Universität Stuttgart, IFKB, Allmandring 7B, 75233 Stuttgart, Germany.
Université de Lyon, INSA de Lyon, Mateis CNRS UMR 5510, 20 Avenue Albert Einstein, F-69621 Villeurbanne Cedex, France.
J Mech Behav Biomed Mater. 2019 Feb;90:395-403. doi: 10.1016/j.jmbbm.2018.11.001. Epub 2018 Nov 3.
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.% AlO, 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.
四方氧化锆多晶（TZP）因其在室温下优异的机械性能而在结构生物医学应用中具有吸引力，这些性能包括高强度、断裂韧性和耐磨性。在这项工作中，通过在 50-60MPa 下热压（HP）和在 1300-1350°C 下烧结 1 小时，制备了 Y 或 Yb 或 Yb+Nd 稳定的氧化锆，其中均含有 0.5 体积%的 AlO。研究了微观结构特征、相组成和力学性能。强度通过四点弯曲（4P-B）、活塞-三个球（P-3B）和三个球-三个球（3B-3B）双向方法测量。通过弯曲压痕强度（ISB）确定韧性。维氏硬度（Hv）和杨氏模量（E）也进行了估算。还考虑了初步时效行为（LTD）。由于四方相到单斜相（t-m）氧化锆相变强烈受到加载配置的影响，测量的双向强度明显高于单向强度（高达 1.83 倍）。测试方法变化的强度归因于相变产生的压缩应力，这种应力在 P-3B 测试中特别有利，并且还归因于从弹性理论计算应力。LTD 初步测试表明 3Yb-0.5A 陶瓷具有优异的耐老化性。
