Formation of Regular Hexagonal Dislocation Network in Chemical-Furnace Sintered Alumina

Polycrystalline alumina was prepared at high temperature and high pressure from combustion reaction plus mechanical pressure. The defect structure in the sintered alumina was investigated by transmission electron microscopy and a regular hexagonal dislocation network was found. Diffraction contrast technique revealed that the regular hexagonal network on the (0001) plane was composed of three dislocations with Burgers vectors: 1/3[1210], 1/3[ 2110] and 1/3[1120]. The formation process of dislocation network was discussed.