The density of the composite, 2.962 g/cm3, was achieved nearly
100% of theoretical density. This could be due to low melting point
of Pb acting as a lubricant [12]. This result is a little higher than
that of the aluminum matrix, 2.71 g/cm3. The ultimate tensile
strength (UTS) of the composite, 131 MPa, is higher than that of
the aluminum matrix, 110 MPa. The elongation of the composite
was evaluated to be 10.8%. Furthermore, the elastic modulus of
the composite is 74.5 GPa, which is more than that of the aluminum
matrix, 72.4 GPa. The comparisons of specific strength and
modulus for red mud shielding materials (RMSM), lead, aluminum
and composite are given in Fig. 4, and it is found that composite
has an evident advantage compared with conventional shielding
materials and similar values with pure aluminum in specific strength and modulus.