Laser measuring device and method for distribution particle size of alloy powder

Abstract

The invention relates to the technical field of particle size distribution detection, in particular to a laser measuring device and method for alloy powder distribution particle size. Analyzing the matching degree of the movement rate, density and particle size section ratio between the current powder and the reference sample powder to obtain the abnormal degree of the distribution particle size measurement of the current powder, then carrying out multiple distribution particle size measurement on the current powder at the rotating speed of a depolymerization grading wheel, and analyzing the distribution deviation degree of the particle size section ratio obtained by multiple measurement to obtain the distribution particle size of the current powder. And in combination with the abnormal degree and the moving speed, determining the rotating speed of the optimized grading wheel when the current powder is subjected to distribution particle size measurement, and finally finishing grading of the current powder. According to the invention, the most suitable rotating speed for measuring the distribution particle size of the powder is obtained, the accuracy of measuring the distribution particle size of the powder is improved, and a reliable data basis is provided for subsequent powder grading.

Description

Technical Field

[0001] The present invention relates to the technical field of particle size distribution detection, and in particular to a laser measuring device and method for alloy powder particle size distribution. Background Art

[0002] Accurately obtaining particle size distribution during alloy powder grading is crucial, as it directly determines the powder's grading effectiveness and application performance. Precise particle size information is a key control parameter in the grading process, directly affecting the powder's flowability, packing density, sintering behavior, and the mechanical properties, density, and surface quality of the final product. Lack of accurate particle size distribution data can lead to inefficient grading, unstable product batches, and the inability to meet the stringent powder specifications required for specific applications (such as additive manufacturing, injection molding, and coating). It can even result in material waste and product failure.

[0003] Micron particles and ultrafine particles are the main forms of alloy powder materials. Combined with the material properties such as 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 industry generally uses laser methods to measure the particle size distribution of alloy powders. However, this method can suffer from low accuracy and efficiency due to particle agglomeration or poor dispersion. Existing techniques primarily remove the agglomeration effect by gradually adjusting the rotational speed of the classifying wheel to obtain the actual distributed particle size, but this is not always accurate. Summary of the Invention

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

[0006] According to a first aspect of an embodiment of the present invention, a laser measurement method for alloy powder particle size distribution is provided, and the technical solution adopted is as follows: The classifying wheel speed is increased gradually with a fixed step size, and the current powder distribution particle size is measured multiple times. The overall distribution change of the particle size fraction obtained from the multiple measurements is analyzed to determine the deagglomeration classifying wheel speed when the current powder is completely deagglomerated. At the rotation speed of the deagglomeration and classification wheel, the degree of matching between the movement rate, density and particle size fraction of the current powder and the reference sample powder is analyzed to obtain the degree of abnormality of the current powder distribution particle size measurement; performing multiple distribution particle size measurements on the current powder at the deagglomeration classifying wheel speed, analyzing the distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combining the abnormality degree and the movement rate to obtain the degree of reduction in the classification wheel speed when the distribution particle size measurement of the current powder is performed, thereby determining the optimized classification wheel speed when the distribution particle size measurement of the current powder is performed; At the optimized classification wheel rotation speed, the distribution particle size of the current powder is measured to obtain the actual distribution particle size of the current powder, thereby completing the classification of the current powder.

[0007] In some embodiments of the present invention, after completing the classification of the current powder, the method further includes: The proportion of problematic powder in the powder group with classification problems is analyzed to obtain the adjusted classification wheel speed of the powder group with classification problems.

[0008] In some embodiments of the present invention, analyzing the proportion of problematic powder in a powder group with classification problems to obtain an adjusted classification wheel speed for the powder group with classification problems includes: Determine the powder group with classification problems in the two powder groups after the current powder classification; Obtaining a first proportion of the problem powder particle size segment in the classified problem powder group to the problem powder particle size segment, and obtaining a second proportion of the non-problem powder particle size segment in the classified problem powder group to the powder particle size segment before classification; Determine whether the powder group in question belongs to the smaller particle size group or the larger particle size group; If the problem powder group belongs to a smaller particle size group, the maximum powder particle size in the problem powder particle size segment is obtained, and the first rotation speed adjustment degree of the classified problem powder group is obtained by combining the first proportion and the second proportion; If the powder belongs to the larger particle size group, the minimum powder particle size in the problem powder particle size segment is obtained, and the second rotation speed adjustment degree of the classified problem powder group is obtained by combining the first proportion and the second proportion; Set different classifying wheel speeds to obtain the powder separation particle size segments corresponding to different classifying wheel speeds as reference data; Based on the reference data, a first classifying wheel rotation speed corresponding to separation of the problem powder particle size segment and a second classifying wheel rotation speed corresponding to the particle size segment of the problem powder particle size segment adjacent to the classified problem powder group are obtained; According to the first speed adjustment degree or the second speed adjustment degree, combined with the first classifying wheel speed and the second classifying wheel speed, an adjusted classifying wheel speed for classifying the problem powder group is obtained.

