Formation Mechanism of Ceramic Cones in Boron Carbide Ceramic Composite Targets with Different Backplates under High-Velocity Impact

To investigate the influence of backplate mechanical properties on the formation mechanism of ceramic cones in boron carbide ceramic composite armor, four typical backplate materials, including 6061 aluminum alloy, 7075 aluminum alloy, T300 carbon fiber board, and ultra-high molecular weight polyethylene (UHMWPE) were selected. A combination of ballistic impact experiments conducted via a one-stage light gas gun and numerical simulations performed with LS-DYNA was adopted to systematically study the effects of backplate yield strength, stiffness, and wave impedance on the morphology and evolution of ceramic cones. The results indicate that: the load transfer from the ceramic cone to the backplate is not solely dependent on a single outer cone but is achieved through the synergistic action of multiple cracks, including the outer and inner cones; the yield strength of the backplate has no significant effect on the crack propagation of the main cone; regarding stiffness, the outer cone angle decreases linearly with increasing elastic modulus, while the inner cone angle increases exponentially; wave impedance alters the internal stress field of the ceramic by modulating stress wave reflection/transmission, resulting in a linear increase in the inner cone angle and an exponential decrease in the outer cone angle with increasing impedance.