Treatment of alumina ceramics by intense electron and ion beams

The paper investigated modification of the microstructure of the surface layers of alumina ceramics under exposure to electron and ion beams. Electron beam irradiation was performed at accelerating voltage U = 15 kV and beam current of J = 70 A and J = 100 A. Ion irradiation was performed with carbon ions at accelerating voltage of U = 180 keV. The current density and energy density varied in the range of 15-85 A/cm(2) and 0.3-1.5 J/cm(2), respectively. The amount of energy acting on the ceramic surface depended on the number of pulses N. It is shown that exposure to electron and ion beams changes the microstructure of the irradiated ceramic layer. In general, the effect of exposure is similar for electron and ion irradiation, and it is characterized not only by surface melting, but also by formation of a finer microstructure through the depth of the irradiated layer, which is oriented in the direction of the electron and ion beam exposure. It is shown that crystallization processes in overheated layers of ceramics depend on its type and melting point.