Abstract Aluminothermic reduction of ZrSiO4 in the presence of carbon was investigated in the SHS (self-propagating high-temperature synthesis) manner. PTFE was employed not only as a reaction promoter to ensure self-sustaining combustion and improve the reduction of ZrSiO4, but as a carburizing agent to take part in carbide formation. The combustion wave velocity and temperature increased with increasing PTFE content, but decreased with carbon. Based on a correlation between combustion temperature and velocity, the activation energy Ea = 180.4 kJ/mol was deduced for the PTFE-activated ZrSiO4/Al/C reaction. According to the XRD and EDS analyses, the phase composition of the synthesized product depended on the total amount of carbon. The SHS reaction produced Al2O3-added Zr-silicides (ZrSi2 and ZrSi)/carbides (ZrC and SiC) composites. With an increase in carbon, the dominate phase was transferred from silicides to carbides. A further increase in carbon led to in situ formation of the ZrC/SiC/Al2O3 composite. The study confirmed ZrSiO4 as a source for the production of zirconium silicides, ZrC, and SiC.

中文翻译：

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ZrSiO4 在碳存在下的铝热还原原位形成 Zr 基硅化物/碳化物复合材料

摘要 以 SHS（自蔓延高温合成）方式研究了在碳存在下 ZrSiO4 的铝热还原。PTFE 不仅用作反应促进剂以确保自持燃烧和改善 ZrSiO4 的还原，而且用作参与碳化物形成的渗碳剂。燃烧波速和温度随着聚四氟乙烯含量的增加而增加，但随着碳含量的增加而降低。根据燃烧温度和速度之间的相关性，推导出 PTFE 活化的 ZrSiO4/Al/C 反应的活化能 Ea = 180.4 kJ/mol。根据 XRD 和 EDS 分析，合成产物的相组成取决于碳的总量。SHS 反应产生了添加了 Al2O3 的 Zr-硅化物（ZrSi2 和 ZrSi）/碳化物（ZrC 和 SiC）复合材料。随着碳的增加，主要相从硅化物转移到碳化物。碳的进一步增加导致 ZrC/SiC/Al2O3 复合材料的原位形成。该研究证实 ZrSiO4 是生产硅化锆、ZrC 和 SiC 的来源。