Fracture toughness of dense cordierite: sintering cycle effect

• Author(s): Oliveira, F. A. Costa ; Fernandes, Jorge Cruz ; Schmitt, Julien ; Rosa, Luís Guerra ; Dias, Diamantino
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.9/2185
• Origin: Repositório do LNEG
• Subject(s): Cordierite; Fracture Toughness; Sintering; Strength
• Document Type: Article
• Language: English

Description

The aim of this work was to analyse the fracture behaviour of commercial dense cordierite bodies sintered in an electrical furnace in static air at 1250ºC, 1275ºC and 1300ºC for 30 min using different cycling schedules in order to obtain tougher materials at minimum energy costs. Using a stereomicroscope and a scanning electron microscope, fracture surfaces of as-sintered bars tested under four-point bending at room temperature were examined at different magnification levels in order to determine the origin of fracture in each sintered bar. Once the fracture origin was identified, it was possible to measure its size, and based on ASTM C1322-96a standard, we were able to estimate the fracture toughness of the sintered parts. Fracture toughness was found to increase with increasing of sintering temperature from 1.8 MPa·m½ to 3.1 MPa·m½ by rising the temperature from 1250ºC to 1300ºC as the fracture process is strongly influenced by the microstructure of the material.