Abstract:
Monoclinic zirconia has been partially stabilized into the tetragonal
phase with the addition of rare earth oxides such as cer ta, dvsurosia, and
gadolinia. Other rare oxide additives such as lanthana, and erbia did not
stabilize this phase. l lowever, a pyrochlore-type structure was formed by
their addition in zirconia.
Zircouia containing 13 mol<Y<> ceria showed highest percentage or
retained tetragonal phase. The mechanical properties such as the diametrical
compression and hardness of Zr02 +Ce02 have been further improved with
the addition of aluminium nitride.
The alumina partially stabilized zirconia ceramics were strengthened
by adding Si]N4 (grain size 40- 60 um). Remarkable high hardness and
flexural strength have been achieved. The steady state creep rate of the
system Zr02+ Si3N4 has been studied. The stress component and the creep
activation energy have been determined.
