Tetragonal Zirconia Polycrystals (TZP) is attractive for structural biomedical applications because of their excellent mechanical properties at room-temperature, which include high strength, fracture toughness and wear resistance. In this work, zirconia stabilized with Y or Yb or Yb+Nd, all containing 0.5 vol.% Al₂O₃, were prepared by hot-pressing (HP) at 50–60 MPa and sintered at 1300–1350 °C for 1 h. Microstructural features, phase composition and mechanical properties were investigated. The strength was measured by 4-point bending (4P-B), piston-on-three-balls (P-3B) and three-balls-on-three-balls (3B-3B) biaxial methods. Toughness was determined by indentation strength in bending (ISB). Vickers hardness (Hv) and the Young modulus (E) were also estimated. Preliminary aging behaviour (LTD) was also here considered.

Measured biaxial strength was significantly higher (until 1.83 times) than the uniaxial one because of the tetragonal to monoclinic (t-m) zirconia phase transformation which is strongly influenced by the loading configuration. The variation of the strength with the testing method is attributed to the compressive stresses generated by the phase transformation which is particularly favoured under P-3B tests and also to the calculation of the stresses from elastic theories. LTD preliminary tests showed excellent aging resistance of 3Yb-0.5A ceramics.

四方晶氧化锆多晶（TZP）在室温下具有出色的机械性能，包括高强度，断裂韧性和耐磨性，因此对结构生物医学应用具有吸引力。在这项工作中，用Y或Yb或Yb + Nd稳定的氧化锆均含有0.5％（体积）的Al ₂ O _3。通过在50-60 MPa的热压（HP）制备并在1300-1350°C的温度下烧结1 h。研究了显微组织特征，相组成和力学性能。强度是通过四点弯曲（4P-B），三活塞上滚珠（P-3B）和三球上三滚珠（3B-3B）双轴方法测量的。韧性由弯曲压痕强度（ISB）确定。还估算了维氏硬度（Hv）和杨氏模量（E）。此处还考虑了初步老化行为（LTD）。

测得的双轴强度显着高于单轴强度（至多1.83倍），这是因为四方晶系向单斜晶系（tm）的氧化锆相转变受负载构型的影响很大。测试方法导致的强度变化归因于由相变产生的压缩应力，这在P-3B测试中尤为有利，并且还归因于根据弹性理论计算的应力。LTD的初步测试显示3Yb-0.5A陶瓷具有出色的耐老化性。