Self-propagating high-temperature synthesis of ZrO_2 incorporated Gd_2Ti_2O_7 pyrochlore

作     者：Le PENG Kuibao ZHANG Zongsheng HE Dan YIN Jiali XUE Chen XU Haibin ZHANG 

作者机构：State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials Southwest University of Science and Technology Science and Technology on Surface Physics and Chemistry Laboratory China Academy of Engineering Physics Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics 

出 版 物：《Journal of Advanced Ceramics》 (先进陶瓷（英文）)

年 卷 期：2018年第7卷第1期

页      面：41-49页

核心收录：

学科分类：0817[工学-化学工程与技术] 08[工学] 

基　　金：supported by the National Natural Science Foundation of China(Nos.51672228 and 51202203) the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials(No.11zxfk26) the Young Outstanding Scientist Fund of Southwest University of Science and Technology(No.13zx9108) the Postgraduate Innovation Fund Project by Southwest University of Science and Technology(No.16ycx010) 

主　　题：self-propagating high-temperature synthesis plus quick pressing (SHS/QP) pyrochlore thermal transmission waste form aqueous leachability 

摘      要：In this research, Zr-doped Gd_2Ti_2O_7 pyrochlores, with the composition of Gd_2(Ti_(1-x)Zr_x)_2O_7, were firstly synthesized by self-propagating high-temperature synthesis plus quick pressing(SHS/QP) using CuO as the oxidant and Ti as the reductant. To improve the radiation resistance of titanate–pyrochlore, up to 35 at% Zr was incorporated to substitute the Ti site of Gd_2Ti_2O_7 pyrochlore(Gd_2(Ti_(0.75)Zr_(0.35))_2O_7). XRD and SEM microstructural characterizations showed the formation of a composite ceramic with the major pyrochlore phase and the minor Cu phase. The generated temperature of samples decreased from 1702to 1011 ℃ with increasing Zr content. The effects of sintering temperature and pressure time on phase composition and microstructure were systematically studied. Besides, the influence of thermal transmission on the whole combustion process was also explored. The pyrochlore-based waste form possessed high bulk density of 6.25 g/cm^3 and Vickers hardness of 10.81 GPa. The MCC-1 leaching test showed the normalized elemental leaching rates(42d) of Cu, Gd, and Zr are 1.27×10^(-2), 1.33×10^(-3), and 8.44×10^(-7)g·m^(-2)·d^(-1), respectively.