Fabrication of the tube-shaped SiCf/SiC by hot pressing

A manufacturing technique for fabricating a dense tubular SiC long fiber-reinforced SiC composite (SiCf/SiC) by hot pressing was developed. After infiltrating a SiC-based matrix phase, containing a 12 wt% of Al2O3–Y2O3 sintering additive, into the fine voids of a TyrannoTM-SA3 SiC fabric preform by electrophoretic deposition combined with the application of ultrasonic pulses, hot pressing was performed using 2 types of specially designed molds filled with graphite powder to transfer the vertical hot press force efficiently to the sidewalls of the tubular SiCf/SiC. Compared to the low density (~60%) of SiCf/SiC hot-pressed using a conventional mold, a density >95% could be acquired using a special mold filled with graphite powder as a pressure delivering medium. This method is suitable for fabricating a dense tubular SiCf/SiC, which cannot be obtained using a conventional extrusion method.