Journal of Inorganic Materials ›› 2017, Vol. 32 ›› Issue (8): 851-856.DOI: 10.15541/jim20160619

• Orginal Article • Previous Articles     Next Articles

Large-sized La2O3-TiO2-SiO2 Amorphous Oxide Fabricated by Hot Press Sintering

LI Ren-Yi1, 2, LI Xiao-Yu2, LI Jian-Qiang2, ZHAO Jian-Ling1, MA Xiao-Guang2, HE Gang3, LI Jiang-Tao3   

  1. (1. School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China; 2. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; 3. Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China)
  • Received:2016-11-08 Revised:2016-12-23 Published:2017-08-10 Online:2017-07-19
  • About author:LI Ren-Yi. E-mail: ryli@ipe.ac.cn
  • Supported by:
    National Natural Science Foundation of China (51674232, 51471158, 51432004);Beijing Natural Science Foundation (2152032, 2131006)

Abstract:

La2O3-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 containerless 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 La2O3-TiO2 amorphous oxide, a small amount of SiO2 was added to the La2O3-TiO2 oxide system to form the amorphous oxide powders by aerodynamic levitation furnace. Subsequently, the high-density La2O3-TiO2-SiO2 materials were fabricated by vacuum hot press sintering. Compositions and microstructure properties were systematically studied by XRD and SEM. The results showed that SiO2 could improve the glass-forming ability of La2O3-TiO2. The raw powders made by aerodynamic levitation furnace 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 La2O3-TiO2-SiO2 amorphous powders was analyzed. Finally, the optical property of hot pressed La2O3-TiO2-SiO2 material was investigated. It is found that La2O3-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.

Key words: amorphous oxide, aerodynamic levitation, hot-press sintering, large-size, densification

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