Method for detecting circularity of silicon carbide micro powder

Abstract

A method for detecting circularity of silicon carbide micro powder relates to the technical field of silicon carbide detection, and comprises the following steps: S1, turning on a flowing particle imager, preheating and then carrying out background detection; s2, adding standard particles into the sample pool, and enabling the flowing particle imager to perform automatic focusing; s3, adding the prepared silicon carbide micro powder sample into a sample pool, and detecting by using a flowing particle imager; and S4, storing the detection result, checking the silicon carbide micro powder particle image, and recording the detection result. The preparation of the silicon carbide micro-powder sample comprises the following steps: S31, adding the dried silicon carbide sample into a dry and clean beaker; s32, sequentially adding an impregnating compound, a dispersing agent and deionized water into the beaker; s33, carrying out ultrasonic dispersion; and S34, taking out the uniformly mixed sample. The method can solve the technical problem of detection failure caused by easy agglomeration of the silicon carbide sample when the flowing particle imager is used for detecting the circularity of the silicon carbide micro powder.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide testing technology, specifically a method for detecting the roundness of silicon carbide micro powder. Background Technology

[0002] Flow particle imaging systems were originally designed to detect samples such as blood mixed with cells and tissue fluid; therefore, the instrument itself requires the sample to be in a liquid state before testing. Due to the limitation of the sample tube diameter (300 μm), if the total particle size of the accumulated particles in the sample is too large, there is a risk of system blockage.

[0003] Because silicon carbide micro powder is a high-density material, and because it is an ultrafine powder with a large specific surface area and high activity, it has a high probability of agglomeration when mixed with liquids such as water for testing if not handled properly, resulting in test failure or even damage to the instrument. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting the roundness of silicon carbide micropowder, which can solve the technical problem that silicon carbide samples are prone to agglomeration and cause detection failure when using a flow particle imager to detect the roundness of silicon carbide micropowder.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A method for detecting the roundness of silicon carbide micro powder includes the following steps: S1. Turn on the flow particle imager, preheat it, and then perform background detection; S2. Add standard particles to the sample cell to enable the flow particle imager to automatically focus; S3. Add the prepared silicon carbide micro powder sample to the sample cell and use a flow particle imager for detection. S4. Save the test results, view the silicon carbide micro powder particle image, and record the test results.

[0007] Furthermore, in step S1, the background detection must satisfy the condition that the values ​​of HPF and LPF are both less than 10.

[0008] Furthermore, in step S2, during autofocus, the 10X lens selects a 2.0µm standard particle and the 20X lens selects a 1.0µm standard particle.

[0009] Furthermore, in step S3, the preparation of the silicon carbide micro powder sample includes the following steps: S31. Add the dried silicon carbide sample to a dry and clean beaker; S32. Add the wetting agent, dispersant and deionized water to the beaker in sequence; S33. Perform ultrasonic dispersion; S34. Take out the well-mixed sample.

[0010] Furthermore, in step S31, a 10 mL beaker is selected, and the beaker is dry and clean; the mass of the added dried silicon carbide sample is 20 mg.

[0011] Furthermore, in step S32, the wetting agent is acetone and the dispersant is NP-40 solution.

[0012] Further, add 0.2 mL of acetone, 1 mL of NP-40 solution, and 5 mL of deionized water, wherein the concentration of NP-40 solution is 3%.

[0013] Furthermore, in step S33, ultrasonic dispersion is performed using an ultrasonic cleaner for a dispersion time of 5 minutes.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects: 1. This invention utilizes a flow particle imager to detect the roundness of silicon carbide particles, providing accurate results and convenient operation; 2. The method for preparing silicon carbide test samples in this invention can reduce the risk of silicon carbide particles agglomerating, which could lead to equipment damage and test failure. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the features and performance of a silicon carbide micropowder sphericity detection method of this invention will be further described in detail below with reference to embodiments.

[0016] A method for detecting the roundness of silicon carbide micropowder includes the following steps.

[0017] S1. Turn on the flow particle imager, preheat it and then perform background detection. The background detection requires that the values ​​of HPF and LPF are both less than 10.

