Ar. Chapman et al., INFLUENCE OF MICROSTRUCTURE ON THE STRENGTH OF NICALON-REINFORCED ALUMINUM METAL-MATRIX COMPOSITES, Journal of Materials Science, 29(17), 1994, pp. 4523-4534
The microstructure and mechanical properties of two aluminium-based co
mposites reinforced with Nicalon fibre are investigated. During compos
ite processing, aluminium carbide forms at the interface as a result o
f a reaction between aluminium and free Magnesium, when present in the
aluminium matrix, diffuses into the outer (approximately 200 nm) laye
r of the fibre where it reacts with the silicon oxycarbide constituent
to form magnesium-containing oxide and also to free carbon for the pr
oduction of more interfacial aluminium carbide. These chemical reactio
ns affect to differing degrees the strength of a fibre, as measured af
ter extraction from the two composites, and influence the respective f
ibre/matrix interfacial friction stress and composite strength. A simp
le rule-of-mixtures approach based upon the measured strength of extra
cted fibres gave some agreement with longitudinal properties of the co
mposite, but treatment of the fibres as bundles, using a Weibull proba
bility distribution of properties, provided more accurate predictions.