Laser apparatus and method for determining the particle size distribution of an alloy powder

Abstract

The present application relates to the technical field of particle size distribution detection, and particularly relates to a laser measuring device and method for alloy powder distribution particle size, wherein the present application firstly determines the disaggregation grading wheel rotating speed when the current powder is completely disaggregated, analyzes the matching degree of the moving speed, density and particle size segment proportion between the current powder and the reference sample powder under the disaggregation grading wheel rotating speed, obtains the abnormal degree of the current powder distribution particle size measurement, then carries out multiple distribution particle size measurement on the current powder under the disaggregation grading wheel rotating speed, analyzes the distribution deviation degree of the particle size segment proportion obtained through multiple measurement, combines the abnormal degree and the moving speed, determines the optimized grading wheel rotating speed when the current powder carries out the distribution particle size measurement, and finally completes the grading of the current powder. Through the present application, the most suitable rotating speed for the powder distribution particle size measurement is obtained, the accuracy of the powder distribution particle size measurement is improved, and reliable data basis is provided for the subsequent powder grading.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of particle size distribution detection, and particularly relates to a laser measuring device and method for distribution particle size of alloy powder. BACKGROUND

[0002] It is crucial to accurately obtain the particle size distribution when the alloy powder is graded, which directly determines the grading effect and application performance of the powder. Precise particle size information is a key control index of the grading process, which directly affects the flowability, packing density, sintering behavior of the powder, and the mechanical properties, density and surface quality of the final product. Lack of accurate particle size distribution data will lead to low grading efficiency, unstable product batches, and cannot meet the stringent requirements of specific applications (such as additive manufacturing, injection molding, coating) for powder specifications, and even cause material waste and product failure.

[0003] Micron particles and ultra-micron particles are the main existing forms of alloy powder materials. Combined with the material characteristics of small particle size, low specific gravity, and interaction between particles, alloy powder particles are more likely to form agglomerated particles, rather than existing in the form of particle monomers and uniformly dispersed in the medium.

[0004] Currently, the laser method is generally used to measure the particle size distribution of alloy powder. However, the laser method may result in low accuracy and low efficiency of particle size detection due to particle agglomeration or poor dispersion during detection. In the prior art, the removal of the agglomeration effect is mainly achieved by gradually adjusting the rotational speed of the grading wheel to obtain the actual distribution particle size, but the obtained distribution particle size is not accurate enough. SUMMARY

[0005] To solve the above technical problems, the purpose of the present application is to provide a laser measuring device and method for distribution particle size of alloy powder.

[0006] According to a first aspect of the embodiments of the present application, a laser measuring method for distribution particle size of alloy powder is provided, and the technical solution is as follows:

[0007] The rotational speed of the grading wheel is increased by a fixed step by step, the distribution particle size of the current powder is measured multiple times, the overall distribution change of the particle size segment proportion obtained by multiple measurements is analyzed, and the disaggregation grading wheel rotational speed when the current powder is completely disaggregated is determined;

[0008] Under the disaggregation grading wheel rotational speed, the matching degree of the moving speed, density and particle size segment proportion between the current powder and the reference sample powder is analyzed, and the abnormality degree of the current powder distribution particle size measurement is obtained;

[0009] a plurality of distribution particle size determinations are performed on the current powder at the depolymerization classification wheel rotation speed, the distribution deviation degree of the particle size segment proportions obtained in the plurality of determinations is analyzed, the abnormality degree and the moving speed are combined, the reduction degree of the classification wheel rotation speed when the current powder is subjected to the distribution particle size determination is obtained, and the optimized classification wheel rotation speed when the current powder is subjected to the distribution particle size determination is determined.

[0010] At the optimized classification wheel rotation speed, the distribution particle size determination of the current powder is performed, the actual distribution particle size of the current powder is obtained, and the classification of the current powder is completed.

[0011] In some embodiments of the present application, after the classification of the current powder is completed, the method further comprises:

[0012] The existence proportion of the problem powder in the problem powder group is analyzed, and the adjusted classification wheel rotation speed of the problem powder group is obtained.

[0013] In some embodiments of the present application, the existence proportion of the problem powder in the problem powder group is analyzed, and the adjusted classification wheel rotation speed of the problem powder group is obtained, comprising:

[0014] The problem powder group existing in the two groups of powders after the classification of the current powder is determined;

[0015] The first proportion of the problem powder particle size segment in the problem powder particle size segment in the problem powder group is obtained, and the second proportion of the non-problem powder particle size segment in the problem powder group in the powder particle size segment before the classification is obtained;

[0016] It is judged whether the problem powder group belongs to the group with smaller particle size or the group with larger particle size;

[0017] If it belongs to the group with smaller particle size, the maximum powder particle size in the problem powder particle size segment is obtained, and the first rotation speed adjustment degree of the problem powder group is obtained in combination with the first proportion and the second proportion;

[0018] If it belongs to the group with larger particle size, the minimum powder particle size in the problem powder particle size segment is obtained, and the second rotation speed adjustment degree of the problem powder group is obtained in combination with the first proportion and the second proportion;

[0019] Different classification wheel rotation speeds are set, and the powder separation particle size segments corresponding to different classification wheel rotation speeds are obtained as reference data;

[0020] Based on the reference data, the first classification wheel rotation speed corresponding to the separation of the problem powder particle size segment is obtained, and the second classification wheel rotation speed corresponding to the adjacent particle size segment of the problem powder group to which the problem powder particle size segment deviates is obtained.

