Tetragonal-to-mono clinic phase transformation in CeO2-stabilised zirconia under uniaxial loading

The critical transformation stresses of five 9 mol% Ce-TZP materials
with different grain sizes have been investigated in bending. It was
found that two different types of phase transformation mechanisms occur
in these materials. a) A homogeneous phase transformation with a
transformation strain increasing continuously with increasing applied
stress. This transformation type produces the initial deviation from
linear-elastic material behaviour in the stress-strain curves. (b) An
autocatalytic phase transformation with the autocatalytic formation of
transformation bands, leading to a strongly inhomogeneous, localised
distribution of the monoclinic phase. Their locations and sizes vary
randomly. The formation of the transformation bands has been monitored
by acoustic emission recording. The amount of monoclinic phase content
has been quantified by X-ray diffractometry and Raman spectroscopy. (