样板晶生长法制备Y-TZP/板状氧化铝复相陶瓷的力学性能和可靠性

MECHANICAL PROPERTIES AND RELIABILITY OF Y-TZP/ PLATELET-ALUMINA COMPOSITES BY TEMPLATED GRAIN GROWTH

  • 摘要: 以带有玻璃涂层的氧化铝微粉、小尺寸板晶(样板晶)和Y-TZP微粉为原料,在常压、不同温度下,通过样板晶生长制备了Y-TZP/板状氧化铝复相陶瓷。对该复相陶瓷的室温力学性能的研究表明,在适当烧结温度下制备的复相陶瓷该材料具有较高的强度(800~900 MPa)和断裂韧性(11.8~15.2MPa·m1/2)。用扫描电子显微镜观察复相陶瓷的显微结构特点,表明该材料的增韧机制为氧化锆相变增韧和板晶对裂纹偏转和桥连机制共同起作用。用二参数Weibull分布来量化强度波动,表明该复相陶瓷具有很高的Weibull模量。

     

    Abstract: Alumina platelets and powders coated with 3 wt% CaO-SiO2 glass and yttria-stabilized zirconia (3Y-TZP) powders were used as starting materials. The compacts were prepared in atmospheric pressure at various temperatures by templated grain growth. The mechanical properties of the composites were investigated. The results show that the composites sintered at proper temperature have high strength (800~900 MPa) and toughness (11.8~15.2MPa·m1/2). The microstructure of the composites was observed using SEM. The possible mechanism could be attributed to the enhancement of phase transformation from tetragonal to monoclinic during fracture and crack-deflection and bridging produced by the platelike Al2O3 grains. The variability in strength was quantified using conventional two-parameter Weibull statistics. The results show that the composite containing higher platelet-alumina has a high Weibull modulus.

     

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