[0009] In some embodiments of the present invention, the speed of the classifying wheel is increased in fixed steps to perform multiple distribution particle size measurements on the current powder, and the overall distribution changes of the particle size fractions obtained from the multiple measurements are analyzed to determine the speed of the deagglomeration classifying wheel when the current powder is completely deagglomerated, including: The particle size distribution of the current powder is measured multiple times by gradually increasing the classifying wheel speed with a fixed step size to obtain the particle size fraction of the current powder at different classifying wheel speeds; Calculate the difference in the proportion of particle size segments corresponding to all adjacent classifying wheel speeds to obtain a first total difference; sorting the first total differences in ascending order of their corresponding grading wheel speeds, calculating the quadratic differences between adjacent first total differences in the sorting, and calculating the ratio of the number of quadratic differences less than 0 to the total number of quadratic differences; According to the ratio and in combination with the first total difference, the degree of deagglomeration of the current powder under each adjusted classification wheel speed is obtained; A deagglomeration degree threshold is preset, and according to the deagglomeration degree, a rotation speed of the deagglomeration classifying wheel when the current powder is completely deagglomerated is determined.

[0010] In some embodiments of the present invention, the degree of matching between the movement rate, density, and particle size fraction ratio of the current powder and the reference sample powder is analyzed at the rotation speed of the deagglomeration and classification wheel to obtain the abnormality of the current powder distribution particle size measurement, including: Under the rotation speed of the deagglomeration and classification wheel, the movement rate and particle size fraction ratio of the current powder and different reference sample powders are obtained; Analyze the difference in movement rate and density between the current powder and different reference sample powders to obtain the reference value of different reference sample powders to the current powder; Obtain the maximum reference value corresponding to different reference samples, and the reference sample corresponding to the maximum reference value is the valid reference sample; Calculating the absolute value of the difference between the effective reference sample and the current powder in all corresponding particle size range proportions to obtain a second total difference; The maximum reference value and the second total difference are combined to obtain the abnormality level of the current powder distribution particle size measurement.

[0011] In some embodiments of the present invention, multiple distribution particle size measurements are performed on the current powder at the rotation speed of the deagglomeration and classification wheel, and the distribution deviation degree of the particle size segment proportions obtained by the multiple measurements is analyzed. In combination with the abnormality degree and the movement rate, the degree of reduction of the classification wheel rotation speed when the current powder is subjected to the distribution particle size measurement is obtained, including: Performing multiple distribution particle size measurements on the current powder at the rotation speed of the deagglomeration and classification wheel to obtain the particle size segment ratios of the current powder under the multiple distribution particle size measurements; Calculate the mean of the proportion of different particle size segments under multiple distribution particle size measurements; Analyze the difference between the proportion of each particle size segment under each distribution particle size measurement and the mean of the proportion of the corresponding particle size segment to obtain a third total difference; The degree of reduction in the rotation speed of the classifying wheel when the current powder distribution particle size measurement is performed is obtained by combining the third total difference, the abnormality degree, and the movement rate.

[0012] In some embodiments of the present invention, determining the optimal classification wheel rotation speed when performing distribution particle size measurement on the current powder includes: The optimized classifying wheel speed for measuring the distribution particle size of the current powder is determined according to the deagglomeration classifying wheel speed and the reduction degree in combination with the fixed step size.

[0013] According to a second aspect of an embodiment of the present invention, a laser measuring device for measuring the particle size distribution of alloy powder is provided, comprising: a grading and screening processor, a laser emitter, a Fourier lens, an annular photodetector array, a laser velocimeter, and a central processing system, wherein: The grading and screening processor includes a grading wheel for adjusting the rotation speed and achieving powder classification during distribution particle size measurement; The laser emitter, the Fourier lens and the annular photodetector array are used to generate a parallel laser beam and capture scattered light signals to achieve particle size measurement; Laser velocimeter, used to measure the movement rate of powder.

[0014] In some embodiments of the present invention, 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 the program code stored in the memory and execute any one of the above methods.

[0015] In some embodiments of the present invention, the processor includes: The deagglomeration module is used to gradually increase the classifying wheel speed with a fixed step size, perform multiple distribution particle size measurements on the current powder, analyze the overall distribution changes of the particle size segment proportions obtained from multiple measurements, and determine the deagglomeration classifying wheel speed when the current powder is completely deagglomerated; An abnormality analysis module is used to analyze the matching degree of the movement rate, density and particle size segment ratio between the current powder and the reference sample powder at the rotation speed of the deagglomeration and classification wheel, and obtain the abnormality degree of the current powder distribution particle size measurement; a speed optimization module for performing multiple distribution particle size measurements on the current powder at the speed of the deagglomeration classifying wheel, analyzing the degree of distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combining the degree of abnormality and the movement rate to obtain the degree of reduction in the classification wheel speed when the distribution particle size measurement of the current powder is performed, thereby determining the optimized classification wheel speed when the distribution particle size measurement of the current powder is performed; The distribution particle size measurement module is used to measure the distribution particle size of the current powder at the optimized classification wheel speed, obtain the actual distribution particle size of the current powder, and complete the classification of the current powder.

