摘要
按96瓷配比,在-αAl2O3中加入烧结助剂(氟化钙-高岭土),通过水基凝胶注模成型出氧化铝陶瓷坯片。在1570℃,2h条件下无压烧结,制备出原位生长棒状晶自增韧氧化铝陶瓷。研究结果表明:1570℃烧结时完全生成棒状晶,棒晶呈现三维网络状交织在一起,样品的体积密度达到了3.77g/cm3。而不含氟化物添加剂的样品在1500~1600℃下烧结时,不能生成氧化铝棒晶,基本呈椭球状或球状。加入少量的氟化物,经过高温烧结,即可在组织内部原位生成棒状晶,这样棒状晶就起到了纤维或晶须的强韧化作用,大大提高了96瓷氧化铝陶瓷的力学性能,断裂韧性达到了5.25MPa.m1/2,比传统96瓷氧化铝韧性提高了60%。
The 96 percent alumina ceramic disc were prepared by gel casting using kaolin and CaF_2 as sintering additive. The high fracture alumina ceramics were preparing by sintering at 1570 ℃ for two hours. The microstructure of sintered samples was investigated, which shows elongated grain and three-dimensional structures. The density of sintered alumina is 3.77 g/cm^3. The microstructure of alumina is global or ellipsoidal without CaF_2. The mechanical properties at different sintering temperatures were examined. The maximal fracture toughness reaches 5.25 MPa·m^(1/2), which is 60% higher than general. The elongated grain structure is considered to play a remarkable role effect in the increment of fracture toughness.
出处
《真空电子技术》
2005年第4期15-18,共4页
Vacuum Electronics
关键词
氧化铝
注模凝胶
柱状晶
氟化物
断裂韧性
Alumina
Gel-casting
Elongted grain
Fluridizer
Fracture toughness
