Ceramics-Silikáty 51 (4) 210-212 (2007)

DILATOMETRIC STUDY OF Si₃N₄–LAS SYSTEM

B. Matović, A. Saponjić, M. Posarac, A. Egelja, A. Radosavljević-Mihajlović, S. Bosković

The possibility of using Li-exchanged zeolite (LAS) as additive for densification of Si₃N₄ ceramic was studied. Dilatometry was used to measure the shrinkage behavior of green bodies prepared from zeolitic precursor and Si₃N₄ powder under a nitrogen atmosphere from room temperature to 1500°C. Results show that the first liquid forms as low as 1080°C, resulting in a significant reduction of sintering temperature. XRD data reveal that phase transformation from a– to b–Si₃N₄ takes place after the second phase has been completely converted into a glassy phase. The results show that the Li-exchanged zeolite is a very effective low temperature sintering additive for silicon nitride.

Keywords: Si₃N₄, Additive, Ion-exchanged zeolite, Dilatometer, XRD