الفهرس 
coverيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
The structural variations and mechanical
properties of Al-Si based ternary alloys containing
either Ag or Sn were studied for samples prepared form
elements of purity 99.99%, homogenized at 823K for
53h and aged at 673K for 2h then quenched into iced
water.
The structural variations of all the tested alloys were
studied by using (TEM) transmission electron
microscope.
The changes in the mechanical properties of the tested
alloys were studied through :
1- tensile tests in the temperature range (413 – 493K).
2- applying the different values of :
a) cyclic stress reduction σcy (0.87, 1.74, 2.6 and
3.48 MPa) at constant frequency υ = 0.38 Hz.
b) frequency υ (0.18, 0.25, 0.33 and 0.38 Hz) at
constant cyclic stress reduction σcy = 3.48 MPa.
Softening behaviour was observed with increasing the
working temperature, σRcyR and/or υ. The mechanical
results were discussed according to the structure
analysis of TEM micrographs. Sn addition improved the