[0016] Compared with the prior art, the laser measurement device and method for alloy powder distribution particle size provided by the present invention have the following beneficial effects: The present invention increases the grading wheel speed in fixed steps, performs multiple distribution particle size measurements on the current powder, analyzes the overall distribution particle size changes of the powder, judges the agglomeration and disaggregation of the current powder, and determines the deagglomeration grading wheel speed when the current powder is completely deagglomerated; further, under the deagglomeration grading wheel speed, analyzes the matching degree of the movement rate, density and particle size segment ratio between the current powder and the reference sample powder, judges the detection accuracy of the powder particle size, judges the presence or absence of the ghost problem, and obtains the abnormality degree of the current powder distribution particle size measurement; adjusts the grading wheel speed suitable for detection according to the matching degree and the distribution particle size difference during different laser detections, and adjusts the grading wheel speed to the most suitable speed for measuring the powder distribution particle size. The present invention obtains the most suitable speed for measuring the powder distribution particle size, thereby improving the accuracy of the powder distribution particle size measurement and providing a reliable data basis for subsequent powder classification. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of the basic flow of a laser measurement method for alloy powder distribution particle size provided by one embodiment of the present invention; Figure 2 The present invention provides a basic structure of a central processing system. DETAILED DESCRIPTION

[0019] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effectiveness of a laser device and method for measuring alloy powder particle size distribution according to the present invention. In the following description, references to different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. Terms such as "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a circuit structure, article, or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such article or device. In the absence of further limitations, the phrase "comprising a ..." to define an element does not preclude the presence of other identical elements in the article or device comprising the element.

[0021] The specific scheme of the laser measurement method for the distribution particle size of alloy powder provided by the present invention is described in detail below with reference to the accompanying drawings.

[0022] See also Figure 1 , which shows the basic process of a laser measurement method for alloy powder distribution particle size provided by an embodiment of the present invention.

[0023] like Figure 1 As shown, an embodiment of the present invention provides a laser measurement method for alloy powder distribution particle size, specifically comprising: S100: gradually increasing the classifying wheel speed with a fixed step size, performing multiple distribution particle size measurements on the current powder, analyzing the overall distribution changes of the particle size segment proportions obtained from the multiple measurements, and determining the deagglomeration classifying wheel speed when the current powder is completely deagglomerated.

[0024] To measure the distributed particle size, the basic measurement equipment is first arranged: a laser emitter (632.8nm helium-neon laser or 473nm semiconductor laser), a Fourier lens system, and a ring photodetector array (such as the detector of the Mastersizer 3000) are set next to the outlet pipe of the grading and screening processor (including the grading wheel) to generate a parallel laser beam and capture the scattered light signal of 0.01°–170°.

[0025] The data obtained from the test is transmitted to the central processing unit, and the proportion of different powder particle sizes is obtained through the integrated inversion algorithm (non-negative least squares method) and the morphology compensation module (which can be linked to the Camsizer X2 dynamic imager).

[0026] Alloy powders are prone to agglomeration. Small-particle powders can form larger agglomerates after agglomeration, which can affect the laser's ability to interpret their size and influence the choice of classifier wheel speed during powder classification. By gradually increasing the classifier wheel speed, the collisions between different powders can be enhanced, thus disaggregating the agglomerates.

[0027] Based on the above analysis, in an embodiment of the present invention, the rotation speed of the classifying wheel is increased in fixed steps, the current powder is subjected to multiple distribution particle size measurements, and the overall distribution changes of the particle size fractions obtained from the multiple measurements are analyzed to determine the rotation speed of the deagglomeration classifying wheel when the current powder is completely deagglomerated. Further, the method includes: First, the initial classifying wheel speed is set. Based on the initial classifying wheel speed, the classifying wheel speed is gradually increased with a fixed step size. The current powder distribution particle size is measured multiple times to obtain the particle size segment ratio of the current powder at different classifying wheel speeds. It should be noted that the particle size segment ratio corresponding to each classifying wheel speed is the average of multiple tests.

[0028] Then, the difference between the proportions of the corresponding particle size segments at two adjacent grading wheel speeds is calculated. Specifically, the value of the proportion of the particle size segment at the current grading wheel speed minus the proportion of the corresponding particle size segment at the previously adjusted grading wheel speed is calculated, and all adjacent grading wheel speeds are traversed and added to obtain the first total difference corresponding to the current grading wheel speed.

[0029] Then, take the When the speed is adjusted (the corresponding classifying wheel speed is ), forward 5 speed adjustments are calculated to obtain multiple first total differences, and the first total differences are sorted in ascending order of their corresponding grading wheel speeds, that is, the multiple first total differences are sorted in ascending order of the grading wheel speeds corresponding to the multiple first total differences, and the secondary differences between adjacent first total differences in the sorting are calculated. Specifically, the current first total difference is calculated minus the value of the previous first total difference in the sorting, and the number of secondary differences less than 0 is counted, and the ratio of the number of secondary differences less than 0 to the total number of secondary differences is calculated, which is recorded as ( Indicates the current speed adjustment times).

[0030] Classifying wheel speed When the ratio The larger the The smaller the first total difference corresponding to each speed adjustment, the smaller the change in the alloy powder distribution particle size under the change of the classifying wheel speed, the smaller the change in the proportion of different particle sizes, and the more all agglomerates are disaggregated. Therefore, based on the ratio and the first total difference, the disaggregation degree of the current powder under each adjustment of the classifying wheel speed is obtained: Where, Indicates that the current powder is in When the speed is adjusted (the corresponding classifying wheel speed is )’s degree of disaggregation; It represents the ratio of the number of quadratic differences less than 0 to the total number of quadratic differences; Indicates the a first total difference corresponding to the secondary speed adjustment; represents the linear normalization function; This is to prevent the denominator from being 0.