[0021] According to the first or second rotational speed adjustment degree, the first and second classification wheel rotational speeds, an adjusted classification wheel rotational speed of the classification problem powder group is obtained.

[0022] In some embodiments of the present application, the classification wheel rotational speed is increased by a fixed step to perform multiple distribution particle size determinations on the current powder, and the overall distribution change of the particle size segment proportion obtained by analyzing the multiple determinations is used to determine the depolymerization classification wheel rotational speed of the current powder when the current powder is completely depolymerized, including:

[0023] The classification wheel rotational speed is increased by a fixed step to perform multiple distribution particle size determinations on the current powder, and the particle size segment proportion of the current powder under different classification wheel rotational speeds is obtained.

[0024] The difference between the particle size segment proportions under all adjacent classification wheel rotational speeds is calculated to obtain a first total difference;

[0025] The first total differences are sorted in ascending order of their corresponding classification wheel rotational speeds, the second difference between adjacent first total differences in the sorting is calculated, and the ratio of the number of second differences less than 0 to the total number of second differences is calculated.

[0026] According to the ratio, in combination with the first total differences, the depolymerization degree of the current powder under the adjusted classification wheel rotational speed of each adjustment is obtained.

[0027] A depolymerization degree threshold is preset, and the depolymerization classification wheel rotational speed of the current powder when the current powder is completely depolymerized is determined according to the depolymerization degree.

[0028] In some embodiments of the present application, under the depolymerization classification wheel rotational speed, the matching degree of the moving speed, density and particle size segment proportion between the current powder and the reference sample powder is analyzed to obtain the abnormality degree of the distribution particle size determination of the current powder, including:

[0029] Under the depolymerization classification wheel rotational speed, the moving speed and particle size segment proportion of the current powder and different reference sample powders are obtained.

[0030] The moving speed difference and density difference between the current powder and different reference sample powders are analyzed to obtain the reference value of different reference sample powders to the current powder.

[0031] The maximum reference value corresponding to different reference samples is obtained, and the reference sample corresponding to the maximum reference value is an effective reference sample.

[0032] The absolute value of the difference between the effective reference sample and the current powder for all corresponding particle size segment proportions is calculated to obtain a second total difference.

[0033] In combination with the maximum reference value and the second total difference, the abnormality degree of the distribution particle size determination of the current powder is obtained.

[0034] In some embodiments of the present application, the current powder is subjected to multiple distribution particle size determinations at the depolymerization classification wheel rotation speed, the deviation degree of the particle size segment proportion obtained from the multiple determinations is analyzed, and the reduction degree of the classification wheel rotation speed when the current powder is subjected to distribution particle size determination is obtained in combination with the abnormality degree and the moving speed, including:

[0035] The current powder is subjected to multiple distribution particle size determinations at the depolymerization classification wheel rotation speed, and the particle size segment proportion of the current powder under multiple distribution particle size determinations is obtained.

[0036] The mean value of the different particle size segment proportions under multiple distribution particle size determinations is calculated.

[0037] The difference between each particle size segment proportion under each distribution particle size determination and the mean value of the corresponding particle size segment proportion is analyzed to obtain a third total difference value.

[0038] The third total difference value, the abnormality degree, and the moving speed are combined to obtain the reduction degree of the classification wheel rotation speed when the current powder is subjected to distribution particle size determination.

[0039] In some embodiments of the present application, the optimized classification wheel rotation speed when the current powder is subjected to distribution particle size determination is determined, including:

[0040] The optimized classification wheel rotation speed when the current powder is subjected to distribution particle size determination is determined in combination with the fixed step length according to the depolymerization classification wheel rotation speed and the reduction degree.

[0041] According to a second aspect of an embodiment of the present application, a laser device for measuring the distribution particle size of an alloy powder is provided, including a classification screening processor, a laser emitter, a Fourier lens, a ring-shaped photodetector array, a laser speedometer, and a central processing system, wherein:

[0042] The classification screening processor includes a classification wheel for adjusting the rotation speed during distribution particle size determination and realizing the classification of the powder.

[0043] The laser emitter, the Fourier lens, and the ring-shaped photodetector array are used to generate parallel laser beams and capture scattered light signals to realize particle size measurement.

[0044] The laser speedometer is used to measure the moving speed of the powder.

[0045] In some embodiments of the present application, the central processing system includes a memory and a processor, wherein:

[0046] The memory is used to store program codes.

[0047] The processor is used to read the program codes stored in the memory and execute any of the above-mentioned methods.

[0048] In some embodiments of the present application, the processor comprises:

[0049] A disaggregation module is configured to increase the classification wheel rotation speed by a fixed step each time, perform multiple distribution particle size determinations on the current powder, analyze the overall distribution change of the particle size segment proportion obtained by the multiple determinations, and determine the disaggregation classification wheel rotation speed at which the current powder is completely disaggregated.

[0050] An anomaly analysis module is configured to analyze the matching degree of the moving speed, density, and particle size segment proportion between the current powder and the reference sample powder at the disaggregation classification wheel rotation speed, and obtain the abnormality degree of the distribution particle size determination of the current powder.

[0051] A rotation speed optimization module is configured to perform multiple distribution particle size determinations on the current powder at the disaggregation classification wheel rotation speed, analyze the distribution deviation degree of the particle size segment proportion obtained by the multiple determinations, combine the abnormality degree and the moving speed, obtain the reduction degree of the classification wheel rotation speed when the distribution particle size determination is performed on the current powder, determine the optimized classification wheel rotation speed when the distribution particle size determination is performed on the current powder, and perform the distribution particle size determination on the current powder at the optimized classification wheel rotation speed to obtain the actual distribution particle size of the current powder and complete the classification of the current powder.

