Al_2O_3基多元纳米复相陶瓷的制备及其超塑性  

Fabrication and Superplasticity of Alumina-based Multi-phase Nanocomposite Ceramics

作　　者：谢杰[1] 陈国清[1] 王旭东[1] 董红刚[1] 

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024

出　　处：《稀有金属材料与工程》2007年第A02期239-242,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(批准号:50505005)

摘　　要：采用溶胶-凝胶法制备了Al_2O_3-ZrO_2(3Y)-Spinel纳米复合粉体,其颗粒大小为20～30 nm,粒度分布均匀,无硬团聚。采用真空热压烧结工艺制备了纳米复相陶瓷,结果表明:由于纳米复合粉体中的第二相阻止了基体Al_2O_3的致密化,纳米复合粉体的烧结温度较普通微米粉体相比并没有大幅度降低,其合适的烧结温度为1450～1500℃。烧结体的超塑性压缩试验表明:在1500℃材料表现出良好的超塑变形能力,变形抗力小于30MPa。在整个压缩变形过程中,材料没有出现明显的应变软化,显示出与超塑性拉伸变形截然不同的特性。Components with complex shape can be made of nanocomposite ceramics by taking advantage of their superplasticity, which is an important way in near-net shape forming. The final powders of Al2O3-ZrO2（3Y）-spinel with excellent chemical homogeneity were synthesized by heating of ethanol-aqueous salt solutions method. The powders have good dispersion, with particle size of 20-30nm and no hard agglomeration. The hot-pressing sintering tests of nanocrystalline-grain powders demonstrate that its densification temperature is not much lower than that of the microcrystalline-grain powders because the second-phase dispersion inhibits the densification of the alumina matrix. The proper sintering temperature of alumina-based nanocrystalline powders is ranging from 1450℃ to 1500℃. The superplastic compressive tests of as-sintered specimens demonstrate that this material behaves good deformability at 1500℃, at which the maximum extrusion pressure is lower than 30MPa. During the compression tests at different temperatures the material did not show any strain softening, which was quite different from the results obtained in the tensile tests of this kind of material.

关 键 词：Al2O3基纳米复相陶瓷 制备 烧结 超塑变形 

分 类 号：TQ174.1[化学工程—陶瓷工业]