Wh. Tuan et al., THE EFFECTS OF MICROSTRUCTURE ON THE MECHANICAL-PROPERTIES OF AL2O3-NIAL COMPOSITES, Materials chemistry and physics, 56(2), 1998, pp. 157-162
In the present study, the room-temperature mechanical properties of Al
2O3-NiAl composites containing 0 to 100 vol.% NiAl are determined. The
composites are prepared by attrition milling Al2O3 and NiAl powders t
ogether followed by hot-pressing in vacuum. The Al2O3 and NiAl grains
in the composites constrain each other's growth. Since the hardness of
NiAl is lower than that of Al2O3, the hardness of the composites decr
eases with the increase of NiAl content. The strength and toughness of
the Al2O3-NiAl composites are higher than the values predicted by the
rule of mixtures. The strengthening effect is mainly contributed by t
he microstructural refinement. Because the Al2O3/NiAl interface is wea
k, cracks propagate mainly along the interfaces. The fracture toughnes
s is thus enhanced. (C) 1998 Elsevier Science S.A. All rights reserved
.