[0031] Finally, the deagglomeration degree threshold is preset, which can be set to 0.8. According to the deagglomeration degree, the deagglomeration classification wheel speed is determined when the current powder is completely deagglomerated. When the current powder is completely deagglomerated, the deagglomeration classifying wheel speed is The minimum classifying wheel speed corresponding to .

[0032] S200: Under the rotation speed of the deagglomeration and classification wheel, the matching degree of the movement rate, density and particle size segment ratio between the current powder and the reference sample powder is analyzed to obtain the abnormality degree of the current powder distribution particle size measurement.

[0033] When the classifying wheel speed is high, the alloy powder may rotate too fast, generating artifacts, causing the laser to misidentify the actual particle size of the alloy powder, and the particle size of some alloy powders may be larger than the actual powder particle size. Because the increase in the classifying wheel speed in step S100 is changed in a fixed step size, the classifying wheel speed obtained when completely deagglomerated may be high, resulting in an inaccurate representation of the actual powder distribution particle size. Therefore, the classifying wheel speed should be appropriately adjusted.

[0034] Based on the above analysis, in an embodiment of the present invention, the degree of abnormality in the particle size distribution of the current powder is determined by analyzing the matching degree of the movement rate, density, and particle size fraction between the current powder and the reference sample powder at the deagglomeration and classification wheel speed. Further including: First, powders with different distribution particle sizes are selected as reference sample powders. At the rotation speed of the deaggregation and grading wheel, the movement rate and particle size segment ratio of the current powder and different reference sample powders are obtained. Specifically, a laser velocimeter is installed in the grading and screening processor to detect the movement rate of the current powder and different reference sample powders respectively, and the average of all detection rates corresponding to each powder is obtained as the overall movement rate of each powder at the rotation speed of the deaggregation and grading wheel, and the movement rate of the current powder and different reference sample powders is obtained. At the same time, at the rotation speed of the deaggregation and grading wheel, the particle size segment ratio of the current powder and different reference sample powders is obtained. In addition, the density of the current powder and the different reference sample powders is also obtained.

[0035] Then, since the movement rate of the powder in the grading and screening processor is related to the density of the powder, the movement rate difference and density difference between the current powder and different reference sample powders are analyzed at the deagglomeration and grading wheel speed. That is, the absolute value of the movement rate difference and the absolute value of the density difference between the current powder and different reference sample powders are calculated, and the reference value of different reference sample powders to the current powder is obtained as follows: Where, Indicates reference sample powder For current powder Reference value; Indicates the current powder With reference sample powder The difference in movement speed; Indicates the current powder With reference sample powder The density difference.

[0036] 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 For current powder The higher the distribution particle size, the more valuable it is for reference.

[0037] Then, we obtain the maximum reference value corresponding to different reference samples, which is recorded as , the reference sample corresponding to the maximum reference value is the valid reference sample, recorded as ; Calculate the absolute value of the difference between the effective reference sample and the current powder in all corresponding particle size segments, traverse all particle size segment ratios, and obtain the second total difference, which is recorded as .

[0038] Finally, combining the maximum reference value and the second total difference, the abnormality degree of the current powder distribution particle size measurement is obtained: Where, Indicates the current powder The degree of abnormality in the distribution particle size measurement; Indicates reference sample powder For current powder The maximum reference value; Indicates a valid reference sample With current powder The sum of the absolute values ​​of the differences in the proportions of all corresponding particle size segments (the second total difference).

[0039] When the maximum reference value The larger the effective reference sample powder, the greater the reference value With current powder The sum of the absolute values ​​of the differences in the proportions of different particle size segments (the second total difference) The larger the current powder The more the movement rate and the obtained powder distribution particle size do not conform to the actual situation, the more likely it is that artifacts will be generated due to excessive movement speed, and there will be problems in the detection of powder distribution particle size.

[0040] S300: Perform multiple distribution particle size measurements on the current powder at the deagglomeration classifying wheel speed, analyze the distribution deviation degree of the particle size segment proportions obtained by the multiple measurements, combine the abnormality degree and the movement rate, obtain the degree of reduction of the classifying wheel speed when the distribution particle size measurement of the current powder is performed, and determine the optimized classifying wheel speed when the distribution particle size measurement of the current powder is performed.

[0041] To ensure that the classifying wheel speed is appropriate, the powder distribution particle size detection is more accurate, and to prevent the classifying wheel speed from being reduced too much, causing some powder to re-agglomerate, the current classifying wheel speed (deagglomeration classifying wheel speed) should be appropriately reduced. In addition to the degree of mismatch between the powder movement speed and the detected distribution particle size, the current overall powder movement speed and the changes in distribution particle size during multiple tests can also be used as reference for judgment.

