Environment-assisted cracking of Al 2195 alloy

摘要: Aluminum-Lithium alloys can be susceptible to environment-assisted cracking (EAC) depending on their composition and aging temper. Our previous studies showed that binary Al-Li are in general resistant EAC whereas ternary such as Al-2.2Li-2.9Cu Al-3Li-ICu susceptible. The degree of embrittlement the latter was found correlate very well with (i) precipitation characteristics T 1 (Al 2 CuLi) phase particular its volume fraction present at grain boundaries (ii) slip behavior is primary determined by matrix precipitates. In study, Al 2195 alloy (Al-lLi-4Cu) studied conducting alternate immersion dynamic charging experiments round cylindrical tensile specimens. role microstructure assessed investigating peak aged two overage tempers. first series experiments, specimens were pre-exposed 3.5% NaCI solution under for various periods time then tested slow strain rate (7.2×10 -6 s -1 ). cathodically charged potensiostatic control -1500 mV (SCE) while they rate. Fractographic examinations conducted using SEM mechanical fracture surface morphology. TEM carried out determine microstructural discussed view results new experimental findings.