ZrSiO_4/α-Al_2O_3反应烧结过程中非晶态物质的形成与演化

Formation and Evolution of Noncrystalline Phase in Reaction-sintering of ZrSiO_4/α-Al2O3 Mixed Powder

采用XRD和TEM等技术研究了ZrSiO4/α-Al2O3反应烧结过程中非晶态物质的形成及演化.结果表明,1400℃莫来石开始形成时体系中的液相是富Al2O3的,随着温度的升高,ZrSiO4分解速率加快及富Al2O3莫来石的形成,液相逐渐向富SiO2方向演化.液相的形成及其演化与莫来石的形成密切相关.

A noncrystalline phase can be formed in the reaction sintering of ZrSiO4/α -Al2O3 mixtures by solid reaction between ZrSiO4 and α-Al2O3. The formation and evolution of the noncrystalline phase was investigated by XRD and TEM techniques. It was shown that the noncrystalline phase is formed at 1400°C, where mullite is initially formed, and it is rich in Al2O3 as compared with stoichiometric mullite. With the temperature increasing, it evolves to be rich in SiO2 due to the enhanced dissociation of ZrSiO4 and the formation of Al2O3-rich mullite. The formation and evolution of the noncrystalline phase is closely related to the growth mechanism of mullite.