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摘要
In this work, Al2O3-ZrO2 (Y2O3) nanoceramics were prepared via pressureless sintering of powders with different degrees of crystallinity. It was demonstrated that, the crystallization of amorphous phase in starting powders highly enhanced the densification during sintering. When the crystal content was 25 vol%, the powders exhibited better sinterability than other powders, and they could be sintered into bulk nanoceramics with relative densities higher than 98% at 1400 degrees C and 1500 degrees C. The superior sinterability of C25 powders was due to the crystallization of amorphous phase promoted by the as-existed nanocrystalline powders as nucleation seeds. The obtained nanoceramic exhibited homogenously distributed ZrO2 and Al2O3 particles with grain size of about 450 nm, and displayed excellent mechanical property with Vickers hardness of 15.3 GPa, fracture toughness of 5.2 MPa m(1/2), and flexure strength of 1190 MPa. This work may provide new guidance for optimization in preparing bulk nanoceramics by managing the crystallinity of starting powders.
- 出版日期2017-12-15
- 单位天津大学; 中国汽车技术研究中心