[0052] A distribution particle size determination module is configured to perform the distribution particle size determination on the current powder at the optimized classification wheel rotation speed to obtain the actual distribution particle size of the current powder and complete the classification of the current powder.

[0053] Compared with the prior art, the laser determination device and method for the distribution particle size of an alloy powder provided by the present application have the following beneficial effects:

[0054] The present application increases the classification wheel rotation speed by a fixed step each time, performs multiple distribution particle size determinations on the current powder, analyzes the overall distribution change of the powder, judges the aggregation and disaggregation of the current powder, determines the disaggregation classification wheel rotation speed at which the current powder is completely disaggregated, analyzes the matching degree of the moving speed, density, and particle size segment proportion between the current powder and the reference sample powder at the disaggregation classification wheel rotation speed, judges the accuracy of the detection of the powder particle size, judges the existence of the ghost problem, obtains the abnormality degree of the distribution particle size determination of the current powder, adjusts the suitable detection classification wheel rotation speed by the matching degree and the distribution particle size difference in different laser detections, and adjusts the classification wheel rotation speed to the most suitable rotation speed for measuring the distribution particle size of the powder. The present application obtains the most suitable rotation speed for measuring the distribution particle size of the powder, thereby improving the accuracy of the distribution particle size determination of the powder and providing a reliable data basis for the subsequent powder classification. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0056] Figure 1 A basic flowchart of a laser measurement method for distributing particle size of an alloy powder provided by an embodiment of the present application;

[0057] Figure 2 A basic composition of a central processing system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined purposes, the following describes a laser measurement device and method for distributing particle size of an alloy powder according to the present application, its specific implementation, structure, features and effects in detail, with reference to the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms such as "comprise", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the circuit structure, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such article or device. Without more limitation, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the article or device comprising the element.

[0060] The following specifically describes a specific scheme of a laser measurement method for distributing particle size of an alloy powder provided by the present application with reference to the drawings.

[0061] Please refer to Figure 1 , which shows a basic flow of a laser measurement method for distributing particle size of an alloy powder provided by an embodiment of the present application.

[0062] As Figure 1 shown, the laser measurement method for distributing particle size of an alloy powder provided by an embodiment of the present application specifically includes:

[0063] S100: gradually increase the classification wheel speed in a fixed step, perform multiple distribution particle size measurements on the current powder, analyze the overall distribution change of the particle size fraction proportion obtained by multiple measurements, and determine the depolymerization classification wheel speed when the current powder is completely depolymerized.

[0064] To realize the measurement of the distribution particle size, first, the layout of the basic measurement device is performed: a laser emitter (632.8 nm helium-neon laser or 473 nm semiconductor laser), a Fourier lens system, and a ring-shaped photodetector array (such as the detector of Mastersizer 3000) are arranged beside the outlet pipeline of the classification screening processor (including the classification wheel) to generate a parallel laser beam and capture 0.01°-170° scattered light signals.

[0065] The data obtained by detection is transmitted to the central processor, and the proportion of different powder particle sizes is obtained by integrating the inversion algorithm (non-negative least squares method) and the morphology compensation module (which can be linked with the Camsizer X2 dynamic image instrument).

[0066] Agglomeration effect is easy to occur in alloy powder, and the particle size of the agglomerate formed after the agglomeration of small particle size powder is large, which will affect the judgment of the size by the laser and affect the selection of the classification wheel speed during powder classification. The classification wheel speed can be gradually increased to enhance the collision between different powders, so as to realize the depolymerization of the agglomerate.

[0067] Based on the above analysis, in the embodiment of the present application, the classification wheel speed is gradually increased in a fixed step, multiple distribution particle size measurements are performed on the current powder, the overall distribution change of the particle size fraction proportion obtained by multiple measurements is analyzed, and the depolymerization classification wheel speed when the current powder is completely depolymerized is determined. Further, it includes:

[0068] First, the starting classification wheel speed is set, the classification wheel speed is gradually increased in a fixed step based on the starting classification wheel speed, multiple distribution particle size measurements are performed on the current powder, the particle size fraction proportion of the current powder under different classification wheel speeds is obtained, and it should be noted that the particle size fraction proportion corresponding to each classification wheel speed is the average value of multiple detections.

[0069] Then, the difference value of the particle size fraction proportion corresponding to two adjacent classification wheel speeds is calculated. Specifically, the particle size fraction proportion under the current classification wheel speed is subtracted from the particle size fraction proportion under the classification wheel speed adjusted last time, and all adjacent classification wheel speeds are added to obtain the first total difference value corresponding to the current classification wheel speed.

[0070] Then, the first total difference value is taken as the first threshold value. The first threshold value is taken as the first threshold value. Five speed adjustments were performed backwards, resulting in multiple first total differences. These first total differences were then sorted in ascending order of their corresponding stage wheel speeds. The quadratic differences between adjacent first total differences were calculated. Specifically, the current first total difference was subtracted from the previous first total difference in the sorted value. The number of quadratic differences less than 0 was counted, and the ratio of this number to the total number of quadratic differences was calculated, denoted as . ( (Indicates the current number of speed adjustments).

