Microstructure simulation and ballistic behaviour of weld zones in friction stir welds in high strength aluminium 7xxx plate

► Investigated the relationship between ballistic impact, and strength reduction in FSWs. ► Simulated and tested microstructures within weld zones in thick plate FSWs. ► Energy dissipation by armour piercing projectiles predicted from cavity expansion theory (CET). ► Fragmentation simulation tests led to a plugging failure. ► Shown that at high strength temper conditions here is a transition to pseudo-brittle fracture.