Si3N4-SiCp composites reinforced by in situ co-catalyzed generated Si3N4 nanofibers

Abstract

Si 3 N 4 - SiC p composites reinforced by in situ catalytic formed nanofibers were prepared at a relatively low sintering temperature. The effects of catalyst Co on the phase compositions, microstructures, and physicochemical-mechanical properties of samples sintered at 1350°C-1450°C were investigated. The results showed that the catalyst Co enhanced the nitridation of Si. With the increase of Co addition (from 0 wt% to 2.0 wt.%), the apparent porosity of as-prepared refractories was initially decreased and subsequently increased, while the bulk density and the bending strength exhibited an opposite trend. The Si 3 N 4 - SiC p composites sintered at 1400°C had the highest strength of 60.2 MPa when the Co content was 0.5 wt.%. The catalyst Co facilitated the sintering of Si 3 N 4 - SiC p composites as well as the formation of Si3N4 nanofibers which exhibited network connection and could improve their strength. © 2014 Juntong Huang et al.