New Technology of Microwave High Temperature Synthesis of Powder Materials

Microwave equipment is quite wide in the field of industrial processing. Today we will talk about the new technology of microwave high temperature synthesis of powders. Microwave high temperature synthesis can reduce the apparent activation energy and reaction temperature. Compared with conventional heating, the reaction temperature can be reduced by 50-300 C and the reaction time can be shortened to l/2-1/20. It has the characteristics of fast reaction speed, uniform structure of reaction products and fine grain size.

Our company used nano-titanium dioxide and carbon black as raw materials to synthesize nano-titanium carbide powder under microwave heating at 1200 ~C. The activation energy was only 86.286 kJ/mol. At the same time, using colloidal AI (OH) 3 and phenolic resin as raw materials, A1N nano-powders with particle size distribution in the range of 5-80 nm were synthesized by microwave heating. The purity of A1N nano-powders was over 98%. Microwave heating can make A1N synthesized in a very short time, prolonging the synthesis time has little effect on A1N. Although AIN powder prepared by traditional liquid phase method has fine particle size and high purity, the preparation process is complex, the cost is high and the output is small. Single-phase Ba (Mgl/3TaO 2/3) O 3 was synthesized from BaCO 3, MgO and Ta205 in a 2.45 GHz multimode microwave cavity at 1300 C for 20 min. The conventional solid-phase method needs to react at 1500 for 10 h.

At present, the known powders that can be synthesized at high temperature in microwave equipment are

nitrides: TiN, AlN, VN, Si3N4

carbides: TiC, SiC, WC, VC, B4C

borides: TiB2, ZrB2

multicomponent compounds: LiCOO 2, LiMnO_4, LiFePO_4, BaTiO_3, Sr_3, ZrWO_8, ZrSiO_3, ceramic colorants, microwave media, etc.