A hybrid approach of NiP coating and STF impregnation of UHMWPE fabric for conductive soft body armor

Abstract

To enhance the ballistic impact performance and impart electrical conductivity into soft armor material made up of UHMWPE fabric, a novel hybrid technique has been devised and incorporated. Initially, the NiP layer was deposited on the UHMWPE fabric surface through the electroless process, subsequently, it was impregnated in the shear thickening fluid (STF) based on nano-silica (40 wt%). The morphology, functional groups, phase structure, thermal stability, breaking load, inter-yarn friction, electro-heating, and ballistic impact performance of the neat (UHM), STF impregnated (UHM-STF), NiP coated(UHM/NiP), and NiP coated STF impregnated (UHM/NiP-STF) fabrics are detailed. The NiP coating enhanced the ballistic impact performance, and thermal stability, and became electrically conductive compared to neat fabric. The ballistic impact test confirmed the enhancement in the energy absorption of UHM-STF (30.84%), UHM/NiP(18.37%), and UHM/NiP-STF(54.82%) compared to UHM. The hybrid technique (UHM/NiP-STF) exhibited higher inter-yarn friction (53.79%) and ballistic impact energy absorption (18.43%) compared to UHM-STF. The significant rise in the impact energy absorption of the UHM/NiP-STF can be ascribed to the synergetic effect of enhanced inter-yarn friction induced by the NiP-coated layer and the shear thickening behavior exhibited by STF. The NiP-coated and STF-impregnated fabrics present a promising prospect for the advancement of soft body armor materials with multifunctional ability.