The Principles And Technology Of Nitriding And Nanoscale Powder Preparation By Atmospheric Pressure Non-equilibrium Plasma

The atmospheic pressure non-equilibrium plasma by gas discharge is one of the hot topic in plasma research. In this paper the status quo of atmospheric pressure non-equilibrium plasma was analyzed and summarized as a base of further research,and the problem needed to be solved was put forward afterwards. Combined with the features of our discipline, the application research of atmospheric pressure non-equilibrium plasma was conducted. One task of vehicle application engineering is to study the measures of reducing friction and anti wear on the metal spare surfaces under bad working circumstances, the commonly used measures are surface modification and the use of lubricants additives, therefore, the research on the application of atmospheric pressure non-equilibrium plasma nitriding on metal material surface was conducted as the beginning, and the corresponding principle and technology were put forward thereby. The study on the application of atmospheric pressure non-equilibrium plasma in nanoscale powder preparation was also conducted, and a new method of nanoscale powder preparation for lubricants additives was given. In conclusion, the following works have been done in the study: 1.An experimental system for atmospheric pressure non-equilibrium plasma had been established and optimized. 2. Studies on nitriding and nanoscale powder preparation by atmospheric pressure non-equilibrium plasma were conducted, and the corresponding principles and technology were got thereby. The experiment results showed that the principles and technology are practicable. Since the technology of atmospheric pressure non-equilibrium plasma breaks away from that of vacuum restriction of normal non-equilibrium plasma technology, it's more valuable in practice. 3. The atmospheric pressure non-equilibrium plasma can be obtained by dielectric barrier discharge (DBD), and it could be used to nitriding and TiO2 nanoscale powder preparation at atmospheric pressure. The nitrided surface has the characteristics as higher hardness, better wear-resistance and seizing-resistance. Since stronger electric field intensity may be got in the filamentary discharging, the discharging gas has higher concentration of ions and activated atoms thus, the preparation efficiency and collecting efficiency are higher in nanoscale powder preparation. 4. Optical emission spectroscopy was used to survey the plasma composition, and it was found that activated particles of NH molecular and ion-molecular N2+( B2 ∑u+)in discharging ammonia play a key role during nitriding. For these ions and moleculars colliding with electrons nearby the nitrided surface, activated nitrogen atoms can be produced and the nitrided surface can be activated at the same time. The activated nitrogen atoms reacts with the nitrided metal surface and some of them are absorbed by the nitrided metal surface, the nitriding process is accomplished by the "ion particles hammering"micro effects. 5.Nanoscale TiO2 powder were prepared by atmospheric pressure non-equilibrium plasma. The experimental result shows that the preparation temperature could be reduced (It may be reduced to 80℃), the reaction speed could be accelerated , the preparation process and equipment could be simplified , and continuous preparation could be conducted by atmospheric pressure non-equilibrium plasma etc. An new method for the preparation of nanoscale TiO2 powder with low cost and high efficiency was put forward. Nanoscale TiO2 powder of spherical and 50nm had been prepared by existing facilities. The nanoscale TiO2 powder prepared by atmospheric pressure non-equilibrium plasma are better in wear-resistance and fiction-reducing when it is used as lubricant additive.