[0071] Grader speed Below, when the ratio The larger, and the first The smaller the first total difference corresponding to each speed adjustment, the smaller the change in particle size distribution and the smaller the change in the proportion of different particle sizes of the alloy powder under the change in the speed of the classifier wheel, and the more effectively all agglomerates are deagglomerated. Therefore, based on the ratio and the first total difference, the degree of deagglomeration of the powder under each adjusted speed of the classifier wheel is:

[0072]

[0073] In the formula, Indicates the current powder at the th During the next speed adjustment (the corresponding grader wheel speed is...), The degree of depolymerization; It represents the ratio of the number of quadratic differences that are less than 0 to the total number of quadratic differences; Indicates the first The first total difference corresponding to each speed adjustment; Represents a linear normalization function; This is to prevent the denominator from being 0.

[0074] Finally, a preset deagglomeration degree threshold is set, which can be 0.8. Based on the degree of deagglomeration, the deagglomeration stage wheel speed at which the current powder is completely deagglomerated is determined, i.e., when... When it is determined that the current powder has been completely deagglomerated, the deagglomerating stager speed at which the current powder has been completely deagglomerated is: The minimum speed of the stage wheel at that time.

[0075] S200: At the deagglomeration and classification wheel speed, analyze the degree of matching between the current powder and the reference sample powder in terms of movement rate, density, and particle size distribution ratio to obtain the degree of abnormality in the particle size distribution measurement of the current powder.

[0076] When the classifier wheel speed is too high, the alloy powder may rotate too fast, producing artifacts and causing the laser to misidentify the actual particle size of the alloy powder, resulting in some alloy powder particles having larger particle sizes than the actual powder size. Since the increase in the classifier wheel speed in step S100 is a fixed step size, the resulting classifier wheel speed at complete deagglomeration may be too high, and the representation of the actual powder particle size distribution may not be accurate enough. Therefore, the classifier wheel speed should be adjusted appropriately.

[0077] Based on the above analysis, in an embodiment of the present invention, by analyzing the degree of matching between the current powder and the reference sample powder in terms of migration rate, density, and particle size distribution ratio at the deagglomeration and classification wheel speed, the degree of anomaly in the particle size measurement of the current powder distribution is obtained. Further aspects include:

[0078] First, powders with different particle sizes are selected as reference sample powders. Under the deagglomeration and classification wheel speed, the movement speed and particle size distribution of the current powder and different reference sample powders are obtained. Specifically, a laser velocimeter is installed in the classification and sieving processor to detect the movement speed of the current powder and different reference sample powders, and the average of all detected speeds for each powder is obtained as the overall movement speed of each powder under the deagglomeration and classification wheel speed, thus obtaining the movement speed of the current powder and different reference sample powders. Simultaneously, under the deagglomeration and classification wheel speed, the particle size distribution of the current powder and different reference sample powders is obtained. Additionally, the density of the current powder and different reference sample powders is also obtained.

[0079] Then, since the powder's movement rate in the classifying and sieving processor is related to its density, the differences in movement rate and density between the current powder and different reference sample powders are analyzed at the deagglomeration and classifying wheel speed. Specifically, the absolute values ​​of the difference in movement rate and density between the current powder and different reference sample powders are calculated to obtain the reference value of different reference sample powders for the current powder.

[0080]

[0081] In the formula, Indicates reference sample powder For the current powder Reference value; Indicates the current powder Compared with reference sample powder The difference in movement speed; Indicates the current powder Compared with reference sample powder The density difference.

[0082] When the reference sample powder With current powder The absolute value of the difference in movement speed The smaller, the absolute value of the density difference The smaller, the reference sample powder The current powder The more valuable the reference sample powder is to the current powder.

[0083] Further, the maximum reference value corresponding to different reference samples is obtained, denoted as The reference sample corresponding to the maximum reference value is the effective reference sample, denoted as ;

[0084] The absolute value of the difference between the effective reference sample and the current powder is calculated for all corresponding particle size segments, and all particle size segment proportions are traversed to obtain a second total difference, denoted as .

[0085] Finally, the maximum reference value and the second total difference are combined to obtain the abnormality degree of the current powder distribution particle size determination as follows:

[0086]

[0087] In the formula, represents the abnormality degree of the current powder distribution particle size determination; represents the maximum reference value of the reference sample powder to the current powder ; represents the sum of the absolute values of the differences between the effective reference sample and the current powder in all corresponding particle size segment proportions (the second total difference).

[0088] When the maximum reference value is larger, and the sum of the absolute values of the differences between the effective reference sample powder of the maximum reference value and the current powder in different particle size segments (the second total difference) is larger, the moving speed of the current powder is less consistent with the actual situation of the obtained powder distribution particle size, and it is more likely that the moving speed is too large, resulting in artifacts and problems in the detection of the powder distribution particle size.

[0089] S300: Perform multiple distribution particle size determinations on the current powder at the disaggregation classification wheel rotation speed, analyze the distribution deviation degree of the particle size segment proportions obtained by the multiple determinations, and combine the abnormality degree and the moving speed to obtain the reduction degree of the classification wheel rotation speed when the current powder is determined for distribution particle size determination. Determine the optimized classification wheel rotation speed when the current powder is determined for distribution particle size determination.

[0090] To make the classification wheel rotation speed appropriate, the distribution particle size detection of the powder is more accurate, and the classification wheel rotation speed is prevented from being reduced too much, causing the re-agglomeration of part of the powder. The current classification wheel rotation speed (de-agglomeration classification wheel rotation speed) should be appropriately reduced. In addition to the matching abnormality degree of the moving speed of the powder and the detected distribution particle size, the moving rate of the current powder as a whole and the change of the distribution particle size during multiple detections can also be referred to for judgment.

