Microstructural evolution and mechanical properties of nano-ATZ ceramics by solid solution precipitation
Yongdong Yu, Xudong Liu, Yuchen Yuan, Wanjun Yu, Hang Yin, Zhao Yin, Yongting Zheng, Xiaodong He
Abstract
Alumina toughened zirconia (ATZ) nanoceramics accompanied with high-strength, high-toughness and high-hardness were prepared by in-situ nanoprecipitation from using solid solution micro-powders. The submicron-sized Al2O3 (∼445 nm) and ZrO2 (∼361 nm) grains contained low-density precipitated nano-ZrO2 (∼35 nm) and nano-Y4Al2O9 (YAM, ∼87 nm) particles, respectively, making high-performance nano-ATZ ceramics with ultrafine intracrystalline nanostructure yet achieved. There was a parallel or eutectic lattice orientation relationship between the submicrocrystals and its internal nanoparticles of their crystal planes, which is very conducive to the improvement of the mechanical properties of nano-ATZ ceramics. The fracture toughness and hardness of 30wt%Al2O3/70wt%ZrO2(3 mol%Y2O3) can reach up to 5.68 ± 0.17 MPa m1/2 (single-edge V-notched beam method, SEVNB) and 16.32 ± 0.45 GPa, respectively, which are improved by ∼25% and ∼20% compared with those of 3Y-TZP ceramics. Therefore, this method can be used to prepare nano-ATZ ceramics contained ultrafine nanoparticles and uniform distribution of Al2O3 phases.