size, which is dictated by the sintering temperature [82]. Above a grain size of 1 μm, 3Y-TZP is less
stable and more susceptible to spontaneous tetragonal to monoclinic transformation [83]. Below a
grain size of 0.2 μm, transformation toughening is not possible, which results in reduced fracture
toughness [84]. Higher sintering temperatures and longer sintering times lead to larger grain sizes