Improvements in Stress Corrosion Cracking (SCC) of Aluminium Alloy (AA) 7075

Abstract

Aluminium has a wide variety of applications because of its combinations of its uses due to its approving properties. The characteristic of aluminium which makes it attractive is good formability, high strength to weight ratio and far above electric and thermal conductivity. In recent years the alloy has high usage in the place of wood and metals in the numerous engineering applications. In the 1940's, utilizing aluminium compounds that were alloyed with zinc and magnesium for considerably higher qualities prompted the improvement of 7075-T6. Recent commercial and defence aircrafts has many designs that are advanced and good performance in the way of the growth of aluminium alloys. The most important study of 7075 aluminium alloy is more alloy strength broadly used in the structure of aircraft parts. The Aluminium-Zinc-Magnesium 7075 can be heat treated and age hardening can also be done in the aircraft applications because of good weight to strength ratio [1]. Stress Corrosion Cracking (SCC) is a reduction of the mechanical property due to stress induced and corrosive environment. The 7075 series of aluminium alloys provide high strength in the T6 condition but are less proved to resistance for stress corrosion cracking (SSC). But the strength can be retained and also SCC resistance can be increased by the T6 tempering. Retrogresion and Reaging (RRA) heat treatment helps in enhancing the SCC resistance, while retaining the T6 strength of the 7075 alloy.