Effect of defects introduced by temperature lowering and doping on the α-alumina toughness

It is well-known that network intrinsic distortions or introduction of impurities, into this last, modifies the nature of the traps energy present in material, affecting in an important way material toughness. In this work, we were interested to the effect of both structural defects effect introduced by a lowering in temperature and doping on the alumina toughness, measured by Vickers indentation. The obtained results reveal the importance of these defects which behave, in this case, like trapping electric sites and modify, in a more or less strong way, material toughness. We show that the dopants are generally unfavorable to toughness. However, we underlined an interesting case of increase in the tenacity of the single crystal alumina doped with chromium.