ZnAl2O4-Ca3Al4ZnO10复相材料的制备及化学稳定性  

Preparation and Chemical Stability of ZnAl2O4-Ca3Al4ZnO10 Composites

作　　者：叶明亮 滕元成[1] 王山林 唐佳媛 YE Mingliang;TENG Yuancheng;WANG Shanlin;TANG Jiayuan(College of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学材料科学与工程学院,绵阳621010

出　　处：《中国陶瓷》2020年第11期19-26,共8页China Ceramics

基　　金：国家自然科学基金(NO.11275158);西南科技大学龙山人才计划项目(17LZX407,18LZX412)。

摘　　要：针对SiC陶瓷固化高放石墨难烧结问题,拟用ZnO-Al2O3-CaO(ZAC)多相材料为SiC陶瓷固化体的低温烧结助剂,阐明ZAC烧结助剂组成-结构-性能的调控机制是SiC陶瓷安全固化高放石墨的关键问题之一。采用熔融水淬工艺制备ZnAl2O4-Ca3Al4ZnO10复相材料,利用X射线衍射、扫描电镜、水化放热、耐酸耐水等分析测试方法,研究了ZnO含量对ZnAl2O4-Ca3Al4ZnO10复相材料的熔融特性、物相组成及化学稳定性的影响。结果表明,在ZAC体系中,随着ZnO含量的增加,复相材料的高温流动温度(FT)逐渐降低,CaAl2O4和Ca3Al2O6的相对含量逐渐减少或消失,ZnAl2O4、Ca3Al4ZnO10和ZnO的相对含量逐渐增加,化学稳定性逐渐变好;ZAC体系的高温熔体在冷却过程中具有较强的析晶性能,CaAl2O4和Ca3Al2O6的存在会对ZnAl2O4-Ca3Al4ZnO10复相材料的化学稳定性造成严重的负面影响;制备ZnAl2O4-Ca3Al4ZnO10复相材料的较佳配方为C-40(CaO含量为25.09 wt%,Al2O3含量为34.91 wt%,ZnO含量为40 wt%),其样品的高温流动温度为1366.2℃,晶相为ZnAl2O4、Ca3Al4ZnO10、ZnO,且化学稳定性优良。Aiming at the problem that SiC ceramics for immobilization of high-level radioactive graphite is difficult to be sintered,multiphase material of ZnO-Al2O3-CaO(ZAC)is proposed to be used as the assistant agent for the low temperature sintering of SiC ceramics.The regulation mechanism of composition,structure and performance of ZAC sintering assistant agent is one of the key issues for SiC ceramics safe curing high-level radioactive graphite.In this paper,ZnAl2O4-Ca3Al4ZnO10 composites was prepared by meltingwater quenching process.The effects of ZnO content on the melting characteristics,phase composition and chemical stability of ZnAl2O4-Ca3Al4ZnO10 composite were studied by X-ray diffraction,scanning electron microscopy,hydration heat release,acid and water resistance and other analytical and testing methods.Results show that in ZAC system,as the increase of ZnO content,complex material of high temperature and flow temperature(FT)gradually reduce,relative content of CaAl2O4 and Ca3Al2O6 reduce or disappear,relative content of ZnAl2O4,Ca3Al4ZnO10 and ZnO increased gradually,chemical stability get better.The high temperature melt of ZAC system has strong crystallization performance during cooling.The presence of CaAl2O4 and Ca3Al2O6 will seriously affect the chemical stability of ZnAl2O4-Ca3Al4ZnO10 complex materials.The better formulation of ZnAl2O4-Ca3Al4ZnO10 composites was C-40(CaO content 25.09 wt%,Al2O3 content 34.91 wt%and ZnO content 40 wt%),its high temperature flow temperature was 1366.2℃,its crystal phase was ZnAl2O4,Ca3Al4ZnO10 and ZnO,it has excellent chemical stability.

关 键 词：ZnO-Al2O3-CaO ZNAL2O4 Ca3Al4ZnO10 化学稳定性 SIC 

分 类 号：TQ174.758.11[化学工程—陶瓷工业]