Abstract:
                                      Porous alumina ceramics were obtained by preparing the specimens with various amounts of carbon powder used as pore-forming material. Samples of from 20% to 55% porosity were sintered. Effect of porosity and degree of specimen sintered on strength were investigated. It is show that the strength (
σ) of specimens with changing porosity (
ρ) can be represented by the empirical equation 
σ=
σ0(1-
ρ)
m at low degree of specimens sintered or 
σ=
σ0exp(-
bρ)at high degree of specimens sintered. The empirical constants 
m,σ0 and 
b is dependent on the degree of specimens sintered. With increasing of the degree of specimens sintered, the value of 
m, σ0 and 
b decrease. The only method to obtain the specimens with high porosity and strength was by addition of pore-forming material not by decreasing degree of specimens sintered.