الفهرس 
Literature ReviewOnly 14 pages are availabe for public view
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Abstract
The aim of this investigation is the study of the effect of both the molding conditions,
silicon content (2% - 5% ), magnesium content (2% - 6% ) and the dimensions of the
mold on the mechanical and tribological behavior of aluminum alloys. The
solidification behavior, grain size and x-ray diffraction of the alloys have been taken
into consideration to discuss the mechanical and the mechanical and tribological
I properties.
Literature review has been carried out for the researches that investigate the effect of
the alloying elements on the metallurgical, mechanical and tribological behavior of
aluminum alloys. This was followed by the distribution for chemical analysis of the
material under consideration, the test specimens, the measuring equipments and the
cross-pin testing machine. The obtained results are drawn graphically and discussed.
The conclusions drawn from this work can be summarized as follows:
I. The increase of silicon content increases the solidification time and temperature of
beginning of solidification and decrease the temperature range of complete
solidification, while the increase of magnesium content decreases the solidification
time, temperature of beginning of solidification and the temperature of complete
solidification.
2. The increase of mold diameter increases the solidification time, and the elongation
percent, while it decreases ultimate tensile strength and hardness.
3. The relative higher solidification rate and under cooling temperature have been
achieved by using copper shell mold which provides a significant improvement for the
metallurgical properties.
4. An increase of silicon content tends to an increase of both the ultimate tensile
strength and the hardness with decrease of the elongation percent. However, an increase of both the ultimate tensile strength, the hardness and the elongation percent is
observed by the increase of the magnesium content.
5. Copper shell mold provides aluminum alloys relative higher ultimate tensile strength
and hardness and lower elongation percent compared to sand and cast iron molds.
Also, it provides the aluminum alloys relative higher wear resistance and minimal
coefficient of friction compared to sand and cast iron molds.
6. Aluminum-Silicon-Magnesium alloy with 3.67 % Si and 4.9 % Mg shows the best
wear resistance due to the precipitation of the AL4Si phase.
7. The increase of mold dimensions decreases the wear resistance and increase the
coefficient of friction.