ABSTRACT
Optical microscopic examination is the primary method of examining the microstructures of aluminum alloys. They are performed in both as-polished and etched conditions Aluminum alloys present some of the most complex microstructural features in terms of the nature of phases, constituent particles, and precipitates among various alloy systems The microstructural changes that occur from the as-cast stage (namely, sand casting, die casting, or direct chill casting) through homogenization (a function of temperature and time) and thermomechanical processing to different temper conditions are wide and significant. No other alloy system has as many temper conditions as aluminum alloys. With the advent of tailor-made temper conditions to obtain balanced strength-toughness-corrosion resistance for advanced aerospace alloys, it is physical metallurgist’s paradise to design and develop the cocktails of alloys with varying properties for specific applications.
