Tensile Deformation and Fracture Behaviour of an Aerospace Aluminium Alloy AA2219 in Different Ageing Conditions

AbstractAluminium alloys due to their high strength to weight ratio coupled with good corrosion resistance find many applications in aeronautical field. 2XXX series of aluminium alloys with their high specific strength are selected for structural applications of aerospace vehicles. AA 2219 alloy is widely used for fabrication of components for aircraft, missile and space vehicles. Fracture toughness of this alloy is the most important design criteria for some select aero applications. Therefore, the study of fracture toughness in different ageing conditions is taken up. The effect of ageing on the crack opening mode (Tensile or mode I) fracture toughness (KIC) was evaluated for Al alloy AA2219 in Limited under Ageing (LUA), Under Ageing (UA) and Peak Ageing (PA) conditions. Comparison was done in the peak aged condition (T6) and as received T652 tempers. Sheet tensile samples were also prepared and tested in all the ageing conditions. Optical microscopy has been carried out and fractographic studies with SEM have been conducted to know the deformation and fracture, which observations form the basis for the observed variations in fracture toughness