Tetragonal Zirconia Polycrystal, ZrO2-Y2O3
Since the mid-1980s, zirconia has held a steady position in high-performance ceramics. By using additives from the group of oxides of rare-earth elements (yttrium, cerium), the tetragonal phase can be stabilized. Such materials with a submicron grain size are generally designated as TZP (Tetragonal Zirconia Polycrystals) and, depending upon the stabilizing element, as Y-TZP or Ce-TZP. TZP is characterized by its outstanding mechanical properties, in particular high bending strength and fracture toughness, and a Young’s-modulus comparable to that of steel. The effect of partial stabilization of ZrO2 by yttrium (Y) and cerium (Ce) oxides has been widely reported.
TZP ceramics show a high fracture toughness, i.e. a high tolerance against both, slow and fast applied loads.