热压烧结法制备大尺寸La2O3-TiO2-SiO2非晶材料的研究  

Large-sized La_2O_3-TiO_2-SiO_2 Amorphous Oxide Fabricated by Hot Press Sintering

作　　者：李仁意[1,2] 李晓禹[2] 李建强[2] 赵建玲[1] 马晓光[2] 贺刚[3] 李江涛[3] 

机构地区：[1]河北工业大学材料科学与工程学院,天津300130 [2]中国科学院过程工程研究所,湿法冶金清洁生产技术国家工程实验室,中国科学院绿色过程与工程重点实验室,北京100190 [3]中国科学院理化技术研究所,北京100190

出　　处：《无机材料学报》2017年第8期851-856,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(51674232,51471158,51432004);北京市自然科学基金(2152032,2131006)~~

摘　　要：La_2O_3-TiO2非晶氧化物是一种具有优异光学性能的材料,有着广泛的应用前景,但其非晶形成能力较差,通过无容器凝固制备的材料尺寸通常在10 mm以下。为了获得大尺寸La_2O_3-TiO_2非晶氧化物材料,本研究在La_2O_3-TiO_2氧化物体系中加入少量SiO_2。先通过气动悬浮技术制备非晶粉末,然后用真空热压烧结的方式制备出了高致密度的大块La_2O_3-TiO_2-SiO_2材料,并用XRD、SEM等技术手段进行表征。结果表明:SiO_2可以提高La_2O_3-TiO_2体系的非晶形成能力,通过气动悬浮技术获得的原料粉末呈完全非晶态,通过热压烧结方式获得的块体材料高度致密,仅存在少量的气孔。烧结样品有微弱的晶化,晶化是其无法完全致密的一个重要原因。通过研究烧结曲线,分析了La_2O_3-TiO_2-SiO_2非晶粉末的烧结机制。烧结的La_2O_3-TiO_2-SiO_2材料在可见光区域的折射率大于2.2,具有优异的光学性能。La203-TiO2 amorphous oxide has prospective applications because of its remarkable optical properties. However, due to its poor glass-forming abilities, it is difficult to prepare this material in a traditional way. The contain- erless solidification method can overcome this shortcoming, but the formed material size is generally restricted to be less than 10 mm. In order to obtain large-sized La203-TiO2 amorphous oxide, a small amount of SiO2 was added to the La203-TiO2 oxide system to form the amorphous oxide powders by aerodynamic levitation furnace. Subsequently, the high-density La203-TiO2-SiO2 materials were fabricated by vacuum hot press sintering. Compositions and microstruc- ture properties were systematically studied by XRD and SEM. The results showed that SiO2 could improve the glass-forming ability of La203-TiO2. The raw powders made by aerodynamic levitation fiLrnace were completely non-crystal, while the sintered samples had weak crystallization, which affected fully densification of sintered samples. There was a small amount of porosity in the high-density product made by vacuum hot press sintering. In addition,sintering densification mechanism of the La203-TiO2-SiO2 amorphous powders was analyzed. Finally, the optical property of hot pressed La2Oa-TiO2-SiO2 material was investigated. It is found that La203-TiO2-SiO2 material still kepts high refractive index of above 2.2 in the visible light region. Small amount addition of SiO2 species improves the glass-forming abilities, yet decreases the refractive index slightly.

关 键 词：非晶氧化物 气动悬浮 热压烧结 大尺寸 致密 

分 类 号：TQ171[化学工程—玻璃工业]