphericity and average particle size of the alloy powder. The morphology characteristic index = first weighting coefficient × average sphericity / sphericity threshold + second weighting coefficient × particle size threshold / average particle size, wherein the first weighting coefficient is 0.6, the sphericity threshold is 0.85, the second weighting coefficient is 0.4, and the particle size threshold is 45μm. However, the above values ​​are not limited to these values, and those skilled in the art can adjust the above values ​​according to actual needs.

[0058] Specifically, the process of determining whether the atomization process meets the preset standards based on the morphological characteristic index of the alloy powder includes:

[0059] Compare the morphological feature index with the preset index;

[0060] The atomization process is determined to be non-compliant with the preset standard based on the condition that the morphology characteristic index is less than the preset index, and the reason for non-compliance with the preset standard is determined based on whether there is segregation in the alloy powder.

[0061] The atomization process is determined to meet the preset standard based on the condition that the morphological characteristic index is greater than or equal to the preset index, and the qualification of the alloy powder preparation is determined based on the oxygen content.

[0062] In this embodiment of the invention, the preset index is 0.8, but the value is not limited to this. Those skilled in the art can adjust the value according to actual needs.

[0063] Specifically, the reasons why the atomization process does not meet the preset standards are determined based on whether there is segregation in the alloy powder.

[0064] If segregation exists, the reason why the atomization process does not meet the preset standard will be further determined based on the type of segregation.

[0065] If there is no segregation, the reason why the atomization process does not meet the preset standard is that the atomization parameters are not up to standard, and the atomization parameters are adjusted according to the specific manifestation of the morphological characteristics.

[0066] Specifically, the process of determining the type of segregation includes:

[0067] Several samples of different particle size ranges were selected from the same batch of powder.

[0068] The chemical composition of each sample was determined using inductively coupled plasma atomic emission spectrometry.

[0069] If there is a systematic difference in the content of the same element among different particle size ranges, it is determined that there is component segregation.

[0070] When there is no component segregation, each sample powder is made into a metallographic sample and observed using a scanning electron microscope and an energy dispersive spectroscopy instrument.

[0071] If an element-enriched or depleted region is observed inside a single powder particle, or if the element distribution map shows uneven light and dark stripes or clumps, then intraparticle segregation is determined to exist.

[0072] Specifically, different particle size ranges, for example, between the maximum and minimum particle size, are divided into three consecutive intervals equally according to particle size, without any specific numerical limit.

[0073] Specifically, the atomization parameters are adjusted according to the specific characteristics of the morphology, including:

[0074] If the average sphericity is less than the preset sphericity, the superheating temperature of the alloy liquid flow is increased according to the difference between the preset sphericity and the average sphericity.

[0075] If the average particle size is greater than or equal to the preset particle size, the atomizing gas pressure is increased based on the difference between the average particle size and the preset particle size.

[0076] In this embodiment of the invention, the preset sphericity is 0.9 and the preset particle size is 40 μm. However, the above values ​​are not limited to these. Those skilled in the art can adjust the above values ​​according to actual needs.

[0077] Specifically, the atomizing gas pressure is increased based on the difference between the average particle size and the preset particle size. If the particle size difference is less than the preset difference of 5 μm, the atomizing gas pressure is increased to the corresponding value using a first pressure adjustment coefficient of 1.1.

[0078] If the particle size difference is greater than or equal to the preset difference, the atomizing gas pressure is increased to the corresponding value using the second pressure adjustment coefficient of 1.3.

[0079] The particle size difference is the difference between the average particle size and the preset particle size.

[0080] In this embodiment of the invention, the preset difference value is 5 μm, but the value is not limited to this. Those skilled in the art can adjust the value according to actual needs. The adjusted atomizing gas pressure is the product of the initial atomizing gas pressure and the first pressure adjustment coefficient or the second pressure adjustment coefficient. The initial atomizing gas pressure is not limited here and can be determined according to the actual alloy powder preparation situation.

