Transactions of the INDIAN CERAMIC SOCIETY Vol. 57 1998
Processing of Al20/Al Interpenetrating Composites
R. BHAT, K. BHANUMURTHY AND S. K. Rov
Pages : 134-136
DOI : 10.1080/0371750X.1998.10804853
Abstract
Microstructural developments duriag the processing of
Al20/Al interpenetrating composite by an exchange reaction
between silica glass preform and molten aluminium at the
temperature range of 1000°-l200°C with varying reaction
time between 10 min and 24 h were studied. Reaction was
arrested after predetermined times and partly reacted
!amples were analyzed for phase composition and microstructure.
It is observed that an intermediate phase of several
microns thick separates the glass and the composite phases
and is consumed in the fully converted composites. This transition
phase contain predominantly AI as revealed by EPMA,
and seems to act as source of AI for continued reaction with
Si02• Small nuclei of the Al20 3 are formed in this phase which
subsequently grow and impinge into each other. The space
among the Al20 3 crystals are tilled up with molten metal to
form dense composite with interpenetrating network of AI
and Al20 3• The size of the Al20_, grains are dependent on the
temperature of composite formation. No texture formation
was obsened.