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Effect of heat treatment on mechanical properties and ballistic resistance of AA-7017 aluminium alloy plates has been investigated. The stress-strain behaviour of AA-7017 plates subjected to different heat treatment schedules namely under-aging, peak aging and over-aging, is evaluated from quasi-static tension tests. The heat-treated plates display large differences in static mechanical properties in terms of strength and ductility. The peak-aged plate shows the highest strength and hardness followed by the under-aged and over-aged materials. The ballistic resistance of these plates are evaluated by impacting deformable projectiles at a velocity of 830±10 m/s at a normal angle of attack. The peak-aged plate exhibits the best ballistic penetration resistance. The changes in the mechanical properties with different heat treatments have been correlated with ballistic performance of the AA-7017 alloy. Both the post ballistic micro-structural observations and micro-hardness measurements adjacent to the impacted crater walls have been carried out to understand the change in material deformation behaviour with heat treatment. [ABSTRACT FROM AUTHOR]

The present study describes the experimental results pertinent to the penetration of AA-2024, AA-6061 and AA-7017 plates with two different non-deformable steel projectiles. The diameters of the projectiles used for ballistic impact testing are 7.62 and 12.7 mm. The projectiles are impacted on the aluminium targets of 70 mm thickness with velocities in the range of 840±10 m/s. The results presented include variation in damage pattern in experimental alloys with respect to different projectiles. The microstructures and micro-hardness values along the projectile penetration path have been investigated to understand the material deformation behaviour. Some observations relating to the adiabatic shear band formation have also been presented. From the ballistic testing experiments, it is observed that AA-7017 plates display higher ballistic resistance among the tested aluminium alloys. The ballistic performance of the aluminium alloy plates have been correlated with their respective mechanical properties. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the ballistic behavior and penetration mechanism of metal–metal and metal–fabric layered structures against 7.62armour piercing projectiles at a velocity of 840±15m/s at 30° angle of impact and compares the ballistic results with that of homogeneous metallic steel armour. This study also describes the effect of keeping a gap between the target layers. Experimental results showed that among the investigated materials, the best ballistic performance was attained with metal–fabric layered structures. The improvements in ballistic performance were analyzed in terms of mode of failure and fracture mechanisms of the samples by using optical and electron microscope, X-ray radiography and hardness measurement equipments. [Copyright &y& Elsevier]