Fabrication and characteristic of non-oxide fiber tow reinforced silicon nitride matrix composites by low temperature CVI process

Non-oxide fiber tow reinforced silicon nitride matrix composite was fabricated by low temperature CVI process with PyC as interphase. The tensile strength of the C and SiC fiber tow composites were 547 MPa and 740 MPa, respectively. The difference in tensile strength was analyzed based on the length, amount of pull-out fiber and also interface bonding. The infiltration uniformity of CVI silicon nitride (SiN) matrix within SiC fiber tow was comparable with that of CVI SiC matrix. These results suggested that the low temperature CVI process is suitable for the fabrication of fiber reinforced SiN matrix composites with proper interface bonding and high strength.