中文摘要：

针对单一相ZrO_2增韧Al_2O_3（ZTA）陶瓷在提高韧性的同时不能合理兼顾其耐磨性能,利用稀土氧化物能促进复合陶瓷材料热压烧结的工艺特点,将La_2O_3/Y_2O_3添加到ZTA陶瓷材料中,XRD衍射图谱表明：La_2O_3/Y_2O_3的添加可以有效阻碍ZrO_2不稳态晶型相变,促进介稳态t-ZrO_2的形成。当添加量为4%（质量分数）时,烧结后晶粒分布最为均匀,致密程度高,其维氏硬度、抗弯强度、断裂韧性分别比相应未添加稀土氧化物的ZTA材料提高了8%、21%、33%,且La_2O_3与Al_2O_3会发生原位反应生成片状LaAl_（11）O_（18）,这种片晶不仅可以阻碍Al_2O_3、ZrO_2颗粒长大,还可通过晶粒拔出等增韧机制提高材料韧性。摩擦磨损试验结果表明：稀土氧化物的添加能提高ZTA陶瓷材料的耐磨性能,添加量为4%时其磨损率最低。

英文摘要：

Aiming at the mutual exclusion of moderate wear resistance and improved fracture toughness in single phase ZrO_2-toughened Al_2O_3（ZTA）ceramic,taking advantage of rare earths′benefit to the hot-pressing sintering of composite ceramics,La_2O_3/Y_2O_3 were added into ZTA ceramic to toughen and reinforce the material.X-ray diffraction patterns showed that La_2O_3/Y_2O_3 can not only hinder the unsteady crystal phase transition of ZrO_2,but also promote the formation of t-ZrO_2.The grain size was fine in the matrix and the high density was achieved when La_2O_3/Y_2O_3 content was 4%,while the hardness,flexural strength and fracture toughness increased by 8%,21%,33%,respectively,compared with traditional monolithic ZTA ceramics.Under the condition of hot-pressing sintering,the LaAl_（11）O_（18） compound generated by in-situ reaction of La_2O_3/Y_2O_3 can act as an inhibitor against the growth of Al_2O_3,ZrO_2 particles,and moreover,improve the toughness through‘pull-out＇effect.Friction and wear testing results indicated that rare earth oxides can improve the wear resistance of ZTA ceramic materials,with an optimum content of 4% to achieve the lowest wear rate.