CHARACTERIZATION OF LIQUID PHASE SITERED SIC AND SIC/SIC COMPOSITE MATERIALS

Abstract

The characterization of liquid phase sintered(LPS) SiC based materials has been investigated with the analysis of microstructure and flexural strength. Especially, LPS - SiC materials were examined for the variation of test temperature and composition ratios ( Al 2 O 3,/ Y 2 O 3) of sintering additives. LPS - SiC based materials were fabricated by hot pressing(HP) associated with the liquid phase formation of sintering additives( Al 2 O 3, Y 2 O 3). LPS - SiCf / SiC composites were also fabricated with plane-woven(PW) Tyranno-SA fibers without an interfacial layer. LPS - SiC materials showed a dense morphology with the creation of the secondary phase like YAG. The composition ratio of sintering additives led to the variation of sintered density and flexural strength. The flexural strength of LPS - SiC materials was greatly decreased at the temperature higher than 1000°C. LPS - SiCf / SiC composites represented an average flexural strength of about 260 MPa, accompanying the catastrophic fracture behavior without any full-out phenomena.