Preparation and characterization of zirconia-yttria/zirconia-magnesia composites

Author(s)

Caproni, E. ; Muccillo, R. ; Salgado, L ; Filho, FA

• Document type: Journal article
• Source: Materials Science Forum; v. 530-531, p. 2-pg., 2006-01-01.

Abstract

ZrO2: 3mol% Y2O3 powders were mixed in different proportions to ZrO2: 8 Mot% MgO, pressed and sintered at 1500 degrees C for producing composites with oxygen ion conductivity better than that of ZrO2: 8 mol% MgO and thermal shock resistance better than that of ZrO2: 3 Mot% Y2O3 The electrical conductivity was evaluated by the impedance spectroscopy technique at 600 degrees C as a function of the partial pressure of oxygen using zirconia-based oxygen pump and sensor. The thermal shock resistance was studied by room temperature-1550 degrees C dilatometry on sintered pellets. Moreover the composites were studied by X-ray diffraction and scanning electron microscopy. All composites are partially stabilized in the monoclinic-tetragonal phase and the apparent density is higher than 90% of the theoretical density. The thermal shock behavior of the composites is similar to that of ZrO2:8 mot% MgO materials used in disposable high temperature oxygen sensors. The electrical response of the composites at high temperatures is better than the electrical response of ZrO2:8 mot% MgO. (AU)

• FAPESP's process: 98/14324-0 - Multidisciplinary Center for Development of Ceramic Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 99/10798-0 - Study of intergranular phenomena in ceramic oxides
• Grantee: Reginaldo Muccillo
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 03/07331-0 - Estudo de eletrólitos sólidos cerâmicos a base de óxido de zircônio para a detecção de teor de oxigênio
• Grantee: Érica Caproni
• Support Opportunities: Scholarships in Brazil - Doctorate