Abstract: Yb-Y-TZP with high flexural strength and excellent fracture toughness was acquired with the complex stablizers containing Yb₂O₃ and Y₂O₃.
XRD was used to investigate the phase composition and increment of monoclinic phase content before and after fracture. The microstructure of Yb-Y-TZP was
observed and grain size was determined by SEM. The relationship between the mechanical properties, microstructure and the increment of monoclinic phase content was studied.
It was found that the fracture toughness was improved with the original flexural strength by doping 0--3 mol% Yb₂O₃ in Y-TZP. The experimental results
showed that the excellent mechanical properties were not decreased if Yb₂O₃ was added in Y-TZP to inhibit the low temperature aging and to improve the thermal shock resistance.

Key words: Yb-Y-TZP, toughening ceramics, phase transformation, microstructure, mechanical properties