Fracture behaviour of Al2O3/SiC nanocomposite ceramics after crack healing treatment

✍ Scribed by Zdenek Chlup; Petr Flasar; Ando Kotoji; Ivo Dlouhy

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 769 KB
• Volume: 28
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2007.09.007

✦ Synopsis

The self-crack-healing ability was systematically studied using flexural strength measurement of beams containing a semi-elliptical surface crack made by Vickers indenter. Beams of Al 2 O 3 /SiC ceramic nanocomposite with a good self-crack-healing ability predetermined for four-point and three-point bend test were prepared by ceramographic techniques. Flexural strength and fracture toughness were determined using three-and four-point bend method. Thermal aging in range from 1000 • C up to 1300 • C for 1 h was applied to find optimal conditions to heal the samples pre-cracked by the indentation technique. Fractographical analyses using an optical and/or scanning electron microscopy has been carried out to investigate the surface crack behaviour. Very good self-crack healing ability has been proved for surface micro-cracks having length up to 250 m and depth no higher than 100 m.