Effect of the t-m transformation morphology and stress distribution around the crack path on the measured toughness of zirconia ceramics: A case study on Ce-TZP/alumina nanocomposite

摘要

The t-m transformation zone and related residual stress fields around two types of crack used for toughness measurements, i.e. SEVNB (arrested crack induced by a V-notch) and IF methods (indentation crack induced by a Vickers impression), are reported for a Ce-TZP/Al_2O_3 nanocomposite, in comparison with 3Y-TZP. The fact that Ce-TZP/Al_2O_3 exhibits significant high toughness value on occasions when evaluated by the IF method was determined to be clearly linked to the presence of wide ranged three-dimensional transformation configuration and resulting substantial compressive residual stress fields. In contrast, for 3Y-TZP, transformation behaviors around the two types of crack were quite similar, which proves that 3Y-TZP shows near toughness values for both SEVNB and IF methods.