镁铝尖晶石对95氧化铝陶瓷显微结构与力学性能的影响

Effect of magnesium aluminate spinel on the microstructures and mechanical properties of 95 alumina ceramics

在95氧化铝陶瓷粉末中添加6%(质量分数)镁铝尖晶石(MgAl2O4)粉末,于1550℃分别烧结2 h和4 h,制备95氧化铝陶瓷材料。用扫描电镜和X射线衍射仪对陶瓷的形貌和物相组成进行观察和分析,并测试材料的硬度,研究镁铝尖晶石对95氧化铝陶瓷显微结构和力学性能的影响。结果表明,不含MgAl2O4颗粒的Al2O3陶瓷晶粒较粗大,密度较低,延长保温时间可提高陶瓷的致密度和硬度。烧结2 h和4 h得到的纯95氧化铝陶瓷,维氏硬度分别为12.6±0.4 GPa和14.7±0.4 GPa;加入6%MgAl2O4后,陶瓷晶粒细化,且致密度提高,烧结2 h和4 h的陶瓷硬度分别提高到13.5±0.4 GPa和15.5±0.9 GPa。

The effects of 6%magnesium-aluminum spinel(MgAl2O4)on the microstructures and mechanical properties of 95 alumina(Al2O3)ceramics sintered at 1550℃with different holding times(2 h and 4 h)were studied.Scanning electron microscopy and X-ray diffraction were used to observe the ceramic and examine phase assemblage.The results showed that the grain size of Al2O3 ceramics without MgAl2O4 was coarser and have lower density.Prolonging the holding time could increase the density of the ceramics,thereby increasing the hardness of the material.The Vickers hardness with sintered 2 h and 4 h were 12.6±0.4 GPa and 14.7±0.4 GPa,respectively.When 6%MgAl2O4 was added,the grain size of Al2O3 ceramics was decreased,and the relative density was also increased.The hardness were increased to 13.5±0.4 GPa(1550℃/2 h)and 15.5±0.9 GPa(1550℃/4 h).