In order to reduce the energy consumption, the use of porous refractory ceramics as high-temperature insulating materials has grown significantly. Among the techniques employed in the production of these materials, such as the addition of foam and organic compounds, the generation of pores by phase transformation presents great technological interest, due to its easy processing route and lack of toxic volatiles. In the present work, this technique was employed to produce porous ceramics by the decomposition of aluminum and aluminum-magnesium hydroxides. The in-situ spinelization reaction reduces the densification at high temperatures. It was verified that the use of complex hydroxides generates greater porosity, mechanical strength and refractoriness.
porous ceramics; transformation of phase and spinelization