[0091] Based on the above analysis, in the embodiments of the present application, by performing multiple distribution particle size determinations on the current powder at the de-agglomeration classification wheel rotation speed, analyzing the distribution deviation degree of the particle size segment proportion obtained by multiple determinations, combining the abnormality degree and the moving rate, the reduction degree of the classification wheel rotation speed when the current powder is subjected to distribution particle size determination is obtained, and the optimized classification wheel rotation speed when the current powder is subjected to distribution particle size determination is determined. Further comprising:

[0092] First, multiple (5 times) distribution particle size determinations are performed on the current powder at the de-agglomeration classification wheel rotation speed, and the particle size segment proportion of the current powder under multiple (5 times) distribution particle size determinations is obtained. Further, the mean value of the different particle size segment proportions under multiple distribution particle size determinations is calculated.

[0093] Then, the difference between each particle size segment proportion under each distribution particle size determination and the mean value of the corresponding particle size segment proportion is analyzed to obtain a third total difference value. Specifically, the absolute value of the difference between the particle size segment proportion of the current powder obtained by the first distribution particle size determination at the de-agglomeration classification wheel rotation speed and the mean value of the particle size segment proportion (particle size segment proportion mean value) is calculated, and the absolute values of the differences of different particle size segments are summed to obtain the third total difference value, denoted as

[0094] Finally, the third total difference value, the abnormality degree and the moving rate are combined to obtain the reduction degree of the classification wheel rotation speed when the current powder is subjected to distribution particle size determination as follows:

[0095]

[0096] In the formula, represents the reduction degree of the classification wheel rotation speed when the current powder is subjected to distribution particle size determination; represents the abnormality degree of the distribution particle size determination of the current powder; represents the moving rate of the current powder; represents the third total difference value obtained by the first distribution particle size determination at the de-agglomeration classification wheel rotation speed; ​​​​​​​​​The sum of the absolute values ​​of the differences between the proportion of each particle size segment and the mean of the corresponding proportion (the third total difference). This indicates the number of times the particle size distribution was measured at the deagglomeration and classification wheel speed; This represents the linear normalization function.

[0097] when The results of the test and When the size is larger, the current powder movement speed The larger the current powder at the deagglomeration and classification wheel speed. The degree of anomaly in the match between the moving speed and the distribution granularity of the detection. When the size is larger, the current powder The higher the movement speed in the classifying and sieving processor, the more obvious the artifacts become. At the same speed as the deagglomeration classifier wheel, the resulting powder... The less accurate the particle size distribution, the greater the reduction in the speed of the classifier wheel should be to obtain an accurate particle size distribution.

[0098] After obtaining the degree of reduction in the classifier speed during particle size distribution measurement of the current powder, the optimal classifier speed for particle size distribution measurement of the current powder is further determined. Specifically, based on the deagglomeration classifier speed and the degree of reduction, combined with a fixed step size, the optimal classifier speed for particle size distribution measurement of the current powder is determined as follows:

[0099]

[0100] In the formula, Indicates the current powder Optimize the classifying wheel speed when determining particle size distribution; Indicates the rotational speed of the depolymerization stager; This indicates the fixed step size when adjusting the speed of the graded wheel at different stages; Indicates the current powder The degree of reduction in the rotational speed of the classifying wheel during particle size distribution determination.

[0101] When the degree is reduced When the size is larger, the speed of the grading wheel is at Under the premise that, the reduction should be greater.

[0102] S400: Under optimized classifier rotation speed, the particle size distribution of the current powder is measured to obtain the actual particle size distribution of the current powder, thus completing the classification of the current powder.

[0103] By optimizing the classifier wheel speed, the particle size distribution of the current powder is measured to obtain the actual particle size distribution of the current powder, thus completing the classification of the current powder. In other words, the particle size distribution of the current powder obtained under this optimized classifier wheel speed is... distribution granularity of the current powder distribution granularity of the current powder

[0104] S500: Analyze the existing proportion of the problem powder in the existing classification problem powder group to obtain the adjusted classification wheel rotation speed of the classification problem powder group.

[0105] The actual situation of the mixed powder of different particle sizes may be different, for example, the powder density is different, the collision situation is different, etc. The corresponding classification wheel rotation speed in a single reference data may cause an actual classification error when separating the powder of different particle sizes, and further adjustment should be made according to the actual classification effect.

[0106] Based on the above analysis, in some embodiments of the present application, the adjusted classification wheel rotation speed of the classification problem powder group is obtained by analyzing the existing proportion of the problem powder in the existing classification problem powder group. Further, it includes:

[0107] Firstly, the existing classification problem powder group in the two groups of powder after the classification of the current powder is determined. The two groups of powder obtained after the classification of the current powder are the larger particle size group and the smaller particle size group; the existing classification problem powder group contains powder of non-corresponding particle size in the expected separation particle size, that is, the smaller particle size powder that does not belong to the classification wheel rotation speed range of the larger particle size group or the larger particle size powder that does not belong to the classification wheel rotation speed range of the smaller particle size group. It should be noted that the existing classification problem powder group in the two groups of powder after the classification of the current powder may be the smaller particle size group and the larger particle size group, may be the smaller particle size group or the larger particle size group, or may not exist the classification problem powder group.

[0108] Then, the first proportion of the problem powder particle size section in the classification problem powder particle size section in the classification problem powder group is obtained, and the second proportion of the non-problem powder particle size section in the powder particle size section before classification in the classification problem powder group is obtained. The problem powder particle size section is the powder particle size section of non-corresponding particle size in the expected separation particle size, that is, the powder particle size section of smaller particle size that does not belong to the classification wheel rotation speed range of the larger particle size group or the powder particle size section of larger particle size that does not belong to the classification wheel rotation speed range of the smaller particle size group.

