In-situ reactive infiltration of carbon-fiber and C/SiC core-shell fiber fabrics with Ti-rich melt in thermally initiated combustion synthesis of ceramic matrix composites

Polyacrylonitrile derived carbon-fiber fabric and C/SiC core-shell fiber fabric have been examined to assess their applicability to the synthesis of fiber-reinforced Ti 3 SiC 2 MAX phase ceramic composites using a method based on thermally initiated combustion reaction followed by an in-situ reactive melt infiltration process. The synthesis was conducted in a vacuum hot press furnace at 1500 °C under 2.5 MPa for 30 min. Microstructural analysis of the synthesis products revealed that the behavior of carbon fibers and C/SiC core-shell fibers toward Ti-rich melts differed significantly from each other, resulting in the different degrees of fiber fabric impregnation. In the case of the carbon fiber fabric, a large portion of the fibers were found to remain essentially unimpregnated. In the case of the C/SiC core-shell fiber fabric, all fabric layers were well infiltrated with matrix material , but the fibers themselves underwent severe structural degradation and were therefore recognized to be virtually incompatible with Ti-rich melts.