| 摘 要： | Silicon nitride ceramics show great
potential for wide applications. It is difficult to densify silicon nitride due to its
covalent nature of bonding. A new sintering aid with combination of MgO and CeO2
was used in the present study. The effects of MgO-CeO2 on densification and
phase transformation during sintering of Si3N4 were discussed. For
Si3N4-MgO-CeO2 ceramics，a lot of liquid phase existed
at 1450℃，and densification process took place rapidly from 1550℃ to 150℃；the
phase transformation from α-Si3N4 to β-Si3N4
took place rapidly from 1550℃ to 1660℃，the phase transformation process lags behind
the densification process. The nonpressure sintered Si3N4-MgO-CeO2
ceramics achieved a bending strength of 948MPa. MgO-CeO2 can be considered as
an effective sintering aid for Si3N4.
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