Gas atomization metal powder preparation method capable of actively and adaptively regulating and controlling atomization pressure

Abstract

The invention discloses a gas atomization metal powder preparation method capable of actively and adaptively regulating and controlling atomization pressure, and relates to the technical field of gas atomization powder preparation control. The method comprises the following steps: acquiring a plurality of metal powder samples and collecting performance parameters; evaluating the comprehensive performance of the powder based on the performance parameters, and constructing and optimizing a prediction model based on a sample with relatively high comprehensive performance of the powder; adopting the prediction model to obtain initial values of atomization pressure, air inflow and feeding quantity; the optimal atomization pressure is obtained through atomization pressure dichotomy self-adaptive regulation and control; an exhaustion method is adopted to find the optimal air inlet amount and the optimal feeding amount under the current atomization pressure; and the atomization pressure bisection method and the exhaustion method are circularly executed until the comprehensive performance of the powder is stable. The technical problems that in the prior art, metal powder machining equipment cannot adjust the atomization pressure based on the real-time state of powder, and consequently the surface appearance, particle size distribution, the specific surface area and other performance of the machined and prepared metal powder are poor are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of controlling powder preparation by gas atomization, and particularly relates to a method for preparing metal powder by gas atomization with actively adaptive regulation of atomization pressure. Background Art

[0002] The gas atomization powder preparation method is a common method for preparing metal powder. Specifically, a metal is melted into a metal melt, and the molten metal flows through a high-speed inert gas stream, and is atomized into tiny droplets under the combined action of gas shear and extrusion. Laminar flow fibrosis will also occur. When the metal droplets start to leave the effective atomization area, the external pressure of the metal droplets will rapidly decrease. Due to the imbalance between the internal and external pressures of the metal droplets, the metal droplets will undergo self-excited fragmentation.

[0003] In the current gas atomization powder preparation method, the atomization gas pressure is usually fixed and cannot be adaptively adjusted according to the actual situation. This may lead to problems such as uneven specific surface area distribution and irregular shape, and it is difficult to precisely control the quality and performance of the powder, and the production efficiency is relatively low. Therefore, it is of great practical significance to develop a method for preparing metal powder by gas atomization with actively adaptive regulation of atomization pressure. Summary of the Invention

[0004] To solve the problems in the prior art, the present invention provides a method for preparing metal powder by gas atomization with actively adaptive regulation of atomization pressure. The present invention predicts the atomization pressure and the intake / feed rate through a multiple linear regression model, and adjusts the atomization pressure by the dichotomy method of atomization pressure based on the real-time state of the powder, and coordinately adjusts the intake air volume and the feed rate, thereby improving the control efficiency and realizing the two-way development of high quality and high efficiency in powder preparation.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing metal powder by gas atomization with actively adaptive regulation of atomization pressure, wherein the test method includes the following steps:

[0007] S1: Obtain a plurality of metal powder samples prepared by the gas atomization method, and collect the performance parameters of the metal powder samples;

[0008] S2: Evaluate the comprehensive performance of the powder based on the performance parameters, eliminate the samples with low comprehensive performance of the powder, collect the first process parameters and the second process parameters of the remaining samples. The first process parameters include atomization pressure, intake air volume and feed rate; taking the first process parameters as the dependent variables and the second process parameters as the independent variables, construct and optimize a multiple linear regression model, and the optimized model is the prediction model;

[0009] S3: Obtain the second process parameters of powder production and input them into the prediction model to obtain the initial value of the first process parameter;

[0010] S4: Keep the intake air volume and feed rate unchanged, and perform adaptive regulation through the bisection method of atomization pressure to maximize the comprehensive properties of the powder, and obtain the current optimal atomization pressure;

[0011] S5: Based on the current optimal atomization pressure and the current intake air volume and feed rate, use the exhaustive method to obtain the intake air volume and feed rate that maximize the comprehensive properties of the powder under the current optimal atomization pressure, as the current optimal intake air volume and optimal feed rate;

[0012] S6: Repeat steps S4 and S5 until the comprehensive properties of the produced powder reach stability.

[0013] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0014] (1) Through the multiple linear regression model, the present invention constructs a prediction model for atomization pressure and intake / feed volume, predicts the atomization pressure, intake air volume and feed rate in the process of preparing technical powder, so as to improve the efficiency of adaptive regulation. At the same time, the data accumulated in the actual production process can also continuously optimize the prediction model and improve the accuracy of prediction.

