Densification of Ceramic Matrix Composite Preforms by Si2N2O Formed by Reaction of Si with SiO2 under High Nitrogen Pressure. Part 1: Materials Synthesis

Ceramic matrix composites (CMCs) have been designed and developed for extreme operating environments. The aim of the present study is to look a rapid densification process providing high level material performance. fibrous preform was made Hi-Nicalon S fibers woven in 3D interlock weave. composed Si2N2O prepared inside CMCs by reacting mixture Si SiO2 under nitrogen pressure (1 3 MPa). Silica either impregnated slurry or obtained oxidation silicon grains preform. synthesis reaction initiated heating means carbon resistor submitted Joule effect. Composition, homogeneity porosity formed were studied interpreted as function experimental parameters (nitrogen pressure, rate preform) well recorded thermal history process. results show that formation almost completed less than one minute. Melting has major influence on Competition observed between Si3N4 Si2N2O, which could be mainly controlled partial pressure.