[0109] When the first proportion is larger, the second proportion is larger, and the maximum powder particle size in the classification problem powder group is larger or the minimum powder particle size is smaller, the classification error powder is more, the rotation speed used in the classification is less suitable, and the adjustment should be larger. When the classification problem powder group is the smaller particle size group, the rotation speed should be increased for correct re-classification; when the classification problem powder group is the larger particle size group, the rotation speed should be decreased for correct re-classification.

[0110] Therefore, it is determined whether the classified problem powder group belongs to the smaller particle size group or the larger particle size group.

[0111] If it belongs to the smaller particle size group, the maximum powder particle size in the problem powder particle size section is obtained, combined with the first proportion and the second proportion, to obtain the first rotational speed adjustment degree of the classified problem powder group:

[0112]

[0113] In the formula, represents the first rotational speed adjustment degree of the classified problem powder group (belonging to the smaller particle size group); represents the first proportion of the problem powder particle size section in the classified problem powder particle size section in the classified problem powder group; represents the second proportion of the non-problem powder particle size section in the pre-classification powder particle size section in the classified problem powder group; represents the maximum powder particle size of the problem powder in the smaller particle size group; represents a linear normalization function.

[0114] If it belongs to the larger particle size group, the minimum powder particle size of the problem powder is obtained, combined with the first proportion and the second proportion, to obtain the second rotational speed adjustment degree of the classified problem powder group:

[0115]

[0116] In the formula, represents the second rotational speed adjustment degree of the classified problem powder group (belonging to the larger particle size group); represents the first proportion of the problem powder particle size section in the classified problem powder particle size section in the classified problem powder group; represents the second proportion of the non-problem powder particle size section in the pre-classification powder particle size section in the classified problem powder group; represents the minimum powder particle size of the problem powder in the larger particle size group; represents a linear normalization function.

[0117] And different classified wheel rotational speeds are set, the separation of powders of different particle sizes under different classified wheel rotational speeds is observed, and the powder separation particle size section corresponding to different classified wheel rotational speeds is obtained as reference data; further, based on the reference data, the first classified wheel rotational speed corresponding to the separation of the problem powder particle size section is obtained, and the second classified wheel rotational speed corresponding to the adjacent particle size section of the problem powder particle size section of the classified problem powder group is calculated. The absolute value of the difference between the first classified wheel rotational speed and the second classified wheel rotational speed.

[0118] According to the first rotational speed adjustment degree or the second rotational speed adjustment degree, combined with the first classified wheel rotational speed and the second classified wheel rotational speed, the adjusted classified wheel rotational speed of the classified problem powder group is obtained. Wherein:

[0119] When the classification problem powder group belongs to the smaller particle size group:

[0120]

[0121] In the formula, represents the adjusted classification wheel rotation speed of the classification problem powder group (belongs to the smaller particle size group); represents the first classification wheel rotation speed corresponding to the separation of the problem powder particle size section; represents the absolute value of the difference between the first classification wheel rotation speed corresponding to the separation of the problem powder particle size section and the second classification wheel rotation speed corresponding to the adjacent particle size section of the classification problem powder group; represents the first rotation speed adjustment degree of the classification problem powder group (belongs to the smaller particle size group).

[0122] When the classification problem powder group belongs to the larger particle size group:

[0123]

[0124] In the formula, represents the adjusted classification wheel rotation speed of the classification problem powder group (belongs to the larger particle size group); represents the first classification wheel rotation speed corresponding to the separation of the problem powder particle size section; represents the absolute value of the difference between the first classification wheel rotation speed corresponding to the separation of the problem powder particle size section and the second classification wheel rotation speed corresponding to the adjacent particle size section of the classification problem powder group; represents the second rotation speed adjustment degree of the classification problem powder group (belongs to the larger particle size group).

[0125] Finally, the proportion of different particle size powders in the mixed powder is visualized. Specifically, the proportion of different particle size section powders in the mixed particle size powder is accurately obtained by the above method. The obtained particle size section and the existing proportion are stored in the database.

[0126] The proportion of different particle size section powders is visualized by using the SQL query statement, and the display form is shown in Table 1.

[0127] Table 1 Proportion of different particle size section powders

[0128]

[0129] Based on the same inventive concept as the above method, the embodiment also provides a laser measuring device for distribution particle size of alloy powder.

[0130] A kind of alloy powder distribution particle size laser measuring device includes: hierarchical screening processor, laser emitter, Fourier lens, annular photodetector array, laser speedometer and central processing system, wherein:

[0131] Hierarchical screening processor includes hierarchical wheel, for adjusting rotational speed and realizing the classification of powder when distribution particle size is measured;

[0132] Laser emitter, Fourier lens and annular photodetector array are used to generate parallel laser beam and capture scattered light signal, realize particle size measurement;

[0133] Laser speedometer is used to measure the moving rate of powder.

[0134] Please refer to Figure 2 , it shows the basic composition of a kind of central processing system provided by one embodiment of the present application.

