Preparation technique of high-porosity ceramics

A new technique has been developed for preparing high porousity ceramics. S pray freeze drying of magnesium sulfate aqueous solution produced porous fi ne salt particles, which were calcined to porous particles of magnesium oxi de. The oxide particles were treated to form magnesia ceramics that showed high porosity in a range of 0.5 similar to 0.85. The following equation whi ch can assess ceramics strength for high porosity is proposed. sigma = sigma(o)(1 - a epsilon)(m) where sigma[Nm(-2)] strength, epsilon[-] porosity and sigma(o), a, m consta nts. The validity of the equation is confirmed by the present investigation data and also the ones published.