The aluminum alloys are important in many industrial applications
because of their light weight and good mechanical properties. For this reason
many researches had been done to enhance their properties. In this work a
modifier was applied to Al-12%Si alloys by adding different percentage of
Antimony powder (0.1, 0.2, 0.3, 0.4 and 0.5 Wt %). The mechanical properties of
the modified alloys were considered. The optimum properties were found by
adding 0.3% Antimony powder. This alloy was used as the matrix for the
production of composite material (aluminum matrix reinforced by ceramic
particles (Y2O3) with different weight percent (3,6,9 and 12%Wt)) using vortex
technique. The casting parameters were 3 minute as a mixing time and 300 r.p.m
as a mixing speed. The microstructure, hardness and wear test were applied on the
modified alloy and composite materials. The effect of the addition of Antimony
and reinforcement particles on the microstructure, hardness and wear rate of the
composite material were considered. The results show that the addition of
Antimony leads to the microstructure refinement and change the silicon shape in
the alloy from the flake – like or lamellar – like to fibrous – like In addition to the
increasing the hardness when Sb is up to 0.3%, after that the hardness will
decrease, as well as the addition of ceramic particles increase the hardness and
d e c r e a se the wear rate.