[0135] As shown in Figure 2 , central processing system includes: memory 10 and processor 20, wherein:

[0136] Memory 10 is used to store program code;

[0137] Processor 20 is used to read the program code stored in memory 10, and execute to increase the rotational speed of hierarchical wheel with fixed step length, carry out multiple distribution particle size measurement on current powder, analyze the overall distribution change of particle size fraction proportion obtained by multiple measurement, determine the disaggregation hierarchical wheel rotational speed when current powder is completely disaggregated;Under the disaggregation hierarchical wheel rotational speed, the matching degree of moving rate, density and particle size fraction proportion between current powder and reference sample powder is analyzed, and the abnormal degree of current powder distribution particle size measurement is obtained;Under the disaggregation hierarchical wheel rotational speed, multiple distribution particle size measurement is carried out on current powder, the distribution deviation degree of particle size fraction proportion obtained by multiple measurement is analyzed, the reduction degree of hierarchical wheel rotational speed when current powder is measured for distribution particle size is obtained in combination with abnormal degree and moving rate, and the optimization hierarchical wheel rotational speed when current powder is measured for distribution particle size is determined;Under the optimization hierarchical wheel rotational speed, the distribution particle size of current powder is measured, and the actual distribution particle size of current powder is obtained, and the classification of current powder is completed.

[0138] Further, processor 20 includes: disaggregation module 21, abnormal analysis module 22, rotational speed optimization module 23 and distribution particle size measurement module 24, wherein:

[0139] Disaggregation module 21 is used to increase the rotational speed of hierarchical wheel with fixed step length, carry out multiple distribution particle size measurement on current powder, analyze the overall distribution change of particle size fraction proportion obtained by multiple measurement, and determine the disaggregation hierarchical wheel rotational speed when current powder is completely disaggregated;

[0140] The abnormality analysis module 22 is configured to analyze the matching degree of the moving rate, the density and the proportion of the particle size section between the current powder and the reference sample powder at the disaggregation classification wheel rotating speed, to obtain the abnormality degree of the current powder distribution particle size measurement;

[0141] The rotating speed optimization module 23 is configured to perform multiple distribution particle size measurements on the current powder at the disaggregation classification wheel rotating speed, analyze the distribution deviation degree of the proportion of the particle size section obtained by the multiple measurements, and combine the abnormality degree and the moving rate to obtain the reduction degree of the classification wheel rotating speed when the current powder is measured for the distribution particle size, and determine the optimized classification wheel rotating speed when the current powder is measured for the distribution particle size.

[0142] The distribution particle size measurement module 24 is configured to perform the distribution particle size measurement on the current powder at the optimized classification wheel rotating speed, to obtain the actual distribution particle size of the current powder, and complete the classification of the current powder.

[0143] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description, and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0144] Each of the embodiments in the specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other. Each embodiment mainly describes the difference from other embodiments.

Claims

1. A method for laser measurement of the particle size distribution of an alloy powder, characterized in that The method comprises: successively increasing the classification wheel rotation speed at a fixed step, performing multiple distribution particle size measurements on the current powder, analyzing the overall distribution change of the particle size segment proportion obtained by the multiple measurements, and determining the depolymerization classification wheel rotation speed when the current powder is completely depolymerized; under the depolymerization classification wheel rotation speed, analyzing the matching degree of the moving speed, density and particle size segment proportion between the current powder and the reference sample powder to obtain the abnormality degree of the current powder distribution particle size measurement; under the depolymerization classification wheel rotation speed, performing multiple distribution particle size measurements on the current powder, analyzing the distribution deviation degree of the particle size segment proportion obtained by the multiple measurements, combining the abnormality degree and the moving speed, obtaining the reduction degree of the classification wheel rotation speed when the current powder performs the distribution particle size measurement, and determining the optimized classification wheel rotation speed when the current powder performs the distribution particle size measurement; under the optimized classification wheel rotation speed, performing the distribution particle size measurement on the current powder to obtain the actual distribution particle size of the current powder, and completing the classification of the current powder.

2. The method of claim 1, wherein the alloy powder is a powder of an alloy of iron and chromium. After completing the classification of the current powder, the method further comprises: analyzing the existing proportion of the problem powder in the existing classification problem powder group to obtain the adjustment classification wheel rotation speed of the classification problem powder group.

3. The method of claim 2, wherein the alloy powder is a powder of an alloy of iron and chromium. analyzing the existing proportion of the problem powder in the existing classification problem powder group to obtain the adjustment classification wheel rotation speed of the classification problem powder group, comprising: determining the existing classification problem powder group in the two groups of powders after the classification of the current powder; obtaining the first proportion of the problem powder particle size segment in the classification problem powder particle size segment and the second proportion of the non-problem powder particle size segment in the powder particle size segment before the classification in the classification problem powder group; determining whether the classification problem powder group belongs to the smaller particle size group or the larger particle size group; if it belongs to the smaller particle size group, obtaining the maximum powder particle size in the problem powder particle size segment, combining the first proportion and the second proportion to obtain the first rotation speed adjustment degree of the classification problem powder group; if it belongs to the larger particle size group, obtaining the minimum powder particle size in the problem powder particle size segment, combining the first proportion and the second proportion to obtain the second rotation speed adjustment degree of the classification problem powder group; setting different classification wheel rotation speeds to obtain the powder separation particle size segment corresponding to different classification wheel rotation speeds as reference data; based on the reference data, obtaining the first classification wheel rotation speed corresponding to the separation of the problem powder particle size segment, and the second classification wheel rotation speed corresponding to the adjacent particle size segment of the classification problem powder group to which the problem powder particle size segment deviates; according to the first rotation speed adjustment degree or the second rotation speed adjustment degree, combining the first classification wheel rotation speed and the second classification wheel rotation speed to obtain the adjustment classification wheel rotation speed of the classification problem powder group.

