2020 年 128 巻 9 号 p. 577-581
Direct foaming is one of the most widely used fabrication processes for macro porous ceramics. We previously reported on direct foaming using phenolic resin as both the thermal foaming agent and the binder. This study investigates the effect of the heating rate during thermal foaming on the porous structure of an alumina/resin foamed body. In this process, a ceramic compact is prepared by mixing alumina powder with phenolic resin powder, and it is followed by press molding. The ceramic compact is then heated at different heating rates of up to the thermal foaming temperature of the phenolic resin. The effect of the heating rate on the thermal foaming behavior of the ceramic compact is examined using differential scanning calorimeter-thermogravimetry. After thermal foaming, the effect of heating rate on the porous structure of the foamed body is characterized via morphological observations using a scanning electron microscope, optical microscope imaging, porosity measurements, and pore size measurements. The foamed body is finally debound and sintered to obtain a sintered porous alumina.
