7075 aluminium alloy is widely used in automobile manufacturing, aerospace, and other fields like military, due to its high strength, excellent toughness, low density and superior fatigue properties. Factors affecting its corrosion and stress corrosion cracking resistance in certain environments are important as stress corrosion cracking of 7XXX aluminum alloys have previously been know to cause aircraft accidents. It is well known that heat treatment is a key factor affecting its corrosion and stress corrosion cracking resistance. For example, under some conditions, 7075 alloys with T7 heat treatment have better corrosion and stress corrosion cracking resistance than those with T6 heat treatment. 

In this study, accordingly, effects of 5 different heat treatments including T6 and T7 and three other shorter heat treatments on the corrosion and stress corrosion cracking behaviours of 7075 aluminium alloy in chroline-contained solutions will be investigated to find a cost-effective heat treatment which can also provide a good corrosion and stress corrosion cracking resistance. Mechanistic analysis related to these effects will also be conducted.