Mechanical properties of aluminium matrix composites reinforced with intermetalics

In this work 2124 aluminium matrix composites reinforced with Ni3Al, NiAl, MoSi2 and Cr3Si intermetallic powder particles have been investigated. For comparision purposes, unreinforced 2124 and reinforced with SiC have also b een studied. In all cases, the same powder metallurgy route was used, i.e. the 2124 alloy was obtained by rapid solidification and the intermetallic p articles by self-propagating high-temperature synthesis (SHS). The matrix a nd the intermetallics were mechanically blended, cold compacted and finally hot extruded. Tensile tests were carried out in T1 and T4 treatments. Resu lts indicate that mechanical properties depend strongly on the tendence to form new phases at the matrix-intermetallic interface during procesing and/ or futher thermal treatments. TI-ic materials which pro-sent better propert ies are those that present less reaction between matrix and intermetallic r einforcement, i.e. MoSi2 and SiC reinforced Composites.