Effect of La2O3 additives on the strength and microstructure of mullite ceramics obtained from coal gangue and γ-Al2O3

被引：100

作者：

Ji, Haipeng ^{[1
]}

Fang, Minghao ^{[1
]}

Huang, Zhaohui ^{[1
]}

Chen, Kai ^{[1
]}

Xu, Youguo ^{[1
]}

Liu, Yan'gai ^{[1
]}

Huang, Juntong ^{[1
]}

机构：

[1] China Univ Geosci Beijing, Natl Lab Mineral Mat, Sch Mat Sci & Technol, Beijing 100083, Peoples R China

来源：

CERAMICS INTERNATIONAL | 2013年 / 39卷 / 06期

基金：

中国国家自然科学基金;

关键词：

Microstructure; Strength; Clays; Mullite; TAPE-CAST KAOLIN; PHASE-FORMATION; FLY-ASH; WHISKERS; GROWTH; ALUMINA; MIXTURES; SYSTEMS; Y2O3;

D O I：

10.1016/j.ceramint.2013.02.016

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Self-strengthened mullite ceramics with interlocking columnar grains formed through enhanced anisotropic growth by adding La2O3 were prepared from coal gangue and gamma-Al2O3 within the temperature range 1400-1550 degrees C and holding time of 4 h. The effects of La2O3 on the bending strength, microstructural evolution, and phase composition were studied. The results showed that the bending strength of the as-prepared ceramics was significantly improved by the addition of La2O3. For samples sintered at 1550 degrees C, the bending strength increased from 64 MPa to 218 MPa as the La2O3 content increased from 0 mol% to 10 mol%. X-ray diffraction analysis suggested that the formation temperature of secondary mullite was lowered by about 50 degrees C by adding La2O3. Scanning electron micrographs revealed that the La2O3-added mullite mostly existed in long, columnar form, with aspect ratios of 3-6, forming an interlocking network structure. The interlocking mullite columns, together with the enhanced densification behaviour, contributed to the improved bending strength. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

引用

页码：6841 / 6846

页数：6

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