Properties of SiC Ceramics Sintered via Liquid Phase Using Al2O3 + Y2O3, Al2O3 + Yb2O3 and Al2O3 + Dy2O3 as Additives: a Comparative Study

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Author(s):	Ribeiro, Sebastiao ; Ribeiro, Giseli Cristina ; de Oliveira, Marcela Rego Total Authors: 3
Document type:	Journal article
Source:	MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 18, n. 3, p. 5-pg., 2015-05-01.
Abstract
Silicon carbide (SiC) ceramics show excellent performance at high temperatures. Due to the high covalence of Si-C bonds, these ceramics are produced successfully only via liquid phase sintering (LPS). In this work, SiC ceramics were sintered via LPS using eutectic mixtures of Al2O3+Y2O3, which served as a standard for comparison, Al2O3+Yb2O3 and Al2O3+Dy2O3. The oxides mixtures were used to form liquid phase during the SiC sintering. Mixtures of SiC and additives were ground, pressed at 300 MPa and sintered at 1950 degrees C for 2 hours. All mixtures showed similar hardness, fracture toughness and flexural strength slightly different. Also the microstructure and crystalline phase were similar, showing that the ytterbium's and dysprosium's oxides can be also used as additive as well the most used oxide, yttrium oxide. (AU)

FAPESP's process:	10/51925-6 - Implementation of the SEVNB method to measure the fracture toughness of liquid phase sintered SiC ceramics using Al2O3-Yb2O3 or Al2O3-Nd2O3 as additives
Grantee:	Sebastião Ribeiro
Support Opportunities:	Regular Research Grants