[0015] (2) Through the bisection method of atomization pressure, the present invention achieves adaptive regulation of atomization pressure, and through the exhaustive method, obtains the optimal intake air volume and feed rate, so as to better adjust the atomization pressure based on the real-time state of the powder and improve the quality of metal powder. At the same time, based on the predicted values of the atomization pressure and intake / feed volume prediction model, the efficiency of atomization pressure regulation is greatly improved, realizing the two-way development of high quality and high efficiency. Description of the Drawings

[0016] Figure 1 It is the overall flowchart of the method for preparing metal powder by gas atomization in an embodiment of the present invention;

[0017] Figure 2 It is the construction diagram of the multiple linear regression model of the method for preparing metal powder by gas atomization in an embodiment of the present invention;

[0018] Figure 3 It is the flowchart of the first adaptive judgment of the method for preparing metal powder by gas atomization in an embodiment of the present invention;

[0019] Figure 4 It is the flowchart of the adaptive bisection method adjustment of the method for preparing metal powder by gas atomization in an embodiment of the present invention;

[0020] Figure 5 It is the flowchart of the adaptive error feedback of the method for preparing metal powder by gas atomization in an embodiment of the present invention. Detailed implementation manners

[0021] In an embodiment of the present application, a method for preparing metal powder by gas atomization with actively adaptive regulation of atomization pressure is provided, which solves the technical problem in the prior art that the metal powder processing equipment cannot adjust the atomization pressure based on the real-time state of the powder, resulting in poor performance such as surface morphology, particle size distribution and specific surface area of the processed and prepared metal powder, and further affecting the practical application of the metal powder.

[0022] Next, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. It should be understood that the present application is not limited by the exemplary embodiments described herein. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application. Additionally, it should be noted that for the sake of description, only parts related to the present application are shown in the accompanying drawings rather than all of them.

[0023] Embodiment 1

[0024] As Figure 1 shown, the present invention provides a method for preparing metal powder by gas atomization with actively adaptive regulation of atomization pressure, including the following steps:

[0025] Step S1:

[0026] Obtain multiple metal powder samples prepared by the gas atomization method, and obtain the specific surface area, particle size distribution, sphericity and roughness of the powder samples through a laser particle size analyzer. The powder data acquisition devices are all installed on the metal powder processing equipment for real-time acquisition of the performance parameters of the metal powder.

[0027] Wherein the performance parameters of the metal powder only include the specific surface area, particle size distribution, sphericity and roughness of the powder.

[0028] Quantify the specific surface area and particle size distribution of the powder to obtain the performance parameters of the metal powder sample, and the performance parameters include roughness R, sphericity Q, quantified result E of particle size distribution and quantified result K of specific surface area. Among them, since the particle size distribution of the powder approximately follows a normal distribution, the reciprocal E of the standard deviation can be used to quantify the particle size distribution, and the specific surface area of the powder is quantified through linear conversion to obtain the quantified result K of the specific surface area.

[0029] Specifically, E = , where is the middle value of the set range, is the actual value, and the set range represents the corresponding preparation requirements.

[0030] Specifically, , where S is the actual value, and S min is the minimum value of the set range, and S max is the maximum value of the set range.

[0031] Step S2:

[0032] Calculate the comprehensive powder properties of the metal powder samples based on the comprehensive powder properties formula; eliminate the powder samples with lower comprehensive powder properties, and collect the first process parameters and the second process parameters of the remaining samples. The first process parameters are the atomization pressure, the intake air volume, and the feeding volume, and the second process parameters include the temperature of the metal liquid flow, the flow rate of the metal liquid flow, the aperture of the atomization nozzle, the flow rate of the inert gas, the type of atomization medium, the cooling temperature of the liquid cooling mechanism, the pressure in the melting chamber, the gas-liquid ratio, the nozzle angle, and the type of metal.

[0033] Specifically, the comprehensive powder properties formula is:

[0034] where M is the comprehensive powder properties, R is the roughness, Q is the sphericity, E is the quantization result of the particle size distribution, K is the quantization result of the specific surface area, and w1, w2, w3, w4 are the weight coefficients. The weight coefficients are all set according to requirements.

[0035] Based on the collected powder property parameters and the comprehensive powder properties formula, obtain the quantified comprehensive powder properties, which can provide a judgment standard for the subsequent adaptive adjustment of the powder process parameters.

