Published online by Cambridge University Press: 25 February 2011
The influence of toughness on the Weibull modulus of ceramics is discussed. It is shown that an increase in toughness does not give a higher Weibull modulus if the ceramic is truly brittle, following the Griffith criterion of fracture. However, R curve behaviour, such as that shown by tetragonal zirconia, by Dugdale material, or by fibrous ceramic composites, leads to an improved Weibull modulus. Theoretical argument and experimental results support these conclusions.