BRITTLE FRACTURE IN MONOLITHIC ALUMINA
Alumina
with 5 vol% of Nano sizedSiCwas sintered by a hot pressing method at 30 MPa for
1 h in an argon gas atmosphere. Hot
pressed temperature was varied from 1500 to 1800ºC. Since the alumina matrix was
significantly dependent upon the hot pressing temperature, tribological
properties related to microstructure should be investigated. As the sintering temperature was
increased, wear volume increased. However,
wear volume of nanocomposites sintered at high temperatures had lower values
than those of monolithic alumina. The
wear mechanism of nanosized silicon carbide reinforced alumina nanocomposites
can be explained by observing the worn surface by scanning electron microscopy
and transmission electron microscopy. Monolithic
alumina showed dislocation layers inside single grains along the sliding
direction. However,
alumina-silicon carbide nanocomposite showed interference of dislocations by
silicon carbide particles in the alumina matrix grains. Also, alumina-silicon carbide
nanocomposites show more wear resistance due to the micro crack pinning by the
nanosized silicon carbide particles.
(MICROSTRUCTURE OF BRITTLEFRACTURE IN MONOLIOTHIC ALLUMINA)
(CRYSTALSTRUCTURE OF BRITTLE FRACTURE)
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