Phase formation of Si-based ceramic composites from polyureasilazane prepared by hot pressing and EFAS

Si-based ceramic composites were fabricated using two sintering techniques: hot pressing and electric-field-assisted sintering (EFAS). Liquid polyureasilazane was cross-linked and pyrolysed, then subjected to planetary ball milling for 24 h, followed by sintering at 1500–1700 °C in a hot press for 1 h and EFAS for 10 min. The phase formation behavior was different in the hot pressing than in the EFAS. The decomposition of Si2N2O began at 1600 and 1500 °C in the hot pressing and EFAS, respectively.