On impact of cryogenic temperature rolled 6082 Al alloy by dome- and conical-nosed projectiles

Abstract

The simultaneous improvement in strength and toughness through cryogenic temperature rolling observed in recent studies is of profound interest for designers in defence, automobile and aerospace domains. The present work discusses the effects of different projectile nose shapes – dome and conical – on the ballistic impact behaviour of the 1 mm thick AA 6082 alloy targets, rolled to different cryogenic strains, using the experimental data for impact velocities ranging from 50 to 250 m/s reported in our earlier work. The cryogenic rolling strains were imparted by providing different thickness reductions, namely, 50%, 66.66%, 75% and 80%. The target performance was also analysed using velocity drop approach. The projectile nose shape influenced the ballistic limit strongly for 50% and 75% thickness reductions. Conical-nosed projectiles were found to be better penetrators than the dome-nosed projectiles within the overall tested velocity range of 50–250 m/s. The observations confirmed the dominance of the samples with 66.66% thickness reduction impacted with both dome and conical-nosed projectiles in the average and maximum velocity drops after the ballistic limits, indicating superior performance.