What roles do ceramic matrix and woven fibers have in bending strength of SiO2/SiO2 composites: An experimental investigation and acoustic emission analysis

Abstract The main purpose of this paper is to analyze the key impact factors of bending strength of long fiber reinforced ceramic matrix woven composites (LFRCWC), and to distinguish the contributions from fibers and matrix. Four-point bending experiments on 2.5D woven quartz fiber reinforced silicon dioxide ceramic matrix (SiO 2 /SiO 2 ) composites were conducted; in the meantime acoustic emission (AE) signals were collected. Material damage types were discriminated by clustering and analyzing the AE signals as well as comparing with SEM images. The damage types and bending strength of different fiber directions and matrix qualities were considered integrally and the following conclusions can then be drawn: 1) matrix quality has an important role in the strength of SiO 2 /SiO 2 composites; 2) the tensile loading capacity of fibers can also influence the bending strength; 3) the porosity and a new proposed parameter- evaporation characteristic time (ECT) can be used to evaluate matrix quality.