RELATIONSHIP BETWEEN MICROSTRUCTURE, FRACTURE AND WEAR IN Al2O3/SiC NANOCOMPOSITES AND CONTAINING 5 AND 10% SiC

• Published in: Journal of the European Ceramic Society 2009-10, Vol.29 (13), p.2841-2848
• Main Authors: Limpichaipanit, A, Todd, R I
• Format: Article
• Language: English
• ISSN: 0955-2219

Alumina/SiC nanocomposites are much more to severe wear than monolithic alumina. To the mechanisms responsible for these alumina and alumina/SiC nanocomposites with 5 and vol% SiC and various alumina grain sizes were For comparison, a 10 vol% SiC 'microcomposite' also fabricated using 3 micron SiC particles. The of cracking beneath hardness indentations was and the specimens were tested in abrasive wear. surface fractography of the worn surfaces was out. The wear properties depended strongly on the size in pure alumina, but were independent of the grain size in the nanocomposites. This is with the idea that much of the improvements in resistance when SiC was added to alumina stemmed a reduction in the size of the individual owing to the accompanying change in fracture Crack initiation by plastic deformation during and indentation was strongly inhibited when 10 nanosized SiC was added to alumina. The addition 3 micron 'micro-sized' SiC did not have the same The ability of fine SiC particles to suppress is attributed to the blocking of twins and pileups by intragranular SiC nanoparticles. This the length of the twins or pileups and hence ability to nucleate microcracks.