Uniaxial stress behaviour of yttria-tetragonal zirconia polycrystal (Y
-TZP) was investigated using a novel split Hopkinson pressure bar tech
nique. The Y-TZP specimens were loaded by a single compressive pulse o
f predetermined shape and duration. The stress-strain response of the
material revealed a linear elastic regime followed by an inelastic reg
ime during which tetragonal to monoclinic transformation occurs. After
the transformation was complete, the stress-strain behaviour was foun
d to be elastic with a slope similar to that of the untransformed mate
rial. This behaviour suggests that the modulus of the transformed mono
clinic zirconia is essentially the same as that of the untransformed t
etragonal zirconia, and microcracking during transformation does not s
ignificantly affect the subsequent uniaxial stress-strain relation in
Y-TZP. Ultrasonic measurements before and after the experiments, and m
icroscopic observations on transformed zirconia specimens also support
this conclusion, the latter revealing a very small number of nanometr
e-size cracks where martensitic laths in partially transformed grains
interface with grain boundaries.