▎ 摘　　要

The individual and synergistic effects of multi-walled carbon nano tubes (MWCNT) and graphene nano-platelets (GNP) on the ballistic performance (low and high velocity) of functionalized Kevlar reinforced polymer matrix composites have been investigated. Low-velocity impact tests were carried out on the composite targets (6 layers) using a gas gun setup. Surface hardened conical nose projectiles of 10 mm diameter were used and the inlet velocity was in the range of 122-128 m/s. Similarly, high-velocity ballistic impact experiments were conducted on the targets (24 layers) using a 9 mm full metal jacketed (FMJ) projectile with an initial velocity of 430 +/- 15 m/s. Acid treatment was done to functionalize the Kevlar fiber surface. From the low-velocity impact experiments, the hybrid targets had better ballistic resistance when compared to the unfilled and individually filled nanocomposites. A reduced projectile exit velocity, improved impact energy absorption (32.5 J), and an improved energy absorption percentage of 27.57 were observed for the hybrid combination. Similar improvements were observed during high-velocity ballistic experiments which were evident from the fractographic analysis. The macroscopic investigation on the target containing both the nano-fillers had the least penetration depth of 5.8 mm and a high damage area compared to the other targets. This is due to the addition of f-MWCNT and f-GNP which has increased the matrix toughening and functionalization of Kevlar which increased the interfacial bonding. In addition, the crack bridging property of CNTs and encapsulation behavior of graphene due to stacking has synergistically improved the overall toughness of the composites.