WANG Ling 1, YAN Jin 2, GAO Pengzhao 1, XIE Zhiyong 3, XU Tao 3, GAO Bo 2, XIAO Hanning 1
(1. College of Materials Science and Engineering, Huna University, Changsha 410082, Hunan, China; 2. Hunan Zhongtai Special Equipment Co., LTD, Linli 415211, Hunan, China; 3. Hefei Cement Research and Design Institute Co., Ltd., Hefei, 230051, Anhui, China)
Abstract: The effects of 3Y-ZrO2 and sintering temperature on composition, microstructure, mechanical properties and bulletproof properties of Al2O3 ceramics were studied. With increasing sintering temperature, the density of the Al2O3 ceramics with 3Y-ZrO2 was increased first and then decreased. At 1550 ℃, the sample has the highest density and the lowest porosity. The added particles can promote the refinement of Al2O3 grains through pinning and improve the sintering activity. The Al2O3 ceramics mainly contain a-Al2O3 phase and a small amount of tetragonal and monoclinic ZrO2.With increasing content of 3Y-ZrO2, its dispersion uniformity in the Al2O3 matrix was increased first and then decreased. As the content is 1.5%, the dispersion uniformity is the highest. When the sintering temperature was increased from 1450 °C to 1650 ℃, the bending strength, Vickers hardness and fracture toughness of the sample are all increased first and then decreased. The sample sintered at 1550 ℃ has the highest mechanical properties, with a bending strength of 345.03 MPa, a fracture toughness of 3.87 MPa×m1/2 and a Vickers hardness of 1572.8 MPa. The high mechanical properties are attributed to the uniform distribution of the 3Y-ZrO2 phase in the Al2O3 matrix and the T-M transformation toughening effect. When the product of the main parameters of the Al2O3 ceramics (including density, bending strength, hardness, fracture toughness and thickness) is larger than 4.49×107, the bulletproof of the ceramic chip meets the five level protection requirements.
Key words: Al2O3 ceramics; microstructure; mechanical property; bulletproof property; mechanical criterion