Method for determination of particle size of metal and its compound powders

Method for determination of Fischer particle size of metal and its compound powders

1. Introduction

The Fischer particle size of metal and its compound powders is an important physical property that has a significant impact on the properties and applications of materials. This article will provide a detailed introduction to several common measurement methods.

Method 1: Moore's integral method 
Using Fisher's law: the mass of metal or compound consumed is directly proportional to the surface area of the powder. 
• Determine the surface area of the powder: Calculate the equivalent surface area of the powder by measuring its nitrogen adsorption value. 
The Mohr integral method can be used to calculate the Fischer particle size of metals or compounds.

Method 2: Electron Microscopy Method 
Observe the morphology and size of the powder using a scanning electron microscope (SEM). 
Place the powder sample in the SEM device and interact with the sample using an electron beam. 
SEM can provide the morphology and distribution of powder particles, thereby determining the size of Fischer particle size. 
Method 3: Chromatography 
The Fischer particle size can be determined by the settling velocity of the powder using chromatography. 
Suspend the powder in a solution, and the settling speed of the powder particles in the solution varies depending on the density and viscosity of the powder. 
By measuring the settling height of powder samples at different times, the Fischer particle size can be calculated. 
Method 4: X-ray diffraction method 
X-ray diffraction can be used to determine the crystal structure and lattice constant of a substance. 
Place the powder sample in an X-ray diffraction instrument, and after being irradiated with X-rays, the sample will produce a diffraction pattern. 
Based on the diffraction pattern, the Fischer particle size of the powder can be calculated using empirical formulas. 
Method 5: Laser Particle Size Analysis Method 
Laser particle size analyzer can be used to measure the size and distribution of particles in powder samples. 
Laser particle size analyzer irradiates the sample with a laser beam and measures the changes in scattered light intensity. 
Based on the variation of scattered light intensity, the Fischer particle size of the powder can be calculated. 
7. Summary 
This article introduces several common methods for determining the Fischer particle size of metal and its compound powders: Mohr integral method, electron microscopy method, chromatography method, X-ray diffraction method, and laser particle size analysis method. Each method has its own applicability, and selecting the appropriate method can effectively evaluate the Fischer particle size of the powder. In practical applications, suitable methods can be selected for measurement based on specific requirements and equipment conditions. 
Method 1: Moore's integral method 
The Mohr integral method is a commonly used method for determining the Fischer particle size of metal and its compound powders. This method is based on Fischer's law, which states that the mass of metal or compound consumed is directly proportional to the surface area of the powder. 
The specific steps are as follows: 
Firstly, place the powder sample to be measured for Fischer particle size in a closed container. 
Next, inject a certain amount of nitrogen into the container and seal it. 
Then, measure the nitrogen content of nitrogen adsorbed on the surface of the powder using colorimetric or infrared methods. The equivalent surface area of the powder can be calculated based on the measurement results of nitrogen content. 
Finally, according to the Moore's integral formula, the equivalent surface area of the powder can be substituted into the calculation to obtain the Fischer particle size of the powder. 
The advantages of the Mohr integral method are simple operation, high accuracy, and suitability for the determination of Fischer particle size of various metal and compound powders. 
Method 2: Electron Microscopy Method 
Electron microscopy is a method of observing the morphology and size of metal and its compound powders using scanning electron microscopy (SEM). 
The specific steps are as follows: 
Firstly, place the powder sample in the SEM apparatus and perform appropriate pretreatment, such as surface coating, frozen section, etc. 
Next, observe the surface morphology and particle size of the sample through SEM. SEM interacts with the sample through an electron beam, generating signals such as reflected electrons, secondary electrons, and scattered electrons. 
Based on the morphology and distribution of powder particles observed by SEM, the size of Fischer particle size can be determined. 
The advantage of electron microscopy is that it can provide detailed morphology and distribution of powder particles, but the disadvantage is that it requires expensive SEM equipment and high pre-treatment requirements for the sample. 
10. Method 3: Chromatography 
Chromatography is a method of determining the Fischer particle size of metal and its compound powders by measuring their settling velocity in solution. 
The specific steps are as follows: 
Firstly, suspend the powder sample in the solution at an appropriate concentration and shake well for a certain period of time. 
Next, let the suspension stand for a period of time, and the powder particles will gradually settle due to gravity. 
Measure the settling height of powder samples at different times, and calculate the density of the powder and the viscosity of the solution to obtain the Fischer particle size. 
The advantages of chromatography are simple operation and low cost, but its accuracy is low, making it suitable for the determination of Fischer particle size of larger metal and compound powders. 
11. Method 4: X-ray diffraction method 
X-ray diffraction is a common method for determining the Fischer particle size of metal and its compound powders. This method is based on the interaction between X-rays and matter, and can determine the crystal structure and lattice constant of matter. 
The specific steps are as follows: 
Firstly, prepare the powder sample into a uniform solid sample and select the crystal structure and lattice constant as needed for identification. 
Next, place the sample in an X-ray diffraction instrument, and after being irradiated with X-rays, the sample will produce a diffraction pattern. 
Based on the diffraction pattern, the Fischer particle size of the powder can be calculated using empirical formulas. 
The advantage of X-ray diffraction method is that it can accurately determine the crystal structure and lattice constant of metal and its compound powders, but its equipment and technical requirements are high.

Method 5: Laser Particle Size Analysis Method 
Laser particle size analysis is a method of measuring the particle size and distribution of metal and its compound powders using laser particle size instruments. 
The specific steps are as follows: 
Firstly, place the powder sample in a laser particle size analyzer to ensure it is fully dispersed. 
Next, the laser particle size analyzer irradiates the sample with a laser beam and measures the change in scattered light intensity. 
By analyzing the changes in scattered light intensity, the Fischer particle size of the powder can be calculated. 
The advantages of laser particle size analysis method are fast measurement speed, reliable results, and suitability for the determination of Fischer particle size of smaller metal and compound powders. 
13. Summary 
This article introduces several common methods for determining the Fischer particle size of metal and its compound powders: Mohr integral method, electron microscopy method, chromatography method, X-ray diffraction method, and laser particle size analysis method. Each method has its own applicability, and selecting the appropriate method can effectively evaluate the Fischer particle size of the powder. In practical applications, suitable methods can be selected for measurement based on specific requirements and equipment conditions.