摘要
La_2O_3-TiO_2-ZrO_2玻璃具有很高的折射率,在镜头材料和上转换发光基质材料等领域表现出良好的应用前景,但其玻璃形成能力低,通常只能采用快速冷却的方法制备,因此难以获得大尺寸材料。为了获得大尺寸La_2O_3-TiO_2-ZrO_2玻璃,本研究采用La_2O_3-TiO_2-ZrO_2非晶粉末为原料,利用非晶在玻璃转变温度以上的塑性行为,在温度动力学窗口ΔT内进行热压烧结制备了大尺寸La_2O_3-TiO_2-ZrO_2玻璃,在保持非晶的前提下实现了La_2O_3-TiO_2-ZrO_2粉末的完全致密化。采用SEM、XRD等方法研究了样品的显微结构和相组成。研究发现,当烧结温度高于910℃时,烧结过程中会析出La4Ti9O24晶相;当烧结温度低于900℃时,样品保持良好的非晶性,并随着烧结温度的增加,样品的致密度有所升高。烧结压力也会影响烧结过程,样品的致密度随着烧结压力升高而增加。大尺寸La_2O_3-TiO_2-ZrO_2非晶材料具有很高的折射率,在587.6nm处折射率可达到2.33。在La_2O_3-TiO_2-ZrO_2非晶粉末烧结过程中,塑性流动是其主要的传质机理。
La2O3-TiO2-ZrO2 glass has great potential applications in lens and upconversion host materials for its ultrahigh refractive index. However, due to its low glass forming ability, it can only be prepared by some extremely rapid melt cooling method, which is hard to produce large-sized materials. On the basis of amorphous plastic behavior above the glass transition temperature Tg, large-sized La2O3-TiO2-ZrO2 bulk glasses were obtained by hot pressed sintering within the thermodynamic window ΔT. 30.8% LaO3/2-59.2% TiO2-10% ZrO2 amorphous spheres were firstly prepared by aerodynamic levitation furnace. Whereafter, these spheres were smashed and ground into powders. Then these glass powders were hot pressed into a bulk glass with dimension of Φ20 mm×1 mm. The effects of sintering temperature and pressure on the process of hot pressed sintering were investigated. Microstructures and phase compositions of samples were studied by SEM and XRD. The results show that the samples sintered above 910 ℃ contain a few La4Ti9O24 crystal phases, while the samples sintered below 900 ℃ are totally amorphous. When the sintering temperature is below 900 ℃, the increase of sintering temperature in a certain range can reduce the number of pores apparently to improve the density of samples. And with the increase of pressure from 20 MPa to 60 MPa, the density of bulk glass prepared by hot pressing at 900 ℃ increases from 4.8797 g/cm3 to 5.1178 g/cm3. The large-sized La2O3-TiO2-ZrO2 glass displays excellent optical performance with refractive index of 2.33 at the wavelength of 587.6 nm and the abbe number of 13.2. By analyzing the shrinkage curve of the samples, it is confirmed that the plastic flow is the main mass transfer way during densification process.
作者
王椎
韩建军
李建强
李晓禹
李江涛
贺刚
谢俊
WANG Zhui;HAN Jian-Jun;LI Jian-Qiang;LI Xiao-Yu;LI Jiang-Tao;HE Gang;XIE Jun(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China;CAS Key Laboratory of Green Process and Engineering,National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China;Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第4期433-438,共6页
Journal of Inorganic Materials
基金
国家自然科学基金(51674232
51471158
51432004)~~
关键词
无容器凝固
非晶
热压烧结
致密化
塑性流动
containerless method
amorphous
hot-pressed sintering
densification
plastic flow
作者简介
王椎(1994-),男,硕士研究生.E-mail:wangzhui@ipe.ac.cn;通讯作者:李建强,研究员.E-mail:jqli@ipe.ac.cn.
