High-temperature mechanical spectroscopy was applied to pure 3mol%yttria-stabilized polycrystalline tetragonal zirconia, and to the same material but doped with multiwalled C nanotubes or with SiC whiskers. The latter doping resulted in an increase in the high-temperature mechanical loss with respect to the pure material, with the appearance of a relaxation peak. On the other hand, doping with C nanotubes led to a decrease in the mechanical loss, with respect to the pure material. Because high-temperature mechanical loss in the latter was interpreted as being due to grain boundary sliding, it appeared that doping with nano-sized objects affected the sliding process.

Influence of Carbon Nanotubes and Silicon Carbide Whiskers on the Mechanical Loss due to Grain Boundary Sliding in 3mol% Yttria-Stabilized Tetragonal Zirconia Polycrystals. C.Ionascu, R.Schaller: Materials Science and Engineering A, 2006, 442[1-2], 175-8