Dynamic mechanical properties of aluminum alloys GIGAS

New high-strength aluminum alloys of YKK Corporation, GIGAS-30 and GIGAS-51 were studied in plane impact experiments with impact velocities ranged from 100 to 500 m/sec. The projectiles with 2-mm flat impactors were accelerated in 25-mm powder (SWRC) and 25-mm pneumatic (BGU) guns. In parallel the same set of experiments was performed on commercial high-strength aluminum alloy 7075-T6. Both the samples and the impactors were made of the rods of the same material. The free surface velocity of the samples was measured by the VISARs with velocity constants 130 and 97 m/sec per fringe. The dynamic response of GIGAS-30 alloy is close to that of commercial alloy 7075-T6: both have the HEL of about 0.9 GPa and the velocity pull-back corresponding the spall strength of about 1.8 GPa, increasing slightly with the increase of the impact velocity. The HEL of GIGAS-51 alloy was found about 0.6 GPa. The spall strength of GIGAS-51 alloy was found about 1.5 GPa with the trend to increase with the increase of the impact strength. 1-D numerical simulations of the impact response of the alloys allow to explain the differences and the similarities in the behavior of these materials.