Electric field assisted bonding of ceramics

Bonding between oxide ceramics using an electric field is reviewed. There is a general prerequisite for an effective bonding by an electric field. Only cations should be moved effectively by an applied electric field. If anions can be transported effectively by an applied electric field bonding does not occur. Near the anode lattice was annihilated and near the cathode lattice was created. The microstructure near anode is significantly different from that near cathode. For a given temperature, bonding between manganese–zinc ferrites was accelerated with the application of an electric field. The degree of bonding increased remarkably as the bonding time and bonding temperature increased. Moreover, the direction of an applied current should be from the poly- to single-crystalline ceramics regions in order to enhance bonding effectively. These phenomena can be applied to the preparation of large single crystal cost effectively. Above 1100°C the effect of electric field was not obvious due to thermally activated self-motion of atoms. Bonding between manganese–zinc ferrites improved with increased oxygen partial pressure. This was attributed to the higher diffusion coefficient of the cations at higher oxygen partial pressures.