[0036] Step S3:

[0037] For the remaining powder samples with higher comprehensive powder properties, taking the first process parameters as the dependent variables and the second process parameters as the independent variables, construct and optimize a multiple linear regression model. The optimized model is the atomization pressure and intake / feeding volume prediction model. The model optimization here refers to performing stepwise regression of multiple linear regression and eliminating the factors that have insignificant effects on the atomization pressure, so as to obtain the optimal multiple linear regression equation.

[0038] The above construction of multiple linear regression and stepwise regression are completed through the stepwise and regress functions in the MATLAB software.

[0039] Specifically, the independent variables of multiple linear regression: the temperature of the metal liquid flow , the flow rate of the metal liquid flow , the aperture of the atomization nozzle , the flow rate of the inert gas , the type of atomization medium , the cooling temperature of the liquid cooling mechanism , the pressure in the melting chamber , the gas-liquid ratio , nozzle angle , metal type ; Dependent variable of multiple linear regression: atomization pressure , intake air volume , feed rate .

[0040] After collecting the data of the independent variables and the dependent variable of the above powders and the comprehensive performance M of the corresponding powders, after obtaining enough sample data, the combinations of the independent variable x and the dependent variable y with higher comprehensive performance M of the powders are selected, and then each corresponding set of data is integrated to obtain the following form:

[0041] =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]; =[……]

[0042] Call stepwise in the MATLAB software to perform fitting of multiple linear regression on the integrated data set, and then use the regress function to perform stepwise regression to optimize the multiple linear regression model, so as to obtain the atomization pressure and intake / feed rate prediction models.

[0043] Input the data of the second process parameters in the current powder production process into the atomization pressure and intake / feed rate prediction models to obtain the initial values of the first process parameters (atomization pressure, intake air volume, feed rate).

[0044] The data accumulated in the actual production process, including the first process parameters and the second process parameters, can also be used to continuously optimize the prediction model and improve the prediction accuracy.

[0045] Step S4:

[0046] After that, keeping the intake air volume and the feed rate unchanged, perform adaptive regulation of the atomization pressure through the dichotomy method of the atomization pressure. The dichotomy method of the atomization pressure is divided into two steps: the first judgment stage and the dichotomy adjustment stage.

[0047] First judgment stage: Based on the current atomization pressure, intake air volume, and feed rate, with the intake air volume and feed rate fixed, increase (decrease) the atomization pressure in small increments multiple times. If, within the error range, the comprehensive powder properties improve or remain unchanged (decrease), then continue with the dichotomy adjustment stage in the adjustment direction of the last increase (decrease) in atomization pressure.

[0048] Dichotomy adjustment stage: Based on the result of the first judgment, continue to increase (decrease) the atomization pressure by X pa, where X represents the preset atomization pressure adjustment amplitude. This process includes error feedback measures after adjustment errors. Repeatedly adjust the atomization pressure according to the most recent atomization pressure adjustment and the change in the comprehensive powder properties until the comprehensive properties are stable. Each adjustment is specifically divided into two cases.

[0049] The first case (increasing the atomization pressure):

[0050] When the adjustment direction of the most recent atomization pressure is an increase, if the comprehensive powder properties improve or remain unchanged, then increase the atomization pressure by another X pa; if the comprehensive powder properties decrease, then decrease the atomization pressure by X / 2 pa.

[0051] The second case (decreasing the atomization pressure):

[0052] When the adjustment direction of the most recent atomization pressure is a decrease, if the comprehensive powder properties improve or remain unchanged, then decrease the atomization pressure by another X pa; if the comprehensive powder properties decrease, then increase the atomization pressure by X / 2 pa.

[0053] Meanwhile, the dichotomy adjustment stage process of the atomization pressure dichotomy includes error feedback measures: If, within the error range (same as the first judgment process), after continuously changing the atomization pressure multiple times, the number of times the comprehensive powder properties decrease during this period reaches the preset threshold, then all the adjustments that caused the performance to decrease during this period are marked as incorrect adjustments. Based on the atomization pressure P before the first incorrect adjustment, adjust the atomization pressure to P to return to the atomization pressure before the incorrect adjustment.

[0054] After returning, perform a reverse dichotomy adjustment according to the atomization pressure adjustment amount and adjustment direction of the first incorrect adjustment, clear the incorrect adjustment mark, bring the dichotomy adjustment back on track, and continue to improve the comprehensive powder properties.

[0055] The specific reverse dichotomy is as follows:

[0056] If the adjustment direction of the most recent atomization pressure is an increase, then decrease pa of atomization pressure.

[0057] If the adjustment direction of the most recent atomization pressure is a decrease, then increase pa of atomization pressure.

