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

Autor(es)

Ribeiro, Sebastiao ; Ribeiro, Giseli Cristina ; de Oliveira, Marcela Rego

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 18, n. 3, p. 5-pg., 2015-05-01.

Resumo

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)

• Processo FAPESP: 10/51925-6 - Implantação do método SEVNB para medida da tenacidade a fratura de cerâmicas de SiC sinterizadas via fase líquida com aditivos de Al2O3-Yb2O3 ou Al2O3-Nd2O3
• Beneficiário: Sebastião Ribeiro
• Modalidade de apoio: Auxílio à Pesquisa - Regular