Comparative study between monolithic and hexagonal ceramic structure against 7.62 × 39 hard steel core projectile:...

The experimental work examines the ballistic performance of boron carbide (B₄C) ceramics, both as a hexagonal and monolithic cell structure, when used with ultra-high molecular weight polyethylene (UHMWPE) as backing material against 7.62 mm × 39 hardened steel core (HSC) ammunition. The microstructural characteristics of the B₄C were studied utilizing Raman spectroscopy and scanning electron microscopy (SEM). Standard test methodology in accordance with National Institute of Justice (NIJ) and Bureau of Indian Standards (BIS) was followed. Parameters like area of destruction (DA), back face signature (BFS), penetration depth, and fragmentation were considered. The study indicates that the total area of destruction for monolithic B₄C was approximately 5.6%, whereas for hexagonal B₄C it was significantly higher at 12.1% due to stress concentration at tile interfaces. In monolithic panels, the projectile exhibited a length reduction of up to 40% and a weight loss of ~27% due to a superior "anvil effect," whereas in hexagonal panels, maximum projectile length loss was 37% with a weight loss of 13%. Overall, the study highlights the critical trade-off between the superior multi-hit structural integrity of monolithic panels and the reduced back face signature of hexagonal panels, providing essential data for forensic reconstruction of armor failure modes.