[0058] Step S5:

[0059] In the embodiment, the adjustment of the atomization pressure is achieved by adjusting the intake air volume and the feed rate. Under different combinations of the intake air volume and the feed rate, the comprehensive properties of the powder will also vary. Therefore, it is necessary to find the optimal combination of the intake air volume and the feed rate corresponding to the atomization pressure to maximize the comprehensive properties of the powder.

[0060] Based on the atomization pressure adjusted by the dichotomy method and the initial values of the intake air volume and the feed rate, while keeping the atomization pressure unchanged, list the possible combinations of the intake air volume and the feed rate by the exhaustive method. In the range of 500 - 1000 m 3 / h, with an interval of 1 m 3 / h, and in the range of 5 - 20 kg / h, with an interval of 0.1 kg / h, sequentially change the process parameters of the intake air volume and the feed rate, produce the powder based on each combination, continuously evaluate the comprehensive properties of the powder, and find the intake air volume and the feed rate that maximize the comprehensive properties of the powder under this atomization pressure.

[0061] Step S6:

[0062] Loop through steps S4 and S5. Under the continuous adjustment of the atomization pressure dichotomy method, the atomization pressure is continuously iteratively optimized, and at the same time, the corresponding optimal intake air volume and feed rate are also output until the comprehensive properties of the currently produced powder reach stability.

[0063] The present invention uses a multiple linear regression model to predict the initial values of the atomization pressure, the intake air volume, and the feed rate for powder making, and adapts through the atomization pressure dichotomy method to improve the preparation efficiency, reduce the defective rate. At the same time, the active adaptive technology can also improve the control efficiency and achieve two-way development of high quality and high efficiency.

[0064] Example 2

[0065] Taking nickel-cobalt alloy as an example, the atomization medium is nitrogen, the atomization temperature is 1585 - 1653 °C, the nozzle structure is a dual-gas-channel gas atomization nozzle, and the method described in Example 1 is used for the preparation of metal powder with active adaptive adjustment.

[0066] First, sample data collection and analysis are carried out. In this embodiment, the laser particle size analyzer, the data collection device, is installed on the metal powder processing equipment.

[0067] Set the laser wavelength to 632.8 nm, the dispersion medium to ethanol, the refractive index of the dispersion medium to 1.36, and the measurement range to 0.02 -2000 。To ensure the accuracy of measurement, the standard sample is compared with the produced powder. If the deviation exceeds the range, a calibration operation is required. The instrument emits a laser beam in real-time to irradiate the produced metal powder, and the detector collects the scattered light signal. After processing, data is obtained. After the software processes and analyzes the data, the specific surface area, particle size distribution, sphericity, and roughness of the powder sample in real-time are obtained.

[0068] The specific surface area and particle size distribution of the powder sample are quantified using a quantization formula to obtain the performance parameters of all powder samples. Based on the powder performance parameters obtained from data analysis, the comprehensive performance of the powder is quantified through the powder comprehensive performance formula. Samples with a powder comprehensive performance lower than the set threshold are excluded, and the first process parameters (atomization pressure , air intake , feed rate ) and the second process parameters (temperature of the metal liquid flow , flow rate of the metal liquid flow , aperture of the atomization nozzle , flow rate of the inert gas , type of the atomization medium , cooling temperature of the liquid cooling mechanism , pressure buildup in the melting chamber , gas-liquid ratio , nozzle angle , metal type ) of the remaining samples are retained, and a multiple linear regression model is constructed and optimized to obtain the atomization pressure and air / feed rate prediction models.

[0069] Among them, the temperature of the metal liquid flow and the cooling temperature of the liquid cooling mechanism are monitored by thermocouple sensors, the flow rate of the metal liquid flow is monitored by an electromagnetic flowmeter, the flow rate of the inert gas is monitored by a vortex flowmeter, and the pressure buildup in the melting chamber is monitored by a pressure sensor. The aperture of the atomization nozzle, the type of the atomization medium, the metal type, and the nozzle angle are set by the experimenter before powder production, and the gas-liquid ratio is calculated from the flow rates of the gas and the liquid.

[0070] Based on the obtained atomization pressure and air / feed rate prediction models, the real-time process parameters, environmental parameters, and metal type of the powder production corresponding to the independent variables are input into the model to obtain the initial values of the atomization pressure, air intake, and feed rate.

[0071] Atomization pressure bisection control is performed based on the initial values. The atomization pressure bisection control process is divided into two stages: the first judgment stage and the bisection adjustment stage.

