آلیاژهای هیپویوتکتیک آلومینیوم-سیلیسیوم

Nucleation mechanism of the eutectic phases in

aluminum–silicon hypoeutectic alloys

سازوکار جوانه‌زنی فازهای یوتکتیک در آلیاژهای هیپویوتکتیک آلومینیوم-سیلیسیوم

ABSTRACT

A theory is presented to explain the mechanism of formation of the eutectic phases in Al–Si hypoeutectic alloys. Results include optical, scanning and transmission electron microscopy, as well as selected area electron diffraction analysis and elemental X-ray mapping performed on Al–Si hypoeutectic alloy samples. The alloy samples had precisely controlled chemistry and were solidified at various cooling rates. The data presented support the proposed theory with microstructural and crystallographic evidence.

 

رفتار خوردگی-خستگی آلیاژ آلومینیوم 7075-T651 تحت بارگذاری های متناوب

Corrosion-fatigue behaviour of 7075-T651 aluminum

alloy subjected to periodic overloads

رفتار خوردگی-خستگی آلیاژ آلومینیوم 7075-T651  تحت بارگذاری های متناوب

ABSTRACT

The corrosion-fatigue behaviour of 7075-T651 aluminum alloy subjected to periodic overloads was examined. This aluminum alloy is typically used in aerospace structural components such as the wing spars of aircraft. Axial fatigue specimens were subjected to a loading spectrum that consisted of a fully reversed periodic overload of near-yield magnitude followed by 200 smaller cycles at high Rratio. The specimens were fatigue tested while they were fully immersed in an aerated and recirculated 3.5 wt% NaCl simulated seawater solution.