XUE Haifeng , CHEN Han , CHEN Cheng , GUO Lucun
(College of Materials Science and Engineering, Nanjing University of Technology, Nanjing Jiangsu 210009,China)
Abstract: SiCsf/SiC (Short SiC fiber reinforced SiC) composites were fabricated by pressless sintering with Y2O3 and Al2O3 as the additives. The effect of oxidation treatment of SiC fibers on the microstructure and mechanical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the measurement of fracture strength and fracture toughness. The results show that after oxidation treatment, the fracture strength and fracture toughness of the composites increased. Composites with 5wt% treated SiC fibers obtained the highest fracture toughness, 5.41MPa·m1/2, which is an increase of 6.5% compared with those with untreated fiber reinforced SiC, a further increase of 27% over those monolithic SiC samples. The combination of fiber and matrix is found to be compact by SEM photographs.
Keywords: SiCsf/SiC composites, pressless sintering, mechanical property, oxidation treatment