论文部分内容阅读
通过低温还原,以Si_2OCl_6为原料,以Na溶液为还原剂,在液氨溶液中成功合成了纳米非晶态Si_2N_2O粉末.在不加任何烧结助剂的条件下,通过放电等离子体烧结,得到了致密的陶瓷块体.制得的纳米非晶粉末颗粒尺寸约为20 nm,XRD结果显示样品在1 100℃开始晶化.进一步考察了不同烧结温度下陶瓷的抗氧化性和力学性能,致密块体在1 600℃下经过20 h氧化后,其增重仅有1.1%,烧结块体的力学性能随着烧结温度的增加而迅速增加,当烧结温度高于1 500℃时,继续增加烧结温度力学性能的增加趋势变得平缓.1 500℃烧结样品的维氏硬度、强度和断裂韧性分别达到了19.6 GPa,440 MPa和4.1 MPa·m1/2.
Through the low-temperature reduction, Si 2 OCl 6 as raw material and Na solution as reductant, nano-amorphous Si 2 N 2 O powders were successfully synthesized in liquid ammonia solution, and without any sintering additives, Dense ceramic block.The prepared nano-amorphous powder particle size of about 20 nm, XRD results show that the sample began to crystallize at 100 ℃ further investigated the oxidation resistance and mechanical properties of ceramics at different sintering temperatures, compact block After 20 h oxidation at 1600 ℃, the weight gain of the sintered body increases only 1.1%. The mechanical properties of the sintered lump increases rapidly with the increase of the sintering temperature. When the sintering temperature is higher than 1500 ℃, the sintering temperature continues to increase The trend of increase of mechanical properties becomes gentle.Vickers hardness, strength and fracture toughness of 1 500 ℃ sintered samples reach 19.6 GPa, 440 MPa and 4.1 MPa · m1 / 2, respectively.