Influence of Heat Treatment on the Ballistic Behavior of AA-7017 Alloy Plate against 7.62 Deformable Projectiles

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.