研究了以Y，Y＋Sm和Sm分别作为α－Sialon形成离子、组份为90wt％α－Sialon（m=1，n=1.7）＋10wt％12H的样品在1650～1800℃热压条件下微观结构变化．结果表明，不同稀土离子对材料中。α-Sialon的晶粒形貌、微观结构的均匀性等都有较明显的影响，α－Sialon在三个组份中都为长柱状晶粒，但长径比不同．因此，改变材料中稀土的种类可能会为材料显微结构设计提供新途径．
The microstructures of Ln-α-Sialon-AlN-polytypoid(Ln=Y, Y+Sm and Sm)dual-phase ceramics, with a overall composition 90wt%α-Sialon(m=1, n=1.7)+10wt%12H,
hot-pressed in the range of 1650～1800℃, were studied by SEM. The results show that in all compositions, α-Sialon grains are small at 1650℃ and part of them exhibits elongated morphology at 1800℃.
The morphologies of α-Sialon grains are slightly varied with different rare-earth elements. Sm-α-Sialon exhibites the finest microstructures
with the aspect ratio of elongated grains of 7～9. In Y-composition, α-Sialon is coarsest grains with the aspect ratio of elongated grains of 2～3. There is
agglomerated AlN-polytypoid in all compositions, and which shows fiber-like morphology. The extent of non-uniform distribution of AlN-polytypoids in these
composite ceramics decreases in the sequence of Y-, Y+Sm- and Sm-composition. These differences of microstructure may be attributed to the effect of different
rare-earth elements on the formation kinetics of Ln-α-Sialon-AlN-polytypoid dual-phase ceramics.
参考文献
| [1] | |
| [2] | Cao G Z, Metselaar R, Chem.Mater., 1991, 3: 242--252. [2] Becher P F. J. Am. Ceram. Soc., 1991, 74: 255--269. [3] Mitom M. J. Am. Ceram. Soc., 1992, 1: 103--108. [4] Jack K H, MRS Vol. 287, ed. I. Wei Chen et al. Massachusetts, 1992, 15--28. [5] Li H X, Sun W Y, Yan D S, et al. In: Yan D S et al ed. Proc. 5th Inter. Sym. on ceramic materials & |
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