[0081] Specifically, the superheating temperature of the alloy liquid flow is increased according to the difference between the preset sphericity and the average sphericity, wherein if the sphericity difference is less than the preset sphericity difference, the superheating temperature of the alloy liquid flow is increased to a first preset temperature.

[0082] If the sphericity difference is greater than or equal to the preset sphericity difference, the overheating temperature of the alloy liquid flow will be increased to the second preset temperature.

[0083] The sphericity difference is the difference between the preset sphericity and the average sphericity.

[0084] In this embodiment of the invention, the preset sphericity difference value is 0.05, the first preset temperature is 100℃, and the second preset temperature is 200℃. However, the above values ​​are not limited to these, and those skilled in the art can adjust the above values ​​according to actual needs.

[0085] Specifically, the qualification of alloy powder preparation is determined based on oxygen content, among which,

[0086] If the oxygen content is less than the preset oxygen content, the alloy powder preparation is deemed qualified.

[0087] If the oxygen content is greater than or equal to the preset oxygen content, the alloy powder preparation is deemed unqualified, and the refining and degassing time is increased according to the oxygen content exceedance rate, wherein the oxygen content exceedance rate = (oxygen content - preset oxygen content) / preset oxygen content.

[0088] In this embodiment of the invention, the preset oxygen content is 300 ppm, but this value is not limited to this. Those skilled in the art can adjust this value according to actual needs.

[0089] Specifically, the refining degassing time is positively correlated with the oxygen content exceeding the standard rate. The higher the oxygen content exceeding the standard rate, the longer the refining degassing time. The increase in refining degassing time is between 10% and 50% of the initial refining degassing time, and there is no specific limit to the initial refining degassing time.

[0090] Specifically, the reasons why the atomization process does not meet the preset standards are determined based on the type of segregation.

[0091] If the segregation type is component segregation, the reason why the atomization process does not meet the preset standard is that the alloy liquid flow after melting is uneven, and the speed of electromagnetic stirring during melting should be increased.

[0092] If the segregation type is intraparticle segregation, the reason why the atomization process does not meet the preset standard is that the cooling rate during the atomization process is not up to standard, and the flow rate of the atomizing gas is increased according to the segregation coefficient.

[0093] Specifically, the speed of the electromagnetic stirring during the smelting process can be adjusted within the range of 40% to 80% of the rated maximum stirring current.

[0094] Specifically, there are several adjustment methods for the flow rate of the atomized gas. Each adjustment method has a different adjustment range for the flow rate of the atomized gas. If the segregation coefficient is less than the preset segregation coefficient, the flow rate of the atomized gas is increased to the corresponding value using the first flow rate adjustment coefficient of 1.1.

[0095] If the segregation coefficient is greater than or equal to the preset segregation coefficient, the flow rate of the atomizing gas is increased to the corresponding value using the second flow rate adjustment coefficient of 1.25.

[0096] The segregation coefficient is the ratio of the maximum component concentration difference between the interdendritic region and the dendritic trunk region within the alloy powder particles to the overall average component.

[0097] In this embodiment of the invention, the preset segregation coefficient is 0.15 and the initial atomizing gas flow rate is 40 m / s. However, the above values ​​are not limited to these values, and those skilled in the art can adjust the above values ​​according to actual needs.

