Monthly Archives - 五月 2022

Preparation and application of magnesium nitride

Chemical formula of magnesium nitride Mg3N2, greenish yellow powder or lump, relative density of 2.712, decomposition at 800℃, sublimation at 700℃ in vacuum, magnesium nitride as ionic compound, rapid hydrolysis in water. Soluble in acid, insoluble in ethanol: magnesium nitride is widely used. Magnesium nitride is an indispensable sintering agent in the solid state reaction of boron nitride and silicon nitride, which are new ceramic materials with high hardness, high thermal conductivity, wear resistance, corrosion resistance and high temperature [...]

Preparation of aluminum nitride powders

1.1 Direct nitriding Aluminum nitride does not exist in nature. It is now prepared by direct nitriding of metallic aluminum powder or direct nitriding method after carbon thermal reduction of Al2O3. Its chemical reaction formula is: 2 al (s) + N2 (g) – > 2 aln (s) Direct nitriding has several advantages: 1) low cost; 2) Rich raw materials; 3) The reaction system is simple and there is no side reaction; 4) The reaction temperature is lower than that of carbothermic reduction; [...]

Synthesis of nano – neodymium oxide by homogeneous precipitation method

Nano Nd_2O_3 powder material was prepared by homogeneous precipitation method. The preparation process, the kinetics of precipitation reaction and thermal decomposition reaction of precursor precipitate were studied. Other lanthanide elements (except promethium) and yttrium oxide were prepared. The main research contents and results are as follows: Nano Nd_2O_3 was prepared by uniform precipitation method by dissolving crude Nd_2O_3 in concentrated nitric acid (Nd(NO_3)_3) and urea as precipitator. The effects of the concentration of Nd~(3+), urea concentration, reaction temperature and [...]

A preparation method and process of nano-holmium oxide

The main uses of holmium oxide are :(1) yttrium aluminum garnet doped with holmium (Ho∶YAG) can emit 2μm laser, human tissues to 2μm laser absorption rate is high, almost 3 orders of magnitude higher than Hd∶YAG. Therefore, the Ho∶YAG laser can not only improve the efficiency and precision of surgery, but also reduce the thermal damage area to a smaller extent. (2) A small amount of holmium can also be added to the magnetostrictive alloy Terfenol-D to reduce the [...]