[0042] Based on the above analysis, in an embodiment of the present invention, by performing multiple distribution particle size measurements on the current powder at the deagglomeration classifying wheel speed, analyzing the distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combining the abnormality degree and the movement rate, the degree of reduction in the classifying wheel speed when the current powder is subjected to distribution particle size measurement is obtained, and the optimized classifying wheel speed when the current powder is subjected to distribution particle size measurement is determined. Further including: First, perform multiple (5) particle size distribution measurements on the current powder at the same speed as the deagglomeration and classification wheel to obtain the particle size fractions of the current powder obtained from these multiple (5) particle size distribution measurements. Then, calculate the average of the particle size fractions obtained from these multiple particle size distribution measurements.

[0043] Then, the difference between the proportion of each particle size segment under each distribution particle size measurement and the mean of the proportion of the corresponding particle size segment is analyzed to obtain the third total difference. Sub-distribution particle size determination of the current powder In the particle size range The upper proportion and the corresponding proportion average (particle size segment The absolute value of the difference between the two groups (the average of the upper proportion) and the absolute value of the difference between the two groups of different particle size segments are summed to obtain the third total difference, which is recorded as .

[0044] Finally, combining the third total difference, the degree of abnormality, and the moving rate, the degree of reduction in the classification wheel speed when the current powder is subjected to distribution particle size measurement is obtained as follows: Where, Indicates the current powder The degree of reduction in the classifying wheel speed when measuring the distribution particle size; Indicates the current powder The degree of abnormality in the distribution particle size measurement; Indicates the current powder Movement rate; Indicates the depolymerization and classification wheel speed Sub-distribution particle size determination of the current powder The sum of the absolute values ​​of the differences between the proportions in all particle size segments and the corresponding mean proportions (the third total difference); Indicates the number of times the distribution particle size is measured at the rotation speed of the deagglomeration and classification wheel; represents the linear normalization function.

[0045] when The results of the test of The larger the current powder Movement speed The larger the deagglomeration and classification wheel speed, the current powder The degree of abnormality in matching the moving speed with the distribution granularity of the detection The larger the current powder The greater the moving speed in the grading and screening processor, the more obvious the artifacts are. When the deagglomeration and grading wheel speed is The less accurate the distribution particle size is, the greater the reduction in the classifying wheel speed should be to obtain an accurate distribution particle size.

[0046] After obtaining the degree of reduction of the classifying wheel speed when the current powder is subjected to the distribution particle size measurement, the optimized classifying wheel speed when the current powder is subjected to the distribution particle size measurement is further determined. Specifically, based on the deagglomeration classifying wheel speed and the degree of reduction, combined with the fixed step size, the optimized classifying wheel speed when the current powder is subjected to the distribution particle size measurement is determined as: Where, Indicates the current powder Optimized classifier wheel speed for distribution particle size determination; Indicates the speed of the depolymerization and classification wheel; Indicates the fixed step size when adjusting the speed of different sub-grading wheels; Indicates the current powder The degree of reduction in the classifying wheel speed when measuring the distribution particle size.

[0047] When the degree of reduction The larger the value, the faster the classifying wheel speed. Under the premise of , the greater the reduction should be.

[0048] S400: Under the optimized classification wheel rotation speed, the distribution particle size of the current powder is measured to obtain the actual distribution particle size of the current powder, and the classification of the current powder is completed.

[0049] Under the optimized classification wheel speed, the current powder distribution particle size is measured to obtain the actual distribution particle size of the current powder and complete the classification of the current powder. The distribution particle size, as the current powder The actual distribution particle size is determined to complete the classification of the current powder.

[0050] S500: Analyze the proportion of problematic powder in the powder group with classification problems, and obtain an adjusted classification wheel rotation speed for the powder group with classification problems.

[0051] The actual conditions of mixed powders with different particle sizes may vary, for example, the powder density and collision conditions may be different. Separating powders of different particle sizes using the corresponding classifying wheel speed in a single reference data may lead to errors in actual classification. Further adjustments should be made based on the actual classification results.

[0052] Based on the above analysis, in some embodiments of the present invention, by analyzing the proportion of problematic powder in the problematic powder group, the adjustment of the grading wheel speed for the problematic powder group is obtained. Further, it includes: First, determine which powder group has grading problems in the two powder groups after the current powder classification. The two powder groups obtained after the current powder classification are a larger particle size group and a smaller particle size group. The powder group with grading problems contains powders with particle sizes that do not correspond to the expected separation particle sizes, that is, the larger particle size group contains smaller particle size powders that do not fall within the grading wheel speed range of the group, or the smaller particle size group contains larger particle size powders that do not fall within the grading wheel speed range of the group. It should be noted that the powder group with grading problems in the two powder groups after the current powder classification may be the smaller particle size group and the larger particle size group, the smaller particle size group or the larger particle size group, or there may be no powder group with grading problems.

[0053] Then, a first ratio of the problem powder particle size segment in the classified problem powder group to the problem powder particle size segment in the classified problem powder group is obtained, and a second ratio of the non-problem powder particle size segment in the pre-classification powder particle size segment in the classified problem powder group is obtained. The problem powder particle size segment is a powder particle size segment that does not correspond to the expected separation particle size, that is, a powder particle size segment with a smaller particle size that is not within the rotation speed range of the grading wheel in the larger particle size group, or a powder particle size segment with a larger particle size that is not within the rotation speed range of the grading wheel in the smaller particle size group.