4. The method of claim 1, wherein the alloy powder is a powder of an alloy of iron, chromium, and at least one of aluminum, silicon, and titanium. successively increasing the classification wheel rotation speed at a fixed step, performing multiple distribution particle size measurements on the current powder, obtaining the particle size segment proportion of the current powder under different classification wheel rotation speeds, and determining the depolymerization classification wheel rotation speed when the current powder is completely depolymerized, comprising: successively increasing the classification wheel rotation speed at a fixed step, performing multiple distribution particle size measurements on the current powder, obtaining the particle size segment proportion of the current powder under different classification wheel rotation speeds, and determining the depolymerization classification wheel rotation speed when the current powder is completely depolymerized, comprising: successively increasing the classification wheel rotation speed at a fixed step, performing multiple distribution particle size measurements on the current powder, obtaining the particle size segment proportion of the current powder under different classification wheel rotation speeds, and determining the depolymerization classification wheel rotation speed when the current powder is completely depolymerized, comprising: Calculate the difference value of the proportion of each particle size segment corresponding to the adjacent classification wheel speed, and obtain the first total difference value; Sort the first total difference value in the order of its corresponding classification wheel speed from small to large, calculate the second difference value between adjacent first total difference values in the sorting, and calculate the ratio of the number of second difference values less than 0 to the total number of second difference values; According to the ratio, combined with the first total difference value, the degree of deagglomeration of the current powder under the classification wheel speed of each adjustment is obtained; A deagglomeration degree threshold is preset, and the deagglomeration classification wheel speed of the current powder when the deagglomeration is complete is determined according to the deagglomeration degree.

5. The method of claim 1, wherein the alloy powder is a powder of an alloy of iron, chromium, and at least one of aluminum, silicon, and titanium. Under the deagglomeration classification wheel speed, the matching degree of the moving speed, density and particle size segment proportion between the current powder and the reference sample powder is analyzed to obtain the abnormality degree of the current powder distribution particle size measurement, including: Under the deagglomeration classification wheel speed, the moving speed and the particle size segment proportion of the current powder and different reference sample powders are obtained; The difference in moving speed and the difference in density between the current powder and different reference sample powders are analyzed to obtain the reference value of different reference sample powders to the current powder; The maximum reference value corresponding to different reference samples is obtained, and the reference sample corresponding to the maximum reference value is the effective reference sample; The absolute value of the difference between the effective reference sample and the current powder in all corresponding particle size segments is calculated to obtain the second total difference value; Combined with the maximum reference value and the second total difference value, the abnormality degree of the current powder distribution particle size measurement is obtained.

6. The method of claim 1, wherein, Multiple distribution particle size measurements are performed on the current powder under the deagglomeration classification wheel speed, and the distribution deviation degree of the particle size segment proportion obtained by multiple measurements is analyzed, combined with the abnormality degree and the moving speed, to obtain the reduction degree of the classification wheel speed when the current powder is measured for distribution particle size, including: Multiple distribution particle size measurements are performed on the current powder under the deagglomeration classification wheel speed to obtain the particle size segment proportion of the current powder under multiple distribution particle size measurements; The mean value of different particle size segment proportions under multiple distribution particle size measurements is calculated; The difference between each particle size segment proportion under each distribution particle size measurement and the mean value of the corresponding particle size segment proportion is analyzed to obtain the third total difference value; Combined with the third total difference value, the abnormality degree and the moving speed, the reduction degree of the classification wheel speed when the current powder is measured for distribution particle size is obtained.

7. The method according to claim 6, wherein Determine the optimized classification wheel speed when the current powder is measured for distribution particle size, including: According to the deagglomeration classification wheel speed and the reduction degree, combined with the fixed step length, the optimized classification wheel speed when the current powder is measured for distribution particle size is determined.

8. An apparatus for laser measurement of the particle size distribution of an alloy powder, characterized in that The device includes a classification screening processor, a laser emitter, a Fourier lens, a ring-shaped photodetector array, a laser speedometer and a central processing system, wherein: The classification screening processor includes a classification wheel for adjusting the rotation speed during distribution particle size measurement and realizing the classification of the powder; The laser emitter, the Fourier lens and the ring-shaped photodetector array are used to generate parallel laser beams and capture scattered light signals to realize particle size measurement; The laser speedometer is used to measure the moving speed of the powder; The central processing system includes a memory and a processor, wherein: The memory is used to store program code; The processor is configured to read program codes stored in the memory and perform the method according to any one of claims 1 to 7.

9. The apparatus according to claim 8, wherein The processor comprises: a disaggregation module configured to gradually increase the classification wheel rotation speed in a fixed step, perform multiple distribution particle size determinations on the current powder, analyze overall distribution changes of the particle size segment proportions obtained through the multiple determinations, and determine the disaggregation classification wheel rotation speed at which the current powder is completely disaggregated; an anomaly analysis module configured to analyze matching degrees of the moving speed, the density, and the particle size segment proportion between the current powder and the reference sample powder at the disaggregation classification wheel rotation speed, and obtain an anomaly degree of the distribution particle size determination of the current powder; a rotation speed optimization module configured to perform multiple distribution particle size determinations on the current powder at the disaggregation classification wheel rotation speed, analyze distribution deviation degrees of the particle size segment proportions obtained through the multiple determinations, combine the anomaly degree and the moving speed, obtain a reduction degree of the classification wheel rotation speed when the distribution particle size determination is performed on the current powder, and determine an optimized classification wheel rotation speed at which the distribution particle size determination is performed on the current powder; a distribution particle size determination module configured to perform the distribution particle size determination on the current powder at the optimized classification wheel rotation speed, obtain an actual distribution particle size of the current powder, and complete the classification of the current powder.

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