On the deterioration of ß″-alumina ceramics under electrolytic conditions

The degradation ofβ′'-alumina under electrolytic conditions was investigated at room temperature. With the use of an electrical-mechanical analogue, it was demonstrated that a large current concentration exists at the peripheries of blocked or unwetted areas. Thus, actual current densities at the sites of failure can be several times larger than the average current density. Implications regarding wetting ofβ′'-alumina by sodium are discussed. The concept of current focusing at the tips of sodium-filled cracks is demonstrated in a room temperature test.