[0018] S2. Add standard particles to the sample cell to enable the flow particle imager to autofocus. During autofocus, select 2.0µm standard particles for the 10X lens and 1.0µm standard particles for the 20X lens.

[0019] S3. Add the prepared silicon carbide micropowder sample to the sample cell and detect it using a flow particle imager. The preparation of the silicon carbide micropowder sample includes the following steps.

[0020] S31. Add the dried silicon carbide sample to a dry and clean beaker. Use a 10 mL beaker that is dry and clean; the mass of the added dried silicon carbide sample is 20 mg.

[0021] S32. Add 0.2 mL of acetone, 1 mL of NP-40 solution, and 5 mL of deionized water to a beaker in sequence. The acetone is acetone, and the dispersant is NP-40 solution. The concentration of NP-40 solution is 3%.

[0022] S33. Perform ultrasonic dispersion using an ultrasonic cleaner for 5 minutes.

[0023] S34. Take out the well-mixed sample.

[0024] S4. Save the test results, view the silicon carbide micro powder particle image, and record the test results.

[0025] In practice, this detection method uses the Sysmex FPIA-3000S flow particle image analyzer from Malvern, UK. The laboratory is also equipped with a KQ118 ultrasonic cleaner as an external ultrasonic device.

[0026] The Sysmex Flow Particle Imager was originally designed for detecting samples such as blood mixed with cells and tissue fluid, therefore the instrument itself requires the sample to be in a liquid state before testing. Its sample tube diameter (300 μm) is limited; if the total particle size of the aggregated sample is too large, there is a risk of system blockage. Furthermore, because silicon carbide powder is a high-density material, and its ultrafine powder nature results in a large specific surface area and high activity, improper handling when mixed with liquids such as water before testing can easily lead to agglomeration, causing detection failure or even instrument damage. Therefore, a key issue in researching the use of the Sysmex Flow Particle Imager for silicon carbide powder detection is solving the agglomeration problem of silicon carbide powder during detection.

[0027] Take 20 mg of dried silicon carbide sample and place it in a clean, dry 10 mL beaker. Add 0.2 mL of acetone (analytical grade) as a wetting agent, 1 mL of NP-40 (3% concentration) as a dispersant, and 5 mL of deionized water to the beaker. Place the beaker in an ultrasonic cleaner and ultrasonically disperse for 5 min. After dispersion, remove the beaker and mix the sample thoroughly. Then, perform the analysis according to the Sysmex Flow Particle Image Analyzer operating instructions and obtain the corresponding values.

[0028] This detection method is based on the general testing method of the Sysmex Flow Particle Imager. After optimization, different variables are set in three aspects: the selection of sample wetting agent dosage, dispersant concentration, and ultrasonic water bath treatment time. On the basis of the uniformity of other aspects, the degree of aggregation of different types of samples under the treatment of each variable combination is repeatedly tested, and the combination with the lightest aggregation degree of the relative types is selected.

[0029] For the three mainstream silicon carbide micro powders, GC#1200, GC#1500, and GC#2000, the test method parameter combination with the least agglomeration is: 1. Acetone dosage 0.20mL + NP-40 concentration 3% + ultrasonic water bath treatment time 3 minutes; 2. Acetone dosage 0.20mL + NP-40 concentration 3% + ultrasonic water bath treatment time 5 minutes.

[0030] It can be seen that by processing the three mainstream types of silicon carbide micro powders with the above combination, the relevant samples showed the least degree of aggregation in the detection field of the Sysmex flow particle imager, exhibiting good dispersibility, which is conducive to the correct identification and detection of the samples by the instrument.

[0031] Further increasing the detection amount for the two combinations mentioned above, the results showed that the combination of test method parameters: acetone dose 0.20mL + NP-40 concentration 3% + ultrasonic water bath treatment time 5 minutes, resulted in more stable sample dispersion.

[0032] The operating procedure for the FPIA-3000S Sysmex Flow Particle Image Analyzer is as follows.

[0033] 1. Turn on the power of the instrument main unit and allow the instrument to warm up for 30 minutes.

