Microstructure and work hardening behavior of Al–Cu–Li alloy (AA2198) in different temper conditions

In this paper, Al–Cu–Li alloy (AA2198) sheets have been imparted under different temper conditions to obtain different precipitate morphologies. The tensile testing of the samples in the solution treated, peak-aged, and over-aged conditions at ambient and cryogenic temperatures has been carried out to compare the hardening behavior. The strain hardening in the alloy is a strong function of the nature of obstacles present in individual temper conditions and extrinsic factors such as temperature. The decreased strain hardening capacity of peak-aged and over-aged samples is manifested in terms of a considerable decrease in uniform elongation. The effect of temperature is mainly manifested in terms of a decrease in dynamic recovery parameter and increase in dislocation storage capacity, irrespective of temper condition.