[0072] In this embodiment, the atomization pressure bisection specifically includes:

[0073] 1) First judgment stage: Based on the current atomization pressure, intake air volume, and feed rate, by either fixing the feed rate and changing the intake air volume or fixing the intake air volume and changing the feed rate, increase the atomization pressure multiple times within a variation range of 0.001 Mpa. If the comprehensive powder properties improve or remain unchanged in 8 out of 10 times, the first atomization pressure adjustment in the dichotomy adjustment stage is an increase;

[0074] Reduce the atomization pressure multiple times within a variation range of 0.001 Mpa. If the comprehensive powder properties decrease in 8 out of 10 times, the first atomization pressure adjustment in the dichotomy adjustment stage is a decrease;

[0075] 2) Dichotomy adjustment stage: Based on the result of the first judgment, continue to significantly increase (decrease) the atomization pressure by X Mpa until the change in the comprehensive powder properties is within ±0.1% after 3 consecutive adjustments. The atomization pressure adjustment amplitude X is set to 0.001 Mpa.

[0076] In this embodiment, the adjustment of the atomization pressure is achieved by changing the intake air volume and the feed rate. For example, when the intake air volume increases (decreases), the atomization pressure increases (decreases); when the feed rate increases (decreases), the atomization pressure increases (decreases). However, due to the differences in the comprehensive powder properties under different combinations of intake air volume and feed rate, it is necessary to find the best combination of intake air volume and feed rate corresponding to the atomization pressure to maximize the comprehensive powder properties.

[0077] In this embodiment, the error feedback measure is specifically as follows: If the number of times the comprehensive powder properties decrease during 10 consecutive changes in the atomization pressure reaches 8 times or more, the adjustments that cause the performance to decrease during these 10 times are all marked as incorrect adjustments and return to the atomization pressure P before the first incorrect adjustment.

[0078] After returning, perform a reverse dichotomy adjustment according to the atomization pressure adjustment amount and the adjustment direction of the first incorrect adjustment, clear the incorrect adjustment mark, and continue the dichotomy adjustment stage.

[0079] Based on the atomization pressure after the dichotomy adjustment, while keeping the atomization pressure unchanged, through the exhaustive method, within the range of ±10% of the initial intake air volume, with an interval of 1 m 3 / h, and within the range of ±15% of the initial feed rate, with an interval of 0.1 kg / h, sequentially change the process parameters of the intake air volume and the feed rate, exhaustively find the combinations of the intake air volume and the feed rate that satisfy the unchanged atomization pressure, and conduct a quality assessment for each combination until the best combination of the intake air volume and the feed rate under this atomization pressure is found.

[0080] Continuously iterate and optimize the atomization pressure, intake air volume, and feed rate until the fluctuation of the comprehensive powder performance M is less than ±0.1% in three consecutive iterations, and it is determined that the stable state is reached. Output the corresponding optimal intake air volume and feed rate to achieve a stable production state, ultimately improving the preparation efficiency, reducing the defective rate, and at the same time improving the control efficiency to achieve a two-way development of high quality and high efficiency.

[0081] The above-described embodiments merely represent several implementation manners of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure, characterized in that: include: S1: Obtain multiple metal powder samples prepared by gas atomization method and collect performance parameters of the metal powder samples; S2: Evaluate the comprehensive performance of the powder based on the performance parameters, eliminate samples with low comprehensive performance of the powder, collect the first process parameters and the second process parameters of the remaining samples, where the first process parameters include atomization pressure, air intake volume and feed volume; take the first process parameter as the dependent variable and the second process parameter as the independent variable, construct and optimize a multivariate linear regression model, and the optimized model is the prediction model; S3: Obtain the second process parameter of powder production and input it into the prediction model to obtain the initial value of the first process parameter; S4: Keep the air intake and feed amount unchanged, and perform adaptive regulation through the atomization pressure dichotomy to maximize the comprehensive performance of the powder and obtain the current optimal atomization pressure; S5: Based on the current optimal atomization pressure and the current air intake and feed amount, an exhaustive method is used to obtain the air intake and feed amount that can achieve the highest comprehensive performance of the powder under the current optimal atomization pressure, which are used as the current optimal air intake and optimal feed amount; S6: Steps S4 and S5 are repeated repeatedly until the comprehensive properties of the produced powder are stable.

2. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 1, characterized in that: The performance parameters include roughness, sphericity, quantified results of particle size distribution and quantified results of specific surface area.

3. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 2, characterized in that: The calculation formulas for the particle size distribution quantification results and the specific surface area quantification results are as follows: ； ； Among them, E is the quantitative result of particle size distribution, K is the quantitative result of specific surface area, Set the middle value of the range for the particle size, is the actual value of particle size, S is the actual value of specific surface area, S min Set the minimum value of the interval for the specific surface area, S max Sets the interval maximum value for the specific surface area.

4. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 2, characterized in that: The roughness, sphericity, actual value of particle size and actual value of specific surface area are all collected by a laser particle size analyzer.

5. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 1, characterized in that: In S2, the quality assessment of the powder is performed based on the performance parameter evaluation of the comprehensive performance of the powder, and the specific calculation formula used is: ； Among them, M is the comprehensive performance of powder, R is the roughness, Q is the sphericity, E is the quantitative result of particle size distribution, K is the quantitative result of specific surface area, and w1, w2, w3 and w4 are weight coefficients.

6. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 1, characterized in that: The second process parameters include the temperature of the molten metal flow, the flow rate of the molten metal flow, the aperture of the atomizing nozzle, the flow rate of the inert gas, the type of atomizing medium, the cooling temperature of the liquid cooling mechanism, the holding pressure of the smelting chamber, the gas-liquid ratio, the nozzle angle and the type of metal.

7. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 1, characterized in that: The atomization pressure dichotomy method specifically includes: 1) First judgment stage: Based on the current atomization pressure, air intake and feed amount, the atomization pressure is increased multiple times within a range of 0.001Mpa by fixing the feed amount and changing the air intake, or fixing the air intake and changing the feed amount. If the ratio of the powder's comprehensive performance improvement or unchanged reaches the preset threshold, the adjustment direction of the first atomization pressure in the binary adjustment stage is to increase; The atomization pressure is reduced multiple times within the range of 0.001Mpa. If the comprehensive performance of the powder decreases 8 times within 10 times, the adjustment direction of the first atomization pressure in the binary adjustment stage is to decrease. 2) Binary adjustment stage: Based on the results of the first judgment stage, the atomization pressure is repeatedly adjusted according to the most recent atomization pressure change and the change in the comprehensive performance of the powder, until the comprehensive performance of the powder is stable and the atomization pressure is output; Each adjustment in the binary adjustment stage is as follows: When the most recent atomization pressure adjustment direction is increasing, if the comprehensive performance of the powder is improved or unchanged, then increase the atomization pressure by Xpa; if the comprehensive performance of the powder is reduced, then reduce the atomization pressure by X / 2pa; where X represents the preset atomization pressure adjustment range, 0.001Mpa≤X≤0.1Mpa; When the most recent atomization pressure adjustment direction is to decrease, if the comprehensive performance of the powder is improved or unchanged, then reduce the Xpa atomization pressure; if the comprehensive performance of the powder decreases, then increase the X / 2pa atomization pressure.

8. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 7, characterized in that: The binary adjustment stage of the atomization pressure binary adjustment also includes error feedback measures. Specifically, the error feedback measures are as follows: if the number of times the comprehensive performance of the powder decreases after the atomization pressure is adjusted for multiple times in a row reaches a preset threshold, the atomization pressure adjustment that causes the comprehensive performance of the powder to decrease during the period is marked as an incorrect adjustment, and the atomization pressure is adjusted back to the pressure before the first incorrect adjustment. The atomization pressure adjustment amount of the first incorrect adjustment is adjusted. Perform a reverse dichotomy adjustment in the adjustment direction, clear the wrong adjustment flag, and then continue the dichotomy adjustment stage; Each adjustment of the reverse dichotomy is as follows: If the first incorrect adjustment direction is to increase, the atomization pressure will decrease. ; If the first incorrect adjustment direction is to decrease, the atomization pressure will increase .

9. The method for preparing metal powder by gas atomization with active and adaptive control of atomization pressure according to claim 1, characterized in that: The exhaustive method described in S5 is specifically: The process parameters of air intake and feed amount are changed in sequence, and the air intake amount varies in the range of 500-1000m 3 / h, 1m 3 / h is an interval, the feed rate varies in the range of 5-20kg / h, and 0.1kg / h is an interval. All combinations of air intake and feed rate are listed, and the comprehensive powder performance of the metal powder samples prepared under each combination is evaluated. The optimal air intake and feed rate with the highest comprehensive powder performance under the current atomization pressure are screened.

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