Influence of carbon nanotubes and silicon carbide whiskers on the mechanical loss due to grain boundary sliding in 3-mol% yttria-stabilized tetragonal zirconia polycrystals

High-temperature mechanical spectroscopy was performed in pure 3Y-TZP, i.e. 3-mol% yttria-stabilized polycrystalline tetragonal zirconia, in 3Y-TZP doped with multiwalled carbon nanotubes and in 3Y-TZP doped with silicon carbide whiskers. Silicon carbide doping results in an increase in the high-temperature mechanical loss with respect to pure 3Y-TZP, with appearance of a relaxation peak. On the contrary, doping with carbon nanotubes leads to a decrease in the mechanical loss with respect to pure in 3Y-TZP. As high-temperature mechanical loss in 3Y-TZP has been interpreted as due grain boundary sliding, it appears that doping with nano-sized objects may affect the sliding process.