Properties of porous alumina ceramics
Porous alumina ceramics have good mechanical properties. Haitao Geng et al. used alumina hollow spheres as pore forming agent and silica phosphate as binder to form closed cell structure in high temperature sintering, and obtained alumina ceramics with porosity of 62.5% and compression strength of 11.97MPa.
Porous alumina ceramics also have high thermal insulation performance. Through the change of solid content and the addition of foaming agent, wu haibo et al. obtained the compressive strength of 9.4 ~ 32.5mpa and the thermal conductivity of 0.8w /(m·K) at 1000℃.
Guimaraes et al. studied the frictional and wear properties of ZrO2/Al2O3 composite ceramic materials. The study showed that when the volume fraction of ZrO2 was 5%, the wear rate was 3.5×10-6mm3/Nm, which was much lower than that of other ceramics.
Ieva Zake-Tiluga et al. studied the thermal shock resistance of porous alumina ceramics and found that appropriate SiC addition is conducive to the uniform dispersion of mullite phase, thereby improving mechanical properties, thermal conductivity and thermal shock, and reducing linear thermal expansion coefficient.
Porous alumina ceramics also have excellent corrosion resistance. Wu Qin et al. found that after soaking 20% sulfuric acid and 10% (wt%) NaOH for 8h, the weight loss was 0.55% and 0.48% respectively, and the strength decreased by 9.85% and 8.08% respectively.
Menchavez et al. introduced conductive phase into porous alumina ceramics with insulation, and the increase of conductive monomer phase would affect the decrease of resistivity.
Porous alumina ceramics were prepared by sol - gel method.Porous alumina prepared by adding 20% polyvinyl alcohol as pore-making agent has the best adsorption performance.
Isobe et al prepared porous alumina ceramics by extrusion forming, and the gas permeability was much higher than other methods