Analyses of metallurgical behavior of Al–SiCp composites after ballistic impacts

Abstract

The dynamic failure of SiC particle reinforced aluminum alloy composite; AA5083 is studied under ballistic impact loading. Tests were done with two different projectile types, AP (Army Piercing) 7.62 and 9 mm, and the hole surfaces created by the projectiles were investigated using both optical and scanning electron microscopy. Examination of the hole surface of the composite after dynamic failure showed microscopically ductile failure in the matrix following brittle cracking of the particles. The dynamic failure process involved both matrix and particle cracking. The high velocity of the projectile led to the melting of some surface layers because of the excess heat resulting from high velocity friction. Because of high friction, some melted regions had a porous structure due to shrinkage during rapid solidification caused by the high-speed projectile at the hole surface. The type of projectile strongly influenced the damage formation and the deformation type was also affected by the backing condition.