[0098] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0099] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing low-oxygen content alloy powder for metal additive manufacturing, characterized in that, include: Step S1: The pretreated alloy raw material is loaded into the induction melting furnace of the atomizing equipment. The melting chamber is evacuated to a high vacuum and the raw material is heated and melted. During the melting process, high-purity inert gas is injected into the melting chamber for protection. Step S2: After the alloy raw materials are melted, they are vacuum degassed and refined. After refining, the alloy liquid is allowed to flow out stably through the guide pipe, and the alloy liquid is atomized with inert gas using a high-pressure atomizing nozzle. Step S3: The atomized alloy powder is collected by a cyclone separator, and high-purity inert gas is continuously introduced for protection during the collection process. Step S4: Observe the morphology of the alloy powder using a scanning electron microscope and measure the particle size distribution of the alloy powder using a laser particle size analyzer. Obtain the morphology characteristic index of the alloy powder to determine whether the atomization process meets the preset standard. If the atomization process does not meet the preset standard, determine the reason why the atomization process does not meet the preset standard based on whether there is segregation in the alloy powder. Step S5: Under the condition that the atomization process meets the preset standard, the oxygen content in the alloy powder is detected by the inert gas melting-thermal conductivity method. The qualification of the alloy powder preparation is determined according to the oxygen content. Under the condition that it is unqualified, the refining and degassing time is increased according to the oxygen content exceeding the standard rate. The process of determining the type of segregation includes: Several samples of different particle size ranges were selected from the same batch of powder. The chemical composition of each sample was determined using inductively coupled plasma atomic emission spectrometry. If there is a systematic difference in the content of the same element among different particle size ranges, it is determined that there is component segregation. When there is no component segregation, each sample powder is made into a metallographic sample and observed using a scanning electron microscope and an energy dispersive spectroscopy instrument. If an element-enriched or depleted region is observed inside a single powder particle, or if the element distribution map shows uneven light and dark stripes or clumps, then intraparticle segregation is determined to exist.

2. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 1, characterized in that, The morphological characteristic index of the alloy powder is determined by the average sphericity and average particle size of the alloy powder.

3. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 2, characterized in that, The process of determining whether the atomization process meets the preset standards based on the morphological characteristic index of alloy powder includes: Compare the morphological feature index with the preset index; The atomization process is determined to be non-compliant with the preset standard based on the condition that the morphology characteristic index is less than the preset index, and the reason for non-compliance with the preset standard is determined based on whether there is segregation in the alloy powder. The atomization process is determined to meet the preset standard based on the condition that the morphological characteristic index is greater than or equal to the preset index, and the qualification of the alloy powder preparation is determined based on the oxygen content.

4. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 3, characterized in that, The reason why the atomization process does not meet the preset standard is determined by whether there is segregation in the alloy powder. If segregation exists, the reason why the atomization process does not meet the preset standard will be further determined based on the type of segregation. If there is no segregation, the reason why the atomization process does not meet the preset standard is that the atomization parameters are not up to standard, and the atomization parameters are adjusted according to the specific manifestation of the morphological characteristics.

5. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 4, characterized in that, Adjusting atomization parameters based on specific morphological characteristics includes: If the average sphericity is less than the preset sphericity, the superheating temperature of the alloy liquid flow is increased according to the difference between the preset sphericity and the average sphericity. If the average particle size is greater than or equal to the preset particle size, the atomizing gas pressure is increased based on the difference between the average particle size and the preset particle size.

6. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 5, characterized in that, The qualification of alloy powder preparation is determined based on oxygen content, among which, If the oxygen content is less than the preset oxygen content, the alloy powder preparation is deemed qualified. If the oxygen content is greater than or equal to the preset oxygen content, the alloy powder preparation is deemed unqualified, and the refining and degassing time is increased according to the oxygen content exceedance rate, wherein the oxygen content exceedance rate = (oxygen content - preset oxygen content) / preset oxygen content.

7. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 6, characterized in that, The reasons why the atomization process does not meet the preset standards are determined based on the type of segregation. If the segregation type is component segregation, the reason why the atomization process does not meet the preset standard is that the alloy liquid flow after melting is uneven, and the speed of electromagnetic stirring during melting should be increased. If the segregation type is intraparticle segregation, the reason why the atomization process does not meet the preset standard is that the cooling rate during the atomization process is not up to standard, and the flow rate of the atomizing gas is increased according to the segregation coefficient.

8. The method for preparing low-oxygen content alloy powder for metal additive manufacturing according to claim 7, characterized in that, There are several adjustment methods for the flow rate of the atomized gas, and each adjustment method has a different adjustment range for the flow rate of the atomized gas.

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