The expansion in using Al-Si Alloys for the industrial and engineering
applications for their distinguished properties, presented in the combination between
mechanical properties and corrosion resistance in addition to the light weight, leads to
find substitution resources to produce these alloys and more than 40% of the world
production depends upon such a kind of production. Therefore, it is necessary and
important to search in details the mechanical properties and microstructure of the
recycled or secondary alloys. In this research , many types of practical experiments
are made for the Al- Si alloys by adding recycled alloys in different percentages (25-
36%) , which produced by precision casting ,specimens prepared for the testing of
tension , torsion, impact, fatigue and microstructure ,to find the optimum mechanical
properties with different variables by preventing the defects produced by casting such
as the presence of hydrogen and Al2O3 and their effect on the mechanical properties .It
has been found the higher percentage of the original alloy improving the mechanical
properties in the new alloy.