Formation of porous alumina with oriented pores

Adopting the theories describing the bubble forming in the metal–hydrogen solidification process, porous alumina with oriented pores was prepared by combining a foaming method with sol-gel technology. The bubble forming process in the sol-gel is different from that in the metal–hydrogen system. Samples were calcined at temperature from 800 to 1200C. The volume-shrinkage and compressive-strength increased with increasing calcination temperature. The porous alumina exhibited a bimodal pore structure when prepared below 1200°C.