【摘要】 为了研究3Y TZP为基体的3Y TZP/mullite Alumina复合陶瓷的断裂韧性及其增韧机制,将3Y TZP、mullite、Alumina3种粉料球磨混合,经干压、等静压成型,在1480℃,4h无压烧结,通过改变Alumina/mullite体积比,得到了不同断裂韧性的陶瓷复合材料,利用XRD与SEM技术分析了复合材料的成分及微观结构.研究结果表明:Al2O3/mullite体积比影响复合材料中四方氧化锆(t ZrO2)向单斜氧化锆(m ZrO2)转变的相变量、复合材料的微观结构和t ZrO2晶面间距,进而影响材料的断裂韧性;用单边切口梁法测试复合材料断裂韧性(KIC)为9 26～10 4MPa·m1/2;此系统中存在ZrO2相变增韧、非相变第二相颗粒增韧等机制.更多还原

【Abstract】 The composites were prepared by a process of mixing 3Y-TZP, mullite and alumina by ball-milling, pressing unidirectionally, cold-pressing isostatically, and sintering in air. The composites with different fracture toughness were obtained by change of volume ratio of alumina to mullite. The compositions and microstructure of composites were examined by a X-ray diffractometer and a scanning electron microscope. The volume ratio of Al₂O₃ to mullite affected the transformable fraction of t-ZrO₂to m-ZrO₂, microstructure of the composites, and plane distance of t-ZrO₂, which lead to the difference of the fracture toughness. The fracture toughness of composites sintered at 1 480 ℃ for 4 hour in air was 9.26 ～10.4 MPa·m^1/2 tested by the single-edge notched bending （SENB）. In the composites, in addition to the contribution of the enhanced phase transformation, the dispersion-toughening of particles was also one of the main toughening mechanism.更多还原