[0054] When the first and second proportions increase, and the maximum powder particle size in the problem powder group increases or the minimum powder particle size decreases, there are more misclassified powders, the speed used during classification is more inappropriate, and a greater degree of adjustment is required. If the problem powder group is a smaller particle group, the speed should be increased to correctly classify it again; if the problem powder group is a larger particle group, the speed should be decreased to correctly classify it again.

[0055] Therefore, it is necessary to judge whether the powder group in the classification problem belongs to the smaller particle size group or the larger particle size group.

[0056] If the problem powder group is smaller, obtain the maximum powder particle size in the problem powder particle size segment, and combine the first proportion and the second proportion to obtain the first speed adjustment degree of the classified problem powder group: Where, Indicates the first speed adjustment degree of the powder group with classification problems (belonging to the group with smaller particle size); It represents the first proportion of the problem powder particle size segment in the problem powder group among the problem powder particle size segments in the classification; It represents the second proportion of the non-problem powder particle size segment in the problem powder group in the powder particle size segment before classification; Indicates the maximum powder particle size of the problem powder in the particle size group; represents the linear normalization function.

[0057] If the problem powder belongs to the larger particle size group, the minimum powder particle size of the problem powder is obtained, and the second speed adjustment degree of the classified problem powder group is obtained by combining the first proportion and the second proportion: Where, Indicates the degree of adjustment of the second speed for the powder group with classification problems (the group with larger particle size); It represents the first proportion of the problem powder particle size segment in the problem powder group among the problem powder particle size segments in the classification; It represents the second proportion of the non-problem powder particle size segment in the problem powder group in the powder particle size segment before classification; Indicates the minimum powder particle size of the problem powder in the larger particle size group; represents the linear normalization function.

[0058] In addition, different classifying wheel speeds are set, and the separation of powders of different particle sizes by different classifying wheel speeds is observed, and the powder separation particle size segments corresponding to different classifying wheel speeds are obtained as reference data; furthermore, based on the reference data, the first classifying wheel speed corresponding to the separation of the problem powder particle size segment and the second classifying wheel speed corresponding to the particle size segment adjacent to the problem powder group of the problem powder particle size segment are obtained, and the absolute value of the difference between the first classifying wheel speed and the second classifying wheel speed is calculated.

[0059] According to the first speed adjustment degree or the second speed adjustment degree, combined with the first classifying wheel speed and the second classifying wheel speed, the adjusted classifying wheel speed for classifying the problem powder group is obtained. Classification Problem When the powder group has a smaller particle size: Where, Indicates the adjustment of the classifying wheel speed for the powder group with classification problems (the group with smaller particle size); Indicates the speed of the first classifying wheel corresponding to the separation of the problem powder particle size segments; It represents the absolute value of the difference between the first classifying wheel speed corresponding to the separation of the problem powder particle size segment and the second classifying wheel speed corresponding to the adjacent particle size segment of the problem powder group being classified; Indicates the first speed adjustment degree for the powder group with classification problems (the group with smaller particle size).

[0060] Classification Problem When the powder group belongs to the larger particle size group: Where, Indicates the adjustment of the classifying wheel speed for the powder group with classification problems (belonging to the group with larger particle size); Indicates the speed of the first classifying wheel corresponding to the separation of the problem powder particle size segments; It represents the absolute value of the difference between the first classifying wheel speed corresponding to the separation of the problem powder particle size segment and the second classifying wheel speed corresponding to the adjacent particle size segment of the problem powder group being classified; Indicates the second speed adjustment degree for the powder group with classification problems (the group with larger particle size).

[0061] Finally, the proportion of powders of different particle sizes in the mixed powder is visualized. Specifically, the above method is used to accurately obtain the proportion of powders of different particle size segments in the mixed particle size powder. The obtained particle size segments and their corresponding proportions are stored in a database.

[0062] The SQL query statement is used to visualize the proportion of powders in different particle size segments, as shown in Table 1.

[0063] Table 1 The proportion of powders in different particle size segments Based on the same inventive concept as the above method, this embodiment also provides a laser measuring device for alloy powder distribution particle size.

[0064] A laser measuring device for alloy powder distribution particle size includes: a grading and screening processor, a laser transmitter, a Fourier lens, a ring photoelectric detector array, a laser velocimeter, and a central processing system, wherein: The grading and screening processor includes a grading wheel, which is used to adjust the rotation speed and achieve powder classification during distribution particle size determination; Laser emitter, Fourier lens and annular photodetector array are used to generate parallel laser beams and capture scattered light signals to achieve particle size measurement; Laser velocimeter, used to measure the movement rate of powder.

[0065] See also Figure 2 , which shows the basic composition of a central processing system provided by an embodiment of the present invention.

