Effect of Uniaxial Pre-strain on Room Temperature Tensile and Creep Behavior of Aluminum Alloy AA2219-T87 for Propellant Tanks of Satellite Launch Vehicles

In this study, the effect of uniaxial pre-strain in the range of 1-9%, has been studied on room temperature tensile and creep behavior of aluminum alloy AA2219-T87. Tensile properties of pre-strained specimens showed an increase in yield strength up to 3% pre-strain, beyond which ductility in terms of percentage elongation was below the specification limit of 6%. Room temperature creep test results indicated that as the applied stress increases, the creep rate increases and time to failure decreases, in a linear manner. Fracture toughness of AA2219-T87 calculated based on an empirical relationship showed a decreasing trend with increasing pre-strain. Based on extensive experimental results, it is recommended to limit the amount of pre-strain to 3% during the fabrication of hardware to meet the material specifications.