ZrC formation and the phase relations in the Si–Zr–Mg–O–C system

When MgO+ZrO 2 were used as a sintering aid to SiC ceramics, it was found that ZrO 2 reacted with SiC and MgO to form ZrC and a magnesium silicate. This reaction may provide a new route to synthesize ZrC or prepare ZrC/SiC composites by reaction sintering using ZrO 2 , SiC, and MgO as starting materials. In the present work, formation process of the ZrC phase in the SiC–MgO–ZrO 2 system was addressed. Subsolidus phase relations at 1550 °C of the SiC–MgO–ZrO 2 system and the related SiC–SiO 2 –ZrC–ZrO 2 –MgO (Si–Zr–Mg–O–C) system were investigated.