Experimental Testing of Hybrid Composite of Kevlar and Basalt Under Low Velocity Impact and Flammability Test

Aiming at aerospace applications where impact resistance and fire safety are vital, the present work studies the mechanical and flammability performance of hybrid Fibre-Reinforced Polymer (FRP) composites made of Kevlar and basalt fibres. The Low-Velocity Impact (LVI), flammability, compression, and interlaminar shear tests were executed on five different stacking sequences—Kevlar-Kevlar-Basalt (KKB), Basalt-Basalt-Kevlar (BBK), and their variations that were created by hand layup methods. With an interlaminar shear strength of 12.09 N/mm2 and a compressive strength of 53.66 N/mm2, the BBK configuration outperformed KKB 9.35 N/mm2 and 29.65 N/mm2, respectively. It’s because the basalt has a higher volume fraction and is stiffer than KKB. Kevlar-dominated laminates (KKB and NK), on the other hand, demonstrated notable impact resistance, with damage areas as small as 81.41mm². However, hybridisation with basalt marginally decreased energy absorption by about 4%. Flammability testing showed that BBK (V-1) and BKBK (V-2) offer moderate-to-poor fire resistance, while KKB obtained a UL-94 V-0 rating, which is defined by minimal flame propagation (2.94 mm/min) and no dripping. The role of fibre volume fractions in predicting mechanical behaviour was validated by the strong correlation between analytical modelling using the rule-of-mixtures and experimental data. These results demonstrate how the performance of Kevlar-basalt hybrids can be altered, with KKB performing best in fire-critical settings and BBK performing best in structural applications. The study offers practical advice for creating next-generation composites with implications for the automotive, aerospace, and defence industries that strike a balance between mechanical strength, thermal stability, and impact resilience. Major Findings: BBK exhibited superior mechanical performance, achieving higher Interlaminar Shear Strength (ILSS) (12.09 N/mm2) and compressive strength (53.66 N/mm2) compared to Kevlar-dominant KKB. Kevlar-based configurations showed better impact resistance, while basalt improved thermal stability, though KKB achieved the best flammability rating (UL-94 V-0). Overall, hybridisation enables tailoring composites for structural strength and fire-critical applications.