Characterization of Liquid Phase Sintered SiC Ceramics with Oxide Additive Materials

Abstract

This paper dealt with the fabricating process of liquid phase sintered (LPS) SiC ceramics containing the oxide additives of Al2O3 and Y2O3, in conjunction with the evaluation of their mechanical properties. LPS-SiC ceramics was sintered at the temperature of 1820 oC under an applied pressure of 20 MPa and a pressure holding time of 2 hour. A commercial SiC powder with an average size of about 0.3 μm was used as a starting powder. LPS-SiC ceramics with additive composition ratios of 1.5 and 2.3 (Al2O3/Y2O3) represented an excellent density of about 3.2 Mg/m3. LPS-SiC ceramics had a flexural strength of about 800 MPa and a fracture toughness of about 8.0 MPa⋅m0.5 at an additive composition ratio (Al2O3/Y2O3) of 1.5.

High temperature characterization of LPS-SiC based materials with oxide additives

“…of additive materials in the complex mixture were 10 wt% and 1.5, respectively. Such a blending condition of additive materials was determined for the proper dispersion of secondary phases, based on the results of previous work [7,10]. The plain woven fabrics of uncoated Tyranno SA SiC fiber (Ube Ltd., Japan) were used for the fabrication of LPS-SiC f /SiC composites.…”