[0066] like Figure 2 As shown, the central processing system includes: a memory 10 and a processor 20, wherein: Memory 10, for storing program code; The processor 20 is used to read the program code stored in the memory 10, and execute the method of gradually increasing the grading wheel speed with a fixed step size, performing multiple distribution particle size measurements on the current powder, analyzing the overall distribution changes of the particle size segment ratios obtained by the multiple measurements, and determining the deagglomeration grading wheel speed when the current powder is completely deagglomerated; at the deagglomeration grading wheel speed, analyzing the matching degree of the movement rate, density and particle size segment ratio between the current powder and the reference sample powder, and obtaining the abnormality degree of the distribution particle size measurement of the current powder; performing multiple distribution particle size measurements on the current powder at the deagglomeration grading wheel speed, analyzing the distribution deviation degree of the particle size segment ratios obtained by the multiple measurements, combining the abnormality degree and the movement rate, obtaining the reduction degree of the grading wheel speed when the current powder is subjected to the distribution particle size measurement, and determining the optimized grading wheel speed when the current powder is subjected to the distribution particle size measurement; performing the distribution particle size measurement of the current powder at the optimized grading wheel speed, obtaining the actual distribution particle size of the current powder, and completing the classification of the current powder.

[0067] Furthermore, the processor 20 includes: a deaggregation module 21, an abnormality analysis module 22, a rotation speed optimization module 23 and a distribution particle size measurement module 24, wherein: The deagglomeration module 21 is used to gradually increase the classifying wheel speed with a fixed step size, perform multiple distribution particle size measurements on the current powder, analyze the overall distribution changes of the particle size fractions obtained from the multiple measurements, and determine the deagglomeration classifying wheel speed when the current powder is completely deagglomerated; The abnormality analysis module 22 is used to analyze the matching degree of the movement rate, density and particle size fraction between the current powder and the reference sample powder at the rotation speed of the deagglomeration and classification wheel, and obtain the abnormality degree of the current powder distribution particle size measurement; The speed optimization module 23 is used to perform multiple distribution particle size measurements on the current powder at the deagglomeration classifying wheel speed, analyze the distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combine the abnormality degree and the movement rate to obtain the degree of reduction in the classification wheel speed when the current powder is subjected to the distribution particle size measurement, thereby determining the optimized classification wheel speed when the current powder is subjected to the distribution particle size measurement; The distribution particle size measurement module 24 is used to measure the distribution particle size of the current powder under the optimized classification wheel rotation speed, obtain the actual distribution particle size of the current powder, and complete the classification of the current powder.

[0068] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0069] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

Claims

1. A laser measurement method for alloy powder distribution particle size, characterized in that: The method comprises: The classifying wheel speed is increased gradually with a fixed step size, and the current powder distribution particle size is measured multiple times. The overall distribution change of the particle size fraction obtained from the multiple measurements is analyzed to determine the deagglomeration classifying wheel speed when the current powder is completely deagglomerated. At the rotation speed of the deagglomeration and classification wheel, the degree of matching between the movement rate, density and particle size fraction of the current powder and the reference sample powder is analyzed to obtain the degree of abnormality of the current powder distribution particle size measurement; performing multiple distribution particle size measurements on the current powder at the deagglomeration classifying wheel speed, analyzing the distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combining the abnormality degree and the movement rate to obtain the degree of reduction in the classification wheel speed when the distribution particle size measurement of the current powder is performed, thereby determining the optimized classification wheel speed when the distribution particle size measurement of the current powder is performed; At the optimized classification wheel rotation speed, the distribution particle size of the current powder is measured to obtain the actual distribution particle size of the current powder, thereby completing the classification of the current powder.

2. The laser measurement method for alloy powder distribution particle size according to claim 1, characterized in that: After completing the classification of the current powder, the method further includes: The proportion of problematic powder in the powder group with classification problems is analyzed to obtain the adjusted classification wheel speed of the powder group with classification problems.

3. The laser measurement method for alloy powder distribution particle size according to claim 2, characterized in that: Analyze the proportion of problematic powder in the powder group with classification problems and obtain the adjusted classification wheel speed for the powder group with classification problems, including: Determine the powder group with classification problems in the two powder groups after the current powder classification; Obtaining a first proportion of the problem powder particle size segment in the classified problem powder group to the problem powder particle size segment, and obtaining a second proportion of the non-problem powder particle size segment in the classified problem powder group to the powder particle size segment before classification; Determine whether the powder group in question belongs to the smaller particle size group or the larger particle size group; If the problem powder group belongs to a smaller particle size group, the maximum powder particle size in the problem powder particle size segment is obtained, and the first rotation speed adjustment degree of the classified problem powder group is obtained by combining the first proportion and the second proportion; If the powder belongs to the larger particle size group, the minimum powder particle size in the problem powder particle size segment is obtained, and the second rotation speed adjustment degree of the classified problem powder group is obtained by combining the first proportion and the second proportion; Set different classifying wheel speeds to obtain the powder separation particle size segments corresponding to different classifying wheel speeds as reference data; Based on the reference data, a first classifying wheel rotation speed corresponding to separation of the problem powder particle size segment and a second classifying wheel rotation speed corresponding to the particle size segment of the problem powder particle size segment adjacent to the classified problem powder group are obtained; According to the first speed adjustment degree or the second speed adjustment degree, combined with the first classifying wheel speed and the second classifying wheel speed, an adjusted classifying wheel speed for classifying the problem powder group is obtained.

