Microfracture Analysis of SiC Reinforced Glass Composites by Acoustic Emission

SiC particulate reinforced glass matrix composites were fabricated by hot pressing. The volume fraction of SiC was changed from 0% to 30%. The elastic modulus of the fabricated composites was consistent with a law of mixture based on the micromechanics. In order to evaluate the mechanical properties of the materials we measured four-point bending strength and fracture toughness (KIC) by Single Edge Pre-cracked Beam (SEPB) method. Acoustic emission (AE) tests were performed during four-point bending and fracture toughness tests. We observed fracture surfaces after bending tests. The bending strength increased with increasing volume fraction of SiC particle. The bending strength of glass was 96MPa and that of the composite reinforced with 30vol% SiC particle was 144MPa. The fracture toughness KIC also increased with increasing volume fraction of SiC particle. The fracture toughness KIC of the composite reinforced with 30vol% SiC particle was 2.1MPam1⁄2. The number of AE events increased with increasing volume fraction of SiC particle. However AE behavior during bending tests is different from that during fracture toughness tests. The total number of AE during fracture toughness tests is more than that during bending tests.