Effect of surface-modified Si-Al-C Fiber Addition on Mechanical Properties of Silicon Carbide Composite

Abstract

The conditions for the fabrication of silicon carbide (SiC) composite with chopped SA fibers having carbon interface (SA/C) addition were investigated by hot-pressing technique, using the sintering aids (5 mass% Al₄C₃ and 1 mass% B₄C). An acid treatment (75 cm³ H₂SO₄, 25 cm³ HNO₃; 1.0 g SA/C) was carried out in order to enhance the dispersibility of SA/C in the SiC matrix, owing to the bond formation of COO^- groups with the surface of SA/C. The fracture toughness of the SiC composite with no acid-treated SA/C addition was 5.6 MPa∙m^1/2, whereas that of the SiC composite with acid-treated SA/C fiber increased to 7.0 MPa∙m^1/2.