Effects of impact velocity on the dynamic fragmentation of rigid-brittle projectiles and ceramic composite armors

Abstract

The silicon carbide (SiC)/metal composite armors with the composite cover on the front of the SiC plate were impacted by 12.7mm armor piercing incendiary (API) projectiles at velocities from 412.6m/s to 802.2m/s. The resulting projectile core and ceramic fragments were collected and then screened through a range of standard sieving screens. The mass distributions of fragments produced by projectile and ceramic impacting each other were obtained. The failure mechanism of the rigid-brittle core of 12.7mm API projectile after impacting SiC/metal composite armor was studied by examination of the failed core. The results show that the cumulative mass of core and ceramic fragments follow the Schuhmann distribution law. With the increase of impact velocity, the mass proportion of small core fragments increases, while for ceramic fragments, the mass proportion of fragments in different fractions does not change. The failure mechanism of the large equivalent diameter fragment ( >8mm) is tensile brittle fracture mainly. In contrast, the local plastic shear fracture exists on the fragments with an equivalent diameter of less than 2mm.

Experimental study on the effect of ceramic properties on failure behavior of composite armor

“…The target interaction front of the failed core undergoes shear failure under high-impact stress, and axial fragmentation occurs under internal tensile stress. 13,28 Up to the third stage, wherein the remaining projectile directly impacts the backplate, and until the remaining projectile loses kinetic energy or perforates the backplate, that is the fourth stage. For different projectile-target configurations, the projectile−target interaction ends at different stages.…”

“…The hard‐steel core plays the most important role in the penetration process. The failure modes of cores with different properties are different, among which the ductile and low strength cores 11,12 are plastic deformation and erosion, and the failure modes of the core of 12.7 mm API projectile brittle fracture 13–15 . The high‐strength core material 16–18 is made of high‐carbon steel after some heat treatment, with a hardness of 62 ± 2RC and a density of 7.85 g/cm 3 .…”

“…The clear fractures seen in tests No. Previous work 13 had shown that the fracture mode of large fragments of the projectile was a brittle fracture.…”

“…The failure modes of cores with different properties are different, among which the ductile and low strength cores 11,12 are plastic deformation and erosion, and the failure modes of the core of 12.7 mm API projectile brittle fracture. [13][14][15] The high-strength core material [16][17][18] is made of high-carbon steel after some heat treatment, with a hardness of 62 ± 2RC and a density of 7.85 g/cm 3 . It has obvious tension-compression asymmetry and no obvious tensile-plastic strain in the quasi-static tensile test.…”

“…It has obvious tension-compression asymmetry and no obvious tensile-plastic strain in the quasi-static tensile test. 13 This is one of the main reasons for the fragmentation behavior of the core while penetrating a composite target. The tested ceramic UHMWPE composite armors made the ceramic tiles and the UHMWPE laminate tiles as, respectively, faceplates and backplates, where a single aramid fabric was bonded onto the impacted side of each armor.…”