The role of metal–ceramic interfaces on the high temperature mechanical response of nanostructured nickel–yttria tetragonal zirconia polycrystals (Ni–YTZP)

High temperature creep of a metal–ceramic composite consisted of yttria tetragonal zirconia polycrystals (YTZP) with a certain amount of nickel grains (Ni–YTZP, 2.5% vol.) has been studied. The average grain size of YTZP grains was 0.20 lm, whereas that of the Ni grains was 50–70 nm. This work reports the mechanical response under creep of such composite materials. It is found that the activation energy for creep is significantly higher than that reported in similar systems with much larger nickel grains. This fact has been explained in terms of the chemical nature of the metal–ceramic interfaces