锆莫来石材料的反应烧结机制

Reaction-Sintering Mechanism of Mullite-Zirconia Composites

本文通过研究烧成温度和添加物MgCl_2·5H_2O对反应烧结锆-莫来石材料物理性能、相组成和显微结构的影响,讨论了锆莫来石材料的反应烧结机理。认为ZrSiO_4-Al_2O_2反应过程中莫来石形成和ZrsiO_4分解两步骤并不同步发生;添加物MgCl_2·5H_2O能促进反应烧结过程;反应烧结过程中封闭气孔的出现与原始ZrSiO_4大颗粒有密切关系;材料结构中ZrO_2有较均匀分布和聚集体两种分布形式。

In order to clarify the reaction-sintering mechanism of mullite-ZrO_2 composites,the ef-fect of heat treatment temperature and MgCl_2· 5H_2O additive on physical properties,phasecomposition and microstructure was investigated. The results indicate that the formation ofmullite and the decomposition of ZrSiO_4 during ZrSiO_4-Al_2O_3 reaction do not occur simulta-neously; the reaction-sintering process is promoted with MgCl_2· 5H_2O addition;the appear-ance of enclosed pores is closely related to the starting large ZrSiO_4 particles and ZrO_2 in mi-crostructure of reaction--sintered composite can be relatively well distributed or aggregated.