Since ultrafine powder has surface effect, small size effect, quantum effect and macroscopic quantum tunneling effect, it has many special properties in catalytic, optical, magnetic and mechanical properties compared with crystalline materials of the same composition. There are many important applications in the fields of medicine, microelectronics, and nuclear technology.
"Plasma milling" refers to a new type of milling process that uses plasma as a heat source to provide energy conditions during gas phase synthesis. Generally, this process is used to prepare ultrafine powders having a small particle size, and it is difficult to prepare fine powders by ordinary processes, or powders having certain special surface properties.
"Plasma milling" refers to a new type of milling process that uses plasma as a heat source to provide energy conditions during gas phase synthesis. Generally, this process is used to prepare ultrafine powders having a small particle size, and it is difficult to prepare fine powders by ordinary processes, or powders having certain special surface properties.
At present, the main methods for manually obtaining plasma are: 1 electron impact method; 2 ray irradiation method; 3 photoionization method; 4 laser plasma method; 5 shock wave method. Among them, the electron impact method is an industrial plasma production method which has been widely used. Plasma milling equipment for production mainly includes: reaction, cooling, and collection of 3 parts. The cooling and collecting devices are mostly similar, and the reactor can be classified into a direct current type, a high frequency type, a microwave type, and the like in a manner of generating plasma.
1. Direct current (DC) plasma milling
DC plasma milling relies on a DC power source to generate plasma, which causes ultrafine particles to form. DC plasma powdering has the advantages of no fear of interference, stable arc column, small radiation, and high power, but its significant disadvantage is the existence of electrode corrosion and electrode contamination.
If a large solid is used as a raw material, the raw material can be used as a pole, and an electric field is directly applied between the other electrode and an arc to generate a plasma, which is also called an arc method.
2. High frequency (RF) plasma milling
High-frequency plasma milling relies on the high-frequency electromagnetic induction coil to provide energy to generate plasma, thus causing ultra-fine particles to form conditions. Since the method has no electrodes, the plasma torch is very pure, and the plasma gas has a small flow rate and high heating efficiency, but the RF is susceptible to interference and unstable, and its electrical efficiency is low.
3. Microwave (MP) plasma milling
Microwave plasma milling technology is the latest development of new ultra-fine powder preparation technology since the 1990s. Using microwaves as a heat source for generating plasma has many unique advantages over DC and high frequency plasmas:
1 High activity. Microwave discharge plasmas have higher electron temperatures and can operate at lower gas pressures, thus providing higher ionization and dissociation.
2 No pollution. There is no internal electrode in the microwave discharge, which avoids the pollution caused by the sputtering of the electronic material, and the pure plasma can be obtained, which is suitable for the preparation and processing of the high-purity substance.
3 A wide range of excitation. The emission spectrum of the microwave plasma is wider than that when the same kind of gas is discharged by other methods, and the lifetime of the excited state particles generated by the microwave discharge is longer.
4 Easy to control. Microwave plasmas can be transmitted and controlled in a specific space using so-called "cavity structures". Based on the above advantages, microwave plasma has great potential and industrial application value in the application of material preparation, so it has become a hot research topic at home and abroad. In recent years, reports on the direct synthesis of nano-powder by microwave plasma are increasing.
The use of plasma technology to prepare nanomaterials has led to a series of technological innovations and great technological advances, especially in the use of high frequency, direct current plasma, which can fully meet the needs of industrialization, while microwave plasma technology has opened up new plasma powdering field.
DC plasma milling relies on a DC power source to generate plasma, which causes ultrafine particles to form. DC plasma powdering has the advantages of no fear of interference, stable arc column, small radiation, and high power, but its significant disadvantage is the existence of electrode corrosion and electrode contamination.
If a large solid is used as a raw material, the raw material can be used as a pole, and an electric field is directly applied between the other electrode and an arc to generate a plasma, which is also called an arc method.
2. High frequency (RF) plasma milling
High-frequency plasma milling relies on the high-frequency electromagnetic induction coil to provide energy to generate plasma, thus causing ultra-fine particles to form conditions. Since the method has no electrodes, the plasma torch is very pure, and the plasma gas has a small flow rate and high heating efficiency, but the RF is susceptible to interference and unstable, and its electrical efficiency is low.
3. Microwave (MP) plasma milling
Microwave plasma milling technology is the latest development of new ultra-fine powder preparation technology since the 1990s. Using microwaves as a heat source for generating plasma has many unique advantages over DC and high frequency plasmas:
1 High activity. Microwave discharge plasmas have higher electron temperatures and can operate at lower gas pressures, thus providing higher ionization and dissociation.
2 No pollution. There is no internal electrode in the microwave discharge, which avoids the pollution caused by the sputtering of the electronic material, and the pure plasma can be obtained, which is suitable for the preparation and processing of the high-purity substance.
3 A wide range of excitation. The emission spectrum of the microwave plasma is wider than that when the same kind of gas is discharged by other methods, and the lifetime of the excited state particles generated by the microwave discharge is longer.
4 Easy to control. Microwave plasmas can be transmitted and controlled in a specific space using so-called "cavity structures". Based on the above advantages, microwave plasma has great potential and industrial application value in the application of material preparation, so it has become a hot research topic at home and abroad. In recent years, reports on the direct synthesis of nano-powder by microwave plasma are increasing.
The use of plasma technology to prepare nanomaterials has led to a series of technological innovations and great technological advances, especially in the use of high frequency, direct current plasma, which can fully meet the needs of industrialization, while microwave plasma technology has opened up new plasma powdering field.
SAT Nano technology Material Co., Ltd is aimed at spreading the nano and mircon material, we can supply ultrafine powder lik copper powder, fe2o3 powder, aluminia powder and so on, please feel free to ask us a quote.
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