The mechanical properties of metal matrix composites (MMCs) are critical to
their potential application as structural materials. A systematic examinat
ion of the effect of particulate volume fraction on the mechanical properti
es of an Al2O3-Al MMC has been undertaken. The material used was a powder m
etallurgy processed AA 6061 matrix alloy reinforced with MICRAL-20(TM), a p
olycrystalline microsphere reinforcement consisting of a mixture of alumina
and mullite. The volume fraction of the reinforcement was varied systemati
cally from 5 to 30% in 5% intervals. The powder metallurgy composites were
extruded then heat treated to the T6 condition. Extruded liquid metallurgy
processed AA 6061 was used to establish the properties of the unreinforced
material. (C) 2001 Kluwer Academic Publishers.