摘要
通过机械激活法制备了Al2TiO5/Al2O3(nAl2TiO5∶nAl2O3=1∶4)的陶瓷复合材料。利用X射线衍射(XRD)、扫描电镜(SEM)以及能谱(EDS)分析了不同的温度制度下Al2TiO5/Al2O3陶瓷复合材料的晶粒生长特性。X射线衍射谱图(XRD)显示烧结样品的主晶相为α-Al2O3和Al2TiO5。SEM和EDS分析显示,较低温度下烧结(1350℃)时Al2TiO5晶粒为等轴状。当温度升高到1450℃时,Al2TiO5开始异向长大,形成棒状晶粒。随着温度的升高(1500℃),棒状Al2TiO5的长径比继续增加。而Al2O3则始终为片状和等轴晶粒,且异向生长的Al2TiO5晶粒填充于Al2O3三角晶界处。研究表明,烧结温度的升高会促进晶体异向生长并增加其体积分数。Al2TiO5会阻碍Al2O3基体颗粒进一步生长,所以当Al2TiO5颗粒平均尺寸随着烧结温度增加而增大,Al2O3基体晶粒生长几乎停滞。
Al2TiO5 /Al2O3 ceramic composite with the mole ratio of 1 ∶ 4 was prepared by mechanical activation. The grain growth of Al2TiO5 /Al2O3 ceramic composite at different temperature was studied by X-ray diffraction（ XRD） ,scanning electron microscope（ SEM） and X-ray energy dispersive spectroscopy （ EDS）. The XRD patterns indicated that the primary crystalline phases of sintered samples are α-Al2O3 and Al2TiO5. The SEM observations and EDS microanalysis revealed that Al2TiO5 develope an anisotropic microstructure at low temperature（ 1350 ℃）. As the temperature up to 1450 ℃,Al2TiO5 started to grow anisotropically and rod-like grains were developed. The aspect ratio of Al2TiO5 continued to increase with temperature increasing to 1500 ℃. But Al2O3 grains were always equiaxed and platelet. Rod-like Al2TiO5 with anisotropic growth located mainly at alumina triple points and grain boundaries. According to this study,increasing sintering temperature could enhance anisotropic growth and increase the volume fraction of anisotropic growth grains. Because Al2TiO5 would inhibit the further growth of Al2O3 matrix grains,which resulted in the stagnation of Al2O3＇s grain growth,while the average grain sizes of Al2TiO5 increased with the increasing of sintering temperature.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2010年第4期982-987,共6页
Journal of Synthetic Crystals
基金
福建省自然科学基金(E0310021)
