Ceramic powders, microwave-assisted

Microwave-assisted hydrothermal synthesis is a novel powder processing technology for the production of a variety of ceramic oxides and metal powders under closed-system conditions. Komameni et al. developed this hydrothermal process into which microwaves are introduced. " This closed-system technology not... 

As is the case with ceramic sintering, joining, and powder synthesis, microwave-assisted fabrication of ceramic coatings can offer unique benefits. To expose the material surfaces for reaction with a gas phase, fibers or powder particles may be suspended by the flow of gas in the fluidized bed. In addition to the flow of the fluidizing gas, low frequency mechanical vibrations (for example, 10-15 Hz) may be applied to the container to reduce the tendency for the powders or fibers to sinter together to form clumps. As the powder size decreases, the powder s sinterability increases. While vibration may not be necessary for particles as large as, say, 50 pm, it may be beneficial for powder particles that are a few microns in diameter. 

Careful control of the microwave-assisted reactions can produce nanometer-thick coatings.For example, during the microwave-assisted fabrication of ceramic coatings on metallic powders, the microwave power may be switched on and off to produce a pulsed... 

Microwave-assisted fabrication of ceramic coatings on fibers and powders can be done at intermediate temperatures. For example, at temperatures of about 800-900° C, carbon fibers have been coated with thin TiN layers using a microwave plasma-assisted fluidized bed with the precursor vapor (TiCU in this case) being introduced into the reactor by the fluidizing gas. ... 

Ganesh I, Srinivas B, Johnson R, Saha BP, Mahajan YR (2004) Microwave assisted solid state reaction synthesis of MgAl204 spinel powders. J Eur Ceram Soc 24 201-207... 

I. Ganesh, R. Johnson, G.V.N. Rao, Y.R. Mahajan, S.S. Madavendra, B.M. Reddy, Microwave-assisted combustion synthesis of nanocrystaUine MgAl204 spinel powder. Ceramics International 31 (2005) 67-74. 

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