Effects of isothermal and interrupted aging on mechanical properties and corrosion behavior of an Al–Cu–Mg alloy

Abstract

Al–Cu–Mg alloys are extensively used in the area of the aerospace industry for the construction of aviation parts due to their extremely good mechanical properties. Al–Cu–Mg alloys achieve high strength through various heat treatments. However, aluminum alloys at peak strength conditions, are highly susceptible to various forms of corrosion, such as pitting corrosion, intergranular corrosion, and environment‐induced cracking. In this investigation, the Al–Cu–Mg alloy was solution treated and isothermally aged to develop quenched, under‐aged, peak‐aged (PA), and over‐aged tempers. Furthermore, interrupted aging treatment was then carried out to develop T6I6 temper. Aging behavior was then studied using hardness data, tensile data, and differential scanning calorimetry. The corrosion behavior of all tempers was studied by measuring open circuit potential and by linear potentiodynamic polarization. It is observed that PA temper exhibits good mechanical properties but poor resistance to corrosion, while T6I6 alloy temper exhibits the best mechanical properties along with the highest corrosion resistance.