[0034] 2. Start your computer and double-click the FPIA-3000 / 3000S software. In the pop-up dialog box, enter your username and password, and click OK to enter the operating software.

[0035] 3. The instrument will enter the self-test program. The instrument's operating status will be displayed in the status bar at the bottom left of the software. You can proceed to the next step only after the status bar displays "Standby".

[0036] 4. Click Test→testing / Analysis Parameters in the menu or the FPIA-3000 / 3000S command in the menu to enter the measurement interface.

[0037] 5. Click "Check Background" in the measurement interface. The instrument will automatically detect the background. If the displayed HPF and LPF values ​​are greater than 10, click "Run" to re-detect the background. Continue until the HPF and LPF values ​​are both less than 10. Then click "Cancel" to end the background detection.

[0038] 6. Click AutoFocus in the measurement interface. The instrument will automatically focus. After the system prompts you to add the sample, add the prepared standard particles to the sample cell. Select 2.0µm standard particles for the 10X lens and 1.0µm standard particles for the 20X lens. Click Start to start automatic focusing.

[0039] 7. The results are automatically saved after autofocusing. When the focused image is clear and the Mean Circularity is between 0.980 and 1.00, it indicates that the focus was successful.

[0040] 8. After autofocusing is complete, the instrument enters the testing state. Select File→New→Select a save path to create and open the Sample.rbk measurement file.

[0041] 9. Access the Sample.rbk measurement file, open the measurement interface, enter the sample information, operator name, and select the measurement mode.

[0042] 10. Click Start. The sample cell cover will open automatically, transferring all the prepared samples into the sample cell. In the pop-up dialog box, select Start to begin the measurement.

[0043] 11. After the measurement is completed, the results are automatically saved. View the particle image and record the test results. When testing the next sample, simply repeat steps nine to eleven.

[0044] 12. After all samples have been tested, click File→Exit in the software menu. The instrument will automatically enter the shutdown procedure. Open the sample cell protective cover, add deionized water, click OK, close the operating software, and then turn off the instrument main unit power.

[0045] It should be noted that the parts not described in detail in this solution are all prior art. The above embodiments are only used to illustrate the present invention, but the present invention is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for detecting the roundness of silicon carbide micropowder, characterized by: The method comprises the following steps, S1, turn on the flow particle image instrument, and perform background detection after preheating; S2, add standard particles to the sample pool, so that the flow particle image instrument performs automatic focusing; S3, add the prepared silicon carbide powder sample to the sample pool, and use the flow particle image instrument to perform detection; S4, save the detection result, view the silicon carbide powder particle image, and record the detection result.

2. The method of claim 1, wherein the method is characterized by: In step S1, the background detection needs to satisfy that the values of HPF and LPF are both less than 10.

3. The method of claim 1, wherein the method is characterized by: In step S2, when automatic focusing is performed, 2.0 um standard particles are selected for a 10X lens, and 1.0 um standard particles are selected for a 20X lens.

4. The method of claim 1, wherein the method is characterized by: In step S3, the preparation of the silicon carbide powder sample comprises the following steps, S31, add the dried silicon carbide sample to a dry and clean beaker; S32, sequentially add a wetting agent, a dispersing agent and deionized water to the beaker; S33, perform ultrasonic dispersion; S34, take out the uniformly mixed sample.

5. The method for detecting the roundness of silicon carbide micro powder as described in claim 4, characterized in that: In step S31, a beaker with a capacity of 10 mL is selected, and the beaker is dry and clean; the mass of the added dried silicon carbide sample is 20 mg.

6. The method of claim 5, wherein the method further comprises: determining the circularity of the SiC micropowder. In step S32, the wetting agent is acetone, and the dispersing agent is an NP-40 solution.

7. The method for detecting the roundness of silicon carbide micro powder as described in claim 6, characterized in that: 0.2 mL of acetone, 1 mL of NP-40 solution and 5 mL of deionized water are added, wherein the concentration of the NP-40 solution is 3%.

8. The method of claim 4, wherein the method is characterized by: In step S33, the ultrasonic dispersion is performed by using an ultrasonic cleaner, and the dispersion time is 5 min.