4. The laser measurement method for alloy powder distribution particle size according to claim 1, characterized in that: Perform multiple distribution particle size measurements on the current powder by gradually increasing the classifying wheel speed with a fixed step size, analyze the overall distribution changes of the particle size fractions obtained from multiple measurements, and determine the deagglomeration classifying wheel speed when the current powder is completely deagglomerated, including: The particle size distribution of the current powder is measured multiple times by gradually increasing the classifying wheel speed with a fixed step size to obtain the particle size fraction of the current powder at different classifying wheel speeds; Calculate the difference in the proportion of particle size segments corresponding to all adjacent classifying wheel speeds to obtain a first total difference; sorting the first total differences in ascending order of their corresponding grading wheel speeds, calculating the quadratic differences between adjacent first total differences in the sorting, and calculating the ratio of the number of quadratic differences less than 0 to the total number of quadratic differences; According to the ratio and in combination with the first total difference, the degree of deagglomeration of the current powder under each adjusted classification wheel speed is obtained; A deagglomeration degree threshold is preset, and according to the deagglomeration degree, a rotation speed of the deagglomeration classifying wheel when the current powder is completely deagglomerated is determined.

5. The laser measurement method for alloy powder distribution particle size according to claim 1, characterized in that: At the rotation speed of the deagglomeration and classification wheel, the degree of matching between the current powder and the reference sample powder in terms of movement rate, density, and particle size fraction is analyzed to obtain the degree of abnormality in the current powder distribution particle size measurement, including: Under the rotation speed of the deagglomeration and classification wheel, the movement rate and particle size fraction ratio of the current powder and different reference sample powders are obtained; Analyze the difference in movement rate and density between the current powder and different reference sample powders to obtain the reference value of different reference sample powders to the current powder; Obtain the maximum reference value corresponding to different reference samples, and the reference sample corresponding to the maximum reference value is the valid reference sample; Calculating the absolute value of the difference between the effective reference sample and the current powder in all corresponding particle size range proportions to obtain a second total difference; The maximum reference value and the second total difference are combined to obtain the abnormality level of the current powder distribution particle size measurement.

6. The laser measurement method for alloy powder distribution particle size according to claim 1, characterized in that: Performing multiple distribution particle size measurements on the current powder at the deagglomeration classifying wheel speed, analyzing the distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combining the abnormality degree and the movement rate to obtain the degree of reduction in the classifying wheel speed when the current powder is subjected to the distribution particle size measurement, including: Performing multiple distribution particle size measurements on the current powder at the rotation speed of the deagglomeration and classification wheel to obtain the particle size segment ratios of the current powder under the multiple distribution particle size measurements; Calculate the mean of the proportion of different particle size segments under multiple distribution particle size measurements; Analyze the difference between the proportion of each particle size segment under each distribution particle size measurement and the mean of the proportion of the corresponding particle size segment to obtain a third total difference; The degree of reduction in the rotation speed of the classifying wheel when the current powder distribution particle size measurement is performed is obtained by combining the third total difference, the abnormality degree, and the movement rate.

7. The laser measurement method for alloy powder distribution particle size according to claim 6, characterized in that: Determine the optimal classifier wheel speed for the current powder distribution particle size measurement, including: The optimized classifying wheel speed for measuring the distribution particle size of the current powder is determined according to the deagglomeration classifying wheel speed and the reduction degree in combination with the fixed step size.

8. A laser measuring device for alloy powder distribution particle size, characterized in that: The device comprises: a grading and screening processor, a laser transmitter, a Fourier lens, a ring photoelectric detector array, a laser speed meter and a central processing system, wherein: The grading and screening processor includes a grading wheel for adjusting the rotation speed and achieving powder classification during distribution particle size measurement; The laser emitter, the Fourier lens and the annular photodetector array are used to generate a parallel laser beam and capture scattered light signals to achieve particle size measurement; Laser velocimeter, used to measure the movement rate of powder.

9. The laser measuring device for alloy powder distribution particle size according to claim 8, characterized in that: 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 the program code stored in the memory and execute the method according to any one of claims 1 to 7.

10. The laser measuring device for alloy powder distribution particle size according to claim 9, characterized in that: The processor includes: The deagglomeration module is used to gradually increase the classifying wheel speed with a fixed step size, perform multiple distribution particle size measurements on the current powder, analyze the overall distribution changes of the particle size segment proportions obtained from multiple measurements, and determine the deagglomeration classifying wheel speed when the current powder is completely deagglomerated; An abnormality analysis module is used to analyze the matching degree of the movement rate, density and particle size segment ratio between the current powder and the reference sample powder at the rotation speed of the deagglomeration and classification wheel, and obtain the abnormality degree of the current powder distribution particle size measurement; a speed optimization module for performing multiple distribution particle size measurements on the current powder at the speed of the deagglomeration classifying wheel, analyzing the degree of distribution deviation of the particle size segment proportions obtained from the multiple measurements, and combining the degree of abnormality and the movement rate to obtain the degree of reduction in the classification wheel speed when the distribution particle size measurement of the current powder is performed, thereby determining the optimized classification wheel speed when the distribution particle size measurement of the current powder is performed; The distribution particle size measurement module is used to measure the distribution particle size of the current powder at the optimized classification wheel speed, obtain the actual distribution particle size of the current powder, and complete the classification of the current powder.

Images